Glycosidase inhibitory phenolic compounds from the seed of Psoralea corylifolia

• Published in: Food chemistry Vol. 121; no. 4; pp. 940 - 945
• Main Authors: Oh, Kyeong Yeol, Lee, Jin Hwan, Curtis-Long, Marcus J., Cho, Jung Keun, Kim, Jun Young, Lee, Woo Song, Park, Ki Hun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.08.2010; [Amsterdam]: Elsevier Science; Elsevier
• Subjects: Biological and medical sciences; chemical constituents of plants; Cullen corylifolium; drug screening; enzyme inhibition; enzyme inhibitors; Food industries; functional properties; Fundamental and applied biological sciences. Psychology; Glycosidase; glycosidases; phenolic compounds; Psoralea corylifolia; seed extracts; seeds; therapeutics; α-Glucosidase inhibitor; α-Mannosidase inhibitor; Glycosidase; α-Glucosidase inhibitor; Psoralea corylifolia; α-Mannosidase inhibitor; Glycosylases; Seeds; α-Glucosidase; Enzyme; Glycosidases; Phenols; Hydrolases; Inhibitor
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2010.01.022

The seeds of Psoralea corylifolia were extracted into five different polar solvents: chloroform, 50% ethanol in water, ethanol, methanol and water. All extracts were evaluated for glycosidase inhibitory activity. The chloroform extract (CE) showed the lowest IC 50 values against α-glucosidase (82.9 μg/ml) and α-mannosidase (132 μg/ml). Chromatography of CE yielded nine phenolic compounds which were identified as isovabachalcone ( 1), 4′- O-methylbavachalcone ( 2), isobavachromene ( 3), corylifolin ( 4), bavachinin ( 5), psoralidin ( 6), neobavaisoflavone ( 7), corylifol A ( 8), and bakuchiol ( 9). All isolated compounds, apart from compound 5, possessed α-glucosidase inhibitory activities. Among them, compounds 6– 8 exhibited potent inhibition with IC 50s of 13.7, 27.7 and 11.3 μM, respectively. Furthermore, compounds 2 and 6 showed α-mannosidase inhibitory activity. Mechanistic analysis of their inhibition modes against α-glucosidase showed that compounds ( 6 and 7) were noncompetitive, whereas compound 8 was mixed. Furthermore, the most active glycosidase inhibitors ( 2, 6– 8) were proven to be present in the native seed in high quantities by an HPLC chromatogram.