Secondary metabolites from the stem of Ravenia spectabilis Lindl

Abstract

Background: Ravenia spectabilis is a medium tall shrub found widespread in South America. It also found in India, Pakistan, Bangladesh etc. Few alkaloid and steroid compounds were reported from the plant previously.Materials and Methods: Methanol extract from the stems of Ravenia spectabilis were partitioned into n-hexane, carbon tetrachloride, chloroform and aqueous soluble fractions, respectively. The crude methanol extract, carbon tetrachloride fraction and chloroform fraction were fractionated by column chromatography of Silica gel and Sephadex LH-20 for isolation and purification of compounds. The structures of the isolated compounds were determined by extensive NMR spectral analysis, including 2D NMR, mass spectroscopy etc.Results: Ten compounds, g-fagarine (1), ravenoline (2), N-methyl atanine (3), 2,3,3,5-tetramethyl-2,3,4,5- tetrahydrofurano [3,2-c] quinolin-4-one (4), arborinine (5), 3-geranyl indole (6), atanine (7), steroids sitosta-4- en- 3-one (8), stigmasterol (9) and 3-methoxy-4-hydroxy cinnamic acid (10) were isolated from the stems of Ravenia spectabilis.Conclusion: Compounds N-methyl atanine (3), 2,3,3,5-tetramethyl- 2,3,4,5-tetrahydrofurano [3,2-c] quinolin-4-one (4), 3-geranyl indole (6), sitosta-4-en-3-one (8) and 3-methoxy-4-hydroxy cinnamic acid (10) were isolated from this plant for the first time. 3-geranyl indole (6) was also isolated second time from natural sources.

Keywords: 3-methoxy-4-hydroxy cinnamic acid; alkaloids; Ravenia spectabilis; rutaceae; steroids