School Science Lessons
2017-09-25 SP MF LI
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16a Chemistry of natural products
Table of contents Aliphatic, aliphatic compounds Aromatic, aromatic compounds Carboxylic acids and fatty acids

16.2.10 Coal tar products, creosote Aliphatic, aliphatic compounds
Aldose sugars Aliphatic, aliphatic compounds Alditols, polyhydric alcohols, mannitol
Allantoin, C4H6N4O3, in face creams, in Symphytum officinale, comfrey Carbohydrate acids, D-gluconic acid Carbohydrates Carboxylic acids and fatty acids Cellulose, hemicellulose Chitin Clove oil, eugenol
CPY3A4 Cyclitols, inositol Disaccharides
Sucralose Glucosides Glycosaminoglycans, glucosamines Glycosides Glycerides, esterification of glycerol
Glycolic acid, hydroxyacetic acid, HOCH2COOH, α-hydroxy acid
Ketose sugars Lecithins Lignans, plant phenols, [C6-C3]2 Lipids, fats and oils, fatty acids, glycerides Monosaccharides Monosaccharides, D and L sugars Nucleosides, nucleic acids, DNA, RNA Pectin, Aspergillus japonicus Polyketides, polyketide antibiotics Polysaccharide gum, phycocolloids Reducing sugars / non-reducing sugars
RuBisCo Phospholipids, (phosphoglycerides) Polysaccharides Starches, amylum, glycogen Sugars Tannins, plant polyphenols Tetrasaccharides Trisaccharides Waxes Aromatic, aromatic compounds Aromatic, aromatic compounds Aramids
Aromatic acids Aromatic alcohols Aromatic aldehydes and ketones Aromatic amines, anilides Aromatic halogen compounds
16.8.0 Aromatic hydrocarbons Aromatic nitro compounds Aromatic sulfonic acids Aryl groups
16.8.1 Reactions of benzene, C6H6 Barbiturates (depressants) Benzodiazepines (tranquillizers) Benzofuranoids, benzopyranoids
Bergamottin, C21H22O4 Catecholamines
Coumarin, C9H6O2 Diazo compounds Five member heterocycles Flavonoids, (Bioflavonoids), plant polyphenols
Geosmin, C12H22O, earth smell, muddy fish smell, after rain smell, cut grass smells Lactams (-NH(CO-), e.g. caprolactam Lignans, plant phenols Parabens Pyridine Tannins, plant polyphenols Carboxylic acids and fatty acids Carboxylic acids, fatty acids and their salts α-hydroxy acids Aromatic carboxylic acids, derivatives Dicarboxylic acids Keto acids, acetoacetic acid, pyruvic acid Perfluorooctanoic acid Saturated carboxylic acids Tricarboxylic acids Unsaturated fatty acids Waxes
Candles, Happy Flame Candles, (commercial)
8.1.1 Candles, (Chemistry)
8.1.1a Candles, (Physics)
Candelilla wax
Carnauba wax
Cetyl palmitate wax
Heelball wax
Jojoba oil
Meadow foam oil
Wool wax, (lanolin) Disaccharides, trisaccharides, tetrasaccharides, polysaccharides
| See diagram Maltose molecule
| See diagram Lactose molecule
| See diagram Sucrose molecule
Disaccharides contain two sugar units:
lactose = (milk sugar, glucose + galactose)
maltose = (malt sugar, glucose + glucose)
sucrose = (glucose + fructose)
Sucralose, C12H19Cl3O8, trichlorogalactosucrose, E 955, Relative sweetness 650
Sucralose in "Splenda".
Each sachet of Splenda contains maltodextrin, dextrose and sucralose.
Sucralose, Soft drinks, carbonated beverages: 15.8.6
16.2.10 Coal tar products, creosote
Creosote, (prohibited substance for schools)
Chemicals produced from destructive distillation of coal when making coke for steel production.
Many organic compounds can be isolated by distillation of coal tar but many are now made from petroleum or natural gas.
The residue of coal tar distillation is called pitch and is used for road tar and waterproofing of roof material.
The residue of petroleum distillation is called asphalt but also called "tar".
Coal tar paints resist heat and moisture.
Coal tar dyes, called azo dyes, are made from azobenzene and were used as food colourings.
Coal tar products include:
1. hydrocarbon oils, e.g. benzene, toluene, xylene
2. phenols, e.g. carbolic acid, and
3. bases.
e.g. pyridine.
Coal tar is a creosol mixture that includes 2-hydroxytoluene, 3-hydroxytoluene, 4-hydroxytoluene.
It sensitizes skin to sunlight, so use gloves because it may cause skin cancer.
It is used as a wood preservative of railway sleepers, telegraph poles., fungicide, soap for treatment of skin diseases, and sheep dip
However, wood creosote is a mixture of phenols of wood tar and is used as a disinfectant, cough medicine, diarrhoea medicine,
preservative, and antiseptic. Trisaccharides
Raffinose, (triose: fructose + galactose + glucose), (C18H32O16),
Also, melezitose, maltotriose, (amylotriose) Tetrasaccharides
See diagram Stachyose, acarbose
Acarbose, (C25H43NO18), anti-diabetic drug
Stachyose, (tetrose: fructose + galactose + glucose + galactose, i.e. raffinose + galactose), (C24H42O21), in green beans Polysaccharides, glycans
Polysaccharides are long carbohydrate molecules consisting of repeated monomer units joined together in a chain by glycosidic bonds
and contain linked monosaccharide units, (C6H10O5)n
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)

