Phytochemistry Midterm PDF

Notes on Phytochemistry  Introduction Lecture 1 What’s a natural product or A natural product is a chemical compound or substance pr...

Notes on Phytochemistry  Introduction Lecture 1 What’s a natural product or A natural product is a chemical compound or substance produced by a living organism , found in nature and usually has a pharmacological or biological activity Active constituents?? for use in pharmaceutical drug discovery and drug design. Without which the plant Claification cannot be alive I. According to their essential effect to the plant life Essential Not essential a. Primary metabolites b. Secondary metabolites Major Minor Alkaloids, glycosides Volatile oils, tannins..ect Proteins, fats, vitamins & carbohydrate hormones II. According to their chemical nature Proteins, carbohydrates, alkaloids, glycosides Volatile oils = ethereal oils = essential oils Definition Complex liquid mixtures of odoriferous principals, of varying Eential oils chemical composition obtained mainly from plant sources Latin essentia = liquid easily changed to a gas and most probably because Characters Easily evaporate when exposed to air at ordinary temperature they represent the essences or so it can be distillate from natural source odoriferous constituents of the plants. Volatile oil Ethereal oils Uses Used mainly for their aroma or certain therapeutic effect Evaporated on From latin exposure to air at volare, to fly room temperature Animal sources Musk, Civet Whale Genuine Ambergris oil Fixed oil Essential oil Local irritants Anthelmentics Antispasmodic Local analgesics Carminatives Antibacterial and Source antifungal Spices , condiments , preservatives Mild antiseptics Non-nutritive CH2 Building H2C unit CH3 Isoprene unit Medicinal and Triglyceride commercial uses of Nutritional Nutritive Non-nutritive value (high calories) (No calories) volatile oils Perfume industry ,cosmetics, soaps, Odor None Fragrant deodorizers, household cleansers, polishes and insecticides Non-volatile Flavouring agents in food and Volatility Volatile pharmaceutical industries especially medicines used for infants Aromatherapy It is a therapeutic usage of plant oils to treat a variety of issues including specific physica ointments, emotional issues or simply relaxation and it is branch of complementary medicine. 2. Ecuelle a 1.Sponge piquer method Distribution of essential oil Water distillation method Mechanical method Direct steam Distillation Scarification distillation methods &Expression methods Water& steam Preparation 3.Mechanical distillation methods of method volatile oil Flower (Rose) Herb (Mentha) Fruits (Anise) Enzymatic hydrolysis of Solvent extraction Bark (cinnamon) glycosides Buds (Clove) methods Preparation of allyl isothiocyanate Volatile solvents Non-volatile Preparation of solvents vanillin a. Enflurage Factors affecting the choice of the method of preparation: method b. Maceration glands method leaves 1-The localization of the oil in the plant 2-The condition of the plant material (fresh or dry) 3-The amount of the oil 4-The nature of its constituents Commercial method (cheap) Principle of distillation methods -The volatile oil are consist of mixture of volatile components , each one have its own boiling point (150C-300C) distillation at this temperature allow decomposition of oil constituents. -The presence of water (immiscible with oil) during distillation allows the process to be carried at a temperature below 100C. -Boiling the plant with water release volatile oil from its secretion sites. Vaporized and distilled off then condenses to form two immiscible liquids that can be separated. -The plant material used for the preparation of volatile by distillation method are either fresh or shade dried plant. Distillation methods Water distillation, Direct steam distillation, Water& steam distillation Industrial scale water distillation 1. Water distillation Plant is introduced with water into the distilling chamber and boiled with water until both volatile matter and steam, are condensed. This method used for dried or fresh plant materials which not damaged by boiling e.g.: turpentine oil Disadvantages of water distillation method: 1. Ester compounds may subject to hydrolysis and another compounds may be subjected to oxidation. 