Chemical constituents from twigs of Euonymus alatus

To investigate the chemical compounds from the twigs of Euonymus alatus, nine compounds were isolated and identified as(+)-delta(2,11)-enaminousnic acid(1), 11-keto-beta-boswellic acid(2), acetyl 11-keto-beta-boswellic acid(3), camaldulenic acid(4), betulinic acid(5), 6beta-hydroxy-stigmast-4-en-3-one(6), 5-hydroxy-6,7-dimethoxyflavone(7), ethyl 2,4-dihydroxy-6-methylbenzoate(8), 4,4'-dimethoxy-1,1'-biphenyl(9). Their structures were elucidated by extensive spectroscopic analysis. Among them, compound 1 was a new natural product. Compounds 2-4 and 7-9 were obtained from the Euonymus genus for the first time. In vitro study showed that compounds 2 and 3 showed significant anti-tumor activities to BEL-7402 and HCT-8 at the concentration of 10 mg x L(-1). The inhibition rate of compound 2 was 61.78% and 68.29%, whereas the inhibition rate of compound 3 had reached to 70.91% and 84.07%.