微生物法还原氯代苯乙酮制备手性醇

手性醇是合成手性药物、农业化学品、香料和液晶等物质的重要中间体[1] 。 2 1世纪是手性药物发展迅速的时代 ,手性醇合成方法的成熟与改进对于手性药物的合成具有积极的促进作用。光学活性的苯乙醇及其衍生物可用于合成手性药物 ,如 :L 氯丙那林、R 沙丁胺醇[2 ] 、R 肾上腺素、S 心得安、S 舒喘宁、S 氟西汀和R 托莫西汀[3,4 ] 等。目前 ,生产手性醇的主要方法有化学法和生物法两种[5] 。利用微生物中酶的立体选择性能够合成一些化学方法难以合成的手性中间体[5] 。化学法中采用的反应体系一般为有机溶剂 ,而微生物法采用水相体系 ,微…     

过渡金属催化手性α-取代丙酸类药物的不对称氢化合成进展

手性α-取代丙酸及其衍生物是一类重要的有机合成彻块和关键中间体,现已被广泛地应用于手性药物的合成之中。如临床正在大量使用的非甾体类抗炎药布洛芬、萘普生、酮洛芬和氟比洛芬等。众所周知的抗疟药青蒿素,其合成关键中间体二氢青蒿酸同样属于此种结构。所以,手性α-取代丙酸及其衍生物的不对称合成一直是科学家研究的热点。不对称催化氢化反应因为其原子经济性和高效性,越来越引起人们的关注。本文主要综述了近年来过渡态金属催化氢化合成手性α-取代丙酸类药物的研究进展。     

酶法制备羟甲基戊二酰CoA还原酶抑制剂手性中间体的研究进展

羟甲基戊二酰CoA(HMG-CoA)还原酶抑制剂是降血脂药物。综述了近年来国内外酶法制备HMG-CoA还原酶抑制剂手性中间体的研究进展,从不对称合成和外消旋体拆分2个方面介绍了酶法制备HMG-CoA还原酶抑制剂手性中间体的工艺路线和研究水平,对其工业化前景进行了展望。     

ω-转氨酶不对称合成手性胺及非天然氨基酸的研究进展

ω-转氨酶不对称合成手性胺及非天然氨基酸是目前生物加工过程的研究热点之一。ω-转氨酶具有优良的立体选择性及区域选择性,利用其进行生物催化生产手性胺,已被应用于医药、农药和化工等领域。本文中,笔者综述了ω-转氨酶的基本结构特性,并以转氨酶法制备西他列汀关键中间体等为例,同时阐述了该酶的高通量筛选方法及分子改造方面的研究进展,并对级联反应提高手性胺产量的策略作了进一步讨论。最后,本文简要总结了ω-转氨酶在不对称合成非天然氨基酸中的具体应用。     

120 例不稳定型心绞痛的地尔硫卓治疗临床观察

目的:探讨地尔硫卓治疗不稳定型心绞痛的临床疗效,以供医生参考使用。方法:将我院2010年1月~2011年5月收治的120例不稳定型心绞痛的患者随机分为两组,对照组患者给予硝酸甘油,实验组患者给予地尔硫卓,比较两组患者的治疗效果。结果:实验组患者的总有效率为93.33%(56/60),对照组患者总有效率为78.33%(47/60),实验组明显优于对照组患者,P<0.05。结论:地尔硫卓治疗不稳定型心绞痛具有较好的疗效,值得在临床应用。     

