School Science Lessons
Topic 16a Chemistry of natural products
2014-11-23
Please send comments to: J.Elfick@uq.edu.au

Table of contents
16.3.0 Chemistry of natural products
16.3.1.0 Aliphatic compounds, acyclic / cyclic, saturated / unsaturated carbon compounds
16.3.4.0 Aromatic compounds, arenes, benzene derivatives
16.3.8.0 Carboxylic acids and fatty acids
16.3.5.0 Terpenes, monoterpenes, terpinenes, oleoresins
16.3.2.0 Tetrapyrroles, porphyrins, (haem, heme), chlorophyll, phytochromes

16.3.1.0 Aliphatic products
16.3.2.3 Alditols, polyhydric alcohols, mannitol
16.3.2.2 Carbohydrate acids, D-gluconic acid, D-glucuronic acid
16.3.1.1 Carbohydrates
16.3.8.0 Carboxylic acids and fatty acids
16.3.1.6 Cellulose, hemicellulose
16.3.1.7 Chitin
16.3.2.1 Cyclitols, inositol
16.3.1.4.0 Disaccharides
16.3.2.4 Glycosaminoglycans (mucopolysaccharides), glucosamines
16.3.2.6 Glycosides
16.3.2.6.01 Betanin
16.3.2.6.1 Glucosides
16.3.3.0.5 Glycerides, esterification of glycerol
16.3.3.0.2 Lecithins
16.3.3.0 Lipids, fats and oils, fatty acids, glycerides
16.3.1.3 Monosaccharides
16.3.1.3.1 Monosaccharides, Left-handed / right-handed structural forms, D and L sugars
16.3.2.8 Nucleosides, nucleic acids, DNA, RNA
16.3.1.8 Pectin, Aspergillus japonicus
16.3.2.5 Phenolic compounds
16.3.2.7 Polyketides, polyketide antibiotics
16.3.2.9 Polysaccharide gums
16.3.7.1 Reducing sugars / non-reducing sugars
16.3.3.0.1 Phospholipids, (phosphoglycerides)
16.3.1.4.3 Polysaccharides
16.3.1.5 Starches, amylum, glycogen
16.3.1.4.1 Trisaccharides
16.3.1.4.2 Tetrasaccharides
16.3.3.1 Waxes

16.3.4.0 Aromatic compounds, arenes, benzene derivatives
16.3.4.2.1 Anthocyanins
16.3.4.0b Aramids
16.3.4.0.10 Aromatic aldehydes and ketones, e.g. benzaldehyde
16.3.4.0.4 Aromatic amines, anilides, e.g. phenylamine
16.3.4.0.9 Aromatic alcohols, e.g. phenyl methanol, (benzyl alcohol)
16.3.4.0.6 Aromatic halogen compounds, e.g. benzyl chloride
16.3.4.0.1 Aromatic hydrocarbons, e.g. benzene, anthracene
16.3.4.0.2 Aromatic nitro compounds, e.g. nitrobenzene
16.3.4.0.7 Aromatic sulfonic acids, e.g. benzene sulfonic acid
16.3.4.0a Aryl groups
16.9.20 Bergamottin
16.8.1 Reactions of benzene, C6H6
16.3.4.0.5a Barbiturates (depressants)
16.3.4.0.5b Benzodiazepines (tranquillizer)
16.3.4.1a Benzofuranoids, benzopyranoids
16.3.4.0.5 Diazo compounds
16.9.19 Coumarin
16.3.4.5 Five member heterocycles
16.3.4.2 Flavonoids, (Bioflavonoids), plant polyphenols
16.3.4.2.2 Flavonols, (flavan-3-ols)
16.3.4.1b Geosmin, Earth smells, rain smells and cut grass smells
16.3.4.0.3 Lactams (-NH(CO-), e.g. caprolactam
16.3.4.4 Lignans, plant phenols
16.3.4.0.12 Parabens
16.3.4.0.13 Pyridine
16.3.4.3 Tannins, (kinotannic acid), plant polyphenols

16.3.8.0 Carboxylic acids and fatty acids, (carboxyl group -COOH), (aliphatic monocarboxylic acids)
16.3.8.0 Carboxylic acids and fatty acids
16.3.8.6 α-hydroxy acids
16.3.4.0.11 Aromatic carboxylic acids and derivatives, e.g. benzoic acid, salicyclic acid
16.3.8.2 Dicarboxylic acids
16.3.8.7 Keto acids, acetoacetic acid, pyruvic acid
16.3.8.5 Perfluorooctanoic acid
16.3.8.1 Saturated carboxylic acids
16.3.8.3 Tricarboxylic acids
16.3.8.4 Unsaturated fatty acids

16.3.5.0 Terpenes, monoterpenes, terpinenes, oleoresins
16.3.5.1
Terpenes
16.3.5.1.1 Monoterpenes, C10, (2 isoprene units), C10H16
16.3.5.1.0 Oleoresins "gums"
16.3.5.1.3 Sesquiterpenes C15, (3 isoprene units), C15H
16.3.5.1.5 Sesterterpenes, C25, (5 isoprene units)
16.3.5.1.6 Triterpenes C30, (6 isoprene units), steroids and sterols
16.3.5.1.11 Terpenoids
16.3.5.3 Steroids, sterols, steroid alcohols, natural steroids
16.3.5.1.2 Terpinenes, C10H16
16.3.5.1.8 Tetraterpenes C40, (8 isoprene units), C40H56, carotenoid pigments
16.3.5.1.9 Carotenes
16.3.5.1.10 Xanthophylls

16.3.2.0 Tetrapyrroles, porphyrins, (haem, heme), chlorophyll, phytochromes
16.3.5.2.1 Tetrapyrroles, related compounds
16.3.5.2.3 Chlorophyll a and chlorophyll b
16.3.5.2.4 Legheamoglobin
16.3.5.2.6 Phycobilins, phycocyanin, phycoerythrin
16.3.5.2.5 Phycobiliproteins, Anabaena azollae, water fern, (Azolla)
16.3.5.2.7 Phytochromes
16.3.5.2.8 Polyvinyl pyrrolidene, povidone, PVP-iodine complex
16.3.5.2.2 Porphyrins

16.3.1.1 Carbohydrates
Monosaccharides, aldoses and ketoses, disaccharides, oligosaccharides, polysaccharides, chitin, branch chain sugars
Carbohydrates were at first compounds such as aldoses and ketoses, with the stoichiometric formula Cn(H2O)n, so "hydrates of carbon". Nowadays, carbohydrates include monosaccharides, oligosaccharides and polysaccharides, and substances made from monosaccharides,
1. by reduction of the carbonyl group, >C=O, (alditols), 2. by oxidation of one or more terminal groups to carboxylic acids, e.g. ethanoic acid, CH3COOH,
3. by replacement of hydroxy groups by a hydrogen atom, an amino group, thiol group or other groups, and derivatives of these compounds.

16.3.1.1a Sugars
The term sugars generally refers to monosaccharides and lower oligosaccharides. Monosaccharides cannot be split into smaller molecules by using dilute acids. They cannot be hydrolysed to simpler compounds.
An aldose has an aldehyde group, -CHO, i.e. a carbonyl, group, C=O, with a hydrogen atom attached to the carbon atom, e.g. glucose.
A ketose is a sugar with one ketone group, e.g. fructose, CH2OHCHOHCHOHCHOHC=OCH2OH
A ketone group is a carbonyl group, C=O, with two single bonds to other carbon atoms. Monosaccharides can have a straight chain form or ring form. Polysaccharides are compounds with more than ten monosaccharides linked by glycosidic bonds, usually between C1 on one sugar and C4 on the other sugar by removal of a water molecule, i.e. a condensation reaction.
A ketose is a sugar containing one ketone group per molecule.
An aldose is a sugar containing one aldehyde group per molecule and has the chemical formula C3nH6nO3n.
Monosaccharides
Triose, 3 carbon atoms, C3H6O3, dihydroxyacetone, glyceraldehyde
Tetrose, 4 carbon atoms, C4H8O4, e.g. erythrose, threose, erythrulose
Pentose, 5 carbon atoms, C5H10O5, e.g. arabinose, lyxose, ribose. xylulose
Hexose, 6 carbon atoms, C6H12O6, e.g. allose, altrose, glucose, mannose, gulose, idose, galactose, talose

16.3.1.3 Monosaccharides
See diagram 16.3.1.3a: Triose, Fisher projection formula | See diagram 16.3.1.3b: Glucose molecule
See diagram 16.3.1.3Cch: Galactose | See diagram 16.3.1.3x: Glucose and fructose, straight chain forms
See diagram 16.3.1.3d: Fructose | See diagram 16.3.2.8.2: Ribose, deoxyribose, nucleotide
Monosaccharides contain a single sugar unit, e.g. glucose, fructose
Glucose, Commercial: D-(+)-Glucose, dextrose
Fructose C6H12O6, D(-), fructose, laevulose, fruit sugar, pure honey,
Fructose, D form, but laevorotatory, so "L-fructose", Commercial: "D-(−)-Fructose, D-Levulose, Fruit sugar"
Classification:
1. Number of C atoms:
2. Aldose or ketose
Aldose contains aldehyde group, (-CHO), at C1, monosaccharide bonded to an aldehyde chain, Cn(H2O)n, e.g. glyceraldehyde, (CHOCHOHCH2OH), the simplest aldose
Ketose, contains ketone group, (-CO-), at C2, monosaccharide sugar containing a ketone group or compound derived from a ketone, e.g. dihydroxyacetone, (CH2OHCOCH2OH), the simplest ketose
Table 16.3.1.3
No. C Atoms
Aldose
-
Ketose
-
3 C
triose
glyceraldehyde
-
dihydroxyacetone
-
4 C tetrose
erythrose, threose
-
erythrulose
-
5 C pentose
arabinose, lyxose,
ribose, xylose
ribulose, xylulose
6 C hexose
allose, altrose, galactose, glucose, gulose, idose, mannose, talose fructose, psicose, sorbose, tagatose

