Five batches of resin from the Pili tree (Canarium ovatum Engl.) were distilled, and their essential oils and hydrosols were analyzed by gas chromatography. The oils, obtained in yields of 13.4–19.7 % v/m, featured α‐phellandrene in high proportions (50–65 %), alongside limonene, β‐phellandrene and para‐cymene. Chiral GC analysis confirmed that both phellandrenes were in fact >95 % (S)‐(+) enantiomers, while the other monoterpenes featured less pronounced enantiomeric excesses. The hydrosols were rich in α‐phellandrene oxidation products including cis‐α‐phellandrene epoxide and a series of para‐menth‐5‐ene‐1,2‐diol isomers. Both essential oils and hydrosols were tested for their antibacterial activity against Escherichia coli and Staphylococcus aureus and exhibited MIC90 of less than 5 and 0.5 mg/mL of total volatiles, respectively. The essential oil features some potential as a source of readily available natural (S)‐(+)‐α‐phellandrene.

中文翻译：

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Pili Tree (Canarium ovatum Engl.) 树脂的抗菌精油和纯露是 (S)-水芹烯衍生物的丰富来源

对来自 Pili 树 (Canarium ovatum Engl.) 的 5 批树脂进行蒸馏，并通过气相色谱分析它们的精油和纯露。以 13.4–19.7% v/m 的收率获得的油以高比例 (50–65%) 的 α-水芹烯为特征，此外还有柠檬烯、β-水芹烯和对伞花烃。手性 GC 分析证实，两种水芹烯实际上都是 >95% (S)-(+) 对映异构体，而其他单萜的对映异构过量则不太明显。水溶胶富含α-水芹烯氧化产物，包括顺式-α-水芹烯环氧化物和一系列对薄荷醇-5-烯-1,2-二醇异构体。精油和水溶胶都经过了对大肠杆菌和金黄色葡萄球菌的抗菌活性测试，其 MIC90 分别低于 5 和 0.5 毫克/毫升的总挥发物。