摩氏摩根菌ZJB-09203酯酶的分离纯化及性质

立体选择性水解2-羧乙基-3-氰基-5-甲基己酸乙酯(CNDE)是化学-酶法合成重大疾病治疗药物普瑞巴林的关键步骤。分离纯化了能够高效水解S-型CNDE的摩氏摩根菌ZJB-09203胞内酯水解酶,并进行酶学性质研究。采用硫酸铵分级沉淀、Phenyl Sepharose 6 FF疏水柱层析、DEAE Sephadex A-50阴离子交换和羟基磷灰石Bio-Scale CHT层析,纯化得到电泳纯的酯水解酶。SDS-PAGE和凝胶过滤HPLC分析确定该酶为单亚基蛋白,分子量为68 kDa。不同碳链长度p-硝基苯酚酯特异性酶解结果表明,该酶为酯酶,酶促合成普瑞巴林手性中间体(S)-2-羧乙基-3-氰基-5-甲基己酸的最适pH为9.0,最适温度为45℃,且在pH 7.0-9.0和40℃条件下具有良好的稳定性。Ca2+、Cu2+、Mn2+对酶活有一定的促进作用,Co2+、Fe3+、Ni2+及EDTA对酶活有较强的抑制作用。此外,考察了该酯酶水解p-硝基苯酚酯的动力学参数,及CNDE浓度对转化率的影响。首次报道了能够立体选择性水解CNDE的酯酶,相关酶学性质研究将为该酶催化合成普瑞巴林手性中间体的工业化应用提供重要依据。     

基于噁唑烷酮的不对称催化合成构建多官能化手性氨基酸类化合物

多官能化手性氨基酸及其衍生物是一类重要的手性药物以及合成手性药的关键中间体,如现在大量用于临床的左甲状腺素、赖诺普利、阿莫西林、缬沙坦、头孢氨苄以及青霉素等。进行多官能化手性氨基酸类化合物的不对称催化合成,可为新型化学药的设计与发现开辟新的视野。噁唑烷酮(Azlactone)被证明是合成四取代氨基酸衍生物的优秀底物。可通过不对称催化手段向其中引入需要的基团,再经多取代的噁唑烷酮直接开环得到一系列的目标化合物。本文主要综述了近年来基于恶唑烷酮的不对称催化反应构建四取代氨基酸类化合物的研究。     

苏氨酸醛缩酶的结构与功能及其在药物合成中的应用

β-羟基-α-氨基酸(β-hydroxy-α-amnio acids,HAAs)是一类广泛应用于制药工业的重要手性中间体。由于其含有双手性中心(C_α和C_β),探索其严格立体选择性的生物合成方法备受关注。苏氨酸醛缩酶(threonine aldolase,TA)可在温和条件下催化不同类型的醛与氨基酸缩合构筑丰富的HAAs产物库,显示了工业应用潜力。由于目前表征的TA普遍存在对C_β立体选择性不严格、活性较低以及催化机制不清晰等问题,为其在HAAs合成中的应用带来了挑战。本文综述了TA在新酶挖掘、结构与催化机理解析、蛋白质工程以及合成应用等方面的研究进展,为推动酶催化绿色、高效合成手性药物提供参考。     

微生物酶转化合成手性药物的研究进展

通过微生物酶催化不对称合成反应或拆分外消旋体合成医药手性中间体具有独特的优势。结合作者自身近年来在该技术领域的实践对相关课题作了介绍,总结了微生物酶催化不对称反应和拆分反应得到手性药物的研究进展。     

羰基还原酶及其催化不对称合成大基团手性羟基类化合物的研究进展

手性羟基化合物以其独特的光、热和化学性质广泛应用于医药、农药、精细化工、功能材料等行业.立体专一性羰基还原酶能够直接针对关键手性位点催化不对称还原潜手性底物获得目的手性产物.基于羰基还原酶的底物多样性,具有不同化学结构和功能的醇类、酯类、氨基酸、环氧化合物等重要手性中间体能够通过不对称还原途径实现单一光学活性对映体的高效制备.然而,针对具有应用价值的含有大基团、结构复杂的潜手性羰基化合物,已知的羰基还原酶通常催化活性较低.本文综述了生物催化不对称氧化还原反应的特点和规律及其关键立体选择性羰基还原酶的性质和结构特征,并在此基础上,重点针对大基团手性羟基化合物的不对称合成,总结了羰基还原酶及其催化系统开发和应用的研究进展,并进一步提出解决该关键问题的主要发展策略.     

