由肉桂酸生物合成L-苯丙氨酸

本文评述了L一苯丙氨酸的各种合成路线、国内外的研究现状及工业化情况，重点讨论了由肉桂酸和氨生物合成L一苯丙氨酸约路线，提出了在国内进一步工作的建议。     

酶法拆分D,L-苯丙氨酸制备D-苯丙氨酸

在固定化青霉素酰化酶(IPA-750)存在下,通过N-苯乙酰-D,L-苯丙氨酸(2)的选择性水解完成了酶法拆分D,L-苯丙氨酸(1)制备D-苯丙氨酸(5)的过程。选择性水解的较适宜反应条件为:22.83g,m(2)∶m(IPA-750)=6∶1,pH7.0,于30℃反应5h,产物为N-苯乙酰-D-苯丙氨酸(4)和L-苯丙氨酸(3,收率63%,光学纯度99%)。4用6mol·L-1盐酸于120℃水解反应8h,经脱盐处理得5,收率67%,光学纯度91%。3在含醋酸酐的醋酸溶液中进行消旋化处理,得到100%消旋的1可继续进行下一轮酶法拆分。     

聚吡咯固定L-氨基酸氧化酶手性电极的制作及其应用

本方法将L·氨基酸氧化酶掺杂在毗咯溶液中用电化学聚合法制备手性电极，该电极对L一苯丙氨酸测定在2．0X10－’－1．4X10－‘。ilL的底物浓度范围内呈良好的线性关系，检测限为4．0X10－‘rnoliL对DL．苯丙氨酸的平均回收率102．8％。     

L-苯丙氨酸键合手性配体交换色谱固定相的制备及手性拆分

合成了L-苯丙氨酸键合手性配体交换固定相，用元素分析和红外光谱对固定相进行了表征；该固定相在反相条件下对DL-氨基酸对映体有良好的拆分能力。     

强酸型树脂催化L—苯丙氨酸甲酯化研究

１前言对酯化反应所用催化剂,一般使用强酸,如浓硫酸、浓盐酸等。另外,许多Ｌｅｗｉｓ酸,如三氟化硼、三氯化铝、氯化锌和硅胶等也能促进羰酸提供质子［１］。近年来的研究发现,强酸型阳离子交换树脂亦可用于催化某些酯化过程［２］。Ｌ－苯丙氨酸的甲酯化反应,传统...     

α—胰凝乳蛋白酶的固定化及其对DL—苯丙氨酸的光学拆分

以氨丙基多孔球为载体，戊二醛为交联剂制得固定化α－胰凝乳蛋白酶。其含酶量为３．６ｍｇ／ｇ，米氏常数Ｋｍ＝１．２×１０＾－３ｍｏｌ／Ｌ，最适宜温度为３５℃，ｐＨ值为７．０，对热、酸碱、甲醇以及尿素的稳定性有较大提高，Ｃａ＾２＋激活效应明显。用该固定化酶连续拆分ＤＬ－苯丙氨酸制备Ｌ－苯丙氨酸时，拆分产率高于９０％，产品纯度超过９６％；连续使用２个月后仍能保持较高酶活力。     

离子交换法提取L-苯丙氨酸的研究

本文介绍一种用离子交换树脂提取L-苯丙氨酸的方法,针对本研究体系得出的最佳工艺条件为：用001×7阳离子交换树脂吸附L-苯丙氨酸,以浓度为0．5％氨水进行洗脱,收集的流份经D354阴离子交换树脂脱色,浓缩结晶后得L苯丙氨酸成品,总提取收率为80％。     

L-苯丙氨酸脲类化合物的合成工艺改进

以L-苯丙氨酸为原料,经甲酯化反应制得中间体丙谷胺酸甲酯盐酸盐(1);以三乙胺为缚酸剂,1经固体光气活化制得苯丙氨酸异氰酸酯后,再分别与伯胺反应合成了4个苯丙氨酸脲类化合物(3a~3d),收率90.7%~94.2%,其结构经1H NMR,MS和X-衍射确证。     

胆酸和L-苯丙氨酸的固相包合作用

研究了胆酸(CA)和L-苯丙氨酸(PAA)以固相熔融法形成的固相包埋配位. 通过粉末X射线衍射图、红外光谱、粉末荧光光谱及差热分析方法, 测定了固相包埋形成的CA-PAA配合物. 同时, 用溶剂共沉淀法和机械研磨法对比了CA-PAA包埋物的形成. 结果表明, 封管固相熔融时PPA以客体形式被包合进主体CA形成的通道; 研磨法中CA部分包埋PPA; 溶剂共沉淀方法中, PPA不被主体CA包埋, 而使用的相应溶剂被CA包埋.     

