Introduction to Secondary Metabolites

Introduction to Secondary Metabolites

• 1.
  Introduction to SecondaryMetabolites (Definition, Classification, Properties & Qualitative Chemical tests) Dr. M. Ramaiah, M.Pharm., Ph.D., IPDRA, DICT (USA) Professor & Head, Department of Pharmacognosy Hindu College of Pharmacy, Guntur, A.P., India By DrMR Digitally signed by DrMR DN: cn=DrMR, c=IN, o=Dept. of Pharmacognosy, ou=HCOP, [email protected] Date: 2021.07.14 12:50:07 +05'30'
• 2.
  Contents: Definition, Classification, Propertiesand Qualitative Chemical tests of Alkaloids Definition, Classification, Properties and Qualitative Chemical tests of Glycosides Definition, Classification, Properties and Qualitative Chemical tests Flavonoids Definition, Classification, Properties and Qualitative Chemical tests of Tannins Definition, Classification, Properties and Qualitative Chemical tests of Volatile oils Definition, Classification, Properties and Qualitative Chemical tests Resins 2
• 3.
  Introduction  Living plantsare solar-powered biochemical and biosynthetic laboratory which manufactures both primary and secondary metabolites from air, water, minerals and sunlight.  The group of pathways synthesizing simpler but essential molecules for normal physiological growth and energy requirements of plants is called primary metabolism and the products are called primary metabolites. They are widely distributed in nature and are also utilized as food by man.  Eg: Sugars, amino acids, coA, mevalonic acid, nucleic acid etc 3
• 4.
  4  Secondary metabolitesare useless for plants and stored in various parts of plants restricted in their distribution are derived biosynthetically from primary metabolites. These are organic compounds that are not directly involved in the normal growth, development, or not necessary for the plant cells themselves but may be useful for the plant as a whole. Since these don’t have primary function so they are called secondary metabolites. They have Pharmaceutical importance.  Eg: Alkaloids, Glycosides, Flavonoids, Tannins, Volatile oil and Resins
• 5.
  5 Introduction to Alkaloids DEFINITION Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom.  This group also includes some related compounds with neutral and even weakly acidic properties.  Some synthetic compounds of similar structure may also be termed alkaloids.  In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and, more rarely, other elements such as chlorine, bromine, and phosphorus.
• 6.
  6  Usually alkaloidsare derivatives from amino acids. Even though many alkaloids are poisonous (e.g. strychnine or coniine), some are used in medicine as analgesics (pain relievers) or anaesthetics, particularly morphine and codeine. Most alkaloids have a very bitter taste.  Ex: morphine, strychnine, quinine, ephedrine, and nicotine
• 7.
  7 CLASSIFICATION There are threemain types of alkaloids: (1) true alkaloids, (2) protoalkaloids, and (3) pseudoalkaloids. True alkaloids and protoalkaloids are derived from amino acids, whereas pseudoalkaloids are not derived from these compounds.
• 8.
  8 True Alkaloids  Truealkaloids derive from amino acid and they share a heterocyclic ring with nitrogen. These alkaloids are highly reactive substances with biological activity even in low doses.  The primary precursors of true alkaloids are such amino acids as L- ornithine, L-lysine, L-phenylalanine/L-tyrosine, L-tryptophan and L-histidine.  Examples of true alkaloids include such biologically active alkaloids as cocaine, quinine, dopamine and morphine.
• 9.
  9 Protoalkaloids  Protoalkaloids arecompounds, in which the N atom derived from an amino acid is not a part of the heterocyclic. Such kinds of alkaloid include compounds derived from L-ty-rosine and L-tryptophan. Protoalkaloids are those with a closed ring, being perfect but structurally simple alkaloids.  Hordenine, mesca-line and yohimbine are good examples of these kinds of alkaloid
• 10.
  10 Pseudoalkaloids Pseudoalkaloids are compounds,the basic carbon skeletons of which are not derived from amino acids. In reality, pseudoalkaloids are connected with amino acid pathways. They are derived from the precursors or post- cursors (derivatives the indegradation process) of amino acids. They can also result from the amination and transamination reactions of the different pathways connected with precursors or post-cursors of amino acids
• 11.
