Elucidation of excogallochaols A-D, four unusual diterpenoids from the Chinese mangrove Excoecaria agallocha.

Diterpenoids, excoagallochaols A-D (1-4), with an unprecedented skeleton, were isolated from the ethyl acetate extract of the stems and leaves of the mangrove Excoecaria agallocha L. The structures of these metabolites were elucidated on the basis of detailed analysis of their spectroscopic data and by comparison with those of related compounds reported in literature.