16.3.1.3.1 Left-handed and right-handed structural forms, D-sugars and L-sugars
See diagram 16.3.1.3a: Monosaccharides, D-sugar and L-sugar
The Fischer projection formula invented by Emil Fischer, (1852 - 1919), allows the three-dimensional sugar and amino acid molecules be represented by two-dimensional diagrams on the page. Horizontal lines show groups projecting above the plane of the page towards you. Vertical lines show groups projecting below the plane of the page away from you. So D-glyceraldehyde has the hydroxyl group on C2 on the right and L-glyceraldehyde has the hydroxyl group on C2 on the left., (Latin: dextro = right, laevo = left), For all other carbohydrates, if the carbon atom farthest from the aldehyde or ketone group has the same arrangement as D-glyceraldehyde, hydroxyl on the right of C2, then the compound is a D-sugar. Similarly, if this "remote carbon atom" has the same arrangement as L-glyceraldehyde, the compound is an L-sugar.
However, monosaccharides exist mainly as cyclic forms, not the aldo-forms or keto-forms. The cyclic form is shown by a Haworth projection, invented by W. N. Haworth. The oxygen atom is at the upper right and the carbon atoms are arranged clockwise with C1 at the far right. The hydroxyl groups on the right in the Fischer projection are down in the Haworth projection, so the hydroxyl groups on the left in the Fischer projection are up in the Haworth projection. The terminal -CH2OH group is up in the Haworth projection for D-sugars, and down for L-sugars.
D-glucose can have α-or β-forms, depending on the position of the hydroxyl group attached to C1, down in the α-form and up in the β-form.
Most monosaccharides have a ring cycle of six atoms, one oxygen atom and five carbon atoms, called the pyranose form. A ring cycle of 5 atoms, one oxygen atom and four carbon atoms is called a furanose form. So D-fructose can exist as α-D-fructofuranose, -OH on C2 is down, and β-D-fructofuranose, -OH on C2 is up.
Glucose, Commercial: "D-(+)-Glucose, dextrose"
Fructose, D form, but laevorotatory, so "L-fructose", Commercial: "D-(−)-Fructose, D-Levulose, Fruit sugar"

16.3.1.4.0 Disaccharides, trisaccharides, tetrasaccharides, polysaccharides
See diagram 16.3.1.4a: Maltose molecule | See diagram 16.3.1.4b: Lactose molecule | See diagram 16.3.1.4c: Sucrose molecule
Disaccharides contain two sugar units, e.g. sucrose, (glucose + fructose), lactose, (milk sugar, glucose + galactose), maltose, (malt sugar, glucose + glucose).

16.3.1.4.1 Trisaccharides
Raffinose, (triose: fructose + galactose + glucose), (C18H32O16), melezitose, maltotriose, (amylotriose)

16.3.1.4.2 Tetrasaccharides
See diagram 16.3.1.4: Stachyose, acarbose
Acarbose, (C25H43NO18), anti-diabetic drug
Stachyose, (tetrose: fructose + galactose + glucose + galactose, i.e. raffinose + galactose), (C24H42O21), in green beans

16.3.1.4.3 Polysaccharides, glycans
Polysaccharides are long carbohydrate molecules consisting of repeated monomer units joined together in a chain by glycosidic bonds.
1. Homopolysaccharides, homoglycans, contain the same type of monomer unit
2. Glucosans, (from glucose)
Starch, amylopectin glucosan + amylose sugar
Glycogen, glucose residues
Cellulose, D-glucose units
2. Fructans, (from fructose)
Inulin, D-fructose, in artichokes
2. Galactans, (from galactose)
Agar
1. Heteropolysaccharides, heteroglycans, contain dufferetn type of monome r units
3. Acidic, mucopolysaccharides, glycosaminoglycans long unbranched polysaccharides, repeating disaccharide units
chitin
4. Heparin
4. Chondroitin sulfate
4. Keratan sulfate
4. Hyaluronic acid

Dextran

Chitin : It is a modified polysaccharides that contains Nitrogen. It is derived from glucose. It forms the external skeleton in many animals and is also bio-degradable. These polysaccharides resembles the cellulose in structure and the protein keratin in terms of function. This polysaccharide has a wide use in the agricultural, industrial and medical fields. Chitin has proven great use as a fertilizer and also to increase the immunity among the plants. It is used as a binder in dyes, adhesives and fabrics in the industrial area. It is also used as a surgical thread in the field of medicine because of its ability to dissolve.

Pectin : This is a polysaccharide that forms the primary cell walls of many terrestrial plants. This is an example of heteropolysaccharides. It has various uses in the food industry as it acts as a gelling agent for jams and jellies. It is also used as a food thickening agent and stabilizer in juices, milk.

Arabinoxylans : It is a polysaccharide found in the primary and secondary cell wall of plants i.e. wood and also in the cereal grains. It is a combination of arabinose and xylose.

β-glucan, (cellotriose, β-D-glucan, glucan, C18H32O16),
D-(+)-cellotriose, glucopyranosyl
Oligosaccharides raffinose, stachyose and verbascose are present in significant quantities in legume seeds

16.3.1.5 Starches, amylum, glycogen
See diagram 16.3.1.5a: Starch, amylose,
(amylum), (amylose, soluble starch, many glucose units), (amylopectin, insoluble starch, 40 to 60 branched glucose units).
(Starch, amylum = amylose + amylopectin)
Glycogen in animals.,
Glycogen, α-1,4- and α-1,6-glucan, unbranched glucose polymer similar to amylopectin
Inulin = D-fructose units, from Helianthus)
Boil cut potato in water then let cool. Filter the solution to separate the soluble amylase from the insoluble amylopectin of the starch grains. Add tincture of iodine to the filtered starch solution An intense blue colour occurs. The solution contains β-amylase, C6H10O5 that forms a complex with iodine: (β-amylase)p, (I-), (I2)r(H2O)s [where r < p < s].

16.3.1.6 Cellulose, hemicellulose
See diagram 16.3.1.6a: Cellulose, three glucose molecules linked to form cellulose
See diagram 16.3.1.7a: Cellulose
See diagram 16.3.1.7C: Linamarin
See diagram 16.3.1.7d: Cyanohydrin
Cellulose is long unbranched glucose polymer. Cellulose in plant cell walls, hemicellulose in some plant endosperm to form vegetable ivory. Gun-cotton was prepared by saturating cotton or cellulose material in nitric acid and sulfuric acid to produce a highly explosive material.

16.3.1.7 Chitin
See diagram 16.3.1.7a: Chitin
Chitin, (C8H33O5N)n, is an insoluble nitrogenous polysaccharide, contains chains of N-acetylglucosamine in support structure of invertebrates and fungi, e.g. shells of arthropods.

16.3.1.8 Pectin, Aspergillus japonicus
Pectin, poly-D-galacturonic acid methyl ester, from apple and citrus peel, is a heterosaccharide component of terrestrial plant cell walls. It  is used as a substrate to identify, differentiate and characterized pectinases. Pectin is used to study its degradation by pectinolytic bacteria. Pectin has high molecular weight, cements adjacent plant cells, and is dissolved by pectinase in ripening fruit. It is sold as a white-brown bpowder and is used to form gels and as thickening agents. Galactouronic acid, C6H10O7, is a component of pectins.
Pectinase,  polygalacturonase, catalyzes hydrolysis in pectin
Pectinesterase, pectin methylesterase, catalyzes hydrolysis of methyl esters of pectin --> pectate + methanol
Pectolyase from Aspergillus japonicus plant cell culture, catalyzes breakdown of methyl esters -->  oligosaccharides

16.3.2.1 Cyclitols
Cyclitols are cycloalkanes containing one hydroxyl group on each of three or more ring atoms, e.g. Inositol, cyclohexane-1,2,3,4,5,6-hexol, C6H12O6

16.3.2.2 Carbohydrate acids
D-gluconic acid, CH2(OH)(CHOH)4COOH, produced by fungi
D-glucuronic acid, C6H10O7, in gums, forms glucuronides
d-gluconic acid, d-glucuronic acid, food additive E574, anti-caking agent, sequestrant

16.3.2.3 Alditols, polyhydric alcohols, mannitol
General formula: HOCH2[CH(OH)]nCH2OH, mannitol CH2OH(CHOH)4CH2OH, from mannose or fructose, sugar in fungi and brown algae, food sweetener.

16.3.2.4 Glycosaminoglycans, (mucopolysaccharides), glucosamines
16.3.0 Amines and alkaloids
Glycosaminoglycans, (mucopolysaccharides), glucosamines, dermatan sulfate, chondroitin, hyaluronic acid, heparin, keratin sulfate. Glucosamine is converted to glycosamineglycans. Glucosamine hydrochloride and glucosamine sulfate may repair cartilage and alleviate osteoarthritis.
Heparin, Chondroitin sulfate, Hyaluronan, Heparan sulfate, Dermatan sulfate, Keratan sulfate

16.3.2.5 Phenolic compounds
Phenolic compounds: citronella, clove oil, dicoumarin, eucalyptol, ubiquinone, urushiol, vanillin
Catechol, C6H4(OH)2, 1,2-dihydroxybenzene, colourless crystalline phenol, Harmful, irritant
pyrocatechol,  powder, C6H4-1,2-(OH)2
Urushiol, mixture of catechol molecules substituted with different alkyl chains, in poison ivy, used in lacquerware, causes allegic reactions in people handling mango leaves and stems
16.9.19 Coumarin
16.9.20 Bergamottin
Citronella grass, Cymbopogon citratus, Poaceae
Phenolic polymers: tannins, lignin
Flavours: eugenol, (olive, cinnamon), cinnamaldehyde, (cinnamon, cassia), anethole, (anise), thymol, (thyme), carvacuol, (oregano), estragola, (tarragon), vanillin, (vanilla)
Polyphenols, e.g. hydrolysable tannins

