LAUSR

Two undescribed polyoxygenated furanocembranoid derivatives, methyl 15-(9-hydroxy-8-methoxy-2,12-dimethyl-15-oxa-bicyclo[10.2.1]pentadeca-2,4,6,11-tetraen-3-yl)propanoate (salmacembrane A) and 1-(16-methyl-2,16-dihydrofuran)-8-methoxy-12-methyl-20-oxabicyclo[10.2.1]pentadeca-2,4,6,11-tetraen-9-ol (salmacembrane B), were isolated from the organic extract of sea urchin Salmacis bicolor (family Temnopleuridae) by extensive chromatographic purification. Their structures were elucidated using detailed spectroscopic evidence. Salmacembrane A displayed significantly greater attenuation property against pro-inflammatory cyclooxygenase-2 (IC50 1.71 mM) than that exhibited by salmacembrane B (IC50 1.99 mM). Salmacembrane A could potentially inhibit 5-lipoxygenase (IC50 1.87 mM) and its activity was significantly greater than that exhibited by anti-inflammatory agent ibuprofen (IC50 4.50 mM, p   1.85 mM). In addition, these antioxidant activities were comparable to the standard α-tocopherol (IC50 DPPH 1.51 mM, IC50 ABTS+ 1.70 mM p < 0.05). The higher electronic parameters obtained from structure–activity relationship analysis along with greater binding affinities of salmacembrane A at the active site of cyclooxygenase-2 ascribed its potential anti-inflammatory activity.