Flavin–cyclodextrin conjugates: effect of the structure on the catalytic activity in enantioselective sulfoxidations
摘要:
A series of flavin cyclodextrin conjugates has been prepared and tested in the enantioselective oxidations of prochiral aromatic and aliphatic sulfides with hydrogen peroxide. The newly prepared conjugates contain isoalloxazinium or alloxazinium moieties attached to the primary rim of alpha- and beta-cyclodextrins at the C-6 positions. In addition, flavinium units were attached to the secondary rim of the beta-cyclodextrin macrocycle. The relationship between the structural features and the catalytic performance of the conjugates, including those recently reported by us, was analyzed. The rate and enantioselectivity of the sulfoxidations catalyzed by flavin cyclodextrin conjugates are influenced mainly by the size of the cyclodextrin cavity, the type of flavin unit (alloxazine or isoalloxazine), and by the relative orientation of the flavin and cyclodextrin moieties. (C) 2012 Elsevier Ltd. All rights reserved.
Flavin–cyclodextrin conjugates: effect of the structure on the catalytic activity in enantioselective sulfoxidations
摘要:
A series of flavin cyclodextrin conjugates has been prepared and tested in the enantioselective oxidations of prochiral aromatic and aliphatic sulfides with hydrogen peroxide. The newly prepared conjugates contain isoalloxazinium or alloxazinium moieties attached to the primary rim of alpha- and beta-cyclodextrins at the C-6 positions. In addition, flavinium units were attached to the secondary rim of the beta-cyclodextrin macrocycle. The relationship between the structural features and the catalytic performance of the conjugates, including those recently reported by us, was analyzed. The rate and enantioselectivity of the sulfoxidations catalyzed by flavin cyclodextrin conjugates are influenced mainly by the size of the cyclodextrin cavity, the type of flavin unit (alloxazine or isoalloxazine), and by the relative orientation of the flavin and cyclodextrin moieties. (C) 2012 Elsevier Ltd. All rights reserved.
A Facile One-pot Synthesis of Pyrido[2,3-d]pyrimidines and Pyrido[2,3-d:6,5-d′]dipyrimidines
作者:Shaker Youssif、Said El-Bahaie、Esam Nabih
DOI:10.1039/a806513f
日期:——
The reactions of enaminones (6-aminouracils) 1a–c and 4 with cyano olefins 2a–b and 5a–f led to the formation of pyrido[2,3-d]pyrimidines 3a–f and 6a–f in good yield, while the treatment of 4-amino-2-thiouracil 4 with aromatic aldehydes afforded pyridodipyrimidines 7a–c.
Compounds inhibiting the aggregation of superoxide dismutase-1
申请人:Lansbury Peter
公开号:US20060194821A1
公开(公告)日:2006-08-31
The invention is directed to methods of inhibiting the rate at which superoxide dismutse-1 (SOD) aggregates using compounds that stabilize SOD dimers. The methods are useful in the study and therapy of amyotrophic lateral sclerosis. The invention also includes assays that can be used to identify compounds that stabilize dimers and SOD molecules that have been modified for use in these assays.