Oleanane hemiacetal glycosides from Gymnema latifolium and their inhibitory effects on protein tyrosine phosphatase 1B. (February 2020)

• Record Type: Journal Article
• Authors: Pham, Ha Thanh Tung; Ryu, Byeol; Cho, Hyo Moon; Lee, Ba-Wool; Yang, Woo Young; Park, Eun Jin; Tran, Van On; Oh, Won Keun
• Is Part Of: Phytochemistry. Volume 170(2020)
• Publication Date: 2020-02
• Subjects: Gymnema latifolium -- Apocynaceae -- Oleanane hemiacetal glycosides -- PTP1B; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2019.112181
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Gymnema sylvestre (Retz.) R. Br. ex Schult. has a long history to be used as an antidiabetic herbal medicine. Various varieties of G. sylvestre, have been studied intensively on their 3 β -hydroxy oleanane triterpenoid composition for hypoglycemic effects. It is also well-known that most species belonging to the same genus have similar chemical composition and biological activity. Thus, an extract of the Gymnema latifolium Wall. ex Wight, which showed considerable protein tyrosine phosphatase 1B (PTP1B) inhibitory activity (>70% inhibition at 30 μg/mL), was studied intensively. Extensive chemical investigation on the 70% EtOH of G. latifolium led to the isolation of four previously undescribed oleanane hemiacetal glycosides, gymlatinosides GL1-GL4, three previously undescribed oleanane glycosides, gymlatinosides GL5-GL7, and two known 3 β -hydroxy oleanane analogs. The structures of the previously undescribed compounds were elucidated using diverse spectroscopic methods. The hemiacetal structure of the glycoside portion was further elaborated precisely by HMBC and J resolved proton NMR. Gymlatinosides GL2 and GL3 showed considerable PTP1B inhibitory effect. Graphical abstract: Image 1 Highlights: Seven previously undescribed oleanane glycosides were isolated from Gymnema latifolium. The hemiacetal glycoside was elucidated with HMBC and J -resolved proton NMR. Total extract and gymlatinosides GL2 and GL3 exhibited PTP1B inhibitory effect.