2. Complete exhaustions of the plant material is difficult to occur due to the higher boiling points are not taken by the steam (this is overcome by addition of glycerol to raise the boiling point).  2. Direct steam distillation: -Saturated or super-saturated steam is forced at low pressure thorough the plant material to liberate the oil and carrying it to the condensing chamber. -This method is applicable for fresh drugs as peppermint. 3. Water and steam distillation -Water is present in the still but steam alone is in contact with the plant material which is placed on a perforated screen and the steam source is supplied to achieve distillation. -Heating of the water will increase the saturation of the steam by providing more steam from water. This provide some sort of heat control to prevent over heating and decomposition of the oil component. -Applied for dried or fresh plant materials as Cinnamon and Clove. Advantages: Microwave assisted in extraction of essential oils 1- Reducing extraction time (due to fast heating). 2- Decreasing fuel consumption & CO2 emission to the environment. Oil recovery -The distilled water and oil are received in the oil separator where the oil can be separated easily. -So the water contains some other volatile oil and this will lead to loss some of the volatile oil. -Cohobation should be done and water should be removed from the oil by saturation with NaCl or extraction with organic solvent as ether. Water is immiscible with ether  Extraction method Used for the preparation of oils which decompose by the action of steam or present in small quantities. Special method (expensive) Used for flowers containing small amount of oil & heat sensitive constituents (no heat) Solvent extraction methods Violet Jasmine a- Enfleurage 1. Non-volatile solvents Heat Cool Flower petals+ fat mixture Fats —> Melt —> Tallow Flowers laid onto the fat lard Wooden frames Fat saturated with oil ( Enfleurage product) Layers of enfleurage Glass plate fat Absolute alcohol, extractions & cooling b- Maceration As enfluarge method except in the maceration we use Triple extract hot fat to yield hot fragrant fat (Pomade) from which oil is recovered by distillation and completed as in case Alcoholic solution of volatile oil + of enfluarge pigments + traces of fats Water + NaCl perfumed fat obtained from flowers either Evaporation of alcohol, by cold or hot enfleurage fractional distillation Absolute of the Volatile oil enfleurage Fats Distillation Oil 2. Volatile solvents Pomade The solvent used for extraction should have the following properties : -Inert (does not react with any of the oil constituents), non-toxic & non-inflammable -Boiling point : has a low boiling point -Water immiscible Oil was extracted using maceration or soxhiet apparatus -Volatility: leaves no residue on evaporation (completely volatile) e.g. Petroleum -ether, diethyl ether or hexane. The disadvantage of this method that some pigments may be extracted with oil Floral concrete: Absolutes: Floral concrete is the concentrated and completely Absolute is obtained by dissolving the floral concretes in purified volatile oil products. It contains the odoriferous absolute alcohols thus precipitating albuminous material, principles of the natural flower perfume and waxes, waxes and pigments…etc, and then concentrating the albuminous materials and colored pigments. alcohol solution.  