16.3.2.6 Glycosides
A compound formed from a simple sugar and another compound by replacement of a hydroxyl group in the sugar molecule.
A glycoside is a natural compound linked to sugar other than glucose. A glycoside has a sugar combined with a non-carbohydrate organic molecule.
Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and non sugar component (aglycone) are formed.
Different glycosides
1. Aminoglycoside, (amikacin hydrate, C22H43N5O13.xH2O, broad spectrum antibiotic)
2. Amygdalin glycoside, C20H27NO11, in almonds, Prunus dulcis,
3. Anthocyanins, C15H11O +, (glucosides of anthocyanidins), red, blue and purple flavonoids, in cell sap, natural antioxidants, (blueberry, boysenberry, black raspberry, blackcurrant pigments), (cyanidin chloride, C15H11ClO6)
4. Anthraquinone, C14H8O2, (derivatives include alizarin and compounds in senna, rhubarb, cascara, alizarin)
5. Cardiac glycosides, (digoxin, C41H64O14, Digitalis purpurea, for heart disease ), (from oleander, Nerium), (Ouabagenin, C23H34O8, G-Strophanthidin)
6. Mustard oil glycosides, glucosinolates, (from Brassica), (phenethyl glucosinolate potassium salt, C15H20NO9S2K)
7. Nightshade glycosides, (solanine in Solanum nigrum), ( α-Solanine from potato sprouts, C45H73NO15)
8. Saponins, foaming glycosides, in soapwort plant (Saponaria), alfalfa (Medicago sativa), chickpeas (Cicer arietinum), horse chestnut (Aesculus hippocastanum),  (triterpenoid aglycone in liquorice plant, Glycyrrhiza glabra). wavy-leafed soap plant, (Chlorogalum pomeridianum), soap bark tree (Quillaja saponaria) bark has sapogenin content ≥10 %, Harmful, irritant.
9. Steroidal glycosides, (sugar + steroid), (from roots of Asclepias curassavica ), (steroid glycoside H.g.-12 from Hoodia gordonii)

16.3.2.6.01 Betanin, C24H27N2O13, is cyanogenic glycoside (betacyanin) betanidin-5-O- b-glycoside, Beetroot Red, the red glycosidic food dye E162 obtained from beets, Beta vulgaris, opuntia cactus, Swiss chard, and amaranth leaves. It is not broken down in the body so can cause temporary red urine (beeturia and red faeces) and distress in people who think it is hematuria (blood in the urine). Also in Bougainvillea and amaranths.

16.3.2.6.1 Glucosides
A glucoside is a glycoside with a glucose sugar component, a glycoside that yield glucose upon hydrolysis. Glucosides are natural compounds linked to glucose.
Glycoside, glucoside: sugar + non-carbohydrate R, e.g. glucose + terpene, glucose + phenolic compound
1. Salicin glucoside, C13H18O7, alcoholic β-glucoside, similar to aspirin, acetylsalicylic acid, from white willow bark, Salix, (digitonin, digitoxin, βcyanin)
2. Stilbenoid glucoside, C20H22O8, (piceid, from grape juice and Picea sitchensis and Polygonum cuspidatum, Japanese knotweed)
3. Cyanogenic glucosides, (amygdalin glucoside, from apricot pits, C20H27NO11), (linamarin glucoside, C10H17NO6, from cassava, Manihot esculanta), from linseed, flax, Linum usitatissimum, and Lotus japonica.)
4. Flavonoid glucoside, icariin, C33H40O15, occurs in horny goat weed, Epimedium grandiflora, Berberidaceae, and is said to be an oriental aphrodisiac.
5. Resveratrol glucoside, C14H12O3, antioxidant and free radical, synthesis in seeds of transgenic oilseed rape (Brassica napus), (produced from Japanese knotweed, piceid)

16.3.2.7 Polyketides, polyketide antibiotics
16.1.5.2: Lactones
Molecules having more than two carbonyl groups connected by single carbon atoms. Occur in some bacteria and fungi, e.g. Aspergillus. They have antibiotic, anticancer, cholesterol-lowering, immunosuppressive effects, e.g. erythromycin, lovastatin. They include polyketide antibiotics, streptomyces metabolites, erythromycin, linear tetracyclines, macrolides and lactones, erythromycin polyenes, nystatin, polyether antibiotics, β-lactams, aflatoxins.
Lactones are components of coconut aroma and peach aroma, e.g. octalactone.

16.3.2.8 Nucleosides, nucleic acids, DNA
Nucleosides, nucleic acids, DNA, (deoxyribonucleic acid), RNA, (ribonucleic acid), Nucleosides, nucleic acids, nitrogenous bases: adenine, guanine, cytosine, thymine DNA, RNA, deoxy-D-ribose, D-ribose
See: Genetic code
See diagram 16.3.2.8: Nucleic acid | See diagram 16.21.10: Purines | See diagram 16.21.13: Pyrimidines
Nucleic acids are macromolecules from the nuclei of cells, composed of nucleotide units, and can be hydrolysed into pyrimidine or purine bases, adenine, cytosine, guanine, thymine, uracil, D-ribose or 2-deoxy-D-ribose, and phosphoric acid. Nucleic acids do several functions in living cells, e.g., the storage of genetic information and its transfer from one generation to the next DNA, (deoxyribonucleic acid), the expression of this information in protein synthesis, (mRNA, tRNA), and may act as functional components of subcellular units such as ribosomes, (rRNA). RNA, (ribonucleic acid), contains D-ribose, whereas DNA contains 2-deoxy-D-ribose as the sugar component. A nucleoside is a compound in which a purine or pyrimidine base is bound via a N-atom to C-1 replacing the hydroxy group of either 2-deoxy-D-ribose or of D-ribose, but without any phosphate groups. Nucleosides include adenosine, guanosine, cytidine, and uridine, (which contain ribose), and deoxyadenosine, deoxyguanosine, deoxycytidine and thymidine, (which contain deoxyribose). A nucleotide is a nucleoside in which the primary hydroxy group of either 2-deoxy-D-ribose or of D-ribose is esterified by orthophosphoric acid. An oligonucleotide is a long linear sequences of nucleotides.

16.3.2.9 Polysaccharide gums
Food stabilizers and thickeners:
1. Gums: (guar gum from Cyamopsis), (gum tragacanth from Astragalus, locoweed), (locust bean gum from carob, Certonia), (gum arabic from Acacia senegal), (gum karyaya from Sterculia), (gum ghatti from Anogeissus), (xanthan gum from fermented corn sugar).
2. Phycocolloids: (alginates, algin, from kelp, Laminaria and Macrocystis), (carrageenan from red algae, Irish moss, Chondrus crispus), (agar from red algae, Gelidium and Gracilaria).

16.3.3.0 Lipids, fats and oils, fatty acids, glycerides
Fatty acids are aliphatic monocarboxylic acids.
See diagram 16.3.3.1: Esterification of glycerol to form fatty acids, fats
See diagram 16.3.3: Lipids, cephalins, glycerides, (triglycerides), glycolipids, lecithins, (choline), phosphoglycerides, prostaglandins
See diagram 19.2.1: Oleic acid, stearic acid, linoleic acid, (cis and trans)
See diagram 16.3.3.2: Fat molecules
See diagram 16.3.3.3: Tristearin
See diagram 16.3.3.4: Human fat molecule

16.3.3.0.1 Phospholipids, (phosphoglycerides)
Phospholipids form when hydroxyl groups form esters with phosphate groups. They occur as two groups:
1. Phosphoglycerides, e.g. lecithin in cell membranes and in bile. Phosphatidyl choline, (formerly lecithin), phosphatide with organic base choline, in biological membranes, e.g. egg yolk, is used as a natural emulsifier. Egg yolk phospholipids (EYPL) are used as carriers for lipophilic drugs and are a major ingredient of lipid microspheres.
2. Sphingolipids in plant and animal cell membranes. It is a fat molecule with a phosphate group, (PO4), replacing the third fatty acid.
glycerol-3-phosphate + 2-monacyl glycerol --> triacyl glycerol + phospholipids.
Sphingolipids: sphingenine, cerebrosides, sphingomyelin.

16.3.3.0.2 Lecithins
Lecithins, diacylphosphatidylcholine, esters of glycerol and choline with fatty acids and H3PO4, in cell membranes. The lecithin group, (phosphatidylcholine group) are yellow-brown fatty phospholipids in egg yolks and plasma membranes of plant and animal cells. They are used as emulsifiers in commercial foods, and cosmetics.

16.3.3.0.4 Lipids
Lipids are biological substances that are soluble in nonpolar solvents:
1. saponification lipids, e.g. glycerides, (fats and oils), and phospholipids,
2. non-saponification lipids, e.g. steroids.
Lipids refers to the oils, fats and waxes found in living organisms. Lipids are insoluble in water but soluble in inorganic solvents, e.g. chloroform. The simple lipids do not contain fatty acids, e.g. steroids, terpenes.
The complex lipids are esters of long chain fatty acids, e.g. glycerides, glycolipids, phospholipids, waxes.

16.3.3.0.5 Glycerides, esterification of glycerol
Glycerides are common biological substances made from esters of glycerol, (propane-1,2,3-triol), with fatty acids:
1. triglycerides,
2. 1,2-diglycerides or 1,3-diglycerides,
3. 1-monoglycerides or 2-monoglycerides.
The fats and oils found in living organisms are mainly triglycerides:
1. Monoglycerols, (monoglycerides), e.g. 1-monoacyl glycerol, 2-monoacyl glycerol,
2. Diglycerols, (diglycerides), e.g. 1,2-diacyl glycerol, 1,3-diacyl glycerol,
3. Triglycerols, (triglycerides), (fats, main storage lipids), e.g. triacyl glycerol.
Glycerides, glycerine esters, are fatty acid esters of glycerol, (HOCH2CH(OH)CH2OH).
Esters can form at one, two or three of the hydroxyl groups to form monoglycerides, diglycerides and triglycerides.
Esterification of glycerol
Plant oils are usually triglyceride molecules, esters, composed of a 3C alcohol, glycerol, + 18C or 16C fatty acids containing 12C to 24C. The number of carbon atoms is counted from the end of the molecule with the carboxylic acid group, COOH. The position of the first double bond is counted from the other end, the methyl or ω end. Whether the fatty acid is an ω-6 fatty acid or an ω-3 fatty acid depends on the position of the first double bond.

