Combining chemometric analysis of HPTLC data and C NMR-based dereplication for the chemotaxonomic investigation of Clusia spp. from the Yucatecan flora.

The study of plant chemotypes is relevant because changes in the metabolome can alter their medicinal or biological properties. The genus Clusia (Clusiaceae family), which includes 1200 species, is part of the flora of the Yucatan peninsula and is recognized for producing diverse specialized metabolites with biological activity. Recently, the chemometric analyses of the HPLC chromatographic profiles of the bark extracts of four Clusia spp. occurring in the Yucatan peninsula suggested the presence of chemotypes among individuals of a same population. In this investigation, a combination of HPTLC and chemometrics has been used to analyze the chromatographic profiles of the bark extracts and semi-purified fractions from C. suborbicularis, C. flava, C. rosea and C. lundelli, to establish similarities and differences between chromatographic profiles. The results obtained strongly supported the presence of chemotypes in individuals from C. suborbicularis and C. flava belonging to the same populations and allowed the identification of medium polarity semi-purified fractions as those containing the metabolites associated with the differences. Finally, the use of C NMR dereplication analyses resulted in the preliminary identification of mainly terpenoids as differential major metabolites responsible for the variations in the phytochemical profiles of the possible chemotypes. Our findings demonstrate that HPTLC is a rapid and cost-effective option for discriminating intraspecific variations. Furthermore, this integrated HPTLC-chemometrics-C NMR approach provides a valuable strategy for characterizing chemical diversity and for discovering new bioactive compounds in medicinally important plant genera.