Xenobiotic C-sulfonate derivatives; metabolites or metabonates?

Abstract

1. The production of sulfate conjugates is a well-known and established pathway within the field of xenobiotic metabolism. In addition to the usual attachment of a sulfonate grouping via an oxygen atom (O-sulfonates) to yield a sulfate conjugate, so-called “N-sulfates” (N-sulfonates) have been reported and “S-sulfates” (S-sulfonates) mooted to exist.

2. The few examples cited in the literature where the sulfur atom of the sulfonate group was attached directly to a carbon atom of the xenobiotic (C-sulfonates) and subsequently excreted as a metabolite have been collated, examined and reviewed.

3. The potential mechanisms of formation of these C-sulfonates are discussed, both biological and chemical; the potential role of the gut microbiome raised and hopefully by highlighting this curiosity further fruitful investigation will be stimulated.

Keywords:

• Andrographolide
• C-sulfonates
• flumipropyn
• nitecapone
• physalin A
• 2-pyridinethiol-1-oxide

Declaration of interest

The author reports no conflicts of interest. The author alone is responsible for the content and writing of this article.