1. Heteropolysaccharides, heteroglycans, contain different type of monomer r units
Acidic, mucopolysaccharides, glycosaminoglycans long unbranched polysaccharides, repeating disaccharide units
Chondroitin sulfate
Keratan sulfate
Hyaluronic acid
Dextran, Modified polysaccharide

Chitin, (C8H13O5N)n, is a polymer of the monosaccharide derivative of glucose, N-acetylglucosamine, (C8H15NO6), in fungi cell
walls, arthropod exoskeletons, e.g. crabs, insect exoskeleton, mollusc radula, cephalopod beak, e.g. squid.
Similar structure to cellulose and keratin
Used as a binder in dyes, adhesives, fabrics and dissolving surgical thread.

Pectin is a polysaccharide that forms the primary cell walls of many terrestrial plants.
Pectin 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 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 Starches, amylum, glycogen
See diagram 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]. Cellulose, hemicellulose
See diagram Cellulose, three glucose molecules linked to form cellulose
See diagram Cellulose
See diagram Linamarin
See diagram Cyanohydrin
Cellulose is a 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. Chitin
See diagram 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. 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 powder and is used to form gels and as thickening agents.
Galactouronic acid, C6H10O7, is a component of pectin.
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 Cyclitols, inositol
Cyclitols are cycloalkanes containing one hydroxyl group on each of three or more ring atoms, e.g. Inositol, cyclohexane,
cyclohexane-1,2,3,4,5,6-hexol, C6H12O6, prescribed for some medical conditions, but should not be taken as a "vitamin supplement"
to the diet.
Inositol is in eggs: 22.15
Commercial: myo-Inositol, 1,2,3,4,5,6-Hexahydroxycyclohexane, meso-Inositol, C6H12O6 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.
Commercial: D-(+)-Glucosamine hydrochloride, C6H13NO5. HCl
Heparin, Chondroitin sulfate, Hyaluronan, Heparan sulfate, Dermatan sulfate, Keratan sulfate
Commercial: Heparin sodium salt from porcine intestinal mucosa, anticoagulant Polyketides, polyketide antibiotics
Molecules having more than two carbonyl groups connected by single carbon atoms.
Occur in some bacteria and fungi, e.g. Aspergillus.
They include polyketide antibiotics, streptomyces metabolites, erythromycin, linear tetracyclines, erythromycin polyenes, nystatin,
polyether antibiotics, β-lactams, aflatoxins.
Commercial: Erythromycin, E-Mycin, Erythrocin, C37H67NO13, white powder Nucleosides, nucleic acids, DNA, RNA
| See diagram Nucleic acid
| See diagram 16.21.10: Purines
| See diagram 16.21.13: Pyrimidines
1. 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.
2. Nucleic acids do several functions in living cells, e.g., the storage of genetic information and its transfer from one generation to the
3. 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).
4. RNA, (ribonucleic acid), contains D-ribose, whereas DNA contains 2-deoxy-D-ribose as the sugar component.
5. 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).
6. 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.
7. An oligonucleotide is a long linear sequences of nucleotides. Polysaccharide gums, Gums, Phycocolloids
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
2. Phycocolloids: (alginates, algin, from kelp, Laminaria and Macrocystis), (carrageenan from red algae, Irish moss, Chondrus
), (agar from red algae, Gelidium and Gracilaria). Lipids, fats and oils, fatty acids, glycerides
Fatty acids are aliphatic monocarboxylic acids.
See diagram 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 Saturated and unsaturated fatty acid, triglyceride
See diagram Tristearin
See diagram Human fat molecule 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, replacing the third fatty acid.
glycerol-3-phosphate + 2-monacyl glycerol --> triacyl glycerol + phospholipids.
Sphingolipids: sphingenine, cerebrosides, sphingomyelin. 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. 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. 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
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. Saturated carboxylic acids
Arachidic acid, (icosanoic acid), C19H39COOH, 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, white crystals (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
Decanedioic acid, HOOC(CH2)8COOH, sebacic acid, from castor oil
Dichloroacetic acid, DCA, CHCl2COOH, (in chlorinated drinking water)
Ethanoic acid, CH3COOH, acetic acid, vinegar
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)
Propionic acid, propanoic acid, C2H5COOH, 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 by all routes, causes severe burns, damages eyes
Trifluoroacetic acid, Solution < 1%, Not hazardous, (used in chemical reactions)
Valeric acid, CH3(CH2)3COOH, pentanoic acid, (valerian herb): 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 Tricarboxylic acids
16.9.5 Citric acid cycle, Krebs cycle
(in Kreb's cycle, plant and animal cells)
Isocitric acid, C6H8O7 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 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 and may be a carcinogen. α-hydroxy acids
Naturally occurring carboxylic acid, hydroxyl group on the carbon adjacent to the carboxyl group.
Use in skin care.
See diagram 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, green apple sour taste, grapes
Mandelic acid, C6H5CH(OH)CO2H, bitter almond
Tartaric acid, L-(+)-Tartaric acid, L-Threaric acid, C4H6O6, HO2CCH(OH)CH(OH)CO2H, leavening agent Keto acids
Acetoacetic acid, diacetic acid, C4H6O3, CH3COCH2COOH
Pyruvic acid, C3H4O3, CH3COCOOH, metabolism of proteins and carbohydrates, release of energy
Palmitoleic CH3(CH2)5CH=CH(CH2)7COOH Oleic acid, red oil
Oleic acid, mono-unsaturated fatty acid, C17H33COOH, CH3(CH2)7CH=CH(CH2)7COOH, colourless viscous liquid, m.p. 14oC
Models, biochemistry, Oleic acid, C18H34O2, 1 molecule, (photograph), "Scientrific", (commercial website) 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:

