Antidiabetic Agents from Fungi with Special Reference to α-Glucosidase Inhibitors

The enzyme α-glucosidases (EC 3.2.1.20) catalyzes the hydrolysis of α-1,4- glucopyranoside bond in oligosaccharides and disaccharides, and thus plays an essential role in regulating glucose content and the level of postprandial hyperglycemia. The inhibition of α-glucosidases is considered a viable strategy to develop new and effective antidiabetic drugs. Many patents like ZA201905405B; US9073897B2 have been published on α- glucosidase inhibitors. In recent years, several classes of fungal metabolites possessing a varying degree of α-glucosidases inhibitory activity have been reported. The primary chemical classes include xanthone, phenanthrene, terpenoid, coumarin, isocoumarin, naphthalene, piperazine, and polyketides. Few of the identified inhibitors exhibited severalfold better activities than well-known α-glucosidases inhibitor acarbose and can be used as a lead to develop new antidiabetic drugs. The present review highlights the recent development in the identification of α-glucosidases inhibitors from various fungal sources. Their chemical class, structures, and inhibitory activity in terms of IC₅₀ or MIC are discussed here.