  11 Alkaloids are mainlydivided into two categories on the basis of their chemical structure, that is, heterocyclic rings. Atypical alkaloids These are also known as nonheterocyclic alkaloids and contain nitrogen in aliphatic chain. Typical alkaloids These are also known as heterocyclic alkaloids and contain nitrogen in heterocyclic ring system.
• 12.
  12 Classification of alkaloids
• 13.
  13
• 14.
  14
• 15.
  15 PROPERTIES  Although numerousalkaloids exist, they have similar properties when separated. In general, they are colourless, crystalline solids which are basic, have a ring structure, and have definite melting points. They are also derived from plants and have a bitter taste. However, some exceptions are known. For instance, some alkaloids are not basic and others are brightly coloured (betanidine, beriberine, sangui-narine) or liquid (nicotine). Other alkaloids are produced synthetically. Most alkaloids are also chiral molecules which mean they have nonsuperimposable mirror images. This results in isomers that have different chemical properties. For example, one isomer may have a physiological function while the other does not.   Generally free bases of alkaloids are soluble in organic solvents and insoluble in water, where as alkaloidal salts are soluble in water and partially soluble in organic solvents. For example, strychnine hydrochloride is much more soluble in water than strychnine as a base.
• 16.
  16 CHEMICAL TESTS: Thechemical tests are performed from neutral or slightly acidic solution of drug. Dragendorff’s Test Drug solution + Dragendroff’s reagent (Potassium Bismuth Iodide), formation of Orangish red colour. Mayer’s Test Drug solution + few drops of Mayer’s reagent (potassium mercuric iodide), formation of creamy-white precipitant. Hager’s Test Drug solution + few drops of Hagers reagent (Saturated aq. Solution of Picric acid), formation of crystalline yellow precipitate. Wagner’s Test Drug solution + few drops of Wagner’s reagent (dilute Iodine solution), formulation of reddish-brown precipitate. Tannic Acid Test Drug solution + few drops of tannic acid solution, formation of buff coloured precipitate.
• 17.
  17 Introduction to Glycosides In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond.  The sugar group is known as the glycone and the nonsugar group as the aglycone or genin part of the glycoside.  Glycosides play numerous important roles in living organisms.  Many plants store chemicals in the form of inactive glycosides.  These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use.  Many such plant glycosides are used as medications.
• 18.
  18 CLASSIFICATION: The glycosidescan be classified by the glycone, by the type of glycosidal linkage, and by the aglycone. On the Basis of Glycone If the glycone group of a glycoside is glucose, then the molecule is a glucoside; if it is fructose, then the molecule is a fructoside; if it is glucuronic acid, then the molecule is a glucuronide, etc. On the Basis of Glycosidic Linkage 1. O-glycosides: Sugar molecule is combined with phenol or OH group of aglycon, for example, Amygd-aline, Indesine, Arbutin, Salicin, cardiac glycosides, anthraxquinone glycosides like sennosides etc 2. N-glycosides: Sugar molecule is combined with N of the NH (amino group) of aglycon, for example, nucleosides 3. S-glycosides: Sugar molecule is combined with the S or SH (thiol group) of aglycon, for example, Sinigrin. 4. C-glycosides: Sugar molecule is directly attached with C -atom of aglycon, for example, Anthraquinone glycosides like Aloin, Barbaloin, Cascaroside and Flavan glycosides, etc.
• 19.
  19 On the Basisof Aglycone
• 20.
  20 CHEMICAL TESTS OFGLYCOSIDES Chemical Tests for Anthraquinone Glycosides Borntrager’s test To 1 gm of drug add “5-10 ml of dilute HCl boil on water bath for 10 min and filter. Filtrate was extracted with CCl4/ benzene and add equal amount of ammonia solution to fil trate and shake. Formation of pink or red colour in ammoni-cal layer due to presence of anthraquinone moiety. Modified borntrager’s test To 1 gm of drug, add 5 ml dilute HCl followed by 5 ml ferric Chloride (5% w/v). Boil for 10 min on water bath, cool and filter, filtrate was extracted with carbon tetra- chloride or benzene and add equal volume of ammonia solution, formation of pink to red colour due to presence of anthraquinone moiety. This is used C-type of anthraqui-none glycosides
• 21.
