Sampangine metabolism studies

Microbial metabolism studies on sampangine have resulted in the isolation and characterization of two metabolites, sampangine-4 -0-methyl-P-glucopyranoside (SAMMl) and sampangine-P-glucopyranoside (SAMM2). 

Mammalian metabolism studies on sampangine gave two water-soluble conjugates. One of those conjugates, SAM MMl, has been identified as sampangine-P-glucuronic acid. 

The chronological order of both studies (microbial and mammalian) will determine the used approach (retrospective, parallel or prospective). However, in this case it is difficult to classify these studies into a distinct approach. The microbial metabolism studies were initiated after tentative information obtained from a limited mammalian metabolism study of sampangine. On the other hand, it is very important to note that complete structure elucidation of mammalian metabolites would not have been possible without the microbial metabolites having been identified first. 

Hufford and co-workers131 in a study of the metabolism of the antifungal copy-rine alkaloid sampangine, used micro-probe technology for the characterization of the alkaloid s major metabolite, which was sampangine /i-glucuronic acid (61). 

In vitro antifungal activities evaluation for sampangine metabolites demonstrated comparable activities to sampangine. However, an in vivo efficacy study revealed that SAh 2 is inactive. The antifungal activity profile of sampangine metabolites led us to conclude that metabolism per se is not the cause for the in vivo inactivity of sampangine, hence, further studies on the other pharmacokinetic parameters (bioavailability, distribution, clearance, etc.) will be necessary. 

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