Studies On The Chemical Constituents And Bioactivities Of Semi-Mangrove Plant Hibiscus Tiliaceus

Hibiscus tiliaceus(Malvaceae) is a tropical semi-mangrove plant that grows in margins of mangrove forest near the Estuary.This plant is used as traditional medicine in Asia and Africa to treat diseases such as fever,cough,phlegm,and dysentery.Up to now,the study on constituents of the species H.tiliaceus have repored rarely,previous chemical works for the genue Hibiscus proved that the constituents included triterpenes,sterols,flavonoids,lignanoids and so on.For the search for bioactive components,we investigated chemically the plant H. tiliaceus collected in Hainan island of China in July 2006,and 21 compounds were isolated from the petroleum ether-ester acetate portion of the methanol extract of the plant by chromatographic methods,including thin-layer chromatography,column chromatography on silica gel,Sephadex LH-20,and semi-prep HPLC.Their structures,named as 19(10→9)-abeo-8α,9β,10α-eupha-5,25(26)-dien-3β,24-diol(1), 19(10→9)-abeo-8α,9β,10α-tircalla-5,25(26)-dien-3β,24-diol(2),19(10→9)-abeo-8α,9β,10α-tircalla-5,23-dien-3β,25-diol(3~*),fernenol(4),fernenone(5),β-amyrone (6),germanicone(7),germanicol(8),glutinol(9),lupenone(10),lupeol(11),friedelin (12),pachysandiol(13),stigmast-4-en-3-one(14),stigmast-4,22-dien-3-one(15),β-sitosterol(16),Stigmasterol(17),Stigmast-5-en-3-ol-7-one(18),Stigmast-5,22 -dien-3-ol-7-one(19),ergosterol peroxide(20),erg0sta-4,6,8(14),22 -tetraen-3-one (21),respectively,were elucidated on the basis of ESI-MS,HR-ESI-MS,1D-NMR, 2D-NMR and comparison the spectral data with literatures.Among them,1~*,2~* and 3~* are new compounds,and 4～11,18～21 were obtained from this plant for the fist time. The cytotoxic activities of 20 compouds were tested by MTT methods. Compounds 1,2,13,18,20 and 21 showed significant cytotoxity toward the growth of P388 cells.Compounds 2,13 and 20 exhibited significant cytotoxity toward the growth of BEL -7402 cells.