TAILIEUCHUNG - Methoxyflavones from orthosiphon stamineus and their PTP1B inhibitory activities
In this assay, ursolic acid displayed an IC50 value of ± μM. This is indicated that 3,3′-dihydroxy-5,7,4′-trimethoxyflavone (4) may be useful for discovery of PTP1B inhibitors as antidiabetic agent. | Vietnam Journal of Science and Technology 56 (4A) (2018) 146-152 METHOXYFLAVONES FROM ORTHOSIPHON STAMINEUS AND THEIR PTP1B INHIBITORY ACTIVITIES Hoang Duc Thuan3, Nguyen Phi Hung1, 2, *, Vu Quoc Trung3 1 Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Ha Noi 2 Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Ha Noi 3 Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Viet, Ha Noi * Email: nguyenphihung1002@ Received: 23 July 2018; Accepted for publication: 10 October 2018 ABSTRACT Phytochemical analysis of the methanol extract of the aerial parts of Orthosiphon stamineus Benth. led to the isolation of four flavone compounds including 5-hydroxy-3,7,3′,4′tetramethoxyflavone (1), 3,5,7,3′,4′-pentamethoxyflavone (2), 3,3′-dihydroxy-5,7,4′trimethoxyflavone (3), and 3,5,3′-trihydroxy-7,4′-dimethoxyflavone (4). Their chemical structures were determined from the spectroscopic evidences, including 1D-NMR and MS, respectively. The inhibitory effects of the isolates (1-4) against protein tyrosine phosphatase 1B (PTP1B) were investigated in vitro using ursolic acid as positive control. Among the isolates, compound 4 exhibited potential activity with IC50 value of ± μM, the others showed weak activity. In this assay, ursolic acid displayed an IC 50 value of ± μM. This is indicated that 3,3′-dihydroxy-5,7,4′-trimethoxyflavone (4) may be useful for discovery of PTP1B inhibitors as antidiabetic agent. Keywords: Orthosiphon stamineus Benth., flavone, ursolic acid, PTP1B inhibitor, type 2 diabetes. 1. INTRODUCTION Nowadays diabetes is a huge and growing problem. The most recent estimate in 2017 shows that 425 million people are living with diabetes and this number is set to rise beyond 625 million in less than 25 years [1]. Type 2 diabetes (T2D), or noninsulin-dependent .
đang nạp các trang xem trước
