Abstract

Seven stilbenes and one catechin were bioactivity-guidedly isolated from the rhizomes of Rheum palmatem. Their structures were identified as piceatannol (1), resveratrol (2), piceid (3), rhapontigenin (4), piceatannol-3´-O-β-D-glucopyranoside (5), rhaponticin (6), catechin (7) and desoxyrhapontigenin (8). Anti-monoamine oxidase (MAO) activities of compounds 1-8 were tested. Compounds 1 and 8 showed significant MAO inhibitory activities with IC50 values 16.4 ± 1.5 μM and 11.5 ± 1.1, respectively, when the IC50 value of iproniazid as a standard was 6.5 ± 0.5 μM. The selectivity of compounds 1-8 against MAO-A and MAO-B were also evaluated. The results showed that compounds 4˴6˴8 preferred to inhibit MAO-A rather than MAO-B with selectivity values ([IC50 of MAO-B]/ [IC50 of MAO-A]) of 4.74, 10.01 and 9.42, respectively. The preliminary structure-activity relationships (SARs) of these compounds were discussed and the molecular modeling was also performed to explore the binding mode of inhibitors at the active site of MAO-A and MAO-B.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.