Structure elucidation of five new iridoid glucosides from the leaves of Avicennia marina.

A chemical examination of the mangrove plant Avicennia marina (Forrsk.) Vierh resulted in the isolation and characterization of five new iridoids, marinoids A-E (1-5), along with 2'-cinnamoyl-mussaenosidic acid (6), 2'-O-(4''-methoxycinnamoyl) mussaenosidic acid (7), 2'-O-(4''-hydroxycinnamoyl) mussaenosidic acid (8), and 3(R)-hydroxy-5-phenyl-4(E)-pentenoic acid (9). The structures of 1-5 were elucidated on the basis of 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) in association with IR and MS data analysis.