Pharmaceutical Biology, Pharmazentrum, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
Molecular Modeling, Pharmazentrum, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
Molecules. 2017 Dec 18;22(12):2252. doi: 10.3390/molecules22122252.
The acid-induced rearrangement of three epoxyderivatives of nobilin , the most abundant sesquiterpene lactone in flowers, was investigated. From the 1,10-epoxyderivative , furanoheliangolide was obtained, while the 4,5-epoxy group of did not react. Conversely, when the 3-hydroxy function of nobilin was acetylated (), the 4,5-epoxy derivative did cyclize into cadinanes ( and ) under Lewis acid catalysis. The reactivity of the 4,5- and 1,10-epoxy derivatives of nobilin ( and ) was compared with that of parthenolide, and rationalized on the basis of quantum chemical calculations. All isolated reaction products were fully characterized by spectroscopic and computational methods, and their in vitro anti-protozoal activity was evaluated. The paper could provide new insights into the biosynthesis of this class of natural products.
研究了三种土木香内酯（花朵中含量最丰富的倍半萜内酯）的环氧衍生物在酸诱导下的重排反应。从 1,10-环氧衍生物中得到了呋喃海莲内酯，而 4,5-环氧基则没有反应。相反，当土木香内酯的 3-羟基乙酰化时（），在路易斯酸催化下，4,5-环氧衍生物会环化成卡丹烷（和）。比较了土木香内酯的 4,5-和 1,10-环氧衍生物（和）的反应活性，并基于量子化学计算进行了合理化解释。所有分离得到的反应产物均通过光谱和计算方法进行了充分表征，并评估了它们的体外抗原生动物活性。本文可为该类天然产物的生物合成提供新的见解。