Extraction using organic solvent (Hexane or petroleum ether) Hexane Evaporation Concrete Soaking Abslote flower oil Evaporate Ethyl alcohol (Most pure & expensive) Ethyl alchol + oil Refrigeration Filtration Using supercritical gas extraction At the supercritical pressure & temperature : Gases have two important characters Flow ability like a gas Extraction ability like solvent Tc = 31.1 C So, it can defuse through plant tissue & extract essential oils. Pc = 73.8 bar Expression methods (For Citrus fruits) It is used for : -Heat sensitive oils -Oil present in large amounts -Oil present in outer peels of fruits -Citrus fruits such as orange & lemon 1. The Sponge method: The rind is squeezed against sponge, as the secretion gland rupture, oil is then collected from the saturated sponge by squeezing the latter on to certain containers 2. Ecuelle a piquer method 3. Machine method Machine may be used to separate the emulsion of oil and water. Enzymatic Hydrolysis of Glycosides A method applied to volatile oils present in glycosidic combination. Plant powder is Hydrolysis by the aid of specific enzymes present in Distillation or extraction moistened with water at 40C/24h the same plant  Enzymatic Hydrolysis of Glycosides Preparation of allyl isothiocyanate Preparation of vanillin “volatile oil of black mustard” Source Sinigrin glycoside obtained from black mustard Source Glucovanillin glycoside, from vanilla pods, seeds , ( Brassica nigra ,F. Cruciferae) (Vanilla planifolia, F. Orchidaceae) S C6H11O5 O-Glucose OH N C Myrosin N C S O-CH3 O-CH3 OSO3K Allylisothiocyanate Sinigrin H2O + glucose KHSO4 + C6H12O6 -glucosidase CHO CHO Non-volatile Glucovanillin Vanillin Volatile (Non-volatile) (Volatile) Free aglycone Adulteration of essential oil Storage of essential oil : 1- Increasing volume (adding organic solvents) a. Vegetable oils, mineral oils -Light, air, heat -Dehydrogenation b. Benzyl alchol -Isomerization -Polymerization 2- Adulteration by addition of cheaper oils -Oxidation -Thermal rearrangements Cinnamon bark oil Cinnamon leaf oil This will lead to deterioration in : 3- Adulteration by addition of synthetic chemicals -Taste (oxidation) Anise oil (original) Anethol (synthetic) -Viscosity (polymerization) -Fragrance (Oxidation) -Biological activity (Skin sensitization & dermatitis) Protection from oxidation Light can lead to —> Oxidation as in limonene File the bottle to the neck to expel all oxygen Isomerization as in anise oil Protection Protection from the heat Protection from light Every 10C raise in temperature will double the rate of -Amber glass -Cobalt glass oxidation reaction. -Aluminum essential oil bottle So, store your oil in refrigerator or cooler Chemistry of essential oilsLecture 2 Types of constituents detected in volatile oil Terpenoids Miscellaneous compounds mono and sesquiterpenoids ( organo- nitrogen and Phenyl propanoids (C6-C3) organo-sulfur compounds) OH Ring Side chain OMe CH2-CH=CH2 Each group includes both oxygenated and non-oxygenated members (hydrocarbons)  Terpenoids = Isoprenoids CH3 CH2 -The largest known group of 2ry metabolites. CH3 H2C CH2 C C CH2 Isoprene unit -The basic unit of terpene is isoprene units. (C5H8) H Head Tail Head Isoprenoid unit C5H8 The terpenoids are classified according to the number of isoprene units Tail involved in their molecules as follows: Head C C C C Head Tail Terpenoid consists of one or two or poly-isoprenoid units attached head to tail. Tail C Isoprene Class Empirical formula units Examples Hemiterpenoids C5H8 1 Isoprene Monoterpenoids C10H16 2 Myrcene, limonene, α-pinene Types of terpenoids in volatile oils Sesquiterpenoids C15H24 3 Santalene Monoterpenoids C10 Acyclic: (aliphatic, Squiterpenoids C15 open chain) Diterpenoids C20H32 Abietic acid, 4 Taxol alkaloid Alicyclic=cyclic, (monocyclic Aromatic or bicyclic rarely tricyclic) Triterpenoids C30H48 6 Saponins p-menthadiene (Monocyclic Optically active monoterpene) Tetraterpenoids C40H64 8 Carotenoids Hydrocarbons and C10H20 oxygenated derivatives I. Hydrocarbons I. Monoterpene C10 II. Sesquiterpene C15 a. Acyclic compounds b. Aromatic compounds c. Alicyclic (Bicyclic) compounds (monocyclic) compounds C10H20 Chromatographic analysis —> by TLC & GLC Isolation of hydrocarbons 1. Fractional distillation. Flask contains oil not the plant (Not accurate method) 2. Crystalline additives products (halides, nitrosochloride &nitrosobromides). 3. Chromatographic methods. TLC Identification of hydrocarbons 1. Physical properties e.g. odor. GLC 2. Preparation of derivatives (determination of mixed melting point with authentic).  