Autocatalytic methylthiomethylation of carboxylic acid/phenol involving the formation of DMSO enolate: convenient synthesis of methylthiomethyl ester/ether.

This work reported a simple and practical protocol for the preparation of methylthiomethyl (MTM) esters/ethers directly from carboxylic acid/phenol and dimethylsulfoxide (DMSO) as solvent and methylthiomethyl source. With different types of carboxylic acids/phenols the reactions underwent smooth transformation to afford the corresponding MTM esters/ethers in moderate to excellent yields. This method features catalyst-free, easy to operate, broad substrate scope, good functional group tolerance and involvement of the formation of DMSO enolate.

A new epigallocatechin gallate derivative isolated from Anhua dark tea sensitizes the chemosensitivity of gefitinib via the suppression of PI3K/mTOR and epithelial-mesenchymal transition.

The acquired resistance to gefitinib limits its clinical application. Epigallocatechin-3-gallate (EGCG) has been found to enhance the efficacy of gefitinib against resistant. However, the cellular and molecular mechanisms have not been completely illuminated in NSCLC. In this study, a new epigallocatechin gallate derivative (2R,3R-6-methoxycarbonylgallocatechin-3-O-gallate, the following referred to as EGCGD) (1) and three known epigallocatechin gallate compounds including epicatechin-3-O-gallate (2), gallocatechin-3-O-gallate (3) and epigallocatechin-3-O-gallate (4, EGCG) were isolated and identified from Anhua dark tea. The pharmacological studies showed EGCGD was more effective against gefitinib-resistant HCC827-Gef cells compared to that of other three epigallocatechin gallate compounds including EGCG, suggesting that introduction of 6-methoxycarbonyl to EGCG might enhance its antitumor activities. Further study on molecular mechanism showed EGCGD increased the potency of gefitinib against HCC827-Gef cells via suppression of epithelial-Mesenchymal transition (EMT) and dual inhibition of PI3K/mTOR.

Sesquiterpenes from cultures of the fungus Phellinus igniarius and their Cytotoxicities.

Four new sesquiterpenoids, phellinignins A-D (1-4), together with four known ones (5-8), were isolated from cultures of the fungus Phellinus igniarius. The structures were established by extensive spectroscopic methods including MS, NMR, and the single crystal X-ray diffraction. Compounds 1-3 and 5-8 are tremulane sesquiterpenoids, while compound 4 possesses a new carbon skeleton that might derive from an illudane framework. Compounds 1, 2, 4, and 5 showed certain cytotoxicities to three human cancer cell lines.