Three novel sulfur-containing compounds were isolated from Scorodocarpus borneensis. Their chemical structures were determined to be 2,4,5,7-tetrathiaoctane 4,4-dioxide (CH3SCH2SO2SCH2SCH3, 1) and 5-thioxo-2,4,6-trithiaheptane 2,2-dioxide (CH3SO2CH2SCSSCH3, 2), while the other compound was assumed to be O-ethyl S-methylthiomethyl thiosulfite (CH3SCH2SS(O)OCH2CH3, 3) on the basis of spectroscopic data. This first isolation of compound 1 strongly suggests that S. borneensis possesses a polysulfide formation pathway similar to that of other Allium species. Compounds 1 and 2 exhibited antimicrobial activity against some bacteria and fungi. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.