  21 Chemical Tests forSaponin Glycosides Haemolysis test A drop blood on slide was mixed with few drops of aq. Saponin solution, RBC’s becomes ruptured in presence of saponins. Foam test To 1 gm of drug add 10-20 ml of water, shake for few minutes, formation frothing which persists for 60–120 s in presence of saponins. Chemical Tests for Steroid and Triterpenoid Glycosides Libermann burchard test Alcoholic extract of drug was evaporated to dryness and extracted with CHCl3, add few drops of acetic anhydride followed by conc. H2 SO4 from side wall of test tube to the CHCl3 extract. Formation of violet to blue coloured ring at the junction of two liquid, indicate the presence of steroid moiety. Salkowaski test Alcoholic extract of drug was evaporated to dryness and extracted with CHCl3, add conc. H2 SO4 from sidewall of test tube to the CHCl3 extract. Formation of yellow coloured ring at the junction of two liquid, which turns red after 2 min, indicate the presence of steroid moiety.
• 22.
  22 Chemical Tests forCardiac Glycosides Keller-kiliani test: To the alcoholic extract of drug equal volume of water and 0.5 ml of strong lead acetate solution was added, shaked and filtered. Filtrate was extracted with equal volume of chloroform. Chloroform extract was evaporated to dryness and residue was dissolved in 3 ml of glacial acetic acid followed by addition of few drops of FeCl3 solution. The resultant solution was transferred to a test tube contain-ing 2 ml of conc. H2SO4. Reddish brown layer is formed, which turns bluish green after standing due to presence of digitoxose. Legal test To the alcoholic extract of drug equal volume of water and 0.5 ml of strong lead acetate solution was added, shaked and filtered. Filtrate was extracted with equal volume of chloroform and the chloroform extract was evaporated to dryness. The residue was dissolved in 2 ml of pyridine and sodium nitropruside 2 ml was added followed by addition of NaOH solution to make alkaline. Formation of pink colour in presence of glycosides or aglycon moiety. Baljet test Thick section of leaf of digitalis or the part of drug con-taining cardiac glycoside, when dipped in sodium picrate solution, it forms yellow to orange colour in presence of aglycones or glycosides.
• 23.
  23 Chemical Tests forFlavonoid Glycosides Ammonia test Filter paper dipped in alcoholic solution of drug was exposed to ammonia vapor. Formation of yellow spot on filter paper. Shinoda test To the alcoholic extract of drug magnesium turning and dil. HCl was added, formation of red colour indicates the presence of flavonoids. To the alcoholic extract of drug zinc turning and dil. HCl was added, formation of deep red to magenta colour indicates the presence of dihydro flavonoids. Vanillin HCl test Vanillin HCl was added to the alcoholic solution of drug, formation of pink colour due to presence of flavonoids.
• 24.
  24 Properties  glycosides arewater soluble compounds and insoluble in the organic solvents. Glycone part: water soluble, insoluble in the organic solvents. Aglycone part: water insoluble, soluble in the organic solvents.  Glycosides are Colorless, solid, amorphous, nonvolatile (flavonoid- yellow, anthraquinone-red or orange.  Give positive reaction with Molisch's and Fehling's solution test (after hydrolysis).  They are water soluble compounds, insoluble in organic solvents  Most of them have bitter taste (except: populin, glycyrrhizin, stevioside).
• 25.
  25  Odorless exceptsaponin (glycyrrhizin).  when a glycosides has a lot of sugars its solubility in water decrease.  Glycosides hydrolyzed by using mineral acids and temperature or by using enzymes such as: a- Emolsin Bitter almond seeds. b- Myrosin or Myrosinase black mustard seeds. c- Rhamnase glycosides containing rhamnose as sugar part.
• 26.
  26 Introduction to Flavonoids Flavonoids (or bioflavonoids; from the Latin word flavus, meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in diets.  Chemically, flavonoids have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and a heterocyclic ring (C, the ring containing the embedded oxygen). This carbon structure can be abbreviated C6-C3-C6.  Flavonoids occur as aglycones, glycosides, and methylated derivatives
• 27.
   According tothe IUPAC nomenclature, they can be classified into: 1. flavonoids or bioflavonoids 2. isoflavonoids, derived from 3-phenylchromen-4-one (3-phenyl- 1,4-benzopyrone) structure 3. neoflavonoids, derived from 4-phenylcoumarine (4-phenyl-1,2- benzopyrone) structure CLASSIFICATION: 2-phenyl-1,4-benzopyrone Isoflavan structure Neoflavonoids structure
• 28.
