Download - major ppt. 1050
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ALKALOIDS, ALKALOIDS, DISTRIBUTION AND DISTRIBUTION AND
ANALYSISANALYSIS
Seat no.: 1050
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INTRODUCTIONINTRODUCTION
• Group of naturally occurring organic substances having a cyclic nitrogenous nucleus.
• Physiologically active
• Widely used to treat diseases from malaria to cancer.
• Extremely poisonous in high doses while in small doses it has many therapeutic uses.
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GENERALGENERAL CHARACTERISTICSCHARACTERISTICS
• Bitter to taste
• Most are crystalline solids except a few are amorphous and some are liquid.
• Insoluble in water
• Sharp melting point
• Colour
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CHEMICALCHEMICAL PROPERTIESPROPERTIES
• Nitrogenous bases with tertiary amines
• Alkaline pH
• Contain one or more rings of carbon atoms, usually with a nitrogen atom in the ring
• Position of the nitrogen atom effects the property of alkaloids
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FUNCTIONFUNCTION OFOF ALKALOIDS ALKALOIDS IN PLANTSIN PLANTS
• Protection against insects and animals
• Final products of detoxification
• Source of nitrogen
• Growth regulators
• Source of energy
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BIOSYNTHESISBIOSYNTHESIS ININ PLANTSPLANTS
• Formed from amino acids
• Alkaloidal precursors: phenylalanine, tyrosine, tryptophan, histidine, anthranilic acid, lysine and ornithine.
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DISTRIBUTIONDISTRIBUTION OFOF ALKALOIDSALKALOIDS ININ PLANTSPLANTS
• Alkaloids are distributed mostly in the following angiosperms:APOCYNACEAEPAPAVERACEAERANUNCULACEAERUBIACEAESOLANACEAE ANDBERBERIDACEAE
• Alkaloid production from monocotyledon – Amaryllidaceae and Liliaceace
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DISTRIBUTIONDISTRIBUTION OFOF ALKALOIDSALKALOIDS ININ PLANTSPLANTS
• All Parts e.g. Datura.
• Barks e.g. Cinchona
• Seeds e.g. Nux vomica
• Roots e.g. Aconite
• Fruits e.g. Black pepper
• Leaves e.g. Tobacco
• Latex e.g. Opium
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NOMENCLATURENOMENCLATURE
• The names of alkaloids are obtained in various ways:
• From the specific name of the plant yielding them. E.g.:- such as Cocaine from Erythroxylon coca
• From the common name of the drug they yield . E.g.:- ergotamine
• From the generic name of the plant yielding them E.g.:- nicotine from Nicotiana tabacum
• From their physiological activity. E.g.:- morphine.
• Occasionally from the discoverer. Eg:- pelletierine
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BASICBASIC NUCLEUSNUCLEUS OFOF ALKALOIDSALKALOIDS
NH NH N
N NH
N-CH3
NN
N-CH3
N
NH
N
N
N N
HN
N
HN
Pyrrole Pyrrolidine Pyrrolizidine Pyridine Piperidine Tropane
IsoquinolineQuinoline Aporphine Nor-lupinane
Indole Indolizidine Imidazole Purine
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CLASSIFICATIONCLASSIFICATION OF OF ALKALOIDSALKALOIDS
• They are broadly classified into:
Proto alkaloids e.g.: ephedrine
Pseudo alkaloids e.g.: caffeine
True or heterocyclic alkaloids e.g.: nicotine
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• Classification based on the ring structure or nucleus of the chief alkaloid group in the plant drug:
– Pyridine and piperidine eg: nicotine from Nicotiana tobacum
– Tropane :- solanaceous alkaloids – Hyoscine from Datura fastuosa and coca alkaloids – cocaine from coca leaves
– Quinoline :- cinchonine from cinchona bark
– Isoquinoline :- morphine from Papaver somniferum
– Indole :- vinblastine and vincristine from Catharanthus roseus
– Imidazole:- pilocarpine from pilocarpus
– Steroidal :- germicides, veratridine from Veratrum viride
– Alkaloidal amines :- ephedrine from Ephedra sinica
– Purine bases :- caffeine from Coca nitida
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NICOTINENICOTINE
• Found in the nightshade family of plants
• Hygroscopic, oily liquid
• It has a pyridine ring with pyrrole side chain
POSITIVE NEGATIVE
Anxiolysis
Cognitive Enhancement
Cerebro-vasodilation
Neuroprotection
Analgesia
Anti-psychotic
Gastrointestinal Distress
Hypothermia
Emesis
Hypertension
Seizures
Respiratory Distress
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PHARMACOLOGICAL PHARMACOLOGICAL ACTIVITYACTIVITY ANDAND USESUSES
ALAKALOID MEDICINAL USES
Vinblastine, vincristine antitumor
Codeine cough medicine, analgesic
Cocaine anesthetic Morphine analgesic
Quinidine antiarrhythmic
Quinine antipyretics, antimalarial
Ergot alkaloids vasodilator, antihypertensive
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GENERALGENERAL TESTTEST PROCEDURES PROCEDURES FORFOR ALKALOIDALKALOID ANALYSISANALYSIS
• All alkaloids in acid solution give precipitates with heavy-metal reagents such as Mayer’s and Dragendroff’s.
