Synthesis and Immunostimulating Activity of Cysteine-Containing Derivatives of Glycyrrhizic Acid

New cysteine-containing derivatives of glycyrrhizic acid were synthesized by its coupling with Cys(Bzl) esters or the Cys(Bzl)-Val-OBu ^t dipeptide by the active ester method (DCC/HOSu) or by Woodward's reagent K. The derivatives with Cys(Bzl) and Cys(Bzl)-Val residues attached to the carbohydrate part of the molecule stimulated the primary immune response and the reaction of delayed-Type hypersensitivity in mice at a dose of 2 mg/kg.     

Transformations of Glycyrrhizic Acid: XV. Synthesis of Triterpene Saponins with Monosaccharide Residues Attached through Ester Bonds

Triterpene saponins, glycoside analogues of glycyrrhizic acid with a modified carbohydrate chain containing monosaccharide residues attached through ester bonds, were synthesized. To this end, peracetylated glycyrrhizic acid or its 30-methyl ester were glycosylated by 2,3,4,6-tetra-O-acetyl--D-gluco- or --D-galactopyranosyl bromide in dichloroethane in the presence of Ag₂CO₃. Glycerrhetinic acid saponin with D-Galp residues exhibited a higher antiulcer activity than glycyrrhizic acid in rats at a dose of 25 mg/kg.     

微生物异源合成咖啡酸及其酯类衍生物研究进展

咖啡酸及其酯类衍生物如绿原酸、迷迭香酸和咖啡酸苯乙酯等具有天然抗氧化、抗肿瘤、抗病毒和抗炎等重要的药理活性,具有广阔的药用开发前景。从天然药物中提取或者化学合成咖啡酸及其酯类衍生物,存在含量低、提取效率不高、催化成本高昂以及环境污染等问题。随着咖啡酸及其酯类衍生物合成途径解析和合成生物学的快速发展,微生物异源合成咖啡酸及其酯类衍生物的研究已逐渐展开。对微生物异源合成咖啡酸及其酯类衍生物合成途径的最新进展以及代谢工程策略进行了综述,并讨论了目前存在的问题和未来的发展趋势。     

甘草酸的提取及其抑菌活性研究

本文对甘草酸的各种提取方法进行了对比研究。结果表明,超声提取与传统搅拌提取、酶解提取及反复冻溶提取相比,是较适于从甘草中快速高效提取甘草酸的新方法,其最优条件为用20倍量0.7%氨水超声处理2次,每次20min。此外,探讨了提取的甘草酸的体外抑菌活性,其对金黄色葡萄球菌,大肠埃希氏杆菌,绿脓杆菌和枯草杆菌的最小抑菌浓度(MIC)分别为:0.0625,0.125,0.25,0.03125mg/mL,表明其具有较好的抑菌活性。     

Synthesis and Biological Evaluation of a Series of Novel Celastrol Derivatives with Amino Acid Chain

The synthesis of celastrol analogues containing amino acid ester at the C(29) position and their evaluation for cytotoxic activities in vitro were reported. The MTT test showed that a set of derivatives with lower IC₅₀ values than that of the positive control group cisplatin and the parent compound celastrol, which exhibited greater antiproliferative activities. The most potent title compounds 2a and 2e exhibited cytotoxic activities in vitro against HeLa and A549 cell lines with IC₅₀ values of 0.371 and 0.237 μm , 0.235 and 0.109 μm , respectively. The apoptosis assay demonstrated that 2a and 2e can induces of A549 cell apoptosis in low concentrations. These results showed that 2a and 2e may be promising for further research as antitumor agents.     

熊果酸衍生物的合成及其对肺癌细胞活性抑制的研究

目的：探讨合成的熊果酸衍生物对肺癌LTEP-α-2肿瘤细胞增殖的抑制作用。方法：熊果酸经氧化、肟化和腙化合成为3-氧代熊果酸、3-肟基熊果酸和3-（2＇,4＇-二硝基）-苯腙熊果酸。采用MTT法检测熊果酸及其衍生物对肺癌LTEP-α-2细胞的体外抗肿瘤活性。结果：熊果酸及其衍生物对肺癌LTEP-α-2细胞有抑制作用,且3-肟基熊果酸对肺癌LTEP-α-2细胞抑制作用高于其他化合物,其抑制率为90.0%,IC50为7.4μg/m L。结论：熊果酸衍生物3-肟基熊果酸抗肺癌LTEP-α-2肿瘤细胞活性高于熊果酸的活性。     

Synthesis and immunomodulating activity of new glycopeptides of glycyrrhizic acid containing residues of L-glutamic acid

