Asymmetric total synthesis of polycyclic xanthenes and discovery of a WalK activator active against MRSA.

The development of new antibiotics continues to pose challenges, particularly considering the growing threat of multidrug-resistant Staphylococcus aureus. Structurally diverse natural products provide a promising source of antibiotics. Herein, we outline a concise approach for the collective asymmetric total synthesis of polycyclic xanthene myrtucommulone D and five related congeners.

A new periplogenin cardenolide from the seeds of Antiaris toxicaria.

A new periplogenin cardenolide, periplogulcoside (1), together with three known cardenolides, was isolated from the seeds of Antiaris toxicaria. The structure of the new compound was characterized as periplogenin-3-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside (1) by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectrometry, and the known compounds were identified by comparison of their NMR and HR-TOF-MS data with those reported in the literature. Compound 1 showed significant cytotoxicity against Hela and HepG-2 cell lines.

[Effects of multi-glycosides of tripterygium wilfordii on histological structures and c-kit expression in testes of pubertal rats].

Objective: To study the short- and long-term effects of multi-glycosides of tripterygium wilfordii (GTWon) the histological structures of testes in pubertal rats and possible mechanisms.

Methods: Forty-eight 5-week-old male Sprague-Dawley rats were randomly intragastrically administered with low-does GTW(6 g/kg daily)and high-does GTW (12 mg/kg daily) or 1% sodium carboxymethylcellulose (6 mL/kg, control group) for four weeks. The testes were sampled for detecting histological structures and c-kit expression by immunohistochemistry 24 hrs and four weeks after drug discontinuance.