1. Capsaicin
Synonyms Axsain; Mioton;
Zostrix.
Biological Sources It is
the pungent principle present in fruit of various species of Capsicum, namely:
Capsicum annuum L. (Family: Solanaceae)-Paprika, Chili, Sweet
Peppers; Capsicum frutescens Linn., [Synonyms C. minimum Roxb.]-Bridchilli.
Preparation Capsaicin, the
oleoresin from capsicum is prepared by extracting the crushed fruit with
either hot acetone or hot ethanol by the method of percolation. The solvent i.e.,
hot ethanol or acetone is evaporated on an electric-water bath in a
fume-cupboard. The resulting residue is once again subjected to successive
extraction with cold acetone or ethanol until the residue is free from the
pungent odour. The solvent is removed and the capsaicin collected is not
less than 8%.
Characteristic Features It
has a monoclinic and rectangular plates, or scales from petroleum ether. Its mp
is 65°C, bp0.01 210-220°C (air-bath temperature), UVmax 227,
281 nm (ε 7000, 2500). It has a burning taste, one part in 100,000 can be
detected easily by tasting. It is practically insoluble in cold water. It is
freely soluble ethanol, ether, benzene, chloroform and slightly soluble in CS2.
Chemical Constituents The
capsicum contains 8-12% of an oleoresin capsaicin and a red colouring principle
known as capsanthin as given below:
However, the pungency of capsaicin
is not affected by dilute alkali, but is destroyed almost completely by
subjecting it to oxidation with either KMnO4 or K2Cr2O7.
Uses
1. It is used as a tool in
neurobiological research.
2. Pretreatment with capsaicin
induces long-lasting desensitization of airway mucosa to various mechanical and
chemical irritants.
Source:Pharmacognosy And Pharmacobiotechnology By Ashutosh Kar
Source:Pharmacognosy And Pharmacobiotechnology By Ashutosh Kar
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