Leaf flavonoids as chemotaxonomic characters in genus Sida L. (Bevila)

Abstract

Theflavonoid distribution pattern of five species of genus Sida was studied to identify the species since the existing classification was mainly based on morphological and anatomical characters. Four main flavonoids and one minor flavonoid were isolated by preparatory paper chromatography. Trace amounts of six flavonoids were observed in two-dimensional paper chromatography. The major flavonoid compounds in S. acuta. S. rhombifolia. S. alnifolia. and S. cordifolia were glycosylated and methylated flavonols where as S. humilis had minor flavonoids. There are remarkable variations in the substitution patterns of these flavonol compounds. The presence ofquercetin 3-methyl ether and the compound C is a common character to S. rhombifolia and S. cordifolia. and hence these two species may be considered as related taxa in the genus Sida. Kaempferol glycosides were the major Jlavonoids in the S. alnifolia in contrast to the S. rhombifolia. which was characterised by the presence of methylated quercetin. This is in agreement with the recent revision of the genus in which they are considered as different entities. The habit ofS. humilis. prostrate trailing, is different from other species, which are erect herbs. This dissimilarity of morphology agreed with its characteristic flavonoid pattern of possessing minor flavonoids.