Sesquiterpenoids from gorgonian Muriceides collaris

Seven guaiane-type sesquiterpenoids, a new compound 6-formyl-5-isopropyl-3-hydroxymethyl-7- methyl-1H-indene (1), a new natural product 5-isopropyl-3, 7-dimethyl-1H-indene-1-one (2), along with five known compounds: guaiazulene (3), 4-formyl-7-isopropyl-10-methylazulene (4), sesquiterpene ketolactone (5), alismoxide (6) and guaia-1 (5), 6-diene (7), were isolated from gorgonian Muriceides collaris collected in South China Sea. Their structures were elucidated on the basis of extensive spectroscopic analysis MS, IR, ¹H NMR, ¹³C NMR (DEPT), HMQC, HMBC, NOESY and by comparison of the spectral data with those of the literatures.