酯化作用

It,s allelchemicals were isolated through extraction, thin-layer chromatography, and column chromatograpathy. After the white clover was infused in ethanol and evaporation, the leavings was dissolved by water. The aqueous extract was extracted by petroleum,chloroform, ethyl acetate and n-Butanol successively, and the bioassay showed that the chloroform phase has obvious inhibitory effect, the inhibitory rate was 44.32%,88.08% on Abutilon theophrasti M., seedling length and root length, 82.08%,92.16% on Echinochloa crusgalli L., seedling length and root length, and the Amaranthus retroflexux L., germination rate is 0, the secondly was ethyl acetate phase.

运用萃取、薄层层析、柱层析等方法对白三叶草地上部分的化感物质进行初步分离，结果表明，白三叶草经乙醇浸提旋转蒸发后用蒸馏水溶解，依次用石油醚、氯仿、乙酸乙酯、正丁醇萃取，生物测定表明氯仿组分对杂草的抑制作用最强，对苘麻芽长和根长抑制率分别为44.32%、88.08%，对稗草芽长和根长的抑制率分别为82.08%、92.16%，反枝苋的发芽率为0；其次是乙酸乙酯相。

We investigated constituent of triterpenoid saponins ofAlbizzia, two new compounds together with two known compounds were isolated from Albizzia julibrissin Durazz. by using column chromatography (macroreticular resin, silica gel, Sephadex gel, reverse phase silica gel),preparative HPLC methods et al.On the basis of spectroscopic analysis, including IR,ESI-MS,~1H-NMR,~(13)C-NMR,HMBC,HMQC,~1H-~1HCOSY and chemical methods, the structure of two new compounds were identified as 3 - O -[β-D-xylopyranosyl(1→2)-β-D-fucopyranosyl (1→6)-β- D -2- deoxy - 2 - acetoamidoglucopyranosyl] -21-O-[(6S)-2- trans- 2,6-dimethyl - 6 - O-β- D - quinovopyranosyl -2,7- octadienoyl] - acacic acid- 28 - O-β-D-glucopyranosyl(1→3)[α-L-arabinofuranosyl(1→4)]-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside acacic acid 3- O -β- D- glucopyranosy(1→3)-β- D- fucopyranosl(1→6) [β-D- xylopyranosyl (1→2)]-β-D-glucopyranoside ;two known compounds were acacic acid lactone 3- O -β-D- xylopyranosyl-(1→2)-β-D-fucopyranosl (1→6)- 2-deoxy -2 -acetoamido -β-D- glucopyranoside ; acacic acid lactone 3- O-β-D-xylopyranosyl(1→2)-α-L- arabinopyranosl (1→6)- 2- deoxy - 2- acetoamido -β-D-glucopyranoside . The study lays chemical foundation and chemical reference substance for enhancing quality standard of Albizzia julibrissin Durazz.

本研究论文在综述国内外对合欢属Albizzia三萜皂苷化学成分和药理作用研究进展的基础上，利用传统植化分离手段和现代分离技术，包括大孔树脂、硅胶、葡聚糖凝胶、反相硅胶等柱色谱，制备高效液相色谱法等技术从中药合欢皮中分离得到了4个化合物，其中，2个新化合物和2个己知化合物，并进一步通过现代分析技术IR，ESI-MS，~1H-NMR，~(13C-NMR，HMBC，HMQC，~1H-~1HCOSY等和化学方法鉴定了2个新化合物的结构分别是：3-O-[β-D-吡喃木糖基(1→2)-β-D-吡喃夫糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖基]-21-O-[(6S)-2-反式-2，6-二甲基-6-O-β-D-吡喃鸡纳糖基-2，7-辛二烯酸基]-金合欢酸-28-O-α-L-呋喃阿拉伯糖基(1→4)[β-D-吡喃葡萄糖基(1→3)]-α-L-吡喃鼠李糖基(1→2)-β-D-吡喃葡萄糖苷，金合欢酸3-O-β-D-吡喃葡萄糖基(1→3)-β-D-吡喃夫糖基(1→6)[β-D-吡喃木糖基(1→2)]-β-D-吡喃葡萄糖苷；2个已知化合物结构分别是：金和欢酸内酯3-O-β-D-吡喃木糖基(1→2)-β-D-吡喃夫糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖苷，金和欢酸内酯3-O-β-D-吡喃木糖基(1→2)-α-L-吡喃阿拉伯糖基(1→6)-β-D-2-去氧-2-乙酰氨基吡喃葡萄糖苷。

The molecular charge distribution of the reactivator is affect the reactivating efficacy directly. Moreover its association with hydroximic acid dissociation constant pAa closely, and it will have a great impact on reactivating ability indirectly.(3) There is likely to exist front molecular interaction between Cholinesterase Reactivators and OPC-inhibited AChE, the action sites mainly lie on the aromatic ring, the substitute R and the hydroixic acid group. They act on the aromatic residues of AChE by Π-Π conjugation .(4) The reached results by Comparative Molecular Field Analysis is useful to design new higher efficacy derivatives for 1, 2, 4-oxadiazole class nonquaternary Cholinesterase Reactivators.

