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this presentation brifly explains the occurance and classification of alkaloids.
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OCCURANCE AND CLASSIFICATION OF ALKALOIDS
OCCURENCE OF ALKALOIDS.
Naturally occurring chemical compounds containing basic nitrogen atoms
Physiologically active Insoluble or sparingly soluble in water Crystalline solids; a few are amorphous Usually classified according to the nature of the basic
chemical structures from which they are derived Form double-salts with compounds of Hg, Au, Pt, and
other heavy metals.
Common amino acid precursors:
Phenylalanine Tyrosine Tryptophan Histidine Anthranilic acid Lysine Ornithine
Important general reactions involved:
DecarboxylationThe process of removing a carboxyl group from a
chemical compound Transamination
The process of transposing an amino group within a chemical compound
CLASSIFICATION
THERE ARE FOUR TYPES OF BASIC ALKALOIDS
PROTOALKALOIDS TRUE ALKALOIDS PSEUDOALAKLOIDS FALSE ALKALOIDS
PROTO ALKALOIDS
It is derived from PHENYLALANINE or TYROSINE
The Methyl group originate from METHEIONINE
The Methylating enzyme TYRAMINE METHYLEPHERASE appear in the root of germinating barley.
TRUE ALKALOIDS
It is derived from the aminoacid and have nitrogen in the heterocyclic ring.e.g; ATROPINE
Derivatives of True Alkaloids
Pyrrolidine derivatives Pyrrolizidine derivative Pyridine derivatives Piperidine derivatives Quinolizidine derivative Isoquinoline derivative Indole derivatives Quinoune derivatives Imidazole derivatives
Pseudo Alkaloids These are not derived from amino acids but
have nitrogen in heterocyclic ring.e.g;Caffeine
Derivative
Terpenoid derivative
CLASSIFICATION. Classification based on the ring structure or
nucleus of the chief alkaloid group in the plant drug: Pyridine-Piperidine Tropane Quinoline Isoquinoline Indole Imidazole Steroid Alkaloidal amines Purine
contain the isoquinoline ring structure
Sources: Alkaloid(s)
Ipecac emetine
hydrastis berberine, hydrastine
sanguinaria sanguinarine
curare tubocurarine
opium morphine, codeine, thebaine
BIOSYNTHESIS OF OPIUM ALKALOIDS:
Tyrosine ------- L Dopa ------ Dopamine+
3,4 – dipydroxyphenylpyruvic acid
PAPAVERINE ----------------- norlaudanosoline( ket intermediate)
Reticuline
Saluteridine
Saluteredinol
THEBALNE
Codeinone
CODEINE
MORPHINE
IPECAC rhizomes and roots of Cephaelisipecacuanha contains 5 alkaloids
3 principal alkaloids 1.emetine 2. elphaeline 3.psychotrine
Ipecac syrup treatment of drug overdose and some poisonings procedure emesis central medullary effect by stimulation of chemoreceptor
Ipecac fluidextract 14x stronger than the syrup
Biosynthesis
Tryptamine ajmaline +
Corynanthe-type
(monoterpenoid precursor)
Serpentine reserpine
contain imidazole (glyoxaline) rings
PILOCARPINE
PILOCARPUS AKA jaborandi Consists of leaflets of:
Pilocarpus jaborandi Holmes Pilocarpus microphyllus Stapf Pilocarpus pinatifolius Lamaire Indigenous to Brazil
THANKS……