Remem ber Isomerism Structural isomers due to shift of Shift in the position of Geometrical ismores (cis & Optical isomers (I,d) the double bonds substituent group trans) e.g. myrecene & ocimene e.g. limonene & sylvestrene e.g. nerol & geraniol Limonene & Sylvestrene B-nerol B-geraniol myrecene Ocimene dipentene I. Monoterpene C10 a. Acyclic hydrocarbons b. Aromatic hydrocarbons c. Alicyclic hydrocarbons 1. Monocyclic monoterpenoid hydrocarbons Myrecene P-cymene Limonene Occurrence Lemon grass (citronella) and oil of turpentine Oil of Lemon Citrus fruits and oil of hops. Uses 1. In scenting soap (aroma). 1. For perfuming soaps and all kinds of medicinal 1. Flavoring agent for cosmetics ,soaps and preparations to overcome the undesirable odour. pharmaceuticals, and added to cleaning products 2. In organic synthesis of other pharmaceutical such as hand cleansers to give a lemon-orange preparations. 2. Important constituent in imitation essential oil. fragrance. COOH 2. Dissolve Gall bladder stone. Oxidation with KMNO4 in acetone or Hot KMNO4 Identification Myrecene KMNO4 in alkaline medium Solid, identified by Oxidation its m.p.155-156 C H3C CH2OH P-Cymene P-Hydroxy isopropyl Properties Preparation of lead salt Different acids benzoic acid 1. Quite stable away from light and air with Orange-like odour. Preparation by semi-synthesis 2. Limonene on exposure to air or moisture is transformed to a Needle crystals mixture of carvone and carveol. (caraway-like odour). From monoterpenoids e.g. limonene, pinene and terpinene (dehydrogenation by heating in presence of sulpher). OH Air/moisture O Autoxidation Limonene & Carvone Carveol Terpinene dipentene  Chemistry of essential oilsLecture 3 c. Alicyclic hydrocarbons 2. Bicyclic Monoterpenoid Hydrocarbons 1. Two condensed 3,4 or 5 & 6 membered rings and one double bond. Different groups of bicyclic monterpenoids: 2. Classified into 5 groups according to the parent saturated hydrocarbons; thujane, carane, pinane, camphane and fenchane. 3 membered + 6 membered rings α-Pinene β-Pinene 4 membered + 6 membered rings 5 membered + 6 membered rings Occurrence Oil of turpentine Coniferous oils II. Sesquiterpene Hydrocarbons C15 Isolation 1- By fractional distillation of oil of turpentine. 2-Alicyclic sesquiterpenes 2- The fraction containing α-Pinene is collected. 1-Acyclic (B.P 155-165C) a- Monocyclic c- Tricyclic 3- α-Pinene is precipitated as crystalline nitroso-chloride which is regenerated by treatment with aniline. b- Bicyclic NOCl aniline Acylic Sesquiterpene Bicyclic sesquiterpenoid hydrocarbons Tricyclic sesquiterpenoid α-Pinene α-Pinene nitroschloride α-Pinene nitrosyl chloride (Naphthalene derivatives) hydrocarbons Sesquicitronellene Cadinene α-Santalene Uses 1-α-Pinene is a starting material for preparation of synthetic borneol, camphor. 2. α-Pinene is an important constituent in any artificial oil and Occurrence/ Oil of Citronella Oil of cade and savin Obtained by fractional insecticides. source distillation of sandal wood oil 3. Pinol hydrate (sobrerol) , used as mucolytic in cough mixtures, it is formed by auto-oxidation of α-Pinene in presence of water and sunlight. Uses 1-Used in perfuming soaps. Used as skin antiseptic (externally). auto-oxidation OH 2-Oil of cade itself has been used as anti-eczematic. water and sunlight OH Sobrerol  Aromatic hydrocarbons Azulene derivatives C15H18 Azulene 1. They are coloured hydrocarbons (blue, violet or green) present in oils of valerian, galbanum, and chamomile. 2. They may occur as colorless precursors called pro-azulenes which could be transformed (dehydrogenated) to give colored azulenes by chemical or physical means as heating or treating with acids. Chamazulene Uses In cosmetic preparations,as anti-inflammatory. Chamazulene Guaiazulene Isolation & 1. Azulenes form adducts with : OH identification -> Conc. H3PO4, H2SO4 O2N NO2 Isolation form other -> Ferrocynaic acid [H4Fe(CN)6] compounds not the plant These adducts are decomposed with water to recover azulene. NO2 2. Nitrocomponds (with picric) form derivatives decomposed by NaOH. Picric acid Oxygenated Compounds Alcohols Esters Oxides & peroxides Aldehydes & ketones Phenols Removal of hydrocarbons Preparation of terpeneless oil: Characters of oxygenated compounds 1. Fractional distillation under reduced 1. They are responsible for strong odour pressure or in atmosphere of inert gas. 2. They are bitter soluble in alcohol 2. Extraction with alcohol. 