CHEMOTAXONOMIC SIGNIFICANCE OF FLAVONOIDS IN THE SOLANUM NIGRUM COMPLEX

Five locally available plant taxa of Solanum nigrum Complex were investigated to resolve the International taxonomic controversy about these plants by analyzing their favonoid profles. Total favonoid contents in the taxa were determined by two complementary colorimetric methods, aluminum chloride method and 2,4-dinitrophenylhydrazine method. Thin layer chromatography was used to detect the glycosides of quercetin. Whereas GC-MS analysis of the hydrolyzed extracts showed the relative percentage of quercetin aglycon in the taxa under study. Statistical analyses of the results were employed for grouping of these taxa into various clusters. The signifcant distance found between S. americanum, S. chenopodioides, S. nigrum and S. villosum indicated them as distinct species. But S. retrofexum did not show such a marked difference and hence might be regarded as a variety or subspecies of S. nigrum.