Journal of Medicinal Materials, 2018, Vol. 23, No. 5 (pp. 277 - 283)

CHEMICAL CONSTITUENTS FROM CROTON TONKINENSIS

AND THEIR FREE RADICAL SCAVENGING ACTIVITY

Nguyen The Hung¹, Ha Van Oanh¹, Nguyen Huu Thien², Nguyen Thi Duc Hanh²,

Dang Bach Tai³, Nguyen Phuong Thao^4,*

¹Hanoi University of Pharmacy, Vietnam;

²Dong A Science and Technology Joint Stock Company, Minh Khai, Hanoi, Vietnam;

³Institute of Science and Technology, Ministry of Public Security, Hanoi, Vietnam;

⁴Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam

*Corresponding author: thaonp@imbc.vast.vn

(Received September, 01^st, 2018)

Summary

Chemical Constituents from Croton tonkinensis and their Free Radical Scavenging Activity

Chromatographic separations of an ethanol extract of the leaves of Croton tonkinensis Gagnep. resulted in the isolation of five compounds (1-5). These compounds were elucidated as phorbol (1), (6R,7E,9S)-6-hydroxy-4,7-megastigmadien-3-one 9-O-β-D-glucopyranoside (2), rutin (3), ent-11α,18-diacetoxy-7β-hydroxykaur-16-en-15-one (4) and ent-11α-acetoxykaur-16-en-18-oic acid (5), by extensive NMR spectroscopic and MS analysis as well as comparison with the reported data. Their antioxidant activity was also measured using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) method. Among them, compound 3 exhibited potent DPPH radical scavenging activity, with an IC₅₀ value of 8.98 ± 0.30 µg/mL. This is the first report of 1-3 from C. tonkinensis.

Keywords: Croton tonkinensis, Euphorbiaceae, Diterpenoid, Megastigmane glycoside, Flavonoid, Antioxidant activity.