3. They are resist oxidation 3. Chromatographic methods. How to get red off Non-oxygenated What is terpeneless volatile oil? terpenes from the volatile oil? Most of the volatile oil mixture are composed of Oxygenated compounds Non-oxygenated terpene By fractional distillation under pressure to give (Terpenless volatile oil) hydrocarbons Terpenless volatile oil (Oxygenated compounds). which are odor carriers, very soluble Which have slight odor, unsaturated in dil.alcohol, stable , resistant to they are ready for oxidation and resinification. resinification acquiring bad odor on storage.  1- Alcohols I. Acyclic III-Alicyclic II. Aromatic Aliphatic Saturated, unsaturated Mono-,bi & sesquiterpenoid Determination of alcohol content in volatile oils Remember Remember General method Acetylation using acetic anhydride —> Determination of ester value of the oil before and after acetylation Drawbacks 1- 3ry alcohols do not react quantitatively 2- Certain aldehydes, ketones and phenols are converted to compounds capable to be acetylated This method is suitable for estimation of 1ry and 2ry alcohols only. Determination of 1ry alcohol Determination of 3ry alcohol 1ry alcohol + known excess of Phthalic anhydride (100C) ͦ Dehydration method: Phthalate ester Depend on catalytic dehydration of alcohol by ZnCl2 or I2 Excess Phthalic anhydride # KOH Amount of water corresponding to the amount of alcohol N.B 2ry alcohol need drastic condition and 3ry not react Reaction of alcohol in oil Used for isolation , identification and estimation of alcohol Reaction similar to terpenoid hydrocarbons Reaction due to hydroxol group Oxidation, hydrogenation and formation Dehydration Ester formation of derivatives with halogen Addition with CaCl2 I-Aliphatic (Acyclic) terpenoid alcohols 1-Aliphatic (Acyclic) terpenoid alcohols 2-Aliphatic (Acyclic) terpenoid alcohols 1ry alcohol 3ry alcohol Gereniol and Nerol Rose like odour, Optical inactive Linalol Lavander like odour Cis isomer Trans isomer OH CH2OH CH2OH H H CH2OH CH2OH Geraniol Nerol Nerol Geraniol (Trans form) (Cis form) Source -Gereniol is present in oil of citronella , rose -> geranium oil Occurrence Oils of nutmeg, lemon , lavander, and rose and (40-50%). coriander. -Nerol and its ester are present in Neroli and Bergamot. Isolation Fractional distillation Isolation of Formation of crystalline CaCl2 derivative: Uses Linalool is used as a scent in 60-80% of geraniol 1.Add anhydrous CaCl2. (No water) perfumed hygiene products and cleaning 2. Extract with organic solvent (to remove other constituents). agents including soaps, detergents, shampoos, 3. Wash the deposited adduct with warm water (decomposes and lotions and cosmetic preparation (vit A). CaCl2 – geraniol complex followed by steam distillation. Action of acids Gives different products according to the Uses reaction conditions and strength of acids. 1. Geraniol is extensively used in perfume, cosmetic, soap and CH2OH flavour industries. +H+ reagent 2. Its gerenyl ester used for preparation of rose like odour. Isomerisation Geraniol OH Identification By formation of diphenylurethane derivative O O N + chromic acid For gereniol m.P. = 82.2 Isomerisation & oxidation CHO For Nerol m.P. = 52.2 Linalol Citral  Monocyclic II-Alicyclic terpenoid alcohols Bicyclic e.g.Menthol (2ry) Borneol (2ry) II-Alicyclic monoterpene alcohols a- Monocyclic monoterpene alcohols Menthol OH P-menthane-3-ol Occurrence Oil of peppermint (Mentha piperita). Isolation Cooling the Peppermint oil afforded menthol crystals after fractional crystallization. Properties 1- Hexagonal needle prisms m.p. 42-43C. 2- Powerful peppermint – like odour. 