Enzyme-mediated enantioselective hydrolysis of soluble polymer-supported dendritic carbonates
摘要:
The easy separation of optically active compounds from enzymatic kinetic resolution products by simple precipitation using poly(ethylene glycol) (PEG)-supported dendritic carbonates is disclosed. The water-soluble polymer-supported Substrates were prepared by immobilization of (+/-)-1-phenylethanol onto a monomethoxy PEG (MPEG; av MW 5000) bearing a dendritic spacer through a carbonate linker. The enantioselective hydrolysis of the dendritic substrates of the 1st and 2nd generations using lipase from porcine pancreas (PPL: Type II, Sigma) smoothly proceeded, and a multimolecule of the corresponding (R)-alcohols was released from one molecule of the racemic substrates. The E Values of the reactions at 0 degrees C in a mixed solvent (hexane/buffer = 9/1) were up to > 200. (C) 2008 Elsevier Ltd. All rights reserved.
Synthesis of 4-hydroxyderricin and related derivatives
摘要:
Naturally occurring chalcones, namely 4-hydroxyderricin (1), xanthoangelol H (2), deoxyxanthoangelol H (3). and deoxydihydroxanthoangelol H (4), were first synthesized and evaluated for antibacterial activities. (C) 2008 Elsevier Ltd. All rights reserved.