2复能剂分子的电荷分布直接影响复活活性，同时对肟酸解离常数pKa具有重要影响，间接影响复活能力；(3)复能剂与磷酰化酶可能存在前线轨道作用，作用部位可能主要在芳香环及其取代基R和肟基上，与AchE的芳香族残基发生л-л电子作用；(4)通过比较分子力场法研究可以指导1，2，4-oxadiazole类非季铵肟胆碱酯酶重活化剂新化合物的合成，可能得到活性更高的复能剂。

ABSTRACT Immobilized penicillin acylase (from E.coli) was used to catalyze 7 phenylacetamido 3 E propenyl cephalosporanic acid hydrolyzation into 7 amino 3 E propenyl cephalosporanic acid. Then, trans APRA was acylated with hydroxyethyl ester of 4 hydroxy D phenylglycine to obtain trans cefprozil.

以7 苯乙酰氨基 3 E 丙烯基 3 头孢菌素 4 羧酸为原料，在青霉素酰化酶作用下，首先酶法水解得到3 E 丙烯基 3 头孢菌素 4 羧酸，过滤固相酶，滤液调pH分离得到反式APRA固体；在青霉素酰化酶作用下，反式APRA再与对羟基苯甘氨酸乙二醇酯缩合，得到反式头孢丙烯；酶法合成所得的产品与进口反式头孢丙烯对照品一致。

During these years (1997-2000) in the research area of annonaceous acetogenins 5 natural products and a number of chiral-pure analogs of annonaceous acetogenins have been synthesized using sugars as the starting materials. Their high activity and selectivity against cell line of colon tumor and a relationship between activity and configuration have been found too. In the respect of inhibitor of sialidase two new methodologies for the synthesis of chiral-pure 3-deoxy-ulosonic acid using hetero-Diels-Alder reaction or asymmetric propargylation as the key reaction were developed. On the topic of anti-leukemia marine natural product clavulactone a synthetic method based on the free radical cyclization and starting from sugar has been developed. In other title of PKC inhibited agent sphingosine a new synthetic route with SN2' as the key reaction has also been disclosed.

项目期间（1997-2000）在番荔枝内酯方面从糖出发合成了五个天然产物和一批手性纯的类似物，它们对肠癌细胞有很高的活性和选择性，并与构型有关；在唾液酸酶抑制剂方面发展了二类全新手性纯高碳糖的合成方法－杂原子D－A反应或丙炔基不对称加成为关键的反应；抗白血病海洋天然产物群柱虫内酯方面研究了由糖出发和自由基环化反应的合成方法；对PKC 起抑制作用的鞘氨醇方面也开创了新的合成途径－由糖出发并以SN2'反应为关键反应。

It was found that the reactions of C_(60) with anthranilic acids and isoamyl nitrite in the presence of triethylamine unexpectedly afforded C_(60)-fusedδ-lactones,which would be difficult to be prepared by other known methods.

通过在三乙胺作用下，富勒烯与邻氨基苯甲酸类化合物和亚硝酸异戊酯的环化反应，首次合成了一系列富勒烯并六元环内酯。

Methods: A model to evaluate lymphocyte proliferation stimulated with a polyclonal activator, concanavalin A, was established by vital dye carboxyl fluorescin diacetate succinmidyl ester labeling technique. Effects of the different doses of anisomycin on the lymphocyte proliferation were estimated by flow cytometry and MTT methods. The propidium iodide labeling technique was applied to assay the effect of the different doses of anisomycin on changes of the lymphocyte cell-cycle stimulated by ConA or by phorbol ester plus Ionomycin. The percentage of the expression level of CD69 and CD25 on the activated lymphocytes was evaluated by fluorescin-conjugated monoclonal antibody double labeling technique.

以活体染料羧基荧光素乙酰乙酸琥珀酰亚胺酯染色，建立在多克隆刺激剂刀豆蛋白A刺激下评价小鼠淋巴细胞增殖的模型，通过流式细胞术和MTT法分析茴香霉素在不同剂量下对淋巴细胞增殖的作用；采用碘化丙锭染色分析茴香霉素对ConA或佛波醇酯加离子霉素刺激的小鼠淋巴细胞周期变化的作用；利用荧光标记的单克隆抗体双染技术和流式细胞术观察茴香霉素对小鼠CD3~+T细胞早期及中期活化标志分子CD69和CD25表达的影响。

Objective:To study the effect of spironolactone inhibiting proliferation on cultured myocardiac myofibroblasts and explore its possible mechanisms.

目的：研究螺内酯对培养的心肌成纤维细胞增殖的作用，揭示螺内酯抑制心肌纤维化的可能机制。

To elucidate the possible mechanism of differentiation and /or apoptosis in NB4, K562 cells induced by tributyrin, a histone deacetylase inhibitor, the level of acetylated histone H3 was detected by Western blot, p21~ WAF1expression was detected by semi-quantitative RT-PCR.

为了探讨组蛋白去乙酰化酶抑制剂三丁酸甘油酯(tributyrin，TB)诱导NB4、K562白血病细胞分化和凋亡的作用机制，利用Westernblot方法及逆转录聚合酶链反应检测TB作用前后NB4、K562细胞组蛋白H3乙酰化水平以及p21WAF1表达量的改变。

To elucidate the possible mechanism of differentiation and/or apoptosis in NB4, K562 cells induced by tributyrin, a histone deacetylase inhibitor , the level of acetylated histone H3 was detected by Western blot, p21(superscript WAF1) expression was detected by semi-quantitative RT-PCR.

为了探讨组蛋白去乙酰化酶抑制剂三丁酸甘油酯(tributyrin， TB)诱导NB4、K562白血病细胞分化和凋亡的作用机制，利用Western blot方法及逆转录聚合酶链反应检测TB作用前后NB4、K562细胞组蛋白H3乙酰化水平以及p21(上标 WAF1)表达量的改变。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。