Tricalycoside, a New Cerebroside from Tricalysia coriacea (Rubiaceae).

A new cerebroside, named as tricalycoside (1), was isolated from the CH2 Cl2 /MeOH (1:1) extract of twigs and leaves of Tricalysia coriacea using repeated silica gel open column chromatography followed by preparative TLC and Sephadex LH-20, together with six known compounds (2 - 7). The structure of the new compound was determined by analysis of 1D- and 2D-NMR, MS data, chemical conversion, and by comparison of these data with those from the literature. Tricalycoside (1) possessed a weak antibacterial activity against Klebsiella pneumoniae (MIC = 75 μg/mL).