16.3.8.0 Carboxylic acids and fatty acids
Carboxylic acids contain the carboxyl group, carbonyl: -COOH, e.g. ethanoic acid (acetic acid) CH3COOH, so the general formula is RCOOH. The carbonyl group, (carboxy) is -COOH. The group of saturated and unsaturated aliphatic carboxylic acids are called fatty acids and are found as esters in fats and oils. Lower carbon fatty acids are corrosive liquids with strong odour and are soluble in water. Higher carbon fatty acids are oily liquids with unpleasant smell and are only slightly soluble in water. Fatty acids from C10 onwards are usually solids and are insoluble in water. The poly unsaturated fatty acids linoleic acid, linolenic acid and arachidonic acids are essential fatty acids in the diet to prevent atheroma, ("hardening of the arteries"), and synthesize prostaglandins. Saturate fatty acids with no double bonds are linked to the development of atheroma. Fatty acids in plants occur as esters of glycerol or other hydroxy compound, or amides of long chain amines, e.g. sphingenine. Fatty acids have trivial and systemic names and the molecule may be saturated, (no double bonds), or unsaturated, (one or more double bonds). The products called "natural oils" are not necessarily unsaturated fats. Common carboxylic acids include the following:

16.3.8.1 Saturated carboxylic acids
Acetic acid (ethanoic acid), CH3COOH, (in vinegar)
Arachidic acid, (icosanoic acid), CH3(CH2)18COOH, (in peanut oil)
Benzoic acid, C6H5COOH, benzenecarboxylic acid, phenylformic acid, Harmful if ingested
Butyric acid, butanoic acid, C3H7COOH, CH3(CH2)2COOH, in rancid butter
Capric acid, decanoic acid, CH3(CH2)8COOH, (in coconut oil, palm oil, mammal milk)
Caproic acid, (hexanoic acid), CH3(CH2)4COOH, (in goat fat)
Caprylic acid, octanoic acid, CH3(CH2)6COOH, (coconuts, breast milk, in sting of whip scorpions!)
Chloroacetic acid, CH2ClCOOH, (used in chemical reactions)
Decanedioic acid, HOOC(CH2)8COOH, sebacic acid, from castor oil
Dichloroacetic acid, DCA, CHCl2COOH, (in chlorinated drinking water)
Formic acid, CH2O2, HCOOH, methanoic acid, (in insect stings, ants)
Lauric acid, dodecanoic acid, CH3(CH3)10COOH, (in coconut oil, soaps)
Myrstic acid, tetradecanoic acid, CH3(CH3)12COOH, (in nutmeg)
Oxalic acid, C2H2O4.2H2O, HO2CCOOH, ethanedioic acid, (in rhubarb, Oxalis)
Palmitic acid, CH3(CH2)14CO2H, hexadecanoic acid, (palm oil, coconut oil, most animals / plants)
Proprionic acid, propanoic acid, CH3CH2COOH, (stored grains preservative)
Stearic acid, octadecanoic acid, CH3(CH2)16COOH, (in fats, soaps, waxes)
Trichloroacetic acid, C2HCl3O2,CCl3COOH, Highly toxic, (used in chemical reactions)
Trifluoroacetic acid, CF3COOH, corrosive, (used in chemical reactions)
Valeric acid, (pentanoic acid), CH3(CH2)3COOH, (valerian herb)

16.3.8.2 Dicarboxylic Acids
Adipic acid, hexanedioic acid, HOOC(CH2)4COOH
Aldaric acid, HOOC-(CHOH)n-COOH
Fumaric acid, butenedioic acid, HCOOHC:CHCOOH } isomers
Maleic acid, butenedioic acid, HCOOHC:CHCOOH } isomers
Malic acid, 2-hydroxybutanedioic acid, HOOCCH(OH)CH2.COOH
Malonic acid, propanedioic acid, HOOCCH2COOH
Oxalic acid, ethanedioic acid, (COOH)2
Oxaloacetic acid, HO2CCH2COCO2H (in Kreb's cycle)
Succinic acid, butanedioic acid, (CH2)2(COOH)2
Tartaric acid, 2,3-dihydroxybutanedioic acid, (CHOH)2(COOH)2

16.3.8.3 Tricarboxylic acids
16.9.5 Citric acid cycle, Krebs cycle
Citric acid, HOOCCH2C(OH)(COOH)CH2COOH (in Kreb's cycle, plant and animal cells)
Isocitric acid, C6H8O7

16.3.8.4 Unsaturated fatty acids (have double bond =)
Acrylic acid, (2-propenoic acid), CH2=CHCOOH
α-linoleic acid, CH3(CH2)CH=CH(CH2)CH=CH(CH2)CH=CH(CH2)7COOH, polyunsaturated fatty acid
Linoleic acid, CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH, polyunsaturated fatty acid
Linolenic acid CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH
Oleic acid, cis-octadec-9-enoic acid, cis-09-octodecanoic acid, CH3(CH2)7CH=CH(CH2)7COOH, mono-unsaturated fatty acid
Oleic acid, C17H33COOH, CH3(CH2)7CHCH(CH2)7COOH, octadec-8-enoic acid, colourless viscous liquid, red oil, m.p. 14oC
MKS117-U Unsaturated fatty, oleic acid, C18H34O2, 1 molecule, (photograph), "Scientrific", (commercial website)
Palmitoleic CH3(CH2)5CH=CH(CH2)7COOH

16.3.8.5 Perfluorooctanoic acid
Perfluorooctanoic acid, (PFOA), C8HF15O2, a surfactant, is used to make non-stick cookware, e.g. PTFE, ("Teflon"), and stain resistant footwear and clothing. It persists in the environment and is toxic to animals may be a carcinogen.

16.3.8.6 α-hydroxy acids
Naturally occurring carboxylic acid, hydroxyl group on the carbon adjacent to the carboxyl group. Use in skin care.
See diagram 16.3.8.6: Alpha hydroxy acids
Citric acid, HOOCCH2C(OH)(COOH)CH2COOH, citric fruits
Glyceric acid, C3H6O4, 2,3-Dihydroxypropanoic acid
Glycolic acid, Hydroxyacetic acid, HOCH2COOH, sugar cane, sugar beet
Lactic acid, L-(+)-Lactic acid , 2-Hydroxypropionic acid, Sarcolactic acid, C3H6O3, sour milk
Malic acid, HOOCCH(OH)CH2.COOH, apples, grapes
Mandelic acid,  C6H5CH(OH)CO2H,  bitter almond
Tartaric acid, L-(+)-Tartaric acid, L-Threaric acid, C4H6O6, HO2CCH(OH)CH(OH)CO2H,  leavening agent

16.3.8.7 Keto acids
Acetoacetic acid, diacetic acid, C4H6O3, CH3COCH2COOH
Pyruvic acid, C3H4O3, CH3COCOOH

16.3.3.1 Waxes
Waxes are fatty acid esters of high molecular weight alcohols, i.e. lipids with a long chain alcohol + more than 3 fatty acids. Solid at room temperature, harder, more brittle and less greasy than fats at the same temperature.
Waxes are found in skin, fur feathers, and outer layers of leaves and fruits as follows:
1. Fats and oils that are fatty acid esters of the trialcohol glycerol. Waxes are esters of long chain C16 and above alcohols, (with one hydroxyl group), and long chain C18 and above fatty acids. Natural waxes are mixtures of esters and some hydrocarbons.
2. Beeswax [C30H61(C=O)OC15H31, C25-27H51-55(C=O)OC30-32H61-65] comes from the cells of the honeycomb and contains esters of C16 and C28 acids with C30 and C32 alcohols + mainly C31 hydrocarbons. Beeswax is used in furniture polishes.
3. Carnauba wax comes from the leaves of the Brazilian wax palm Coperniciaprunifera, (C. cerifera), Arecaceae. It contains esters of the C32 and C34 alcohols and C24 and C28 fatty acids. This wax is harder and more impervious than beeswax. Carnauba wax, glazing agent, E903, used to wax fruit, in cosmetics.
4. Wool wax, wool grease, degras, from the scouring of wool contains fatty acid esters of cholesterol, lanosterol and fatty alcohols. It forms as semi-solid emulsion in water that is purified to make lanolin.
5. Jojoba oil, (Simmondsia chinensis)
6. Candelilla wax, food additive E902, glazing agent, emollient, (Euphorbia antisyphilitica, E. cerifera, Euphorbiaceae), milkweed, spurge, poisonous, unpleasant milky sap, It is yellow-brown, hard, brittle, aromatic, and opaque to translucent, glazing agent E902, in chewing gum
7. Meadow foam oil, (Limnanthes alba), Family Geometridea
8. Cetyl palmitate [(CH3(CH2)13CH2(C=O)O(CH2)15CH3)] [C15H31COO-C16H33] is a component of spermaceti wax in sperm whale oil.

16.3.4.0 Aromatics, aromatic compounds
Aromatics, aromatic compounds, benzene derivatives, ring systems, arenes: benzene, toluene, naphthalene
See diagram 16.3.4.0: Acridine, anthracene, anthroquinone, cinnoline, naphthalene, naphthol, quinoline
See diagram 16.8.0: Acetylsalicyclic acid, (aspirin), benzene, benzoic acid, naphthalene
See diagram 16.3.4.1: Single substitution, more than single substitution
See diagram 16.3.4.4: Heterocyclic compounds: pyridine, (2-aminopyridine, 3-bromopyridine, 3-nitropyridine, nicotinic acid ), (azines: piperidine, pyridinium chloride), pyrylium ion, (quinoline, isoquinoline, 5-nitroquinoline), (pyrimidines: cytisine, thymine, uracil), (diazines: pyrazine, pyridazine, pyrimidine)
Aromatics have planar ring-type groups usually composed of carbon atoms, at least one benzene ring in the molecule, e.g. benzene, naphthalene, with alternating double and single bonds. Extensive localization occurs because some electrons in the molecule are free to move from one atom to another. The term "aromatic" was used to describe the smell of some compounds later were found to contain benzene or fused benzene rings in the structure. It includes arenes and their substitution products, e.g. benzene, naphthalene, toluene, and aromatic heterocyclic structures, e.g. thiophene.

