All-trans retinoic acid (10) was synthesized by β-ionone (5) through knoevenagel condensation, reduction and hydrolysis reaction. Then, hydroxyl-pinacolone retinoate (11) prepared the esterification with 1-hydroxy- 3, 3-dimethylbutan-2-ketone. This route not only reduces synthesis steps but also helps to increase yield. The structure of product characterized 1 H NMR 13 C NMR.

Seven new withanolides (1-7) were isolated from the aerial parts of Jaborosa caulescens var. caulescens and Jaborosa caulescens var. bipinnatifida. Three of the new compounds are related to jaborosalactones R, S, and T with a delta-lactone side chain and a hemiketal (or ketal) ring formed between a 21-hydroxyl and a 12-ketone (1-3). Compounds 4-7 are trechonolide-type withanolides with a gamma-...

The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a phosphitylation reagent in quantitative 31P NMR analysis of the hydroxyl groups in lignins has been thoroughly examined, and an experimental protocol recommended for spectra acquisition has been developed. Quantitative analysis of six “standard lignins” gave results comparable to those obtained by other methods of analysis. Exc...

Surface-initiated atom transfer radical polymerization (ATRP) has been used to prepare antifouling copolymer brushes based on 2-(2-methoxyethoxy)ethyl methacrylate (MEO(2)MA) and hydroxyl-terminated oligo(ethylene glycol) methacrylate (HOEGMA). The amount of hydroxyl reactive groups incorporated into the brushes was varied by changing the composition of the monomer mixture. These coatings were ...

Hydrogen is the most abundant chemical element in the universe, however, it is seldom regarded as a therapeutic gas. Recent studies show that inhaled hydrogen gas (H(2)) has antioxidant and antiapoptotic activities that protect the brain against ischemia-reperfusion injury and stroke by selectively reducing hydroxyl and peroxynitrite radicals. It is also well known that more than a half of the ...