New glycopeptides of glycyrrhizic acid (GA) containing Glu residues and their α-methyl esters, γ-methyl esters, and α,γ-dimethyl esters were synthesized using N,N′-dicyclohexylcarbodiimide in the presence of N-hydroxybenzotriazole or N-hydroxysuccinimide. Formation of amide bonds was observed on all the three COOH groups of GA, or selectively on the COOH groups of the GA carbohydrate part in dependence on the ratio of reagents and the reaction conditions. The GA glycopeptide with three residues of Glu(OH)-OMe at a dose of 2 mg/kg stimulated the production of antibody-forming cells in mouse spleen in comparison with the control. The GA glycopeptide containing Glu residues only in the GA carbohydrate part turned out to be an immunosuppressor. The glycopeptide of the 30-methyl ester of GA with residues of free Glu in its carbohydrate part increased the hemagglutinine titer at oral doses of 2 and 10 mg/kg. All the studied compounds had practically no effect on the delayed-type hypersensitivity in mice.     

Synthesis and Biological Activity of Nitrilic Derivatives of the Methyl Ester of Maleopimaric Acid

An effective method of a modification of the anhydride ring of the maleopimaric acid methyl ester by means of the cyanoethylation reaction was developed. A primary screening of a cytotoxic activity in vitro demonstrated an ability of the cyanoethyl derivative of the maleopimaric acid methyl ester to induce the death of the PC-3 cells of prostate cancer.     

The Amino Acid Sequence of Monal Pheasant Lysozyme and Its Activity

The amino acid sequence of monal pheasant lysozyme and its activity were analyzed. Carboxymethylated lysozyme was digested with trypsin and the resulting peptides were sequenced. The established amino acid sequence had one amino acid substitution at position 102 (Arg to Gly) comparing with Indian peafowl lysozyme and four amino acid substitutions at positions 3 (Phe to Tyr), 15 (His to Leu), 41 (Gln to His), and 121 (Gln to His) with chicken lysozyme. Analysis of the time-courses of reaction using N-acetylglucosamine pentamer as a substrate showed a difference of binding free energy change (-0.4 kcal/mol) at subsites A between monal pheasant and Indian peafowl lysozyme. This was assumed to be caused by the amino acid substitution at subsite A with loss of a positive charge at position 102 (Arg102 to Gly).     

Synthesis and Antiviral Activity of Ureides and Carbamates of Betulinic Acid and Its Derivatives

Ureides and carbamates of betulinic acid and its derivatives were prepared in good yields by interaction of betulinic acid, betulonic acid, and betulonic acid 3-oxime with amines, amino acids, and alcohols. Ureides of betulonic acid containingL-Val and L-Met residues were found to be effective against herpes simplex type 1 virus.     

Synthesis and Antiviral Activity of Hydrazides and Substituted Benzalhydrazides of Betulinic Acid and Its Derivatives

New nitrogen-containing derivatives of betulinic and betulonic acids, hydrazides and N"-benzalhydrazides, were synthesized. Their antiviral activities toward viruses of influenza A virus, herpes simplex type I virus, enterovirus ECHO6, and HIV-1 were studied in vitro. Betulinic acid 3-oxime was found to have the highest activity against the influenza virus. Betulonic acid, betulinic acid 4-chlorobenzalhydrazide, betulonic acid 3-oxime benzalhydrazide, and betulinic acid hydrazide inhibited the replication of herpes simplex type I virus. Betulinic acid hydrazide also showed antiviral activity toward HIV-1. All the derivatives of betulinic acid under study displayed a low antiviral activity toward enterovirus ECHO6.     

氨基酸酰胺类化合物的合成

阐述了氨基酸氨基保护的常用方法和试剂,氨基酸酰胺类化合物合成的基本原理和方法以及在合成中需要注意的问题。重点阐述了氨基酸酰胺类化合物的合成机理和合成方法。展望了氨基酸酰胺类衍生物的合成方向。     

Synthesis and Biological Activity of Fatty Acid Derivatives of Quinine

Derivatives of quinine with fatty acids including polyunsaturated fatty acids were prepared. They showed moderate antimalarial activity as compared with quinine itself using Plasmodium falciparum. The activities were not dependent on whether the fatty acyl group was saturated or unsaturated. On the other hand, the derivatives showed significantly higher cytotoxicity against a mammary tumor cell line FM3A than quinine itself. Calculating from these data, an acetyl derivative of quinine with the shortest acyl group was found to give the highest selectivity.     

