Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University , 500 West 12th Avenue, Columbus, Ohio 43210, United States.
J Agric Food Chem. 2014 Jun 4;62(22):5054-60. doi: 10.1021/jf500802x. Epub 2014 May 27.
Bioassay-guided fractionation of a commercial sample of African mango (Irvingia gabonensis) that was later shown to be contaminated with goji berry (Lycium sp.) led to the isolation of a new pyrrole alkaloid, methyl 2-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]propanoate, 1, along with seven known compounds, 2-8. The structures of the isolated compounds were established by analysis of their spectroscopic data. The new compound 1g showed hydroxyl radical-scavenging activity with an ED50 value of 16.7 μM, whereas 4-[formyl-5-(methoxymethyl)-1H-pyrrol-1-yl]butanoic acid (2) was active in both the hydroxyl radical-scavenging (ED50 11.9 μM) and quinone reductase-induction [CD (concentration required to double QR activity) 2.4 μM)] assays used. The isolated compounds were shown to be absent in a taxonomically authenticated African mango sample but present in three separate authentic samples of goji berry (Lycium barbarum) using LC-MS and (1)H NMR fingerprinting analysis, including one sample that previously showed inhibitory activity in vivo in a rat esophageal cancer model induced with N-nitrosomethylbenzylamine. Additionally, microscopic features characteristic of goji berry were observed in the commercial African mango sample.
生物测定指导下对商业非洲芒果（Irvingia gabonensis）样品进行分离，结果表明该样品受到枸杞（Lycium sp.）污染，随后分离得到一种新的吡咯生物碱，甲基 2-[2-甲酰基-5-（羟甲基）-1H-吡咯-1-基]丙酸盐 1，以及另外 7 种已知化合物 2-8。通过分析其光谱数据确定了分离化合物的结构。新化合物 1g 显示出羟自由基清除活性，ED50 值为 16.7 μM，而 4-[甲酰基-5-（甲氧基甲基）-1H-吡咯-1-基]丁酸（2）在羟自由基清除（ED50 为 11.9 μM）和醌还原酶诱导（CD（使 QR 活性加倍所需的浓度）为 2.4 μM）测定中均具有活性。利用 LC-MS 和（1）H NMR 指纹分析发现，分离得到的化合物在经过分类学鉴定的非洲芒果样品中不存在，但在三种不同的正宗枸杞（Lycium barbarum）样品中存在，其中一个样品之前在 N-亚硝基甲基苄胺诱导的大鼠食管癌模型中显示出体内抑制活性。此外，在商业非洲芒果样品中观察到与枸杞特征一致的微观特征。
