被子植物木脂素研究进展

本文报道了木脂素研究的新进展，着重介绍了木脂素在被子植物中的分布及其在药学和化学分类学上的应用     

抗癌活性物质鬼臼类木脂素的研究进展

本文概述了抗癌活性物质鬼臼类木脂素的生物合成、抗癌机理、生药分布以及利用植物细胞培养技术生产鬼臼类木脂素的研究进展;并介绍了目前应用于该研究领域的一些新的技术方法。     

银胶菊中木脂素类成分的研究CSCD

研究银胶菊Parthenium hysterophorus Linn.中木脂素类化学成分。采用硅胶、Sephadex LH-20、MCI、ODS和半制备型HPLC等色谱技术,从银胶菊地上部分的95%乙醇提取物中分离得到5个木脂素类化合物(1~5),通过波谱学数据分析,将它们的结构分别鉴定为(7S,8S,7′E)-4,9,9′-三羟基-3,5,7,3′,5′-五甲氧基-8,4′-氧新木脂素-7′-烯(1)、丁香脂素(2)、杜仲树脂酚(3)、松脂素(4)、五味子醇甲(5)。其中,化合物1为新化合物,化合物3~5为首次从银胶菊中分离得到。对所有化合物进行了体外抗神经炎症活性筛选,结果显示,化合物1对LPS激活的BV-2小胶质细胞释放NO具有显著抑制作用,IC_(50)为21.10±1.97μmol/L,其余化合物均无活性,且所有化合物在测试浓度下均不影响细胞的存活率。     

抗HIV活性木脂素类化合物研究进展

木脂素类化合物具有多种药理活性,其抗HIV机制是通过影响HIV复制周期的某个环节,从而抑制病毒的复制和感染。按其抗HIV检测方法不同,将木脂素类化合物分成4类,本文对1990～2011年有关抗HIV活性木脂素类化合物研究文献进行综述。     

红蓼中木脂素成分的研究

从红蓼（ＰｏｌｙｇｏｎｕｍｏｒｉｅｎｔａｌｅＬ．）中分得３个木脂素类化合物,经光谱分析和化学方法鉴定为牛蒡子甙（１）、拉帕酚Ｂ（２）和红蓼脂素（３）。其中化合物３为新化合物,１和２为首次从该植物中分离得到。     

苯骈呋喃类和双环[3,2,1]辛烷类新木脂素的合成进展

本文对苯骈呋喃类和双环「３,２,１」辛烷类新木脂素的合成进行了综述。     

鸡脚参中一个新木脂素

从鸡脚参[Orthosiphon wulfenioides (Diels)Hand.-Marzz.]根中提取分离了一个新的木脂素,命名为鸡脚参木脂素。其结构由NMR、MS等波谱分析确定。初步活性实验显示该化合物不具备抗真菌和抗肿瘤活性。     

黑老虎木脂素化学成分及药理作用研究进展CSCD

黑老虎是一种具有药用、食用、观赏等多种价值的经济植物。黑老虎的化学成分及药理作用研究进展较快,目前已分离出200余种化合物,其中木脂素类化合物121种,具有抗炎、抗肿瘤、抗HIV、抗凝血、抗氧化、保肝等多种药理作用。现对黑老虎中木脂素类化学成分和药理作用进行综述,为黑老虎的深入开发利用提供参考。     

匙叶八角中一个新的倍半木脂素

从匙叶八角(Illicium spathulatum)果实中分离得到一个新的倍半新木脂素,通过现代波谱技术确定其结构为7′, 8′-反式-7″, 8″ 顺式-5, 3′,3″-三甲氧基倍半新木脂素。     