以苯丙氨酸为例刍议芳香族氨基酸的生物合成机理

从磷酸烯醇式丙酮酸和4-磷酸赤藓糖为始探讨了3种芳香族氨基酸合成代谢共享的分支酸合成途径,并以苯丙氨酸为例从多学科角度讨论分析其合成代谢的独特性.通过多学科角度展示了生物体内不同代谢路径之间的关联及相似性,旨在展示一种教学新模式,帮助学生建立起跨学科内容的学习及归纳方法.     

稀土苯丙氨酸邻菲咯啉三元配合物的合成、表征及抗菌活性研究

以稀土氯化物、L-苯丙氨酸和邻菲咯啉为原料,在乙醇水溶液中反应,制备了一类新型稀土三元配合物。通过元素分析、摩尔电导、红外光谱、拉曼光谱、紫外光谱和热重-差热分析,确定了该配合物的化学组成:RE(Phe)3PhenCl3.3H2O(RE=La3+,Ce3+,Pr3+,Nd3+,Sm3+,Eu3+,Er3+,Y3+;Phe=L-苯丙氨酸;phen=邻菲咯啉)。通过抗菌实验对其抑菌效果进行研究。结果表明,稀土三元配合物对大肠杆菌、金黄色葡萄球菌和白色念珠菌有较强的抑制作用(最小抑菌浓度MIC分别约为65×10-4%,150×10-4%,400×10-4%),属于广谱抗菌剂;抗菌效果明显优于稀土氯化物、L-苯丙氨酸或邻菲咯啉。     

胶态磁组装分子印迹光子晶体及其对L-苯丙氨酸的响应性

将胶态磁组装光子晶体与分子印迹技术结合, 通过磁场诱导快速、 可逆地组装得到一种灵敏度高、 选择性强且响应速度快的胶态磁组装分子印迹光子晶体(CMA-MIPCs), 并将其用于L-苯丙氨酸(L-Phe)分子的响应性研究. 结果表明, 细乳液聚合法制得的L-Phe磁性分子印迹纳米粒子(MMIPs)具有规则的球形形貌和明显的核-壳结构, 平均粒径为104.3 nm. CMA-MIPCs对L-Phe分子的识别可直接通过光学信号进行表达, 当L-Phe的浓度从6.0×10^-7 mol/L增加至6.0×10^-4 mol/L时, CMA-MIPCs的衍射色发生从紫色到深黄色的明显变化, 最大衍射峰位置红移181 nm, 响应过程仅需1 min. CMA-MIPCs对L-Phe的结构类似物L-酪氨酸(L-Tyr)和L-色氨酸(L-Trp)均无响应性, 表明CMA-MIPCs具有良好的选择性.     

顺-、反-肉桂酸和肉桂酸乙酯的低温燐光特点

研究了肉桂酸、肉桂酸乙酯经UV光照后的低温燐光性质,在1mol／L HClk中UV光照使其反式异构化为顺式,烧光分别增强5与10倍。加碱碱化后燐光进一步增强2与5倍。讨论了两药燐光产生的机制,建立了低温燐光分析法,检出限分别为75与110μg/L。     

Preparation and Chiral Recognition of Thermosensitive Poly(N-isopropylacrylamide) Microgels Containing Modified L-Phenylalanine Groups

Thermosensitive poly[N-isopropylacrylamide(NIPAM)-co-N-acryloyl-L-phenylalanine ethyl ester (NALPE)] microgels were prepared by the free radical polymerization of NIPAM and chiral monomer, NALPE. Such microgels exhibited spherical shape and favorable monodispersity. Increasing the content of NALPE units would enhance the average diameter, but decrease the thermosensitivity and volume-phase transition temperatures of the microgels. Compared with PNIPAM microgels, the microgels containing NALPE units performed chiral recognozable capacities for D-phenylalanine and D-tartaric acid, and the enantioselectivity and adsorption capacity of the microgels improved with increasing the temperature and/or the content of NALPE units.     