Semisynthesis and Antifungal Activity of Novel Oxime Ester Derivatives of Carabrone Modified at C(4) against Botrytis cinerea

To continuously improve the potential utility of the natural lead compound of carabrone in agrochemistry, carabrone oxime and 36 novel oxime ester derivatives of carabrone modified at C(4) were synthesized, and evaluated for their antifungal activities against Botrytis cinerea in vitro and in vivo. Of these 36 oxime ester derivatives, some compounds exhibited antifungal activities in vitro or in vivo. It was found that compounds with a pyridinyl residue can either efficiently inhibit spore germination or efficiently inhibit hyphal growth of B. cinerea, and compound 9 exhibited the highest activity in vitro and in vivo with IC₅₀ and EC₅₀ values of 1.17 and 12.9 μg/ml, respectively. Further, the structure? activity relationships are also discussed.     

有机介质中脂肪酶催化外消旋苯甘氨酸甲酯的对映体选择性氨解反应

由水解酶催化的酯的对映体选择性水解和醇解反应 ,已在外消旋物质的拆分中得到广泛应用[1 ] 。近年来的一些研究表明 ,某些水解酶还可催化一些非天然酰基受体的转化 ,如过氧化氢、烷基胺、联胺和氨等。这些非天然酰基受体的转化反应在多肽的合成及手性化合物的拆分中显示出巨大的应用前景。其中 ,以氨为酰基受体的酶促氨解反应 ,是继酶促对映体选择性水解、酯化及转酯反应之后的另一制备光学纯化合物的新反应[2 ] 。目前国际上对这一新反应的研究尚属起步 ,国内未见有对该反应研究的报道。(Ｄ ,Ｌ) 苯甘氨酸是半合成 β 内酰胺类抗生素的重…     

Synthesis,Cytotoxic, and Antibacterial Evaluation of Quinazolinone Derivatives with Substituted Amino Moiety

A series of novel quinazolinone derivatives containing a substituted amino moiety were synthesized, evaluated for their cytotoxic and antibacterial activities. The results of MTT assay showed that all synthesized target compounds 5A  –  5O showed potent cytotoxicity against SGC‐7901 (IC₅₀, 0.72 – 1.41 μm ). Moreover, the compounds 5D , 5I , and 5K showed better selectivity as compared with positive controls pemetrexed and MTX due to weak cytotoxicity against normal tissue cell line HUVSMC. Among synthesized compounds, the compounds 5E , 5J , 5L , and 5N showed broad‐spectrum cytotoxic activities against at least four cancer cell lines at a micromolar level. The results of antibacteria evaluation revealed that all synthesized compounds showed good to moderate antibacterial activities against Gram‐negative bacteria Escherichia coli. Among them, the MIC values of the compounds 5C , 5F , and 5M were 0.31 μg/mL.     

Synthesis and Antifungal Activity of Curcumol Derivatives

To discover novel and effective antifungal candidates, a series of new curcumol derivatives were designed, synthesized, and evaluated their antifungal activity against five phytopathogenic fungi by the mycelium growth rate method. Derivatives c4 , c22 and c23 exhibited excellent antifungal activity against Phomopsis sp. with EC₅₀ values of 3.06, 3.07, and 3.16 μM, respectively. Specifically, compound c4 exhibited the strongest antifungal activity against Phomopsis sp., which was 44 times that of pyrimethanil (EC₅₀=134.37 μM). The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that compound c4 could cause cell senescence and death of Phomopsis sp. by changing the normal hyphal morphology and disrupting the normal metabolism of hyphal cells. Moreover, compound c4 showed excellent curative effect against Phomopsis sp. on kiwifruit. These findings confirmed that compound c4 has great potential as a potent antifungal agent.     

微生物传感器及其在氨基酸分析中的应用

介绍了微生物传感器的发展状况、制作方法,综述了微生物传感器在氨基酸分析中的应用,引文献４２篇。     

蔗糖脂肪酸脂对离体和活体大豆蔗糖酶活力和构象的影响

研究了蔗糖脂肪酸脂(SFE)对离体和活体大豆蔗糖酶活力和构象的影响。当SFE的浓度大于1.0mmol/L后,开始激活离体蔗糖酶的活力。在大豆的开花期和结荚期,SFE可以增加蔗糖酶的活力。荧光实验结果表明,在小于2mmol/L时,SFE不改变蔗糖酶的荧光最大发射峰峰位和峰高。施用SFE后,大豆叶片中果糖、葡萄糖和蔗糖酶的含量,分别是对照的170%±10%,190%±10%,和260%±20%;而蔗糖的含量几乎不变。对蔗糖酶 的SDS-凝胶电泳图进行扫描分析的结果表明,经SFE处理后的蔗糖酶含量比对照高两倍左右。这些结果说明SFE可以显著增加活体蔗糖酶的活力,但活力的增加既不是因为蔗糖酶构象的改变,也不是蔗糖(作为底物)诱导所致,而是SFE增加了大豆叶片中蔗糖酶的含量引起的。