Mass Spectrometry Analysis of Low-Molecular-Weight Sulfur-Containing Metabolites from an Infusion of Scorodophloeus zenkeri Stem Barks

Scorodophloeus zenkeri is a tree endemic to Central Africa that gives out a garlic-like odour. Therefore, its bark, seeds and wood are commonly used as a condiment in traditional foods in Cameroon and Gabon. Moreover, the infusion of stem barks of S. zenkeri is used in traditional medicine in Gabon as a laxative. In the present study, we report on the phyto-chemical analysis by ultra-high performance liquid chromatography-tandem mass spec-trometry and by Fourier-transform ion cyclotron resonance mass spectrometry of the infu-sion of S. zenkeri barks. We identified numerous novel sulfur-containing metabolites, in-cluding sulfinic, sulfonic, sulfinosulfanyl, thiosulfuric acid derivatives and organosulfur metabolites, containing up to four sulfur atoms. Rules for the MS/MS fragmentation in negative ion mode of these unusual molecules are proposed.