Nguyen Thuy Duong1, Pham Duc Vinh1, Phuong Thien Thuong2, Nguyen Thi Hoai3, Le Nguyen Thanh4, Tran The Bach5, Nguyen Hai Nam6, Nguyen Hoang Anh7. 1. Department of Pharmacology, Hanoi University of Pharmacy, 13 Le Thanh Tong, Hoan Kiem, Hanoi, Viet Nam. 2. Department of Pharmaceutical Analysis and Standardization, National Institute of Medicinal Materials, 3B Quang Trung, Hoan Kiem, Hanoi, Viet Nam. 3. Department of Pharmacognosy, Hue University of Medicine and Pharmacy, 6 Ngo Quyen, Vinh Ninh, Hue, Viet Nam. 4. Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi, Viet Nam. 5. Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi, Viet Nam. 6. Department of Medicinal Chemistry, Hanoi University of Pharmacy, 13 Le Thanh Tong, Hoan Kiem, Hanoi, Viet Nam. Electronic address: namnh@hup.edu.vn. 7. Department of Pharmacology, Hanoi University of Pharmacy, 13 Le Thanh Tong, Hoan Kiem, Hanoi, Viet Nam. Electronic address: anh90tk@yahoo.com.
Abstract
OBJECTIVE: To screen Vietnamese medicinal plants for xanthine oxidase (XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. METHODS: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. RESULTS: Three hundreds and eleven methanol extracts (CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/mL with inhibition rates of over 50%. The extracts of Archidendron clypearia (A. clypearia), Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC50 values below 30 μg/mL. Chemical study performed on the extract of A. clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and (-)-7-O-galloyltricetiflavan. The compound (-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC50 value of 25.5 μmol/L. CONCLUSIONS: From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC50 values of the methanol extracts below 30 μg/mL. Compound (-)-7-O- galloyltricetiflavan was identified as an XO inhibitor from A. clypearia with IC50 value of 25.5 μmol/L.
OBJECTIVE: To screen Vietnamese medicinal plants for xanthine oxidase (XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. METHODS: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. RESULTS: Three hundreds and eleven methanol extracts (CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/mL with inhibition rates of over 50%. The extracts of Archidendron clypearia (A. clypearia), Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC50 values below 30 μg/mL. Chemical study performed on the extract of A. clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and (-)-7-O-galloyltricetiflavan. The compound (-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC50 value of 25.5 μmol/L. CONCLUSIONS: From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC50 values of the methanol extracts below 30 μg/mL. Compound (-)-7-O- galloyltricetiflavan was identified as an XO inhibitor from A. clypearia with IC50 value of 25.5 μmol/L.