Aurones as Antidiabetic Agents and Their Prebiotic Activities

Abstract

Cyperus conglomeratus has been utilized in traditional medicine as an emollient, diuretic, analgesic, anthelmintic, and for other diseases. Furthermore, several biological activities have been reported for the plant extract and the isolated metabolites. The chromatographic investigation of an ethyl acetate extract of the aerial parts led to the isolation of three aurone derivatives (1–3) from the plant for the first time. Their structures were identified as aureusidin (1), aureusidin-4-methyl ether (2), and 5-methyl aureusidin (3) using 1D and 2D NMR techniques, along with mass spectrometry. The compounds were tested for their inhibitory activities against enzymes vital in metabolic diseases, especially diabetes, such as α-amylase, α-glucosidase, and glycogen phosphorylase. The results were expressed as percentage inhibition. The inhibitory activity of aurones against the tested enzymes was also analyzed by computational docking studies to provide a rational explanation for the observed results. The tested compounds formed stable interactions in terms of hydrogen bonding and hydrophobic interaction with the active site residues of the tested enzymes, and the results are in agreement with those of the in vitro antidiabetic activity. The compounds were also evaluated for their ability to support the growth and viability of beneficial bacteria in terms of prebiotic activities using two species, Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus, through the determination of prebiotic activity scores (Pscore). The findings of this study showed that C. conglomeratus is a potential natural source of bioactive agents. There is, however, a need for in vivo testing to evaluate this plant’s efficacy for developing new drug entities in the future.