光学活性叔亮氨酸合成的研究进展

由于叔丁基的特殊结构和性质 ,叔亮氨酸是重要的医药中间体和不对称合成的手性诱导模板。本文综述了近年来光学活性的叔亮氨酸的合成研究及最新进展。     

Asymmetric Biosynthesis of Key Aromatic Intermediates in the Synthesis of an Endothelin Receptor Antagonist

The feasibility of five potential biocatalytic routes were investigated for the chiral synthesis of key intermediates of an experimental endothelin receptor antagonist. Two asymmetric bioreductions of a ketoester and a chlorinated ketone to their corresponding chiral alcohol yielded very encouraging leads. Pichia delftensis (strain MY 1569) and Rhodotorula piliminae (ATCC 32762) were found to respectively bioreduce the esterified ketone and chlorinated substrate to their corresponding (S) alcohol with enantiomeric excesses > 98% and > 99% respectively. When scaled up in laboratory bioreactors (23-liter scale), both processes produced the desired (S) alcohol intermediate with elevated yield, about 88% and 97% for the ketoester and chloroketone respectively. Investigative chemical syntheses employing the (S) ester alcohol showed that unfavorable racemization occurred during the subsequent synthetic steps. However, the use of the (S) chloroalcohol as chiral synthon for the production of the endothelium receptor antagonist was successfully demonstrated at a preparative scale.     

Highly diastereoselective synthesis of enantiopure naphthylaminoalcohols with analgesic properties

The diastereoselective synthesis via Grignard reaction of enantiopure analgesic naphthylaminoalcohols has been performed. The chiral racemic key intermediate 3-dimethylamino-2-methyl-1-(naphthalen-2-yl)propan-1-one and enantiomers were prepared and transformed into the desired compounds by addition of the organometallic reagent. The chemical characterization of all diastereoisomers was accomplished by 1H NMR and HPLC analyses and the absolute configuration assigned by CD spectroscopy. The in vitro and in vivo profile has also been evaluated.     

手性技术与生物催化

简要介绍了手性,手性技术与生物催化的基本概念。手性,是指一个有机分子具有不对称性,形成两种空间排布方式不同的对映异构体。手性技术即生产手性化合物的技术,手性化合物的制备方法主要有手性源、外消旋体拆分、不对称合成等几种。生物催化,即利用酶或微生物等生物材料催化进行某种化学反应,被认为是手性化合物生产取得突破的关健技术。文章还介绍了生物催化外消旋体拆分、生物催化不对称合成等几种生产手性化合物的应用实例。     

Determination of the epimeric composition of ibuprofenyl-CoA

Ibuprofen [racemic2-(4-isobutylphenyl)propionic acid] is a 2-arylpropionic acid nonsteroidal anti-inflammatory drug which undergoes unidirectional, R to S chiral inversion in vivo. It has been proposed that this chiral inversion phenomenon occurs via a coenzyme A (CoA) thioester intermediate. To characterize the formation and metabolism of this metabolic intermediate, ibuprofenyl-CoA, reference standards were needed and thus the CoA derivatives of (R)-, (S)-, and racemic ibuprofen were chemically synthesized. An HPLC assay employing a C18 reverse-phase column was developed to quantitate "total" ibuprofenyl CoA. Samples collected from this assay were then analyzed for ibuprofenyl-CoA epimeric composition by chiral chromatography employing a Chiral-AGP alpha 1-acid glycoprotein column. The applicability of these methods was demonstrated by assessing (R)- and (S)-ibuprofenyl-CoA hydrolysis and epimerization following incubation with rat liver homogenates. Rat liver homogenate catalyzed the complete and rapid epimerization of ibuprofenyl-CoA and the rate constants for (R)- and (S)-ibuprofenyl-CoA hydrolysis were equal. ATP and CoA were found to inhibit rat liver-catalyzed ibuprofenyl-CoA hydrolysis by 70-80% with no effect on epimerization. Additionally, it was demonstrated that traditional indirect ibuprofenyl-CoA assays which employ basic hydrolysis result in erroneous epimeric ratio determinations due to chemical epimerization.     