16.3.4.0a Aryl groups
Groups derived from arenes by removal of a hydrogen atom from a ring carbon atom. Usually, groups having hydrogen removed from an aromatic compound, e.g. (benzene - hydrogen atom = phenyl group, C6H5).

16.3.4.0b Aramids
Aramids are aromatic polyamides, e.g. Kevlar, Nomex. Aramid fibres are made by spinning liquid crystal aramid polymers. The polymer chains are linked laterally by hydrogen bonds, used in rope and textile high performance fibres.

16.3.4.0.1 Aromatic hydrocarbons, arenes
See diagram 16.8.1: Benzene compounds, anthracene
Aromatic hydrocarbons, e.g. Benzene, (C6H6), also in some countries: petrol, pentane-hexane mixture, petroleum spirit. Benzene is the simplest aromatic compound. As it is toxic and carcinogenic, it should not be used in schools.
Aromatic hydrocarbons, arenes, alkylbenzenes, e.g. benzene C6H6, toluene C6H5CH3, [xylene (dimethylbenzene) (CH3)2C6H4], [styrene, (phenylethene), (C6H5CH=CH2)], naphthalene C10H8, anthracenen C14H10, cyclohexane C6H12.
Anthracene, C14H10, paranaphthalene, anthracin, anthracene oil, Irritant, harmful if ingested, Very Hazardous, Toxic

16.3.4.0.2 Aromatic nitro compounds
Aromatic nitro compounds, e.g. Nitrobenzene, oil of mirhan, (C6H5NO2)
16.3.4.0.3 Lactams
Lactams, (-NH(CO-), e.g. caprolactam, (6-hexanelactam), (C6H11NO)
See diagram 16.3.4.3: Lactams, penicillin G, amoxicillin
Lactams in part of a ring, cyclic amides, amino group + carboxylic acid group --> amide linkage, e.g. caprolactam, (6-hexanelactam), (C6H11NO), to make nylon, 4-aminobutanoic acid lactam, (β lactam 4C ring, γ-lactam 5C ring, δ-lactam 6C ring), e.g. the pyrimidine base uracil, β-lactam antibiotics, e.g. penicillin, also: caprolactam, (C6H11NO), also: lactones, (cyclic esters), e.g. 4-hydroxybutanoic acid lactone CH2CH2CH2OC=O, γ-butyrolactone, GBL, C4H6O2.

16.3.4.0.4 Aromatic amines
Aromatic amines, anilides, e.g. phenylamine, (aniline, amino benzene), (C6H5NH2)
(phenylammonium ion, anilinium ion C6H5NH3+), benzylamine, diphenylamine, methylaniline, triphenylamine, dimethylaniline, acetanilide, quinoline, (C9H7N), Magenta is a brilliant red aniline dye derived from coal tar.

16.3.4.0.5 Diazo compounds
Diazo compounds, (2 linked nitrogen compounds), e.g. methyl orange, (dimethyl-aminoazobenzene sulfonic acid), (diazonium ion: C6H5N2+, C6H5N+≡N), diazonium salts [(RN≡N+)Cl-], e.g., methyl orange, (dimethyl-aminoazobenzene sulfonic acid), [(CH2)2NC6H4N=NC6H4SO2O-Na+] benzene diazonium chloride, chrysoidine azo compounds, (-N-N-), (diazonium ion + benzene ring)

16.3.4.0.5a Barbiturates (central nervous system depressants)
See diagram 16.3.4.05a: Amylobarbital, barbital, pentobarbital, phenobarbital, quinalbarbital, sodium phenytoin, thiopental Barbiturates were formerly used as sedatives and hypnotics. Barbituric acid is formed by condensing urea with diethyl malonate, an ester from apples. Barbituric acid derivatives include barbital, (Veronal, formerly used or attempted used by would-be suicides), and phenobarbital (phenobarbitone, "Luminal"), sedative and hypnotic, an anticonvulsant drug used to treat epilepsy. Phenobarbital causes side effects, e.g. sedation, depression and agitation so to some extent it has been replaced by phenytoin [C15H12N2O2, 5,5-diphenyl-2,4-imidazolidinedione] in the anti-epileptic drug sodium phenytoin, (Dilantin). Sodium thiopental ("Sodium Pentathol", thiopentone sodium, "Trapanal"), is a short acting barbiturate general anaesthetic, used to start anaesthesia.

16.3.4.0.5b Benzodiazepines (tranquillizers, sedatives, hypnotics)
See diagram 16.3.4.0.5b: Diazepam (Valium), oxazepam (Serax), nitrazepam (Mogadon), chlordiazepoxide (Librium), flunitrazepam (Rohypnol)
Benzodiazepines assist the neurotransmitter γ-aminobutyric acid to treat anxiety, insomnia, seizures, and preparation for medical procedures.

16.3.4.0.6 Aromatic halogen compounds
Aromatic halogen compounds, aryl halide, halogenarenes, e.g. benzyl chloride, (C6H5COCl)
See diagram 16.3.4.0.6: DDT, methoxychlor, Synergists: piperonyl butoxide
See diagram 16.13.3: Benzene hexachloride, chlorothalanil, DCPA, dalapon
See diagram 16.13.4: aldrin, chlordane, dieldrin, endosulfan, heptachlor
16.7.2 Dalapon
Bromobenzene, iodobenzene, chlorobenzene, (BHC, benzene hexachloride, lindane), chlorothanil
Cyclodienes: chlordane, aldrin, dieldrin, heptachlor, endosulfan
DDT insecticide: (ClC6H4Cl)2CH(CCl3), (Former name: dichlorodiphenyltrichloroethane),
( New IUPAC name: 1,1,1-trichloro-2,2-bis, (4-chlorophenyl)ethane.)!

16.3.4.0.7 Aromatic sulfonic acids
Aromatic sulfonic acids, e.g. benzene sulfonic acid, (C6H5SO2OH), sodium benzene sulfonate

16.3.4.0.9 Aromatic alcohols
Aromatic alcohols, e.g. phenyl methanol, (benzyl alcohol), (C6H5CH2OH),

16.3.4.0.10 Aromatic aldehydes and ketones
Benzoin, C14H12O2, 2-Hydroxy-2-phenylacetophenone, 2-Hydroxy-1,2-Diphenylethanone, desyl alcohol, bitter almond oil
Benzaldehyde, benzenecarbaldehyde, benzene aldehyde, C6H5CHO, almond kernel flavouring, camphor is synthesized from benzaldehyde in a condensation reaction. See diagram 16.8.1

16.3.4.0.11 Aromatic acids
Aromatic acids and their derivatives, e.g. benzoic acid, (C6H5COOH)
See diagram 16.3.4.11: Acetyl salicyclic acid, (aspirin), | See diagram 16.3.4.12: Benzoic acid, caffeine, paracetamol, phenacetin
e.g. benzoic acid, (C6H5COOH), benzoyl chloride, (C6H5COCl), salicyclic acid, (1-hydroxybenzoic acid), (HOC6H4COOH), aspirin, acetyl salicyclic acid, (2-acetoxy benzoic acid), [C6H4(OCOCH3)COOH] alcohol detergent, aromatic detergent, weed killer 2:4-dichlorophenoxyacetic acid, shikimic acid [C6H6(OH)3COOH]
Acetyl salicyclic acid is hydrolysed with hydrochloric acid to salicylic acid and acetic acid. Sometimes old bottles of aspirin have a vinegar (acetic acid) smell because of this reaction.

16.3.4.0.12 Parabens
Parabens get their name from their origin as esters of parahydroxybenzoic acid., Parabens, HO.C6H4.CO.O-R, where R = alkyl group
See diagram 16.3.4.12: Parabens
See 19.4.4.23 Preservatives, food additives: E214 to E219
Parabens are esters of para-hydroxybenzoic acid and are used commonly as preservatives in cosmetics and food. However, some parabens may cause allergic reactions in some people and affect DNA. Some parabens are said to imitate oestrogen and are suspected of causing cancer, but there is no evidence that they are carcinogenic. However, in Australia, some skin care products are labelled "Paraben free" because of this suspicion.
Propyl paraben, propyl 4-hydroxybenzoate, "Nipagin A", E216, is a natural subsonic but is usually manufactured for use as a food preservative against fungi and as a cosmetics industry preservative.
Methyl paraben, methyl 4-hydroxybenzoate, "Nipagin B", E218, CH3(C6H4(OH)COO, is used as anti-fungal agent in hair gels and similar products, it occurs in blueberries
Ethyl paraben, ethyl 4-hydroxybenzoate, E214, is used as a food preservative.

16.3.4.0.13 Pyridine
Pyridine, (pyridino), C5H5N, monodentate ligand
Pyridine, C5H5N, has a penetrating offensive odour and in some countries it is added to methylated spirit to deter ingestion.

16.3.4.1a Benzofuranoids, benzopyranoids
16.9.19 Coumarin | 16.9.20 Bergamottin
See diagram 16.3.4.12: Coumarin, furan, bergamottin | See diagram 16.3.4.13: Bergamottin, lovastatin, atorvastatin
Benzofuranoids: (furan C4H4O), (benzofuran, coumarone, C8H6O, 2,3-benzofuran), (benzodifuran), (isobenzofuran)
Benzofuranoid derivatives used as anti-inflammatory constituents from Eupatorium cannabinum.
Benzopyranoids: (pyran, C5H6O, oxime, 2H pyran, 4H pyran), (1-benzopyrans), (3,4-dihydro-2H-1-benzopyran, chroman), (4-chromanone, C9H8O2), (chromone, C9H6O2), (2-chromeme), (3-chromeme), (flavone, C15H10O2), (flavanone C15H12O2), (fisetin flovanol C15H10O6.nH2O), (coumarin, C9H6O2)
Benzopyrans, chromenes, have a benzene ring + heterocyclic pyran ring, C5H6O.

