Antiproliferative and Hypoglycemic Cucurbitane-Type Glycosides from the Fruits of Momordica charantia

This paper reports that bioassay-guided fractionations of EtOH extract of Momordica charantia fruits led to the isolation of 15 cucurbitane-type triterpene glycosides including 4 new compounds, kuguaosides A–D (1–4), along with 11 known ones, charantoside A (5), momordicosides I (6), F₁ (7), F₂ (8), K (9), L (10), and U (11), goyaglycosides-b (12) and -d (13), 7β,25-dihydroxycucurbita-5,23­(E)-dien-19-al 3-O-β-d-allopyranoside (14), and 25-hydroxy-5β,19-epoxycucurbita-6,23-dien-19-on-3β-ol 3-O-β-d-glucopyranoside (15). Their structures were elucidated on the basis of spectroscopic analyses and chemical methods. This study also established the HPLC-ELSD fingerprinting profile of an antiproliferative fraction of which 11 main peaks were identified. Biological evaluation showed that several isolated cucurbitane-type triterpene glycosides had antiproliferative activities against MCF-7, WiDr, HEp-2, and Doay human tumor cell lines. In addition, compound 14 showed potent hypoglycemic activities by glucose uptake assay.