Functional Molecular Assemblies Coupled to Steric Control with High Enantioselectivity

与空间控制耦合的具有高对映选择性的功能分子组装体

基本信息

批准号：
07650968
负责人：
UEOKA Ryuichi
金额：
$ 1.34万
依托单位：
Kumamoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Enantioselective hydrolysis of amino acid esters by L-histidine derivatives in the molecular assemblies composed of single-and double-chain surfactants was investigated. The noteworthy aspects are as follows :1) The remarkably high enantioselectivity (kappa^L_<a, obsd>/kappa^D_<a, obsd>=1000) was sttained for the hydrolysis of longchained substrate (N-dodecanoyl-D (L) -phenylalanine p-nitrophenylester ; C_<12>-D (L) -Phe-PNP) catalyzed by the active tripeptide (N-(benzyloxycarbonyl) -L-phenylalanyl-L-histidyl-L-leucine ; Z-PheHisLeu) in the coaggregate systems composed of 41mol% single-chained hexadecyltrimethylammonium bromide (CTAB) and 59mol% double-chained ditetradecyldimethylammonium bromide (2C_<14>Br) at the specific ionic strength (mu=0.02).Furthermore, the computer modeling (MOPAC calculation) study suggests that a favorable molecular recognition between the substrate and the catalyst through the effective hydrophobic interactions and hydrogen bonds should be very important for the enhancement of enantioselectivity.2) With respect to the hydrolysis of C_<12>-D (L) -Phe-PNP by the tripeptide catalyst Z-PheHisLeu in the coaggregate systems composed of native lipid and nonionic micellar surfactant, a remarkably high enantioselectivity (kappa^L_<a, obsd>/kappa^D_<a, obsd>=28) along with marked rate-enhancement of the hydrolytic cleavage of C_<12>-D (L) -Phe-PNP was obtained with specific coaggregates of 32mol% L-alpha-dipalmitoylphosphatidyl-choline (DPPC) and 68mol% alpha-[4-(1,1,3,3-tetramethylbutyl) phenyl]-omega-hydroxypoly (exy-1,2-ethanediyl) (Triton X-100). The enantioselectivity was maximized at the phase transition temperature (Te) in the 65mol% DPPC/35mol% Triton X-100 and 32mol% DPPC/68mol% Triton X-100 coaggregate systems. The hydrophobicity and fluidity of the coaggregates can apparently be changed around Te on the basis of isokinetic temperature and fluorescence parameter studies.

研究了由单链和双链表面活性剂组成的分子组件中L-齐丁定衍生物对氨基酸酯的对映选择性水解。 The noteworthy aspects are as follows :1) The remarkably high enantioselectivity (kappa^L_<a, obsd>/kappa^D_<a, obsd>=1000) was sttained for the hydrolysis of longchained substrate (N-dodecanoyl-D (L) -phenylalanine p-nitrophenylester ; C_<12>-D (L) -Phe-PNP)在41mol％单链的己二乙酰基三甲基三甲基铵（CTAB）组成的凝聚酸盐系统中，由活性三肽（N-（N-（N-（苯并氧基）-L-苯基丙苯甲基-L-甲酰基L-甲基）催化在特定离子强度（MU = 0.02）处的溴化物（2C_ <14> br）。Furthermore，计算机建模（MOPAC计算）研究表明，通过有效的疏水相互作用和水力键在12 e-2）<2）<2） - <2） - <2） - 由三肽催化剂Z-Phehisleu在凝聚酸盐系统中由天然脂质和非离子胶束表面活性剂组成的系统，一种非常高的对映选择性（kappa^l_ <a，obsd>/obsd>/kappa>/kappa^d_ <a，obsd> d_ <a，obsd> = 28），以及均值<shydsity（crand）<crabledtice <crydertic <crydertic clydertic clydertix clode and tory（c） -Phe-PNP was obtained with specific coaggregates of 32mol% L-alpha-dipalmitoylphosphatidyl-choline (DPPC) and 68mol% alpha-[4-(1,1,3,3-tetramethylbutyl) phenyl]-omega-hydroxypoly (exy-1,2-ethanediyl) (Triton X-100).在65mol％DPPC/35mol％TRITON X-100和32mol％DPPC/68mol％Triton X-100 coggregregate系统中，在相变温度（TE）上最大化对映选择性。根据同动的温度和荧光参数研究，显然可以在TE周围改变凝聚力的疏水性和流动性。