  Flavone : Luteolin,Apigenin, Tangeritin Examples Flavonol: Quercetin, Kaempferol, Myricetin etc
• 29.
  Flavanone: Hesperetin, Naringenin,etc Flavanonol: Taxifolin (or Dihydroquercetin), Dihydrokaempferol
• 30.
  30 Chemical Tests forFlavonoid Glycosides Ammonia test Filter paper dipped in alcoholic solution of drug was exposed to ammonia vapor. Formation of yellow spot on filter paper. Shinoda test To the alcoholic extract of drug magnesium turning and dil. HCl was added, formation of red colour indicates the presence of flavonoids. To the alcoholic extract of drug zinc turning and dil. HCl was added, formation of deep red to magenta colour indicates the presence of dihydro flavonoids. Vanillin HCl test Vanillin HCl was added to the alcoholic solution of drug, formation of pink colour due to presence of flavonoids.
• 31.
  Introduction to Tannins The name tannin is derived from the French taninâ (tanning substance) and is used for a range of natural polyphenols.  Tannins are complex organic, non-nitrogenous plant products, which generally have astringent properties. These compounds comprise a large group of compounds that are widely distributed in the plant kingdom.  The term tannin was first used by Seguin in 1796 to denote substances which have the ability to combine with animal hides to convert them into leather which is known as tanning of the hide. According to this, tannins are substances which are detected by a tanning test due to its absorption on standard hide powder. The test is known as Goldbeaters skin test.
• 32.
  CLASSIFICATION • The tannincompounds can be divided into two major groups on the basis of Goldbeaters skin test. • A group of tannins showing the positive tanning test may be regarded as true tannins, whereas those, which are partly retained by the hide powder and fail to give the test, are called as pseudotannins • Most of the true tannins are high molecular weight compounds. • These compounds are complex polyphenolics, which are produced by polymerization of simple polyphenols. • They may form complex glycosides or remains as such which may be observed by their typical hydrolytic reaction with the mineral acids and enzymes. • Two major chemical classes of tannins are usually recognized based on this hydrolytic reaction and nature of phenolic nuclei involved in the tannins structure. The first class is referred to as hydrolysable tannins, whereas the other class is termed as condensed tannins.
• 33.
  Hydrolysable Tannins As thename implies, these tannins are hydrolysable by mineral acids or enzymes such as tannase. Their structures involve several molecules of polyphenolic acids such as gallic, hexahydrodiphenic, or ellagic acids, bounded through ester linkages to a central glucose molecule. On the basis of the phenolic acids produced after the hydrolysis, they are further categorized under gallotannins composed of gallic acid or ellagitannins which contains hexahydrodiphenic acid which after intraesterification produces ellagic acid. Hydrolysable tannins are sometimes referred to as pyrogallol tannins as the components of phenolic acids on dry distillation are converted to pyrogallol derivatives. The hydrolysable tannins are soluble in water, and their solution produces blue colour with ferric chloride.
• 34.
  Nonhydrolysable or CondensedTannins • Condensed tannins, unlike the previously explained group are not readily hydrolysable to simpler molecules with mineral acids and enzymes, thus they are also referred to as nonhydrolysable tannins. • The term proanthocyanidins is sometimes alternatively used for these tannins. The compounds containing condensed tannins contain only phenolic nuclei which are biosynthetically related to flavonoids. • When treated with acids or enzymes, they tend to polymerize yielding insoluble red coloured products known as phlobaphens. The phlobaphens give characteristic red colour to many drugs such as cinchona and wild cherry bark. On dry distillation, they yield catechol derivatives. Condensed tannins are also soluble in water and produces green colour with ferric chloride.
• 35.
  Pseudotannins • Pseudotannins aresimple phenolic compounds of lower molecular weight. They do not respond to the tanning reaction of Goldbeaters skin test. • Gallic acid, Chlorogenic acid, or the simple phenolics such as catechin are pseudotannins which are abundantly found in plants, especially in dead tissues and dying cells.
• 36.
  PROPERTIES OF TANNINS 1)Tannins are colloidal solutions with water. 2) Non crystalline substance. 3) Soluble in water (exception of some high molecular weight structures), alcohol, dilute alkali, and glyc-erin. 4) Sparingly soluble in ethyl acetate. 5) Insoluble in organic solvents, except acetone. 6) Molecular weight ranging from 500 to >20,000. 7) Oligomeric compounds with multiple structure units with free phenolic groups. 8) Can bind with proteins and form insoluble or soluble tannin protein complexes.
