One-step gram-scale synthesis of striasteroid B inspired by its nonenzymatic formation.

Striasteroids A and B are fungus-derived hybrid steroids with novel skeletons and promising biological activities. Our investigation suggests that both compounds are likely generated from ergosterol and pyrone derivatives via a nonenzymatic pathway during silica gel chromatography. Based on this finding, we developed an efficient one-step synthesis enabling gram-scale production of striasteroid B. In vitro activity evaluation showed that striasteroid B exhibited anti-renal fibrosis activity comparable to that of the clinical drug pirfenidone (PFD) at a concentration of 10 μM. In addition, preliminary pharmacokinetic studies indicated that this compound possesses favorable drug-like properties. Taken together, these results suggest that striasteroid B holds potential for further development as an anti-renal fibrosis agent.