A new alkaloid glycoside and antifungal metabolites from the aerial parts of Argemone mexicana Linn. collected in Vietnam

A new benzophenanthridine alkaloid glycoside (1), named nitrotyrasanguinarinoside, together with twelve known compounds (2 −13), was isolated from the dichloromethane extract of the aerial parts of Argemone mexicana Linn. Their structures were elucidated using IR, HR-ESI-MS, 1D and 2D NMR, and ECD spectroscopy, as well as by comparison with the published data. The dichloromethane extract exhibited in vivo antifungal activity against Colletotrichum coccodes with 80% inhibition at a concentration of 3000 µg/mL. Five benzophenanthridine alkaloids (1 − 5) inhibited four phytopathogenic fungi in vitro, including Alternaria brassicicola, Cladosporium cucumerinum, Magnaporthe oryzae, and Phytophthora infestans, with MIC values ranging from 0.016 to 0.987 mM. Notably, the new compound 1 showed strong activity against all four tested fungi, with MIC values ranging from 0.016 to 0.063 mM.本研究从蓟罂粟（Argemone mexicana Linn.）地上部分的二氯甲烷提取物中，分离得到1个新的苯并菲啶生物碱苷（benzophenanthridine alkaloid glycoside），命名为硝基酪氨血根碱苷（nitrotyrasanguinarinoside），同时获得12个已知化合物（2~13）。通过红外光谱（IR）、高分辨电喷雾电离质谱（HR-ESI-MS）、一维及二维核磁共振波谱（1D NMR、2D NMR）、电子圆二色谱（ECD spectroscopy），并结合已发表文献数据，阐明了所有化合物的结构。该二氯甲烷提取物在3000 μg/mL浓度下，对刺盘孢属真菌Colletotrichum coccodes展现出体内抗真菌活性，抑制率达80%。5种苯并菲啶生物碱（1~5）在体外对4种植物病原真菌具有抑制活性，涵盖芸苔链格孢菌（Alternaria brassicicola）、黄瓜黑星病菌（Cladosporium cucumerinum）、稻瘟病菌（Magnaporthe oryzae）及致病疫霉（Phytophthora infestans），其最低抑菌浓度（MIC，minimum inhibitory concentration）范围为0.016~0.987 mM。值得注意的是，新化合物1对全部4种供试真菌均表现出较强的抑制活性，MIC值范围为0.016~0.063 mM。