• 37.
  CHEMICAL TESTS 1. Goldbeatersskin test: Goldbeaters skin is a membrane produced from the intestine of Ox. It behaves just like untanned animal hide. A piece of goldbeaters skin previously soaked in 2% hydrochloric acid and washed with distilled water is placed in a solution of tannin for 5 minutes. It is then washed with distilled water and transferred to 1% ferrous sulphate solution. A change of the colour of the goldbeaters skin to brown or black indicates the presence of tannin. 2. Hydrolysable and condensed tannins both give the positive goldbeater’s test, whereas pseudotannins show very little colour or negative test. 3. Phenazone Test: To 5 ml of aqueous solution of tannin containing drug, add 0.5 g of sodium acid phosphate. Warm the solution, cool, and filter. Add 2% phenazone solution to the filtrate. All tannins are precipitated as bulky, coloured precipitate.
• 38.
  4. Gelatin Test:To a 1% gelatine solution, add little 10% sodium chloride. If a 1% solution of tannin is added to the gelatine solution, tannins cause precipitation of gelatine from solution. 5. Test for Catechin (Matchstick Test): Catechin test is the modification of the well-known phloroglucinol test for lignin. Matchstick contains lignin. Dip a matchstick in the dilute extract of the drug, dry, moisten it with concentrated hydrochloric acid, and warm it near a flame. Catechin in the presence of acid produces phloroglucinol which stains the lignified wood pink or red. 6. Test for chlorogenic acid: A dilute solution of chlorogenic acid containing extract, if treated with aqueous ammonia and exposed to air, slowly turns green indicating the presence of chlorogenic acid. 7. Vanillin-hydrochloric acid test: Drug shows pink or red colour with a mixture of vanillin: alcohol : dilute HCl in the ratio 1:10:10. The reaction produces phloroglucinol which along with vanillin gives pink or red colour
• 39.
  Introduction to VolatileOils • Volatile oils are odorous volatile principles of plant and animal source, evaporate when exposed to air at ordinary temperature, and hence known as volatile or etheral oils. • These represent essence of active constituents of the plant and hence also known as essential oils. • In most instances the volatile oil preexists in the plant and is usually contained in some special secretory tissues, for example, the oil ducts of umbelliferous fruits, the oil cells, or oil glands occurring in the sub-epidermal tissue of the lemon and orange, mesophyll of eucalyptus leaves, trichomes of several plants, etc.
• 40.
   Volatile oilsare freely soluble in ether and in chloroform and fairly soluble in alcohol; they are insoluble in water.  The volatile oils dissolve many of the proximate principles of plant and animal tissues, such as the fixed oils and fats, resins, camphor, and many of the alkaloids when in the free state.  These are chemically derived from terpenes (mainly mono and sesqui terpenes) and their oxygenated derivatives.  These are soluble in alcohol and other organic solvents, practically insoluble in water, lighter than water (Clove oil heavier), possess characteristic odour, have high refraction index, and most of them are optically active.  Volatile oils are colourless liquids, but when exposed to air and direct sunlight these become darker due to oxidation.  Unlike fixed oils, volatile oils neither leave permanent grease spot on filter paper nor saponified with alkalis. Properties
• 41.
  CLASSIFICATION OF VOLATILEOILS Volatile oils are classified on the basis of functional groups present
• 42.
  Chemical Tests ForVolatile Oils Natural drugs containing volatile oils can be tested by following chemical tests: 1. Thin section of drug on treatment with alcoholic solution of Sudan III develops red colour in the presence of volatile oils. 2. Thin section of drug is treated with tincture of alkana, which produces red colour that indicates the presence of volatile oils in natural drugs.
• 43.
  Introduction to Resins DEFINITION •Resin can be defined as the complex amorphous product of more or less solid characteristics which on heating first sets softened and then melt. • Resins are produced and stored in the schizogenous or schizolysigenous glands or cavities of the plants. • Isolated resin products which come as an unorganized crude drug in the market are more or less solid, hard, transparent, or translucent materials. • Resins are insoluble in most polar and nonpolar solvents like water and petroleum ether, respectively, but dissolve completely in alcohol, solvent ether, benzene, or chloroform.
• 44.