16.3.4.1b Geosmin, Earth smells, rain smells, cut grass smells
16.9.19 Coumarin
See diagram 16.3.4.1: Coumarin, isocoumarin, cycloalkyls, geosmin
1. The degraded sesquiterpene geosmin, C12H22O, causes the smell of moist soil, produced by Streptomycesis species, e.g. Streptomyces antibioticus and Streptomyces coelicolor and blue-green algae. The "earth smell", "rain smell" noticed after rain and in wet rugby dressing rooms, causes the earthy taste of beetroot, and "off tastes" in water and wine. Blue-green algae in water can also produce geosmin. In Australia, when heavy rain occurs after a long period of dry weather, a bad taste, "off taste", may develop in the drinking water caused by the high concentration of geosmin washed into water supply dams. Actinomycetes bacteria grows in damp soil but produces survival spores during hot weather. During the first rainfall, wind suspends the spores in the air as an aerosol causing the "after the rain smell" from geosmin, C12H22O, (trans-1,10-dimethyl-trans-9-decalol). The smell occurs after you have breathed in tiny particles of soil containing the bacteria. Another explanation for the after rain smell is that volatile chemicals in the air spaces between soil particles are washed out by the rain and become relatively concentrated just above the soil. Some people call the earth smell "petrichor" and say that is caused by plant oils that become adsorbed to clay minerals to produce an argillaceous odour. Some people say they can smell ozone in the smell after rain and this may be true after severe lightning from thunder storms.
2. Geosmin also causes the earthy taste of beetroot and off-flavours in wine and drinking water. It can be isolated from Streptomyces antibioticus. Also, Streptomyces coelicolor may be involved in producing the smell.
3. Geosmins are also produced by blue-green algae and anaerobic bacteria when they die. Geosmins may cause the muddy smell of fish, e.g. catfish, carp and mullet. Geosmins breakdown in acid solutions so fish is generally eaten with lemon juice.
4. The sweet smell of new mown hay is because of a coumarin from cut clover, e.g. white clover, (Melilotus alba), when a glucosidase reacts with glycosylated cinnamic acid to produce hydroxycinnamic acid that esterifies to form coumarin. Newly cut grass produces a variety of volatile organic compounds depending on the species of the grass and when it is cut during its life cycle. The compounds include methanol, ethanol, acetaldehyde, acetone, butane, 1,8-cineole, aldehydes of hexanoic acid, (caproic acid, CH3(CH2)4COOH), and so-called hexenyl compounds. These emitted compounds may be a significant proportion of atmospheric pollution emitted during motorized grass cutting and grazing.

16.3.4.2 Flavonoids, (Bioflavonoids), plant polyphenols
See diagram 16.3.4.2: Flavonoids, (apigenin-7-monoglucoside), flavones, riboflavin, anthicyanin
More than 6,000 bioflavonoids, They have vasodilating actions, antioxidant, anti-allergenic, anti-inflammatory and antiviral properties. They cause the colour, flavour and aroma for many foods and are found in fruits and vegetables, tea, red wine, cacao and some nuts. Chemists and the food industry do not have the same classification of the flavonoids - bioflavonoids group.
Flavonoids, isoflavonoids and neoflavonoids are natural products, derived from flavone, derivatives --> flavanones and flavanols
Flavonoids are 3-ring phenolic compounds with a double benzene ring with OH groups attached to a 3rd benzene ring by a single bond, (flavonoid - sugar = aglycone)
Examples of flavanoids
Apigenin, (4,5,7-trihydroxyflavone), from parsley, C15H10O5
Baicalin, in leaves of Scutellaria lateriflora (blue skullcap) and Scutellaria galericulata (common skullcap) leaves, glucuronide of baicalein, in Chinese medicinal herb Huang-chin (Scutellaria baicalensis) to treat cancer, C21H18O11
Catechin, flavanol, from green tea, cocoa, vinegar, C15H14O6
Catechin gallate, from green tea, C22H18O10
Epicatechin, from green tea, cocoa, kola nut, peach, C15H14O6
Genistein, from Glycine max (soybean), C15H10O5
Naringin, from citrus fruit, C27H32O
Theaflavins, (theaflavin and theaflavin gallates), from black tea

16.3.4.2.1 Anthocyanins, plant pigments, glycosides, hydrolysis --> coloured aglycons, deep red anthocyanidins become tannins
Anthocyanidins include cyanidin, delphinidin, malvidin, pelargonidin, peonidin.
Anthocyanins in fruits and vegetables:. apples, berries, currants, eggplant, grapes, pears, plums, cabbage, radishes, red onions.
Anthocyanins in nuts: e.g. hazelnuts, pecans, pistachios, In red wine.

16.3.4.2.2 Flavonols, (flavan-3-ols), yellow
Flavonols include isorhamnetin, kaempferol, myricetin and quercetin. In fruits and vegetables, e.g. apples, apricots, blueberries, blackberries, arugula, asparagus. In green and oolong tea, cocoa, red wine.
Quercetin (C15H10O7), also called flavone, is the most active of the flavonoids, and many medicinal plants with a high quercetin content. Has anti-inflammatory activity by inhibiting release of histamine and has antioxidant activity.
Rutin, (C27H30O16), citrus flavonoid glycoside, rutin hydrate, C27H30O16.xH2O, quercetin-​3-​rutinoside hydrate, vitamin P hydrate
Apigenin and Luteolin in fruits and vegetables, e.g. peppers, olives, artichokes, celery, onions and parsley.
In green tea.
Flavan-3-ols include catechins, epicatechins, theaflavins and thearubigins. In fruits and vegetables, e.g. apples, apricots, berries, cherries, grapes, nectarines, peaches, pears, plums, Swiss chard. In nuts, e.g. almonds, cashews, hazelnuts, pecans and pistachios. In green, black and oolong teas, cacao, red and white wine.

3. Flavanols, catechin, (C15H14O6), colourless monomer, (isomer epicatechin)

4. Flavanones, usually glycosylated to form flavanone glycosides, e.g. butin, (C15H12O5), in seeds of Vernonia anthelmintica.
Flavonones include eriodictyol, hesperetin, naringenin. In citrus fruits, e.g. kumquats, lemons, limes, grapefruits, oranges and tangerines. In artichokes. In red and white wine.

5. Isoflavones, related to isoflavonoids, phytoestrogens and antioxidants, soy isoflavones may prevent breast cancer, only found in legumes. Isoflavones include genestein and daidzein. In soybeans, pistachios.

6. Other bioflavonoids, e.g. proanthocyanidin, rotenone, pisatin, isoflavan, pisatin, proanthocyanidins, orcein, vulpinic acid, taxol, urushiol, (pentadecyl-catechol), (phytoalexins: resveratrol, psoralen), (flavone alkaloids: ficine, vochysine).
Brazilin, red pigment, (C16H14O5), from Caesalpinia echinata, "Brazil wood" originally "bresel wood", Natural Red 24
Haematoxylin, log wood, (C16H14O6), from Haematoxylum campechianum, logwood tree, Natural Black

7. Classification of flavanoids
Plant secondary metabolites, formerly "Vitamin P"
1. flavones, from 2-phenylchromen-4-one, e.g.quercetin, rutin).
2. isoflavonoids, from 3-phenylchromen-4-one
3. neoflavonoids, from 4-phenylcoumarine.
Flavonoids
1. Flavonols
2. Flavan-3-ols (hydroxy derivative of flavone) --> flavanol, (flavonoid in red wine)
3. Flavones, e.g. Baicalin
4. Flavanones --> flavone C15H10O2
5. Flavanonols
6. Flavan-3,4,diol --> anthocyanidins, anthocyanins

16.3.4.3 Tannins
Tannins, (kinotannic acid), plant polyphenols, phenolic polymers: polyphenols, galloyl ester, vescalagins
Tannin, i.e. tannic acid, a polyphenol, is a yellow-brown compound in coffee beans, oak galls, mahogany, tea leaves, tree bark, walnuts. Reacts with proteins in skins to form leather. Used as a mordant, inks and dyeing. Tannic acid is not an acid. Tannins are any group of yellow-brown astringent compounds derived from gallic acid, found in bark and galls, used to convert animal hide to leather.
Tannins from hemlock, (Tsuga), oak, (Quercus), mangrove, (Rhizophora), wattle, (Acacia), babul, (Acacia sp). chestnut, (Castanea), quebracho, (Schinopsis), sumacs, (Rhus), canaigre from tanner's dock, (Rumex), E181 Tannic acid, tannins, (from oak trees, tea), (clarifying agent).

16.3.4.4 Lignans, plant phenols
Lignans: (from degradation of lignin), plant phenols, dihydroguaiaretic acid, hinokinin, podophyllotaxin

16.3.4.5 Five member heterocycles
See diagram 16.3.4.5: 5-member heterocycles | See diagram 14.05: Histamine, major tranquillizers, tricyclic anti-depressants
Heterocyclic molecules have different atoms in the ring: furan C4H4O, thiephene C4H4S, pyrrole, (CH)4NH, thiazole C3SNH3, saccharin C7H5NO3S, histamine C5H9N3, immidazole C3N2H4, indole C8H7N, [proline (CH2)3NHCHCOOH, an amino acid called pyrrolidine-2-carboxylic acid)]

16.3.5.1 Terpenes
Terpenes, monoterpenes, terpinenes, sesquiterpenes, diterpenes, sesterterpenes, triterpenes, tetraterpenes, terpenoids, oleoresins
See diagram 16.1.1.2.2: Isoprene | See 16.1.1.2.2: Dienes, isoprene units
(limonene, α-pinene, camphene, cadinene, caryophyllene, cedrene, dipentene, phellandrene, terpinene, sabinene, myrcene)
1. Terpenes, (isoprenoids), occur mostly in plants and may be isolated as a water-insoluble oil through distillation. Terpenes contain functional groups, e.g. C=C, OH, C=O and may be acyclic or cyclic. Phenolic compounds often associated with terpenes contain benzene rings with attached hydroxyl groups, (C-OH). Some terpenes are organic solvents and cleaning agents with strong characteristic odours derived from pine trees or citrus fruit, e.g. α-pinene, d-limonene, and turpentine, (a mixture of terpenes). Terpenes are volatile organic compounds, (VOCs), and are flammable or combustible.
2. The degraded sesquiterpene terpene geosmin, C12H22O, produced by Streptomycesis species and blue-green algae, causes "earth smell" after rain.
3. Terpenes may be poisonous and can cause painful rashes
3.1 Manchineel tree, (Hippomane mancinella)
3.2 Cicutoxin water hemlock, (Cicuta douglasii)
3.3 Terpenoid compound thujone in oil of wormwood, (Artemisia absinthium), used in the alcoholic drink absinthe.
4. Polyterpenes contain thousands of C5H8 isoprene subunits in milky latex sap
4.1 Natural rubber, (C5H8)n, [n = 4,000–5,000], (Hevea brasiliensis), and (Ficus elastica)
4.2 Gutta-percha, (Palaquium gutta)
4.3 Chicle polyterpene from the sapodilla tree, (Manilkara zapota), used for chewing gums.

