The chem. constituents of South China Sea soft coral S. microclavate were studied. A series of fatty compounds including octadecyl palmitate, Et myristate, Et palmitate, Et stearate, octadecyl alcohol, hexadecyl alcohol, and a common steroid, ergosta-5,24(28)-diene-3-ol were isolated. In addition 2 alkyl glycerin monoethers containing a C 15 and C 17 alkyl group, resp., and a rarely found compound, N-phenyl-b-naphthylamine were isolated from soft coral for the first time. Finally, 7-hydroxy-8-methoxy-4(1H)-quinolone was identified as the bioactive constituent. All the structures of these constituents were characterized on the basis of their spectral data together with their chem. behaviors.

Key words: C16 COMPOUNDS, ULTRAVIOLET SPECTROPHOTOMETRY, INFRARED SPECTROPHOTOMETRY, MARINE ORGANISMS, PROTON MAGNETIC RESONANCE SPECTROMETRY, CHOLESTEROL, MASS SPECTROGRAPHY, C14 COMPOUNDS, CARBOXYLIC ACID ESTER, QUINOLINONE P