3- Cooling sensation. Few dps of Few dps of Few dps of H2O conc. H2SO4 vanillin/H2SO4 Identification Violet colour Crystals Orange yellow color Glacial acetic acid + Few One drop of HNO3 dps of conc. H2SO4 No green color Thymol give green color Crystals -By successive cooling of mint oil and collection of deposited crystals cooling at 15C and centrifugation gives first crop, then cooling at 5C then at -10C and centrifugation, second and third crops of menthol. -Menthone can be separated by formation of oxime which is separated by shaking with H2SO4. Assay Menthol + Acetic anhydride Acetylation Menthyl acetate Known excess KOH Excess KOH # HCl Uses 1. Local action: antipruritic , mild local anesthetic and antiseptic (mouth wash) 2. Systemic action: Carminative and gastric sedative. 3. Flavoring agent in candy and tooth paste Chemistry of essential oilsLecture 4 b-Bicyclic monoterpene alcohols Borneol-champhor Borneol OH O O H H Occurrence In Pine oil Borneol Camphor Uses Antiseptic, diuretic, prevents calculi formation as it included in Rowachole pills. Borneol derivatives 1- Bornyl isovalerate: sedative of pharmaceutical 2- Bornyl chloride: antiseptic importance: 3- Bornyl salicylate: counter irritant  Separation of a mixture of borneol and camphor Borneol + Camphor O 1. addition of phthalic anhydride 2. Heat for several hours Borneol acid phthalate NaOH Na salt of Borneol is water soluble Camphor is extracted with organic solvent Camphor can be separated by formation of oxime which is separated by shaking with H2SO4 Separation of a mixture of borneol and isoborneol Organic synthesis of borneol gives a mixture of borneol& isoborneol so we need to purify Borneol from isoborneol Borneol + Isoborneol Dehydration by ZnCl2/ benzene (H2O) Borneol not dehydrated Isoborneol dehydrated to solid camphene Isolated by fractional distillation Aromatic alcohols CH2OH Benzyl alcohol Source -As benzyl benzoate and benzyl cinnamate in balsam Peru, and Tolu. -As benzyl acetate in oil of Jasmine. Properties Colourless liquid, when pure it has a faint aromatic odour Bad storage Bitter almond odour (due to formation of benzaldehyde) and a crystalline deposit (benzoic acid) CH2OH CHO COOH Airo oxidation Benzyl alcohol Benzaldehyde Benzoic acid liquid with odor of crystals bitter almound Uses 1.Perfume and cosmetic industries to give flowers odour such as Jasmine. 2.As diluent and fixative in perfume mixtures.  OCH3 OH Phenols & phenolic ethers General method of isolation and estimation of phenols : Being weak acids, phenols form water-soluble salts with dilute alkali solutions, known as “phenolates” or “phenates”. Non phenolic part This method is used also for quantitative determination of phenols Acid properties of phenol is used in separation OCH3 Determination of phenol ether Especially methoxy or ethoxy group KI -> HI HI + AgNO3 -> AgI By using HI which give phenol and allyl halide AgI Weight and equivelent to alkyl group present as ether AgNO3 OCH3 OH H—I 373K + H3C—I Anisole Gravimetric method -> determination of anisole or phenol ether + anthole Phenol Classification of Phenols Monohydric phenols Tetrahydric phenols Dihydric phenols Trihydric phenols Phenyl proponiod alcohol -> anethole & eugenol a. Monohydric phenols Example of phenol ether OMe Thymol Anethole OH CH=CH-CH3 Occurrence Oil of Thymus vulgaris Source Oils of umbelliferous fruits e.g. oil of anise and fennel. Properities Solid crystalline having sweet odour and taste Isolation 1. Extraction by alkali as general method. characteristic of anise fruit. 2. Fractional distillation. Uses Flavouring agent for: Identification To differentiate bet. Thymol & menthol 1. All kinds of food (especially confectionary), and Thymol crystals + 1 ml glacial acetic acid + 6 drops conc H2SO4 beverage products (alcoholic and non-alchoholic). + 1 drop HNO3 deep bluish green 2. Pharmaceuticals and cosmetics, mouth washes and gargles. Thymol + H2SO4 Thymol sulphonic acid + FeCl3 Bad storage Mask bitter teste Thymol + FeCl3 -> -ve test Violet color Effect of light , heat and air and Identification of +ve test Uses 1-Disinfectant and antibacterial (used in antiseptic anethole mixtures applied to mucous cavities such as gargles). Oxidation with KMNO4 to p-anisaldehyde then anisic acid m.p.184C. 2- Local anaesthetic in tooth ache (dental analgesic). OCH3 OCH3 OCH3 OCH3 Light 3- Gastro intestinal disinfectant (in gastritis, enteritis). Or [O] 4- Anthelmentic (for nematodes). CHO HC CH Anisaldehyde Photoanethole OCH3 Viscous, yellow liquid, Anethole [O] 5- Preservative in food and drug industries. Colorless, crystalline bitter taste, immiscible solid, sweet taste, with alcohol 70% soluble in alcohol 70% COOH Anisic acid Yellow viscous, bitter taste photoanethol  OH b. Dihydric phenols Eugenol OCH3 Source Oil of clove and cinnamon Uses 1- Local anaesthetic effect in tooth ache remedies (i.e. dental analgesic). 