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