• Insoluble in water, soluble in alcohol and other organic solvents
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ALKALOIDALALKALOIDAL REAGENTSREAGENTS
• MAYER’S REAGENT: gives a cream precipitate
• DRAGENDROFF’S REAGENT: gives a reddish brown precipitate
• WAGNER’S REAGENT: produces reddish brown precipitate
• PICRIC ACID SOLUTION: gives a yellow precipitate.
• 10% TANNIC ACID SOLUTION: gives a buff colored precipitate
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QUANTITATIVE QUANTITATIVE DETERMINATION OF DETERMINATION OF
ALKALOIDSALKALOIDSPROCESS OF EXTRACTION
LIBERATING FREE BASE BY MEANS OF A SUITABLE ALKALI
EXTRACTION OF ALKALOID WITH ORGANIC SOLVENT LIKE CHLOROFORM
ADD DILUTE ACID AND SHAKE, ALKALOID FORM SOLUBLE SALTS AND PASS INTO SOLUTION IN THE AQUEOUS LAYER
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LIBERATE FREE BASES BY ADDITION OF AKALI
EXTRACT ALKALOID BY MEANS OF AN IMMISCIBLE ORGANIC SOLVENT.
EVAPORATE ON WATER BATH, DRY IN OVEN AND WEIGH
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QUALITATIVE ANALYSIS OF QUALITATIVE ANALYSIS OF ALKALOIDSALKALOIDS
• TLC
• HPTLC
• HPLC
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ANALYSISANALYSIS OFOF ALKALOIDSALKALOIDS BYBY TLCTLC
• For the identification of drugs containing known alkaloids pharmacopoeias commonly employ TLC separations using reference compounds to establish the presence of individual alkaloids.
• Developing reagent used- Dragendroff’s reagent.
• Stationary Phase - Silica gel 60F 254
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DIFFERENTDIFFERENT SOLVENTSOLVENT SYSTEMSSYSTEMSSolvent systems Alkaloid
Toluene-ethyl acetate-diethylamine(70:20:10) (v/v)
For majority of alkaloids
Chloroform-diethyl amine (90:10) (v/v) cinchona alkaloids i.e. quinine, quinidine.
Toluene-acetone-ethanol-conc.ammonia(40:40:6:2) (v/v)
Opium alkaloids like morphine, odine
Acetone-water-conc.ammonia(90:7:3) (v/v) Atropine, hyoscyamine and solanaceaeous alklaoids
Ethyl acetate-methanol-water(100:13.5:10) (v/v)
Rauwolfia alkaloids; xanthine derivatives like caffeine etc.
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DIFFERENTDIFFERENT SOLVENTSOLVENT SYSTEMSSYSTEMSSolvent systems Alkaloid
Toluene-chloroform-ethanol (28.5:57:14.5 v/v)
Secale alkaloids
N-heptane-ethylmethyl ketone-methanol (58:34:8 v/v )
Rauwolfia alkaloids
Toluene-methanol (86:14 v/v ) Colchici semen
n-propanol-formic acid-water (90:1:9 v/v ) Beberidis cortex
Hydrastis rhizoma
Colombo radix
Cyclohexane-chloroform-glacial acetic acid (45:45:10 v/v )
Berberine, and protoberberine type alkaloids
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IDENTIFICATIONIDENTIFICATION OFOF NICOTINE NICOTINE FROMFROM LeucasLeucas asperaaspera
• commonly called chota halkusa.
• used as an insecticide
• indicated in traditional medicine for coughs, colds, painful swellings and chronic skin eruptions.
• antipyretic
• wound healing property and is used in cobra venom poisoning
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HPTLCHPTLC of of Leucas asperaLeucas aspera
• Solvent system - toluene: ethyl acetate: diethyl amine (70:20:10 v/v)• TLC Chromatogram of LAA at 540 nm.
• Peak at Rf =0.66
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HPTLCHPTLC of of Leucas asperaLeucas aspera
• Solvent system - toluene: ethyl acetate: diethyl amine (70:20:10 v/v)
• TLC Chromatogram of nicotine at 540 nm.
• Peak at Rf =0.65
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HPLC OF Leucas asperaHPLC OF Leucas aspera• HPLC of nicotine standard, RT =
2.45 min
• HPLC of Leucas aspera RT = 2.44 min
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REFERENCESREFERENCES
• Pulok K Mukherjee:Quality Control of Herbal Drugs , volume I , 2008, Business horizon, 8190078844
• Isolation and Identification of Nicotine from Leucas aspera (Wild)- Journal: Indian Journal of Pharmaceutical Sciences, Year : 2006 | Volume : 68 | Issue : 1 | Page : 88-90 Copyright: Indian Pharmaceutical Association
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