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.

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.
In food industry, beeswax marketed in two forms:
1. Yellow beeswax, yellow or light brown solid brittle when cold and odour of honey,
2. White beeswax, white to translaucent, faint odour of honey
3. Beeswax is used as a carrier for flavours and clouding agent in water-based drinks, no reported allergenicity.
White and yellow beeswax, food additive, E901, glazing agent, release agent, for craft modelling, ointments, and polishes.
Beeswax from bee honeycomb mixture includes the palmitic acid ester of melissyl alcohol, melissyl palmitate, C15H31COOC30H61.
Sealing wax is usually a mixture of beeswax, shellac and turpentine, which may be coloured red for business or black for mourning.

Candelilla wax, food additive glazing agent E902, emollient, yellow-brown, hard, brittle, lustrous solid, opaque to translucent, with
aromatic odour when heated.
Candelilla wax contains mainly odd-numbered saturated straight-chain hydrocarbons, C29-C33, esters, and alcohols C28-C34.
Candelilla wax is used as a carrier for flavours in chewing gum.and clouding agent in water-based drinks, no reported allergenicity.
Candelilla, (Euphorbia antisyphilitica), Euphorbiaceae.

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.

Cetyl palmitate [(CH3(CH2)13CH2(C=O)O(CH2)15CH3)] [C15H31COO-C16H33] is a component of spermaceti wax in sperm
whale oil.

Heelball is a polishing mixture of hard wax and black colouring used by shoemakers and for brass rubbings of monumental brasses
using heelball over paper.

Jojoba oil, Simmondsia chinensis, Simmondsiaceae, mainly wax esters, in cosmetics, seed is toxic and indigestible.

