Solomonsterols A and B from Theonella swinhoei. The first example of C-24 and C-23 sulfated sterols from a marine source endowed with a PXR agonistic activity.

The finding of new PXR modulators as potential leads for treatment of human disorders characterized by dysregulation of innate immunity and with inflammation is of wide interest. In this paper, we report the identification of the first example of natural marine PXR agonists, solomonsterols A and B, from a Theonella swinhoei sponge. The structures were determined by interpretation of NMR and ESIMS data, and the putative binding mode to PXR has been obtained through docking calculations.