CHEMICAL VARIATION OF SPILANTHES SPECIES (ASTERACEAE) A MEDICINAL HERB IN PENINSULAR INDIA - REVEALED BY GCMS-MS

Spilanthes (Family: Asteraceae, tribe: Heliantheae), commonly known as 'tooth-ache' plant, is used in traditional medicine for curing several diseases across the world and species are reported to be distributed in peninsular India. The study on the comparison of the chemical constituents among Spilanthes species is lacking. A systematic study of chemical compounds could contribute to the knowledge of bioactive compounds but systematics of the genus as well. In this context, species of Spilanthes in peninsular India were selected for carrying out a detailed study of their chemical composition and their significance in chemotaxonomy. The chemical compounds of Spilanthes species in peninsular India were investigated by GCMS-MS. A total of 81 compounds were identified from leaf, inflorescence and root of S. calva, S. ciliata, S. oleracea, S. paniculata, S. radicans and S. uliginosa. The hydrocarbons (28%) formed the major constituent, followed by terpenoids (15%), esters (9%), sterols (8%), aldehydes & ketones (7%), alcohols (3%) and the main bioactive principle alkamide (5%), and rest of compounds forming 25% of total constituent. The chemotaxonomic significance of these compounds in each species was discussed. The phylogeny was constructed and principal coordinate analysis was carried out to study the relationship among species. The present study documented the chemical variation among the six Spilanthes species and some were species specific. The quantification of compounds in leaf, inflorescence and root of six species could contribute to the systematics and application in modern medicines. The phylogeny revealed the distance among the plant parts and the species under study where S. ciliata and S. paniculata were closely related, to this cluster S. oleracea was grouped, then S. uliginosa followed by S. radicans. To this main cluster S. calva was grouped indicating the far distance of this native species with other species including another native species S. paniculata.