A new andirobin, xylomoluccensin A (9), and two new phragmalin-type limonoids, xylomoluccensins B (10) and C (11), were isolated from EtOAc extract of seeds of a Thai mangrove plant, Xylocarpus moluccensis Roem. collected form Phuket province, together with eight known limonoids, including mexicanolide (1), 3β-deacetylfissinolide (2), 2-hydroxyfissinolide (3), 7-deacetylgedunin (4), 7-oxo-7-deacetoxygedunin (5), moluccensin H (6), moluccensin I (7) and xyloccensin E (8). The structures of isolated compounds were established by analysis of spectroscopic data and by comparison with data in the literature for known compounds. In the case of 7-deacetylgedunin (4) and xylomoluccensin A (9), their structures and relative configuration were also confirmed by means of single-crystal X-ray diffraction analysis. Only gedunin-type limonoids, 7-oxo-7-deacetoxygedunin (6) and 7-deacetylgedunin (7), exhibited significant inhibitory activity against nitric oxide production from activated macrophages at a concentration of 10 µg/mL, suggesting that the compounds have anti-inflammatory activity. More importantly, they displayed less toxicity.
