“Chemotypes”– A Fact that should not be Ignored in Natural Product Studies

Kaan      Polatoglu

Abstract

A great number of research articles have been focused describing variation in the secondary metabolites of the organisms as chemotypes or chemovariation. However, the present definition and nomenclature of chemotype portray some problems such as: 1) low repeatability of natural product studies if a mixture of chemotypes is used in isolation studies; 2) risk of reporting chemotypes that do not exist due to similar variations encountered in seasonal and environmental differences, 3) reporting same chemotypes under different names. The problems addressed above demand an exact definition, a system of nomenclature and a systematic method to evaluate chemotypes. In order to solve these problems and to start a debate on the matter, an exact definition, a system of nomenclature and a systematic method to evaluate chemotypes were proposed. Addressing the above mentioned problems, chemotypes were defined as “organisms categorized under same species, subspecies or varieties having differences in quantity and quality of their component(s) in their whole chemical fingerprint that is related to genetic or genetic expression differences”. A trinominal additional name in parentheses after the binominal name of the organism was proposed for naming chemotypes. In this nomenclature, first name informs the initials of the author’s name of the chemotype, second name describes the location of the chemotype and last name explains the frequency of distribution of chemotype in its location. For the identification of chemotypes, an approach that evaluates fingerprint analysis data of the extracts of the organism being obtained with solvents of different polarity together with the fingerprint analysis data of the essential oils (if the subject organism contains any essential oils) has been proposed.

Keywords: Chemotypes, chemovarieties, definition, system of nomenclature, identification