New prenyl flavanone and diarylbutanol from <i>Uvaria siamensis</i> stem bark and their <i>α</i> -glucosidase inhibitory activity
Huong T. M. Nguyen, Thi Thuy Duong Ngo, Phung D. N. Nguyen, Tuyen Nguyen Kim Pham, T. M. Lien, Jirapast Sichaem
Abstract
One new prenyl flavanone (1), (2S)-8-prenyl-5,6-dihydroxy-7-methoxyflavanone, and one new diarylbutanol (2), (7′S)-3′-hydroxylinderagatin-A, were isolated from the stem bark of Uvaria siamensis (Annonaceae), along with five known compounds, eriodictyol (3), quercetin (4), paprazine (5), N-trans-caffeoyltyramine (6), and N-trans-feruloyltyramine (7). Their structures were determined through extensive spectroscopic analyses and comparison with the literature. The α-glucosidase inhibitory potential of 1-7 was evaluated. Compound 6 showed the highest inhibitory activity against α-glucosidase and exhibited superior potency compared to the positive control, with an IC50 value of 0.12 μM.