2. Terpenes are found in the following substances:
2.1 Essential oils that are monoterpenes and sesquiterpenes volatile at room temperature, e.g. eucalyptol, citronella, (citrus oils), and eugenol, (oil of cloves).
2.2 Herbs and spices containing terpinene oil.
2.3 Perfumes that contain aromatic terpenes, and resins, 20-carbon diterpenes and 30-carbon triterpenes.
2.4 Lutein and zeaxanthin are the only xanthophylls found in human serum. Fucoxanthin is found in brown algae.

3. Terpenes are unsaturated hydrocarbons formed by the polymerization of 5-carbon isoprene units . An isoprene unit has a four carbon chain and a one carbon branch at C2. Different structural forms are called isomers.
Isoprene: [2-methyl-1,3-butadiene], [CH2=C(CH3)CH=CH2], (C5H8), Isoprenoids are compounds derived from isoprene, often showing repeated occurrence of isoprene units. Terpenes have linked isoprene units that occur in natural rubber.

4. Terpenes are subdivided as follows:
C5 Hemiterpenes, (1 isoprene unit), (C5H8), Prenol hemiterpenoids, prenols are alcohols of general formula H-[CH2C(Me)=CHCH2]nOH in which the carbon skeleton is composed of one or more isoprene units. So terpenes can be defined as a class of compounds composed of repeating 5-carbon units of hemiterpenes.

16.3.5.1.1 Monoterpenes
Monoterpenes, C10, (2 isoprene units), (C10H16), Monoterpenes include α-pinene in turpentine, (pine needles flavour), α-thujene, β-linene, camphor C10H16O, citronellal C10H18O, (aldehyde), citronellol, eucalyptol, geraniol, (rose flavour), myrcene, [menthol, (-) menthol, C10H20O, hexahydrothymol, peppermint camphor (a methyl cyclohexanol), (mint flavour, peppermint flavour)].
Anethole, (anise flavour), 4-Propenylanisole,
C10H12O, CH3CH=CHC6H4OCH3, p-methyoxypropenylbenzene, trans-1-Methoxy-4-(1-propenyl)benzene, trans-1-Methoxy-4-(prop-1-enyl)benzene, isomer estragole, occurs in anise, anise myrtle, fennel, star anise.
Anise, aniseed, oil of aniseed from Pimpinella anisum is used in absinthe, anisette, (anis), arak, champurrado, (atole de anis), ouzo, pastis, Pernod, raki, sambuca and some root beers.
Thymol, Topical antifungal Thymus vulgaris, (thyme), Origanum vulgare contains thymol, C10H14O

16.3.5.1.2 Terpinenes
Terpinenes, (C10H16), Terpinenes are cyclic terpenes and occur as three isomers:
1. α-terpinene is an oil with a lemon smell. It occurs in cardamom, coriander, and marjoram.
2. β-terpinene occurs in oil of savin.
3. γ-terpinene occurs in coriander, cumin, lemon, samphire. It can be formed from the action of alcoholic sulfuric acid solution on pinene from turpentine.

16.3.5.1.3 Sesquiterpenes
Sesquiterpenes C15, (3 isoprene units), C15H24
9.1.7.5 Abscisic acid, C15H20O4
caryophyllene
chamazulene, (chamomile oil), curcumene
Eugenol, Clove oil, oil of clove
eugenol [C6H3(OH)(OCH3)(CH2CH=CH2)], (in oil of cloves, cinnamon leaf oil, West Indian Bay oil), farnesene
farnesol, (in citronella, chamomile oil, oil of neroli petate, cyclamen, lemon grass, tuberose, rose, musk, and balsam), frankincense
geosmin, C12H22O, is a degraded sesquiterpene
gossypol
humulene
huratoxin
myrrh
nerolidol, (in neroli, ginger, jasmine, lavender, tea tree and lemon grass), oleoresin
β-Selinene, in celery oil
turpentine --> rosin
zingiberene, (in ginger)

16.3.5.1.4 Diterpenes
Diterpenes, C20H32, have four isoprene units, e.g. steviol C20H30O3, from Stevia rebaudiana, artificial sweetener
Diterpenes C20, (4 isoprene units), C20H32, in resins, pine turpentine, distilled essential oils
casbene, (disease resistance), crocin, (in saffron), cembrene
phytol, a building block of the chlorophyll molecule
dehydroleucodine, (medicine from Artemisia douglasiana), gibberellins, (phytohormones and germination), gibberellin A1, gibberellin plant hormones. (stem elongation), podocarpic acid, (disease resistance), retinol, (vitamin A activity), taxadiene, taxol, (in yew tree bark, anticancer), trisporic acid, (fungal hormones).

16.3.5.1.5 Sesterterpenes
Sesterterpenes, C25, (5 isoprene units), insect waxes, fungi
geranylfarnesol
ceroplastol

16.3.5.1.6 Triterpenes
Triterpenes C30, (6 isoprene units), steroids and sterols
Ambrein, C30H52O, a triterpene alcohol, is the main constituent of ambergris found in the sperm whales or floating on the sea as whale barf (vomit), whale spit. It is supposed to protect the intestines of whales from the sharp beaks of cuttlefish. It was used for food flavouring and in the perfume industry to prevent scent from dissipating too quickly. Since 1970 the perfume industry has turned to substitutes to protect whales. It is supposed to be an aphrodisiac.
Saponins are toxic glycosides forming frothy colloidal solutions in water when agitated in water. Although they cause breakdown of red blood cells some saponins have been discovered in traditional medicines, e.g. in the Maesa balansae plant in Vietnam used to treat leishmaniasis. Saponins that foam in water occur in the horse chestnut, Aesculus hippocastanum. One triterpene saponin has formula C30H48O4.
To test for saponins. add ground plant material to test-tube of water, heat to boiling, stopper and shake and note presence of stable froth.
sterols, (steroids) in animal sex hormones, squalene, (in shark liver oil), cephalosporin, gonane, hopane, diplotene, lupeole
Squalene, in liver oil of sharks

16.3.5.1.8 Tetraterpenes C40, (8 isoprene units), C40H56, carotenoid pigments
Tetraterpenes are terpenes with 8 isoprene subunits, (C40H64) lycopene, α-carotene and β-carotene, their derivatives the tetraterpenoids are terpenoids of 8 isoprene units, 40 carbon atoms in the skeleton.
Terpenoids, similar to terpenes are the largest group of natural products and are responsible for many scents and flavours, e.g. citral, menthol, camphor, salvinorin A in Salvia divinorum, and cannabinoids in Cannabis.
Carotenoid pigments are tetraterpenoids derived from the acyclic parent carotene. They occur in chloroplasts of plants and in some algae.
Carotenoids are divided into 1. Carotenes, hydrocarbons only that contain no oxygen, and 2. Xanthophylls, that contain oxygen,yellow pigments in the leaves of most plants. Carotenoids absorb blue light. Carotenoid pigments are tetraterpenoids derived from the acyclic parent carotene. They occur in chloroplasts of plants and in some algae. Carotenoids are yellow, orange, or red fat-soluble plant and animal pigments,with molecular formula C40H56. Many tropical fruits can be considered a reservoir of bioactive substances with a special interest due to their possible health-promoting properties. The interest in carotenoids from a nutritional standpoint has recently greatly increased, because of their alleged important health benefits, perhaps as antioxidants. Carotenoid pigments are usually red, orange, or yellow, e.g. carotene in carrots. Carotenoids have two six-carbon rings connected by a chain of carbon atoms. They do not dissolve in water and are attached to cell membranes. Carotenoids are called accessory pigments because they pass their absorbed energy from sunlight to chlorophyll. The accessory pigment fucoxanthin is the brown pigment in brown algae and diatoms.
Carotenoids include 1. alpha-carotene, beta-carotene, beta-cryptoxanthin, are provitamin A carotenoids, which we can convert to retinol (vitamin A), 2. lutein, zeaxanthin, and lycopene (in tomatoes). Lutein and zeaxanthin, (from spinach, kale, and broccoli), are in the retina and lens of the eye. The carotenoid beta-carotene may decrease sensitivity to the sun.

16.3.5.1.9 Carotenes
Carotenes are hydrocarbon carotenoids, a subclass of tetraterpenes and C5n polyterpenes.
16.4.1.0 Vitamins
1. α-carotene, (C40H56)
2. β-carotene, (C40H56), is a precursor to be digested to form the antioxidant vitamin A, (C20H28O), retinol. α-carotene and yellow pigment β-carotene are in carrot roots and ripe tomato fruits.
Commercial: β-Carotene, Type I, synthetic, ≥93% (UV), powder, β,β-Carotene, Provitamin A, C40H56
Commercial: β-Carotene, Type II, synthetic, ≥95% (HPLC), crystalline, β,β-Carotene, Provitamin A, C40H56
Commercial: β-Carotene, 95%, trans-β-Carotene, Provitamin A, C40H56
Commercial: β-Carotene, ≥97.0% (UV), β,β-Carotene, Provitamin A, C40H56
3. δ-carotene, (C40H56)
4. Lycopene is a bright red carotene and carotenoid pigment, in ripe tomato, carrots, bell peppers, watermelons, papaya, (C40H56)
E160d Lycopene, (carotenoid), (from tomatoes, pink grapefruit), (colour: red), (may decrease risk of cancer)
Commercial: Lycopene, ≥90%, from tomato, ψ,ψ-Carotene, ​"Octamethyl-​dotriaconta-​tridecaene", C40H56
Lycopene is a antioxidant micronutrient of tomatoes associated with decreased risk for cancer and cardiovascular disease. It inhibits cholesterol synthesis and enhances low-density lipoprotein degradation.
Plants rich in carotenes
Sweet potato, (red variety), (9,507 μg in 100 g), Kale, (9,226 μg in 100 g), Carrot, (8,285 μg in 100 g), Mustard greens, (6,300 μg in 100 g), Spinach, (5,626 μg in 100 g), Dried basil, (5,584 μg in 100 g), Butternut squash, (4,570 μg in 100 g), Lettuce, (red leaf variety), (4,495 μg in 100g).