2- Starting material for preparation of high grade vanillin. Identification Euginol + KOH Crystals of K eugenate Euginol + FeCl3 Blue color Note KI ‫ ﺑﻨﺤﻂ‬AgNO3 ‫اي ﺣﺎﺟﻪ ﻓﳱﺎ‬ Aldehydes and ketones Condensation reactions: identification/estimation Hydroxylamine method: To differentiate bet. Aldehydes & ketones Aldo oxime in case of aldehyde and ketooxime in case of ketone, solid Oxime Excess hydroxyl amine hydrochloride Titration against KOH Methyl red -> aldehyde Addition or adsorption reactions: isolation/estimation Dimethyl yellow -> ketone Neutral sulfite method: With aldehyde more than ketone Decompose with water Reversible OH C:O + Na2SO3 + H2O C + NaOH Sodium sulfite Dilute acid or SO3Na Na2CO3/D Titrated aganist HCl, ph ph indicator Methods for aldehydes only Phenyl hydrazine method: Condensation Ph-NH-N=CHR + H2O RCOH + Ph-NH-NH2 Known excess The excess phenyl hydrazine is back titrated against standard HCl Bisulfite method (generally applicable to aldehydes): isolation Measured by cassia flask RCOH + NaHSO3 RCH(OH)SO3Na Water soluble adduct OH OH C:O + NaHSO3 C Or C Dilute acid or + Sodium bisulfite Na2CO3/D SO3Na SO3 Na Bisulfite derivative Hydroxy sulphonic acid salt  Aliphatic Terpene Aldehyde Citronellal Citral CHO CHO H H H H CHO CHO Citral a or geranial Citral b or neral Citronellal Terpinolene form Limonene form Trans isomer Cis isomer Occurrence Oils of citronella & Eucalyptus. Sourse -Lemon grass (4 possible isomers) -Citral a (geranial) & citral b (neral) are geometrical isomers (cis/ trans) Isolation It forms crystalline bisulphate by addition Na2So3 on aldehyde group then regenerated by Na2CO3 rather than NaOH to prevent resinification. Uses 1. Used as a component of synthetic lemon, and orange flavors. 2. In soaps and cosmetics. Uses 1. In perfumes, soaps. 3. Synthesis of Vit.A. 2. Insect repellant (The United States Environmental 4. Synthesis of violet like odour (Ionones). Protection Agency considers oil of citronella as a 5. It has a relaxing effect. biopesticide with a non-toxic mode of action Aromatic Aldehydes CHO Vanillin OMe OH Source -Occurs either free or as glycoside in several plants e.g. glucogovanillin. -Most important source is Vanilla fruits (pods) which contain 1.53%, present also in balsam peru and clove oil. Properties -Solid (M.P. 81-82C) -Sweet characteristic odor. CHO -Sublimable without decomposition when heated carefully. -Soluble in hot water and relatively insoluble in cold water. -Give blue color with FeCl3. OCH2CH3 OH Uses 1- Flavoring agent in food industries and in perfumery. Ethyl vanillin 2- to mask unpleasant odours or tastes in medicines. 3- Ethyl vanillin (Bourbonal ,vanillal, Ethavan®, Ethovan®) finer and more intense vanilla-odour than vanillin. Aliphatic terpene ketones a. Monocyclic ketone Phennote OH Menthone Diosphenol (buchu camphor) O Has the properties of phenol & ketone O Occurrence Oil of peppermint Source Leaves of different Barosma species (Buchu) Uses 1. Antispasmodic Isolation 1. By cooling the oil (if it is present in high 2. Improve digestion concentration). 3. Prevent calculi formation 2. Or by extraction of the oil with alkali (diosphenol is soluble in alkali due to the phenolic nature) followed by acidification and extraction with ether. Regeneration by dichloro acid  b. Bicyclic ketones Differentiate bet. Natural & synthetic Test for chloride + BaSO3 -> +ve synthetic & -ve natural Camphor O Optically active -> natural Not active -> synthetic from α-Pinene Occurrence Oil of lavender Isolation By cooling oil of lavender, camphor crystals will be deposited and filtered. From the camphor tree: 1- The chipped wood is steam distilled and the distillate is received in special chambers Preparation of camphor from natural source Cooling Mix with soda lime, sand and charcol Solid and collect on the bottom subjected to sublimation is pressed into cubes or plates 2- By freezing the oil rich in camphor Uses 1- Acts as slight local anesthetic and antimicrobial substance. 