Encecalol angelate, an unstable chromene from Ageratum conyzoides L.: Total synthesis and investigation of its antiprotozoal activity
作者:Dipak Harel、Sami A. Khalid、Marcel Kaiser、Reto Brun、Bernhard Wünsch、Thomas J. Schmidt
DOI:10.1016/j.jep.2011.06.015
日期:2011.9
ethnomedicinal reports, the dichloromethane extract of Ageratum conyzoides L. (Asteraceae) was recently shown to be of considerable activity against Trypanosoma brucei rhodesiense, the etiologic agent of East African Human Trypanosomiasis (East African Sleeping Sickness). Isolated compounds, namely, methoxylated flavonoids as well as the chromene derivative encecalol methyl ether, were less active than the crude
族裔药理学相关性与族裔医学报道一致,最近发现,香叶香A(Asteratum conyzoides L。)(菊科)的二氯甲烷提取物对东非人类锥虫病(东非昏睡病)的病原体Trypanosoma brucei rhodesiense具有相当大的活性。分离的化合物,即甲氧基化的类黄酮以及色烯衍生物恩斯考洛尔甲基醚的活性低于粗提物。发现提取物的活性在储存在溶液中时会大大降低。通过HPLC在新鲜提取物中检测到不稳定的化合物,当将其储存在甲醇溶液中时,该化合物迅速转化为恩斯卡洛尔甲基醚。该化合物被认为代表具有抗锥虫活性的成分,无法以完整的形式从提取物中分离出来。研究的目的是阐明这种不稳定化合物的结构,并研究其在总提取物的抗锥虫活性中的潜在作用。材料和方法降解产物的UHPLC / ESI-qQTOF MSMS和NMR数据表明其化学性质为encecalol angelate(1),因此是通过线性合成的六