Meadow foam oil, (Limnanthes alba), Family Geometridea

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.
Lanolin, wool fat, palmitate and stearate esters of cholesterol, (from sheep sebaceous glands, used in cosmetics) Aromatic, aromatic compounds
The term "aromatic" may mean a fragrant, pungent, spicy, sweet smelling odour, usually compounds having a benzene ring, or it may
refer to ring-shaped flat molecules with a ring of resonance bonds (changing forwards and backwards) as in the benzene molecule.
Originally the term "aromatic" referred to compounds containing the Phenyl radical.
Aromatics, aromatic compounds, benzene derivatives, ring systems, arenes: benzene, toluene, naphthalene
See diagram Acridine, anthracene, anthroquinone, cinnoline, naphthalene, naphthol, quinoline
See diagram 16.8.0: Acetylsalicyclic acid, (aspirin), benzene, benzoic acid, naphthalene
See diagram Single substitution, more than single substitution
See diagram 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. Aryl groups
Groups derived from usually an aromatic hydrocarbon by removal of a hydrogen atom.
e.g. benzene, C6H6, less 1 hydrogen atom, H --> phenyl group, C6H5. Aramids
Aramids are aromatic polyamides, e.g. "Kevlar", "Nomex".
Aramid fibres are made by spinning liquid crystal aramid polymers to long chain polymer molecules with remarkable strength.
The polymer chains are linked laterally by hydrogen bonds, used in rope and textile high performance fibres.
"Kevlar", a synthetic fibre with of high-tensile strength, is used as a reinforcing material for the rubber in motor vehicle tyres. 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 Aromatic nitro compounds
Aromatic nitro compounds, e.g. Nitrobenzene, oil of mirhan, (C6H5NO2) Lactams
Lactams, (-NH(CO-), e.g. caprolactam, (6-hexanelactam), (C6H11NO)
See diagram 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. 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). Diazo compounds
Diazo compounds, (2 linked nitrogen compounds), e.g. methyl orange, (dimethyl-aminoazobenzene sulfonic acid),
(diazonium ion: C6H5N2+, C6H5N+N), diazonium salts [(RNN+)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) Barbiturates (central nervous system depressants)
See diagram 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 the following:
1. Barbital (US), barbitone, C8H12N2O3, "Veronal", formerly used or attempted used by would-be suicides
2. Phenobarbital (US), phenobarbitone, C12H12N2O3, "Luminal", sedative and hypnotic, an anticonvulsant drug used to treat epilepsy.
Phenobarbital causes side effects, e.g. sedation, depression and agitation, so it may be replaced by phenytoin, C15H12N2O2, in the
anti-epileptic drug sodium phenytoin, "Dilantin".
3. Sodium thiopental, C11H17N2NaO2S, ("Sodium Pentathol", thiopentone sodium, "Trapanal"), "truth drug", is a short acting
barbiturate general anaesthetic, used to start anaesthesia, e.g. for caesarian section operation.
It causes unconsciousness in seconds. Benzodiazepines (tranquillizers, sedatives, hypnotics)
See diagram Diazepam (Valium), oxazepam (Serax), nitrazepam (Mogadon), chlordiazepoxide (Librium), flunitrazepam
Benzodiazepines assist the neurotransmitter γ-aminobutyric acid to treat anxiety, insomnia, seizures, and preparation for medical
procedures. Aromatic halogen compounds
Aromatic halogen compounds, aryl halide, halogenarenes, e.g. benzyl chloride, (C6H5COCl)
See diagram 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.)! Aromatic sulfonic acids
Aromatic sulfonic acids, e.g. benzene sulfonic acid, (C6H5SO2OH), sodium benzene sulfonate Aromatic alcohols
Aromatic alcohols, e.g. phenyl methanol, (benzyl alcohol), (C6H5CH2OH) Aromatic aldehydes and ketones
Benison, 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 Aromatic acids
Aromatic acids and their derivatives, e.g. benzoic acid, (C6H5COOH)
See diagram Acetyl salicyclic acid, (aspirin), | See diagram 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. 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 Parabens
See 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. Pyridine
Pyridine, (pyridino), C5H5N, monodentate ligand
Pyridine molecule is a benzene molecule, C6H6, with one =CH- replacen by N.
Pyridine, C5H5N, has a penetrating offensive fishy odour and in some countries it is added to methylated spirit to deter ingestion.
Pyridine, Solution / mixture < 25%, Not hazardous Benzofuranoids, benzopyranoids
See diagram Coumarin, furan, bergamottin | See diagram Bergamottin, lovastatin, atorvastatin
Atorvastatin calcium salt trihydrate, C33H34FN2O5.0.5Ca.1.5H2O
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.

Coumarin, C9H6O2, 1,2-benzopyrone, a phenylpropanoid, colourless, crystalline, pleasant sweet odour, in many plants and
released on wilting, in perfumes, bitter aromatic burning taste, moderately heptotoxic, in Tonka bean | Aloe | Sweet woodruff
Coumarin is used to make anticoagulants which compete with vitamin K, e.g. warfarin, C19H16O4, a medical anticoagulant and rat
poison, e.g. "Ratsac".
Melilotin, C9H8O2, dihydrocoumarin, coumarin flavouring, in Melilotus officinalis
Scopoletin, C10H8O4, a 7-hydroxycoumarin, 7-hydroxy-6-methoxycoumarin, chrysatropic acid, gelseminic acid, increases lipase
activity, plant growth factor, in Scopolia carniolica, anise, Angelica acutiloba

Umbelliferone, C9H6O3, 7-hydroxycoumarin, 7-hydroxychromen-2-one,  yellow-white crystalline solid, absorbs UV light so in
sunscreens, mutagenic, a phenylpropanoid, possible antioxidant, in Apiaceae, (Umbelliferae) | Asafoetida | Chamomile |
 Mouse-ear hawkweed
Umbelliferone derivatives include furanocoumarins. Furanocoumarins, furocoumarins Five member heterocycles
See diagram 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, [amino acid proline (CH2)3NHCHCOOH]