Studies On Terpenoids Constituents Of Ceriops Tagal

Mangrove plants,growing in the intertidal zones,have different metabolic pathways compared to terrestrial plants.They are rich sources of bioactive secondary metabolites with novel chemical structures.Ceriops tagal,a mangrove plant of the genus Ceriops(Rhizophoraceae),has been used as a folk medicine in the treatment of malignant ulcers and traumatic hemorrhage.Phytochemical analysis indicated that terpenoids were the main chemical components of C.tagal.Most reported terpenoids from C.tagal exhibited various bioactivities,including antitumor,antimicrobial,antifouling and antifeedant activities.Furthermore,over half of naturally occuring dolabranes have been reported from this plant.It has attracted chemists' research interests in recent years.In the present paper,we attempted to find out these bioactive substances from Ceriops tagal to provide scientific basis for further development.Thirty-four compounds,including twenty-five terpenoids were isolated from C.tagal.by the comprehensive utilization of silica gel,Sephadex LH-20 column chromatography and HPLC.Their structures were identified on the basis of spectral data.All the compounds were elucidated as tagalene G(1)?tagalene H(2)?tagalene J(3)?tagalene I(4)?tagalsin P(5)?tagalsin Q(6)?ent-5?,3,15-dioxodolabr-1,4(18)-diene-2,16-diol(7)? tagalsin W(8)?ent-5?,2,15-dioxodolabr-3-ene-3,16-diol(9)? tagalsin R(10)? tagalsin B(11)?ent-5?,2-oxodolabr-3-ene-3,15,16-triol(12)?ent-16-nor-5?,2-oxodolabr-3-ene-3-ol-15-oic acid(13)?(5S*,8S*,9S*,10R*)-13S*,18-dihydroxy-15,16-dinordolabr-4(18)-ene-3-one(14)?tagalsin S(15)?(5S*,8S*,9S*,10R*,13S*)-3,16-dihydroxydolabr-3-ene-2-one(16)?ent-8(14)-pimarane-16,18-dihydroxy-15-one(17)?ent-8(14)-pimarane-15,18-diol(18)?tagalsin J(19)?3-epi-betulin(20)?betulone(21)?3?-Acetylbetulinic acid(22)?3-epi-betulinic acid(23)?3,28-dihydroxyurs-12-ene(24)? pubinernoid A(25)? 4',5,7,8-tetramethoxyflavone(26)?3',4',5,7,8-pentamethoxyflavone(27)? nobiletin(28)? hexahydrocurcumin(29)?4-hydroxybenzaldehyde(30)? 3-methoxy-5-pentane-1-phenol(31)? 6-shogaol(32)?6-hydroxystigmast-4-en-3-one(33)??-sitosterol(34).Among them,compounds 1-4 were new diterpenoids,and compounds 12,21 and 24-33 were obtained from C.tagal for the first time.