Compounds with chelation affinity and selectivity for first transition elements and their use in cosmetics and personal care products, inhibition of metalloenzymes, and inhibition of reperfusion injury
Complexes of cyclic polyaza chelators with cations of alkaline earth metals for enhanced biological activity
申请人:Winchell S. Harry
公开号:US20050112066A1
公开(公告)日:2005-05-26
Cyclic polyaza chelators that possess high affinity and specificity for first transition series metal cations exhibit an unanticipated improvement in biological activity when administered as complexes with cations of the alkaline earth metals, Ca(II) and Mg(II), most notably Ca(II). By virtue of this improvement, these complexes are particularly effective in the treatment of pathological conditions, including ischemia and ischemia-reperfusion injury.
A venerable scaffold for asymmetric synthesis and drug development, chiral 5-substituted oxazolidinones are obtained in almost enantiomerically pure form (up to 99.9% ee) starting fromracemicterminalepoxides. The salient features of this process include the very simple and convenient experimental protocol and the employment of a readily accessible catalyst and inexpensive, easily handled starting
A new dinuclear chiral salen complexes for asymmetric ring opening and closing reactions: Synthesis of valuable chiral intermediates
作者:Santosh Singh Thakur、Shu-Wei Chen、Wenji Li、Chang-Kyo Shin、Seong-Jin Kim、Yoon-Mo Koo、Geon-Joong Kim
DOI:10.1016/j.jorganchem.2005.12.044
日期:2006.4
A new dinuclear chiral Co(salen) complexes bearing group 13 metals have been synthesized and characterized. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity for the asymmetric ring opening of epoxides with H2O, chloride ions and carboxylic acids and consequently provide enantiomerically enriched terminalepoxides (>99% ee). It also catalyzes the asymmetric
Dinuclear salen cobalt complex incorporating Y(OTf)<sub>3</sub>: enhanced enantioselectivity in the hydrolytic kinetic resolution of epoxides
作者:Deepak Patel、Ganesh Ram Kurrey、Sandip S. Shinde、Pradeep Kumar、Geon-Joong Kim、Santosh Singh Thakur
DOI:10.1039/c5ra12408e
日期:——
activation of inactive Jacobsen’s chiralsalenCo(II) (salen = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine) compound is attained by dinuclear chiralsalenCo(III)–OTf complex formation with yttrium triflate. The yttrium metal not only displays a promoting effect on electron transfer, but also assists in forming two stereocentres of a Lewis acid complex with Co(III)–OTf. We found that the binuclear
Structure-Guided Regulation in the Enantioselectivity of an Epoxide Hydrolase to Produce Enantiomeric Monosubstituted Epoxides and Vicinal Diols via Kinetic Resolution
Structure-guided microtuning of an Aspergillus usamii epoxide hydrolase was executed. One mutant, A214C/A250I, displayed a 12.6-fold enhanced enantiomeric ratio (E = 202) toward rac-styrene oxide, achieving its nearly perfect kinetic resolution at 0.8 M in pure water or 1.6 M in n-hexanol/water. Several other beneficial mutants also displayed significantly improved E values, offering promising biocatalysts
对Aspergillus usamii环氧水解酶进行了结构引导的微调。一种突变体 A214C/A250I对消旋-氧化苯乙烯的对映体比 ( E = 202)提高了 12.6 倍,在纯水中 0.8 M 或正己醇/水中 1.6 M 时实现了近乎完美的动力学分辨率。其他一些有益的突变体也显示出显着提高的E值,为获得 19 种结构多样的手性单取代环氧化物(97.1 – ≥ 99% ee s)和邻二醇(56.2–98.0% ee p)提供了有希望的生物催化剂,并且产率很高。