TY  - EJOU
AU  - Luo, Shuaibin 
AU  - Zhang, Xuemei 
AU  - He, Kang 
AU  - Zou, Juan 
AU  - Geng, Chang-An 

TI  - Triterpenoids from <i>Uncaria rhynchophylla</i> and Their PTP1B Inhibitory Activity
T2  - Phyton-International Journal of Experimental Botany

PY  - 2022
VL  - 91
IS  - 8
SN  - 1851-5657

AB  - <i>Uncaria rhynchophylla</i> (Gouteng) is a famous traditional Chinese medicine used for psychiatric and hypotensive purposes in China. In this study, the ethyl acetate (EtOAc) part of <i>U. rhynchophylla</i> was revealed with protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Subsequent investigation on the EtOAc part yielded one new triterpenoid, 3<i>β</i>-formyloxy-6<i>β</i>,19<i>α</i>-dihydroxyurs-12-en-28-oic acid (<b>1</b>) and four known ones, 3<i>β</i>,6<i>β</i>,19<i>α</i>-trihydroxyurs-12-en-28-oic acid (<b>2</b>), 2-oxopomolic acid (<b>3</b>), 3<i>β</i>,19<i>α</i>-dihydroxy-6-oxo-olean-12-en-28-oic acid (<b>4</b>) and sumaresinolic acid (<b>5</b>). The structure of compound <b>1</b> was determined by extensive HRESIMS, IR, 1D and 2D NMR spectroscopic analyses. Two ursane-type triterpenoids (<b>2</b> and <b>3)</b> showed selective inhibition on PTP1B with IC<sub>50</sub> values of 48.2 and 178.7 <i>μ</i>M. The enzyme kinetic study suggested that compounds <b>2</b> and <b>3</b> were mix-type inhibitors on PTP1B with <i>K</i><sub>i</sub> values of 15.6 and 132.5 <i>μ</i>M. This investigation manifests the antidiabetic potency of <i>U. rhynchophylla</i> with triterpenoids as the active constituents.
KW  - <i>Uncaria rhynchophylla</i>; triterpenoids; antidiabetic effects; PTP1B inhibitors

DO  - 10.32604/phyton.2022.020935