Flavones from Combretum quadrangulare Growing in Vietnam and Their Alpha-Glucosidase Inhibitory Activity

Molecules

Thi-Minh-Dinh Tran¹  Thi-Bich-Ngoc Dao²  Truong-Minh-Tri Nguyen²  Thuc-Huy Duong²  Van-Quy Nguyen²  Thi-Hoai-Thu Nguyen³  Cong-Luan Tran⁴  Huu-Hung Nguyen⁵  Nguyen-Minh-An Tran⁶  Jirapast Sichaem⁷  ChuongHoang Nguyen⁸ 

[1]Department of Biology, Ho Chi Minh City University of Education, 280 An Duong Vuong Street, District 5, Ho Chi Minh City 72711, Vietnam

[2]Department of Chemistry, University of Education, 280 An Duong Vuong Street, District 5, Ho Chi Minh City 72711, Vietnam

[3]Faculty of Basic Sciences, University of Medicine and Pharmacy at Ho Chi Minh City, 217 Hong Bang Street, District 5, Ho Chi Minh City 72714, Vietnam

[4]Faculty of Pharmacy and Nursery, Tay Do University, Can Tho 94000, Vietnam

[5]Faculty of Technology, Van Lang University, 45 Nguyen Khac Nhu, District 1, Ho Chi Minh City 71013, Vietnam

[6]Industrial University of Ho Chi Minh City, Ho Chi Minh City 71420, Vietnam

[7]Research Unit in Natural Products Chemistry and Bioactivities, Faculty of Science and Technology, Thammasat University Lampang Campus, Lampang 52190, Thailand

[8]University of Science, Vietnam National University, Ho Chi Minh City 72711, Vietnam

关键词: Combretum quadrangulare Kurz;    flavonoid;    alpha-glucosidase;    antibacterial;    molecular docking;   

DOI  :  10.3390/molecules26092531

来源: DOAJ

【 摘 要 】

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3′,5′-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8–11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6–9, and 11–14 showed good alpha-glucosidase inhibition with IC₅₀ values in the range of 30.5–282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.

【 授权许可】

Unknown