Lignan glycosides from Fritillaria verticillata Willd. and their anti-inflammatory activities.

Three undescribed lignan glycosides, echiunines E-G (1-3), as well as eight known compounds (4-11) were isolated from Fritillaria verticillata Willd. Among them, compounds 1-3 were a series of lignan glycosides reported for the first time from genus Fritillaria. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously, the absolute configuration of compounds were further confirmed by calculated ECD method. The NO release inhibitory effects of compounds were evaluated in LPS-activated RAW264.7 macrophages. Compounds 7-8 showed inhibitory acitivities in a dose-dependent manner.

Recent advances in medicinal chemistry of oleanolic acid derivatives.

Oleanolic acid (OA), a ubiquitous pentacyclic oleanane-type triterpene isolated from edible and medicinal plants, exhibits a wide spectrum of pharmacological activities and tremendous therapeutic potential. However, the undesirable pharmacokinetic properties limit its application and development. Numerous researches on structural modifications of OA have been carried out to overcome this limitation and improve its pharmacokinetic and therapeutic properties. This review aims to compile and summarize the recent progresses in the medicinal chemistry of OA derivatives, especially on structure-activity relationship in the last few years (2010-2021). It gives insights into the rational design of bioactive derivatives from OA scaffold as promising therapeutic agents.

Novel glutamic acid derivatives from the bulbs of Fritillaria verticillate Willd and their antitumor activities.

Four previously undescribed glutamic acid derivatives, verticillamines A-D (1-4), together with six known compounds (5-10) were isolated from the bulbs of Fritillaria verticillate Willd. The structures of (1-10) were established on the basis of UV, IR, MS, 1D and 2D NMR, and the absolute configurations of compounds (1-4) were determined by calculated ECD methods. Among them, compounds (1-3) were rare 2-methyl-γ-lactam alkaloid derivatives. Moreover, both γ-lactam alkaloids (1-5) and pyrrolidine alkaloids (6-7) were discovered in Fritillaria for the first time. Compound 8 exhibited moderate cytotoxic activities against A2780 and HepG 2 cells, with IC50 values of 11.7 ± 5.2 µM and 25.6 ± 2.8 µM.