2- Topical anti-infective, anti-pruritic. (anti-itch gels and cooling gels). 3- Counter irritant In vapor-steam products, such as Vicks ,VapoRub. 4- Cough suppressant. 5- Medications for treating diarrhea, inflammation, and nervous conditions. 6- As preservative in pharmaceuticals and cosmetics. 7- Excellent plasticizer for cellulose esters and ethers; used in manufacture of plastics. 8- Used in manufacture of varnishes and explosives. 9- Moth repellent. Determination of ester by hydrolysis-> alc + acid Esters OH CH2OH -Many volatile oils owe their aroma to esters. H H OH -Most common esters are the acetates of terpineol, borneol and geraniol. -Aging of perfumes is generally done to allow esterification to take place. -Some oils contain mainly esters e.g. oil of winter green which contains 99% methyl salicylate. a. Esters of aliphatic acids b. Esters of aromatic acids O CH2OAc Geranyl acetate O Benzyl benzoate O pleasant rose-like odour CO.CH2 Source Widely distributed, found in oil of citronella, Source Balsam tolu and balsam peru lavender, and coriander. Identification After saponification it give gereniol and acetic Isolation By cooling and crystallization (solid at 20C). acid. Uses Widely used in perfumes, cosmetics and soap industries. Uses 1. Scabicide & pediculicide. 2. As solvent for cellulose esters, nitrocellulose and artificial c. Esters containing nitrogen COOCH3 musk. Example of oil contain nitrogen or “ester contain nitrogen Methyl anthirnilate 3. Perfume fixative. NH2 Source Oil of neroli, sweet orange Oil of Lavender 4. Flavouring agent in confectionery and chewing gum. Identification Preparation of amino derivative as picrate Isolation Methyl anthirnilate + dil H2SO4 Cooling re-crystallaization from alcohol and regenerated by shake with NaOH. Uses 1. Rubificiant 2. Antirheumatic  Peroxide containing volatile oils Explosive O Ascaridol O Occurrence Oil of Chenopodium Not easily solubilized, soluble in acidic solution Determination with iodometry Assay It is based upon the oxidizing action of the peroxide radical present which liberates iodine from acidic solution of KI (HCl + HAc) iodine liberated is tirated against Na2S2O3 under specific experimental conditions using starch OH as indicator. Ascaridol + 2HI (excess KI/ AcOH) + I2 Uses Anthelementic for round and hook worms. OH Oxide containing volatile oils Back titerated against O O st. Soln. Na2SO3 Cineole (eucalyptol) Cineole Occurrence The main constituent of certain Eucalyptus species. Identification 1 drop of cineole (or cineole containing oil in high percentage) + 1 drop of a 5% solution of hydroquinone on a slide, colorless prisms are formed. Uses 1. Used locally as anaesthetic and antiseptic in the treatment of inflammatory conditions. 2. Internally cineole serves as an expectorant in cases of chronic bronchitis. 3. Used in room sprays, skin lotions and all kinds of cosmetic preparations. Nitrogenous & Sulphur containing Volatile Oil Allyl iso thiocyanate (Mustard oil) N C S Occurrence Black mustard seed as glycoside known as sinigrin Isolation Plant powder is moistened with Hydrolysis by the aid of myrosine Steam distillation water at 40oC/24-48h. present in the same plant S-Glucose H2o CH2=CH-CH2-N=C=S + KHSO4 + Glucose CH2=CH-CH2-N=C Myrosin OSO3K Allyl isothiocyanate Potassium acid Sinirgin (Non-volatile) (Volatile) sulphate It has pungent odor & taste Assay 1. Treatment with known excess AgNO3 in presence of ammonia. 2. The precipitated Ag2S is filtered. 3. Excess AgNO3 is titrated against ammonium thiocyanate (NH4SCN) using ferric alum as indicator. Aromatic constituents from animal Ambergris OH Source It is an excretion from intestinal tract of the sperm whale found in tropical seas or sea shores. Constituents Ambrein (triterpenoid alcohol) as a main constituent Properties 1- Grey to black waxy mass. 2- Soluble in organic solvents, fats and volatile oils. Uses In perfumes and for fixation of odours.