RESUMO
Objective: To investigate diterpenoids of Ceriops tagal, from Hainan mangrove. Methods: Eleven dolabrane-type diterpenoids were obtained by HP20 macroporous resin, silica gel, and RP C18 column chromatography and HPLC preparation. The structures of these compounds were elucidated on the basis of physicochemical properties and spectroscopic data. Results: The eleven dolabranes were obtained from the ethyl acetate extraction from the aerial part of C. tagal. These compounds were identified as (5S*,8S*,9S*,10R*)-13S*,18-dihydroxy-15,16-dinordolabr-4(18)-ene-3-one (1), (5S*,8S*,9S*,10R*,13S*)-3,16-dihydroxydolabr-3-ene- 2-one (2), tagalsin S (3), ent-5α,2,15- dioxodolabr-3-ene-3,16-diol (4), ent-16-nor-5α,2-oxodolabr-3-ene-3-ol-15-oic acid (5), tagalsin P (6), ent-5α,3,15-dioxodolabr-1,4 (18)-diene-2,16-diol (7), ent-16-nor-3-oxodolabr-1,4(18)-diene-2-ol-15-oic acid (8), tagalsin W (9), tagalsin V (10), and tagalsin Q (11). Conclusion: Compounds 1 and 2 are new compounds named as tagalditerpene A and tagalditerpene B.