Chemotaxonomic value of alkaloids in Solanum nigrum complex

The comparison of alkaloidal profile of delimited species in the 5 locally available taxa of s. nigrum complex were used to establish the boundaries among close taxonomic groups. several glycoalkaloids (solasonine,α-solamargine,β-solamargine and α-solanine) and their aglycones (solasodine and solanidine) were analysed that were shown to be a valuable tool to resolve the international taxonomic controversy based on morphological characters. hplc and gc-ms were used for the first time for the analysis of alkaloids in s. nigrum complex. qualitative and quantitative comparison by cluster analysis demonstrated significant distances among s. chenopodioides and s. villosum as well as in s. americanum and s. nigrum,in their respective clusters,indicated them as distinct species. but s. retroflexum did not show such a marked difference and hence might be regarded as a variety or subspecies of s. nigrum.