Monoterpenes and sesquiterpenes from Clausena excavata

To investigate monoterpenes and sesquiterpenes of the stems and leaves of Clausena excavata, an AcOEt fraction of the methanol extract was subjected on column chromatographies including silica gel and RP-18, as well as preparative HPLC. The structures of compounds isolated were identified on the basis of spectroscopic data as excamonoterpene (1), (6R, 9S)-9, 10-dihydroxy-4-megastigmen-3-one (2), (3R, 6R, 7E) -3-hydroxy-4, 7-megastigmadien-9-one (3), (3S) -3-hydroxy-7, 8-dihydro-beta-ionone (4), (3S, 5R, 6S) -3-hydroxy-5,6-epoxy-beta-ionone (5), (6R, 9R) -9-hydroxy-4-megastigmen-3-one (6), (3S, SR) -dihydroxy-6, 7-megstigmadien-9-one(7), (-)-loliolide(8), caryolane-1, 9alpha-diol(9) and 2, 6-dihydroxyhumula-3 (12), 7 (13), 9(E)-triene (10), were isolated from the stems and leaves of C. excavata. Compound 1 is a new monoterpene, named as excamonoterpene. Compounds 2-10 were isolated from this plant for the first time.