  CLASSIFICATION Resins are classifiedmostly on the basis of two important features, that is, on the basis of their chemical nature and secondly as per their association with the other group of compounds like essential oils and gums. 1. Resin Acids Resin acids are the carboxylic acid group containing resinous substances which may or may not have association with phenolic compounds. These compounds are found in free states or as the esters derivatives. Being acidic compounds they are soluble in aqueous solution of alkalies producing frothy solution. Resin acids can be derivatized to their metallic salts known as resinates, which finds their use in soap, paints and varnish industries. The abietic acid and commiphoric acid present in colophony and myrrh respectively are the examples of resin acids. 2. Resin Esters Resin esters are the esters of the resin acids or the other aromatic acids like benzoic, cinnamic, salicylic acids, etc. They are sometimes converted to their free acids by the treatment with caustic alkali. Benzoin is the common resin ester containing drugs.
• 45.
  3. Resin Alcohols Resinalcohols or resinols are the complex alcoholic com-pounds of high molecular weight. Like resin acids they are found as free alcohols or as esters of benzoic, salicylic, and cinnamic acids. They are insoluble in aqueous alkali solution but are soluble in alcohol and ether. Resinols are present in benzoin as benzoresinol and in storax as storesinol. 4. Resin Phenols Resin phenols or resinotannols are also high molecular weight compounds which occur in free states or as esters. Due to phenolic group they form phenoxoids and become soluble in aqueous alkali solution. However they are insoluble in water but dissolve in alcohol and ether. Resinotannols gives a positive reaction with ferric chloride. The resinotannol are found in balsam of Peru as peruresinotannol, in Tolu balsam as toluresinotannol and in benzoin as siaresinotannols. 5. Glucoresins Resins sometimes get combined with sugars by glycosylation and produce glucoresins. Glycoresins can be hydrolysed by acidic hydrolysis to the glycone and aglycone.
• 46.
  6. Resenes Chemically inertresin products are generally termed as resenes. They are generally found in free state and never form esters or other derivatives. Resenes are soluble in benzene, chloroform and to some extent in petroleum ether. Resenes are insoluble in water. Asafoetida is an example of resene-containing drug, which contains drug about 50% of asaresene B. Accordingly, other simple classification based on the association of resin with gums and/or volatile oils is given below. 7. Oleoresins Oleoresins are the homogenous mixture of resin with vola-tile oils. The oleoresins posses an essence due to volatile oils. A trace amount of gummy material may sometimes be found in oleoresins. Turpentine, ginger, copaiba, Canada resin are few important examples of oleoresins. 8. Gum Resins Gum resins are the naturally occurring mixture of resins with gums. Due to solubility in water, gums can be easily separated out from resin by dissolving the gum in water. Ammoniacum is an example of natural gum resin.
• 47.
  9. Oleogum Resins Oleogumresins are the naturally occurring mixtures of resin, volatile oil, and gum. The example includes gum myrrh, asafoetida, gamboage, etc. Oleogum resins oozes out from the incisions made in the bark and hardens. 10. Balsams Balsams are the naturally occurring resinous mixtures which contain a high proportion of aromatic balsamic acids such as benzoic acid, cinnamic acid, and their esters. Balsams containing free acids are partially soluble in hot water. Some important balsams containing drugs are balsam of Peru, balsam of Tolu, benzoin, and storax. The oleogum resin containing drugs like copaiba and Canada are sometimes wrongly referred to as balsams.
• 48.
  Physical Properties :- •Insoluble in water and petroleum ether dissolved more and less completely alcohol, ether and chloroform. • Chemically resin are complexe mixture of resin acid, resin alcohol (resinols), resin phenol ( resin otannols) ester and chemically inert compound known as resenes. • Resins are often associated with volatile oil (oleoresins), with gums (gum resins) or with oil and gum (oleo-gum-resins). • Resins do not contain nitrogen element. • Balsams are resinous mixture that contain large properties of cinnomic acid, benzoic acid or both or esters of these acid.
• 49.
  General Chemical Testfor Resins :- Physical Test :- solubility, taste,odor and examination of powder under the microscope. Chemical Test :- For the identification of resins, acid value, saponification value, iodine value. Specific Chemical Test :- for specific constitution such as cinnamic acid, benzoic acid in benzoin tolu balsam and peur balsom.
• 51.
  Thank You!