Chemoenzymatic synthesis of enantiopure 1,4-dihydropyridine derivatives

1,4-Dihydropyridines possess a broad range of biological activities, such as the ability to control the influx of calcium into cells, as well as neuroprotective, antineurodegenerative, cognition and memory enhancing, anti-inflammatory, antiviral and many other properties. Chirality plays an important role in the biological activity of 1,4-dihydropyridines. The chemoenzymatic synthesis of 1,4-dihydropyridine derivatives in enantiopure form as the key intermediates for the synthesis of enantiopure drugs and chiral analogues of symmetrical drugs has become an advantageous alternative to the other synthetic methods. Hydrolytic enzymes, as efficient chemo-, regio- and stereoselective biocatalysts have been successfully applied for the asymmetrisation or kinetic resolution of various 1,4-dihydropyridine derivatives. Several synthetic strategies to overcome the inactivity of hydrolytic enzymes towards 1,4-dihydropyridine carboxylic acids have been developed during the last decade, often based on the introduction of a spacer between an enzymatically labile group and the 1,4-DHP nucleus. Good to excellent enantioselectivities can be obtained by careful optimisation of the reaction temperature and the organic (co)solvent used in the enzymatic transformations.     

生物酶法制备D-对羟基苯甘氨酸的研究

生物酶法生产D-对羟基苯甘氨酸具有良好的应用前景。通过介绍生物酶法生产D-对羟基苯甘氨酸的研究现状,从酶的分离纯化、酶和细胞的固定化、反应介质研究和反应动力学研究以及基因工程进展几个方面作了总结。     

烟酰胺腺嘌呤二核苷酸合成相关酶有助于1,4-丁二醇转化为4-羟基丁酸

4-羟基丁酸(4-HB)不仅具有医学应用价值,而且是合成生物材料P3HB4HB的重要前体.在烟酰胺腺嘌呤二核苷酸(NAD)参与情况下,大肠杆菌Escherichia coli S17-1(pZL-dhaT-aldD)可以把1,4-丁二醇(1,4-BD)转化为4HB.为提高4HB产率,通过过表达烟酸磷酸核糖转移酶(PncB)和烟酰胺腺嘌呤二核苷酸合成酶(NadE)增加胞内NAD含量,从而加速1,4-BD转化反应的进行.结果表明,PncB-NadE的表达使1,4-BD转化率比对照组增加13.03％,由10g/L的1,4-BD得到4.87 g/L的4HB,单位细胞的4HB产量由1.32 g/g提高40.91％至1.86 g/g.因此PncB和NadE可用于促进1,4-BD转化为4HB.     

植物源二萜类化合物微生物合成研究进展

植物源二萜类天然产物结构复杂且功能多样,具有抗癌、抗炎和抗菌等多种药理活性,在药品、化妆品和食品添加剂等方面广泛应用。近年来,基于植物源二萜类化合物(diterpenoids)生物合成途径中功能基因的逐步揭示和合成生物技术的发展,科研人员采用代谢工程技术构建了多种二萜类化合物的微生物细胞工厂,且多个化合物达到克级产量。本文对植物源二萜类化合物微生物细胞工厂的构建情况进行综述,介绍并探讨植物源二萜类化合物微生物合成的研究进展和改造策略,为高产二萜类化合物细胞工厂构建和工业化生产提供参考。     

Polylactosamine synthesis and branch formation of N-glycans in beta1,4-galactosyltransferase-1-deficient mice

Analysis of glycans from erythrocyte membrane glycoproteins from beta1,4-galactosyltransferase-1 (beta4GalT-1)-deficient mice revealed moderately decreased galactosylation but comparable polylactosamine content compared to control beta4GalT-1(+/-) mice. The increased expression of more branched N-glycans was observed in beta4GalT-1(-/-) mice, and its extent was more remarkable in elder beta4GalT-1(-/-) mice (28 weeks old) than in younger beta4GalT-1(-/-) mice (6-9 weeks old). In relation to this issue, the less galactosylation of biantennary glycans was observed in the elder group, suggesting that beta4GalTs actually compete with N-acetylglucosaminyltransferases IV and V in erythroid cells. In contrast, approximately 80% of core 2 O-glycans were not beta1,4-galactosylated regardless of age of the knockout mice. These results suggest that beta4GalT-1 expressed in erythroid cells may regulate a constant branch formation of N-glycans and plays a predominant role in beta1,4-galactosylation of core 2 O-glycan.     

