ABSTRACT
Twelve new grayanoids (-) along with five known compounds were isolated from flowers of . Their structures were fully characterized using a combination of spectroscopic analyses, computational calculations, and single crystal X-ray diffraction. Rhomollone A () possesses an unprecedented 5/6/6/5 tetra-cyclic ring system (B- grayanane) incorporating a cyclopentene-1,3-dione scaffold. Rhodomollein XLIII () is a dimeric grayanoid, containing a novel 14-membered heterocyclic ring with a symmetry axis. The antinociceptive activities of compounds , , , , and - were evaluated by an acetic acid-induced writhing test. Among them, compounds , , , and displayed significant antinociceptive activities at a dose of 20 mg/kg with inhibition rates ranging from 41.9% to 91.6%. Compounds and inhibited 46.0% and 39.4% of the acetic acid-induced writhes at a dose of 2 mg/kg, while compound inhibited 34.3% of the writhes at a dose of 0.4 mg/kg.
ABSTRACT
Six compounds were isolated from the roots of Pithecellobium lucidum by various chromatograhic techniques such as column chromatography on silica gel and Sephadex LH-20, and preparative HPLC, and their structures were elucidated as julibroside A2 (1), 3-[ (2-acetamido-2-deoxy-beta-D-glucopyranosyl) oxy] -16alpha-hydroxyolean-12-en-28-oic acid (2), galloyl acid (3), ethyl gallate (4), (+)-catechin (5), (-)-gallocatechin gallate (6) on the basis of spectrascopic data analysis. Compounds 1-6 were isolated from Pithecellobium lucidum for the first time. Compound 2 showed selective cytoxic activity against the human cell lines A2780 with an IC50 value of 1.72 micromol x L(-1).