Rat intestinal microbiota digest desulfosinigrin to form allyl cyanide and l-cyano-2,3-epithiopropane

摘要

The ability of rat intestinal microbiota to digest sinigrin and desulfosinigrin was studied using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). When sinigrin was incubated with rat intestinal microbiota, up to 64% of the initial amount of sinigrin was degraded during 12 h, yielding allyl isothiocyanate (AITC) as the major product along with a minor amount of allyl cyanide (ACN) and a trace amount of l-cyano-2,3-epithiopropane (CETP), although the amount of ACN exceeded that of AITC after 12 h of incubation. In contrast, when desulfosinigrin was incubated with rat intestinal microbiota for 6 h, desulfosinigrin was digested up to 69% to form ACN and CETP as the major products instead of AITC. Whether the epithiospecifier protein (ESP) is involved in CETP formation in the rat intestinal microbiota-mediated degradation of desulfosinigrin remains to be established. However, only a trace amount of desulfosinigrin was detected during incubation of sinigrin with intestinal microbiota, although the intestinal microbiota had distinct sulfatase activity when p-nitrocatechol sulfate was used as the substrate. This observation suggested that the sulfatase of the rat intestinal microbiota has a very poor specificity toward sinigrin, which may be one reason for the formation of trace amounts of CETP during the intestinal microbiota-mediated digestion of sinigrin.