Synthesis and antitumor activity of a new class of pyrazolo[4,3-e]pyrrolo[1,2-a][1,4]diazepinone analogs of pyrrolo[1,4]benzodiazepines (PBDs)

A new class of Pyrrolo[1,4]benzodiazepines (PBDs) analogs featuring a pyrazolo[4,3-e]pyrrolo[1,2-a][1,4]diazepinone ring system has been designed and synthesized. In these compounds the A-benzene ring, characteristic of PBDs, has been replaced by a dimethylpyrazole ring, a modification suggested by modelling studies performed on the PBD base structure. Biological evaluation releaved appreciable antitumor activity for compounds 14 and 15 (8.84–22.4 μM) which encourages further investigation of the N⁶ and N⁷ alkyl pyrazole analogs.     

Gel-phase synthesis of a difficult sequence peptide on 1,4-butanediol dimethacrylate-crosslinked polystyrene support

Summary The synthetic usefulness of the protocol using NMP/DMSO and DIEA for the synthesis of difficult sequence peptides on amphiphilic and flexible 1,4-butanediol dimethacrylate-crosslinked polystyrene (BDDMA-PS) support was demonstrated by synthesizing [DAla¹⁷] analogue of gonadotropin releasing hormone precursor protein fragment (14–36) [hGnRH (14–36)] using Boc chemistry. The swelling capacity of the peptidyl resin was followed as a measure of the aggregation of pendant peptide chains on the support. The progress of chain assembly was monitored by quantitative ninhydrin test and amino acid analysis. The purity of the peptide was checked by reverse phase HPLC and characterized by amino acid analysis and electrospray ionisation mass spectrometry (ESI-MS).     

Prebiotic synthesis of histidine

Summary The prebiotic formation of histidine (His) has been accomplished experimentally by the reacton of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which has not been synthesized prebiotically until now.     

A facile synthesis of the GalNAcbeta1-->4Gal target sequence of respiratory pathogens

The carbohydrate sequence, GalNAcβ1→4Gal, is the target for the adhesion of several respiratory pathogens. The sequence was prepared in an optimized synthesis in forms that allow conjugation to scaffolds or surfaces.     

外泌体分泌在1,4-苯醌诱导的HL-60细胞凋亡中起保护作用

慢性苯暴露损害造血系统,可引起再生障碍性贫血,甚至白血病。外泌体(exosomes)是细胞分泌的纳米级膜泡,在许多生理和病理过程中发挥重要作用。然而,苯及其代谢产物对外泌体分泌的影响仍不清楚。本研究旨在观察苯的活性代谢产物1,4-苯醌(1,4-benzoquinone,1,4-BQ)能否引起人早幼粒白血病细胞HL-60外泌体分泌量的变化以及外泌体释放在1,4-BQ诱导的细胞凋亡中的作用。应用不同浓度1,4-BQ处理细胞24 h,超高速离心法提取细胞培养基中的外泌体,结果发现1,4-BQ能促进外泌体分泌,呈剂量反应关系。进一步应用外泌体抑制剂GW4869抑制外泌体分泌,流式细胞仪检测细胞凋亡率、蛋白质免疫印迹法检测抑凋亡蛋白质Bcl-2、凋亡通路关键蛋白质cleaved caspase-9和cleaved caspase-3的表达,探讨外泌体分泌对1,4-BQ所致细胞凋亡的影响。结果显示:与对照组相比,1,4-BQ单独处理组的凋亡率、Bcl-2、cleaved caspase-9和cleaved caspase-3的表达均显著增高(P<0.05),而1,4-BQ+GW4869组的凋亡率及凋亡相关蛋白质的表达均显著高于1,4-BQ单独处理组(P<0.05),表明抑制外泌体分泌可增加1,4-BQ诱导的细胞凋亡。综上表明,1,4-BQ能促进外泌体分泌,并在1,4-BQ诱导的细胞凋亡中起保护作用。本研究为了解苯的毒性效应和毒性机制提供了新的实验证据。