16.3.5.1.10 Xanthophylls
1. Astaxanthin is in the red pigment of exoskeletons of lobsters and in egg yolks, (C40H52O4)
2. Canthaxanthin, terpenoid, E161g, (C40H52O2)
3. Flavoxanthin, yellow xanthophyll pigment, E161a, (C40H56O3)
4. Phytoene, (C40H64)
5. Rhodoxanthin, purple xanthophyll pigment, in Taxus baccata, E161f , (C40H50O2)
6. Rubixanthin, natural yellow 27, red-orange xanthophyll pigment, in rose hips, E161d, (C40H56O)
7. Staphyloxanthin, produced Staphylococcus aureus, "golden staph", C51H78O8
8. Violaxanthin, orange xanthophyll pigment, in pansy, E161e, (C40H56O4)
9. Zeaxanthin, most common carotenoid, causes yellow colour of corn, (maize), kernels, (Zea mays), paprika from bell peppers, saffron, (C40H56O2)
10. Xanthophylls are oxygenated carotenoids, the yellow leaf pigments of leave, synthesized within plastids without need for light for synthesis, but do absorb some wavelengths not absorbed by chlorophyll, so appear in etiolated leaves and plants with chlorosis nutrient deficiency. Astaxanthin in red fish, fruits and vegetables, is an antioxidant that may be anti-inflammatory, prevents Alzheimer’s disease, cold and influenza, protect the iris from sunlight and protect skin cells from ultraviolet rays. Canthaxanthin in algae, lobsters, fish and chanterelle mushrooms is an antioxidant that may protect cells from ultraviolet rays. It may be an ingredient in sunless tanning products but this can be very dangerous. Cryptoxanthin in yellow maize, orange and red pumpkins and chillies is an antioxidant that may improve vision and night vision and bone growth and prevent arthritis. Deficiency may cause dry skin, and vision problems. Lutein it in the macula lutea, the oval shaped yellow spot near the centre of the retina, from green vegetables, is an antioxidant that may help pregnant and lactating women and prevent atherosclerosis and damage from ultraviolet rays. Consuming too much lutein causes carotenemia, orange skin. Zeaxanthin from yellow maize, green vegetables. Also part of the macula lutea, is an antioxidant that may prevent macular degeneration and cataracts. Zeaxanthin has a hydroxy function at each end group.

16.3.5.1.11 Terpenoids
Terpenoids are terpenes modified by oxidation or rearrangement of the carbon skeleton. Terpenoids are natural products and related compounds derived from isoprene units. They contain oxygen in various functional groups and are subdivided as follows:
1. C10 Monoterpenoids
Iridoids are cyclic monoterpenoids having the iridane skeleton, (1-isopropyl-2,3-dimethylcyclopentane)
2. C15 Sesquiterpenoids
3. C20 Diterpenoids
4. C25 Sesterterpenoids
5. C30 Triterpenoids
Steroids, sterols
6. C40 Tetraterpenoids

16.3.5.2.1 Tetrapyrroles, related compounds
See diagram 16.3.5.2: Bilin, haeme (heme) | See diagram 16.3.5.2.1: Haeme (heme) | See diagram 16.3.5.2.2 Tetrapyrroles
Tetrapyrroles are natural pigments containing four pyrrole rings joined by one-carbon units linking position 2 of one pyrrole ring to position 5 of the next pyrrole ring. Porphyrins are macrocyclic tetrapyrroles, e.g. bilin, (a linear tetrapyrrole).
Tetrapyrroles have the following related compounds: haemin, haematin, haemoglobin, myoglobin, cytochromes, chlorophylls a and b, bile pigments biliverdin and bilirubin, vitamin B12, bilin,  in congenital disease polyphyria, tetrapyrrole derivative DPEP in geological deposits possibly from chlorophyll, chlorin, (2,3-dihydroporphyrin).
Haeme, (heme), in haemoglobin, globular protein in animals, oxygen carriers
Haeme A, C49H56O6N4Fe, (cytochrome oxidase ligand complex) tetradentate ligand],
Haeme, Constituents of blood: 9.214

16.3.5.2.2 Porphyrins
See diagram 16.3.5.01: Porphine | See diagram 16.3.5.2: Porphyrins, porphine | See diagram 16.3.5.0: Porphyrins (IUPAC)
Porphyrins are natural pigments containing a fundamental skeleton of four pyrrole nuclei united through the α-positions by four methine groups to form a macrocyclic structure. (IUPAC)
Porphyrins refers to any of a group of compounds containing the porphyrin structure of four pyrrole rings connected by methine bridges in a cyclic configuration with usually metal side chains attached, e.g., with iron to form heme, (haeme).
Porphyrin chelates include haeme, in haemoglobin, bonded to iron (II) ion, and chlorophyll bonded to Mg (II) ion. The heme component of the protein haemoglobin has four iron porphyrins. Porphyrins occur in iron-containing cytochrome pigments in mitochondria in plants, animals and bacteria. For oxidative phosphorylation, electron transport system, and ATP production.

16.3.5.2.3 Chlorophyll a and chlorophyll b
See diagram: 16.3.5.2.3: Chlorophyll a and chlorophyll b | See diagram 16.3.5.2: Chlorophyll a
Chlorophyll a C55H72O5N4Mg and chlorophyll b C55H70O6N4Mg are magnesium porphyrins.
Invertebrates with green blood have copper porphyrins.
Colours, food colours, food additives E140 Chlorophylls and chlorophyllins (used to dye oils and wax in medicines and cosmetics)
Chlorophyll pigments are green. The pigment chlorophyll a, (C55H72O5N4Mg), occurs in in plants, algae, and cyanobacteria. The pigment chlorophyll b, (C55H70O6N4Mg), occurs only in green algae. Chlorophyll pigments contain a porphyrin ring with electrons that move freely and be added to the ring or lost from the ring. During photosynthesis, electrons become more energized by sunlight and can be passed on enable the process of sugar formation. The pigment chlorophyll C occurs in photosynthetic Chromista and dinoflagellates.
E140 Chlorophylls and chlorophyllins, (colour: olive to dark green), (used to dye oils and wax in medicines and cosmetics)
E141 Copper complexes of chlorophylls and chlorophyllins, (colour: bright green)

16.3.5.2.4 Legheamoglobin
Legheamoglobin, leghemoglobin, legoglobin) occurs in nitrogen-fixing bacteria in the root nodules of legumes. It is an oxygen carrier and a hemoprotein, produced by legumes in response to the roots being infected by nitrogen-fixing bacteria, Rhizobium. like hemoglobin, it is red in colour. The apoprotein is produced by the plant and the heme (an iron atom bound in a porphyrin ring) is also produced by the plant. It stores enough oxygen to support nodule respiration for a few seconds. Its function is to help transport oxygen to the respiring symbiotic bacterial cells, analogous to hemoglobin transporting oxygen to respiring tissues in animals.

16.3.5.2.5 Phycobiliproteins
Phycobiliproteins occur in cyanobacteria and red algae are composed of water-soluble phycobilin pigments and protein. N-fixing cyanobacteria such as Anabaena azollae live symbiotically within leaf cavities of the water fern Azolla.

16.3.5.2.6 Phycobilins
Phycobilins include the blue-green pigment phycocyanin and the red pigment phycoerythrin to enable red algae to be photosynthetically efficient in deep water where blue light predominates. Phycobilin pigments are soluble in water-soluble and occur in the cytoplasm and stroma of chloroplast. They occur only in Cyanobacteria and Rhodophyta. The blue green pigment phycocyanin occurs in the Cyanobacteria their name. The red brown pigment phycoerythrin occurs in the red algae. Phycobilin pigments absorb light energy that is passed on to other processes. Pycocyanin and phycoerythrin fluoresce are fluorescent.

16.3.5.2.7 Phytochromes
Phytochromes are phycobilin-protein pigments involved in floral induction. activated by the length of day, hours of darkness.

16.3.5.2.8 Polyvinyl pyrrolidene, povidone, PVP
See diagram 16.3.5.2: Povidone, PVP
Polyvinyl pyrrolidene, povidone, PVP, is a water-soluble polymer, E1201, used as a coating or binder in medical tablets, e.g. povidone-iodine complex (PVD-iodine) in the antiseptic "Betadine", that nowadays has replaced tincture of iodine solution in medicine.

16.3.5.3 Steroids, sterols, steroid alcohols, natural steroids
See diagram 19.2.1.7: Steroids | See diagram 16.3.5.3: Cholesterol, cholic acid, bile salt, estradiol, progesterone, northindrone, RU 486, (mifepristone), testosterone, androsterone, cortisone
The sterols, (steroid alcohols), androstane steroids, (testosterone), C20 steroids, 19-norpregnane, pregnane steroids, (progesterone), Steroids are naturally occurring compounds and synthetic analogues, based on the cyclopenta[a]phenanthrene carbon skeleton, partially or completely hydrogenated, and usually with methyl groups at C-10 and C-13, and an alkyl group at C-17.
Natural steroids are derived biogenetically from triterpenoids. Sterols are natural products derived from the steroid skeleton and containing a hydroxy group in the 3 position, closely related to cholestan-3-ol. Steroids have a saturated 4 ring steroid structure. Steroids include sex hormones, coricosteroid hormones, cardiac glycosides, bile acids, cholesterol lanosterol, (animal sterols), β-sitosteron, (plant sterol), ergosterol, (fungus sterol), estrogen, cardiac glucosides, diosgenin, androstane, 19-norpregnane, 7-dehydrocholesterol, previtamin D3, ergocalciferol, (vitamin D2), cholecalciferol, (vitamin D3).