Capsaicin and Capsaicinoids

Like many other idioms in the language of organic chemistry, the term alkaloid is poorly defined. As an anonymous chemist once remarked an alkaloid is like my wife. 

Modem Alkaloids Structure, Isolation, Synthesis and Biology. Edited by E. Eattorusso and O. Taglialatela-Scafati Copyright 2008 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-31521-5 

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Capsaicin and capsaicinoids undergo Phase I metabolic bioconversion to catechol metabolites via hydroxylation of the vanillyl ring moiety (Lee and Kumar, 1980 Miller et al, 1983). Metabohsm involves oxidative, in addition to non-oxidative, mechanisms. An example of oxidative conversion involves the liver mixed-function oxidase system to convert capsaicin to an electrophilic epoxide, a reactive metabolite (Olajos, 2004). Surh and Lee (1995) have also demonstrated the formation of a phenoxy radical and quinine product the quinine pathway leads to formation of a highly reactive methyl radical (Reilly et al, 2003). The alkyl side chain of capsaicin also undergoes rapid oxidative deamination (Wehmeyer et al, 1990) or hydroxylation (Surh et al, 1995 Reilly et al, 2003) to hydroxycapsaicin as a detoxification pathway. An example of nonoxidative metabolism of capsaicin is hydrolysis of the acid-amide bond to yield vanillylamide and fatty acyl groups (Kawada et al, 1984 Oi et al, 1992). 

Capsaicin and capsaicinoids may be involved in complex interactions in vivo related to carcinogenesis, cocarcinogenesis and anticarcinogenesis, which are a reflection, in part, of metabolism and metabolite activity. Capsaicin... 

Olajos EJ and Lakoski JM (2004). Pharmacol-ogy/toxicology of oleoresin capsicum, capsaicin, and capsaicinoids. In Riot Control Agents. Issues in Toxicology, Safety and Health (EJ Olajos and W Stopford, eds), pp. 123-143. Boca Raton, FL, USA CRC Press. 

Immediately after spraying, spontaneous reaction as blue-violet (vis) zones, evaluation in vis. capsaicin and capsaicinoides, detection limit 0.1 pg. 

Capsaicin and capsaicinoids xmdergo phase I metabolic bioconversion to catechol metabolites via hydroxy-lation of the vanillyl ring moiety (Miller et al., 1983). Metabolism involves oxidative, in addition to nonoxida-tive, mechanisms. An example of oxidative conversion... 

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