目的 研究白苞猩猩草Euphorbia heterophylla的化学成分及其体外抗氧化活性。方法 综合运用正、反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和半制备HPLC等色谱技术对化合物进行分离纯化，并用现代波谱技术（1D NMR、2D NMR、HRMS）及单晶X射线衍射等方法进行化合物的结构鉴定。采用2,2-联苯基-1-苦基肼基（2,2-diphenyl-1-picrylhydrazyl，DPPH）和 2,2-联氮二(3-乙基-苯并噻唑-6-磺酸)二铵盐[2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate)，ABTS] 法评价单体化合物的体外抗氧化活性。结果 从白苞猩猩草乙醇提取物中分离得到18个化合物，分别鉴定为 (3R,5R,8R,9R,13S,14R,17R, 18R,21R)-3-羟基-21-异丙基-4,4,9,13,14,17-6甲基-环戊并[a]䓛-1(10)-双键-2-酮（1）、β-amyrin ferulate（2）、豆甾-4-烯-3-酮（3）、异槲皮苷（4）、槲皮素3-O-α-L-鼠李糖苷（5）、山柰酚-3-O-α-L呋喃阿拉伯糖苷（6）、山柰酚-3-O-α-L-鼠李糖苷（7）、multiflorin A（8）、4,6-二甲氧基苯酞（9）、香草醛（10）、对羟基苯甲醛（11）、原儿茶酸（12）、香草酸（13）、3-hydroxy-1-(4-hydroxy-3-methoxyphenyl) propan-1-one（14）、阿魏酸（15）、己二酸二乙基己酯（16）、13-丙基-二十五烷（17）和1-壬酰基羟基苯甲酸（18）。抗氧化活性研究结果表明，化合物5和15对DPPH自由基显示较好的抑制作用，半数抑制浓度（half maximal inhibitory concentration，IC₅₀）值分别为（15.88±0.84）μg/mL和（15.95±0.75）μg/mL。化合物15对ABTS自由基显示明显的抑制作用，其IC₅₀值为（2.54±0.57）μg/mL，优于阳性药L-抗坏血酸 [IC₅₀为（12.25±0.82）μg/mL]。结论 化合物1为新的羊齿烷型三萜，命名为白苞羊齿三萜A；化合物2～3、6～11、14、16～18均为首次从该植物中分离得到。

Objective To study the chemical constituents and in vitro antioxidant activity of Euphorbia heterophylla. Methods Comprehensive separation and purification were performed using normal-phase silica gel column chromatography, Sephadex LH-20 gel column chromatography and semi-preparative HPLC. Their structures were elucidated by comprehensive spectroscopic analyses (1D NMR, 2D NMR, HRMS) combined with single-crystal X-ray diffraction. The in vitro antioxidant activities of the isolated compounds were evaluated by DPPH and ABTS methods. Results A total of 18 compounds were isolated from the ethanol extract of E. heterophylla, their structures were elucidated as (3R,5R,8R,9R,13S,14R,17R,18R,21R)-3-hydroxy-21-isopropyl-4,4,9,13,14,17-hexamethyl-cyclopenta[a]chrysen-1(10)-en-2-one (1), β-amyrin ferulate (2), stigmasterol-4-en-3-one (3), isoquercitrin (4), quercetin 3-O-α-L-rhamnoside (5), kaempferol-3-O-α-arabifuranoside (6), kaempferol-3-O-α-L-rhamnoside (7), multiflorin A (8), 4,6-dimethoxyphthalide (9), vanillin (10), p-hydroxybenzaldehyde (11), protocatechuic acid (12), vanillic acid (13), 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl) propan-1-one (14), ferulic acid (15), diethylhexyl adipate (16), 13-propylheptacosane (17) and 1-n-decanoyl hydroxy-benzoic acid (18), respectively. Antioxidant activity evaluation revealed that compounds 5 and 15 exhibited potent DPPH radical scavenging activity, with half maximal inhibitory concentration (IC₅₀) values of (15.88 ± 0.84) μg/mL and (15.95 ± 0.75) μg/mL, respectively. Moreover, compound 15 also exhibited potent ABTS radical scavenging activity, with an IC₅₀ value of (2.54 ± 0.57) μg/mL, outperforming the positive control L-ascorbic acid [(IC₅₀ 12.25 ± 0.82) μg/mL]. Conclusion Compound 1 is a novel fernane-type triterpenoid and named as euheterophyllfernane A, compounds 2—3, 6—11, 14 and 16—18 are isolated from E. heterophylla for the first time.

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湖北省中央引导地方科技发展资金项目（2024BSB016）；三峡大学人才科研启动基金项目（8253302）