Synthetic studies on naturally occurring sulfonium-type α-glucosidase inhibitors: progress and perspective

Extracts of Salacia, which are woody climbers mainly distributed in South Asian countries, have long been used to treat type-2 diabetes. Eight sulfonium-type α-glucosidase inhibitors salacinol, kotalanol, ponkoranol, salaprinol and their corresponding de-O-sulfonated analogues have been isolated so far. The unique structures, as well as distinguished biological activities, made them attractive targets in diverse research disciplines. The development of facile synthetic approaches is critical and fundamental for other extended investigations, including chemical biology and pharmaceutical development. This report provides an overview of the recent synthetic efforts directed toward the assembly of these sulfonium-containing polyhydroxylated natural products. This review will be helpful to gather insights into the development of a novel sulfonium type molecules with potential therapeutic applications.