Terpenoids from Kenyan Leonotis mollissima

Abstract

Leonotis mollissima belongs Leonotis genus that comprises of ten species. It is called kipserere by Marakwets of Kenya. No phytochemicals have been reported on the Laikipia Kenya species. The leaves were collected from Laikipia University Kenya, identified and voucher specimen kept for reference in Biological Department, Egerton University, Kenya. Dry powder of leaves was successively extracted with hexane, dichloromethane, ethyl acetate and methanol for seventy two hours. The solvents were evaporated under reduced pressure using a rotary evaporator (Buchi type R-205). With repeated column chromatography using a solvent step gradient of 20% and 33% ethyl acetate in hexane three compounds, 4, 7-dimethoxy-5-methylchromen-2-one (1) [an aromatic compound], 12β-acetoxy-20-hydroxy-3, 7, 11, 15-tetraoxo-25, 26, 27-trisnorlanost-8-en-24-oic acid (2) [a triterpenoid] and (13R)-19α, 13α-epoxylabda-6β(19).16(15)-dioldilactone (3)[a diterpenoid] were isolated. Identification of pure compounds was achieved by 1H and 13C NMR (500 MHz) spectroscopy.