Screening of microorganisms producing esterase for the production of (R)-β-Acetylmercaptoisobutyric acid from methyl (R,S)-β-acetylmercaptoisobutyrate

(R)-β-acetylmercaptoisobutyric acid (RAM), a chiral compound, is an important intermediate for the chemical synthesis of various antihypertensive and congestive heart failure drugs. Microorganisms capable of converting (R,S)-β-acetylmercaptoisobutyric acid ((R,S)-ester) to RAM were screened from soil microorganisms. A strain ofPseudomonas sp. 1001 screened from a soil sample was selected to be the best. Cells showed an activity of 540 U/mL from culture broth and the enzyme was thermostable up to 70°C. This strain could produce RAM asymmetrically from (R,S)-ester.     

Synthesis of enantiopure non-natural alpha-amino acids using tert-butyl (2S)-2-[bis-(tert-butoxycarbonyl)amino]-5-oxopentanoate as key-intermediate:the first synthesis of(S)-2-amino-oleic acid.

A general method for the synthesis of enantiopure non-natural alpha-amino acids is described. The key intermediate tert-butyl (2S)-2-[bis(tert-butoxycarbonyl)amino]-5-oxopentanoate was obtained from l-glutamic acid after suitable protection and selective reduction of the gamma-methyl ester group by DIBALH. Wittig reaction of this chiral aldehyde with various ylides led to a variety of delta,epsilon-unsaturated alpha-amino acids. This methodology was applied to the synthesis of (S)-2-amino-oleic acid.     

Synthesis of the [8] gingerol enantiomers

(+)-(S)-5-Hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-dodecanone 1a commonly named (+)-(S)-[8] gingerol is a natural product known to have cardiotonic activity.^1–5 A total synthesis of both enantiomers is described with details for the first time using a general synthetic scheme which was recently outlined in the literature.⁶ This synthesis relies both on the separation of the diastereoisomers 4a and 4b by simple column chromatography on silica gel and on an HPLC analysis on a chiral phase to determine the optical purity of the enantiomers 8a and 8b of protected [8] gingerol. The gingerol isomers were thus obtained in good chemical yields in greater than 96% enantiomeric excess.     

Synthesis and absolute configuration assignment of 5-amino-1,3,5-triphenyl-pentane-1,3-diol stereoisomers

Starting from 2,4,6-triphenylpyrylium perchlorate, 5-amino-1,3,5-triphenyl-pentane-1,3-diol stereoisomers 4 were obtained in a simple two-step synthesis: reaction with hydroxylamine, and reduction with LAH of the resulting 2-isoxazoline ketone derivative 2. The eight stereoisomers of 4 were separated in a single shot on a chiral stationary phase cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD-H). The absolute configuration of the title compounds, intermediate 2-isoxazoline ketone 2 and isoxazoline alcohol derivative 3 were determined using a combination of diastereoselective synthesis, affiliation of the sign in chemical interconversion method, and X-ray determination. 2-Isoxazoline ketone 2 enantiomers and isoxazoline alcohol 3 enantiomers were obtained by chiral HPLC on Chiralpak AD column. 2-Isoxazoline ketone 2 enantiomers can be racemized via a retro Michael addition.     

Synthesis of Optically Active N-(2-Pyridyloxiran-2-ylmethyl) benzenesulfonamide Derivatives and Their Herbicidal Activity

Novel herbicidally active sulfonamide compounds having a 2-arylsubstituted oxiranylmethyl structure are racemates due to a chiral carbon in the oxirane moiety. To clarify the stereochemical structure-activity relationship, we synthesized each enantiomer of 4-chloro-N-[2-(6-chloropyridin-2-yl)-2-oxiran-2-ylmethyl]-3,N-dimethylbenzenesulfonamide and N-[2-(6-chloropyridin-2-yl)-2-oxiran-2-ylmethyl]-N-methyl-5,6,7,8-tetrahydronaphthalene-2-sulfonamide by chemical methods including Sharpless asymmetric chlorohydroxylation. The results of herbicidal tests indicated that the (S)-isomers were the active forms.