Key Laboratory of Plant Resources and Chemistry of Arid Zone and State Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization , Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Urumqi 830011 , People's Republic of China.
University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China.
J Nat Prod. 2018 Sep 28;81(9):2115-2119. doi: 10.1021/acs.jnatprod.8b00461. Epub 2018 Sep 5.
Four ring-A seco-cucurbitane triterpenoids, colocynthenins A-D (1-4), together with seven known cucurbitane triterpenoids (5-11), were isolated from the fruits of Citrullus colocynthis. Their structures and absolute configurations were elucidated based on spectroscopic analysis and quantum chemical ECD calculations. Compound 1 possesses an unprecedented 2,11-lactone moiety, while compound 2 is the first reported cucurbitane triterpenoid with an unusual cyano group. Compounds 1 and 3 showed acetylcholinesterase inhibitory activities in a standard in vitro assay, with IC values of 2.6 and 3.1 μM, respectively.
四种四环-倍半萜类化合物，即苦瓜素 A-D（1-4），以及七种已知的苦瓜烷三萜类化合物（5-11），从苦瓜果实中分离得到。基于光谱分析和量子化学 ECD 计算，确定了它们的结构和绝对构型。化合物 1 含有一个前所未有的 2,11-内酯部分，而化合物 2 是第一个报道的具有不寻常氰基的苦瓜烷三萜类化合物。化合物 1 和 3 在标准体外测定中表现出乙酰胆碱酯酶抑制活性，IC 值分别为 2.6 和 3.1 μM。