Cross-Linked Enzyme Aggregates of Phenylalanine Ammonia Lyase: Novel Biocatalysts for Synthesis of L-Phenylalanine

Cross-linked enzyme aggregates of phenylalanine ammonia lyase (PAL-CLEAs) from Rhodotorula glutinis were prepared. The effects of the type of aggregating agent, its concentration, and that of cross-linking agent were studied. PAL-CLEAs production was most effective using ammonium sulfate (40?% saturation), followed by cross-linking for 1?h with 0.2?% (v/v) glutaraldehyde. Moreover, the storage and operational stability of the resulting PAL-CLEAs were also investigated. Compared to the free enzyme, the PAL-CLEAs exhibited the expected increased stability of the enzyme against various deactivating conditions such as pH, temperature, denaturants, and organic solvents and showed higher storage stability than its soluble counterpart. Additionally, the reusability of PAL-CLEAs with respect to the biotransformation of l-phenylalanine was evaluated. PAL-CLEAs could be recycled at least for 12 consecutive batch reactions without dramatic activity loss, which should dramatically increase the commercial potential of PAL for synthesis of l-phenylalanine. To the best of our knowledge, this is the first report of immobilization of PAL as cross-linked enzyme aggregates.     

EFFECTS OF L-PHENYLALANINE ON THE RADIATION SYNTHESIS OF POLY （N,N＇-METHYLENEBIS A CR YLAMIDE-co-4-VINYLPYRID INE） （MICRO）GELS

The effects of L-phenylalanine （L-Phe） on the synthesis ofpoly（N,N＇-methylenebisacrylamide-co-4-vinylpyridine） （poly（Bis-co-4-VP）） （micro）gels by γ-ray irradiation were studied. The addition of L-Phe could not only decrease the gelation dose （Dg） of the synthesis obviously, but also transform the morphology of copolymer from microgel to gel. In addition, the swelling ability of the （micro）gels was also affected in the presence of L-Phe. The decrease of Dg was ascribed to the effect of pH, while the transformation of the morphology was ascribed to the effect of L-Phe on the stability of the poly（Bis-co-4-VP） microgel. Such an effect was confirmed further as compared with the effects of L-alanine, L-glutamic acid, L-arginine, sulfuric acid and aqueous ammonia.     

对氨基苯甲酸的合成研究进展

综述了以对硝基苯甲酸为原料合成对氨基苯甲酸的近期研究进展。并从技术和经济角度讨论了各种合成方法的优点与不足。     

Synthesis and Anti-Inflammatory Activity of 1-Methylhydantoin Cinnamoyl Imides

In this study, 1-methylhydantoin cinnamic imides were synthesized from 1-methylhydantoin and trans-cinnamic acid, and their anti-inflammatory activity was investigated. The anti-inflammatory activity in vitro was evaluated by measuring the contents of NO, TNF-α and IL-1β in the supernatant of RAW264.7 cells stimulated by LPS. The cytotoxicity of 1-methylhydantoin cinnamoyl imides on RAW264.7 cells was detected using the CCK-8 method. The results showed that compounds 2 and 4 can significantly inhibit the release of NO and reduce the secretion of TNF-α and IL-1β. Compound 3 inhibited the production of TNF-α. The inhibition rate of COX was evaluated in vitro. The in vivo anti-inflammatory activities of the five compounds were evaluated by establishing an animal model of xylene ear swelling. The results showed that 1-methylhydantoin cinnamic imides could alleviate xylene-induced ear edema in mice in a dose-dependent manner. Among them, the effect of compound 5 was the most significant. Under the action of high dosage, its ear swelling inhibition rate was as high as 52.08%.