An efficient method for synthesizing dimethylsulfonio-³⁴ S-propionate hydrochloride from ³⁴ S₈

Dimethylsulfoniopropionate (DMSP, (2-carboxyethyl)dimethylsulfonium) is a highly abundant compound in marine environments. As a precursor to the climatically active gas, dimethylsulfide (DMS), DMSP connects the marine and terrestrial sulfur cycles. However, the fate of DMSP in microbial biomass is not well understood as only a few studies have performed isotopic labeling experiments. A previously published method synthesized ³⁴ S-labeled DMSP from ³⁴ S₈ , but the efficiency was only 26% and required five separate reactions, expensive reagents, and purification of the products of each reaction. In this study, a method of synthesizing ³⁴ S-labeled DMSP from ³⁴ S₈ is described. Improvements include elemental steps, inexpensive reagents, purification of only one intermediate, and less time to complete. The efficiency of this method is 65% and results in pure DMSP with more than 98% isotope enrichment as determined by ¹ H-nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS).