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Using d-glucosamine hydrochloride (GlcNH2·HCl) as starting material, a new amino acid sugar conjugate, arginine–glucosamine (Arg–GlcNH2), was synthesized and characterized by infrared spectroscopy, 13C NMR and element analysis. Its cytotoxicity in vitro was evaluated by MTT assay. The inhibition ratio against human hepatoma cell SMMC-7721 was higher than that of GlcNH2·HCl. This effect was accompanied by a marked increase in the proportion of S cells as analyzed by flow cytometry. In addition, SMMC-7721 cells treated with Arg–GlcNH2 resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis. The manner of Arg–GlcNH2 cytocidal activity was concluded to be apoptosis. 相似文献
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Shuli Man Wenyuan Gao Yanjun Zhang Jieyin Wang Wanshun Zhao Luqi Huang Changxiao Liu 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(29):2943-2948
High-performance liquid chromatographic (HPLC) with evaporative light scattering detection (ELSD) and HPLC with electrospray ionization multistage tandem mass spectrometry (HPLC–ESI-MSn) were used to identify and quantify steroid saponins in Paris and Trillium plants. The content of the known saponins such as Paris I, II, III, V, VI, VII, H, gracillin and protodioscin in Paris and Trillium plants was determined simultaneously using the developed HPLC-ELSD method. Furthermore, other 12 steroid saponins were identified by HPLC–ESI(+/−)-MSn detection. In the end, a developed analytical procedure was proved to be a reliable and rapid method for the quality control of Paris and Trillium plants. In addition, the alternative resources for Paris yunnanensis used as a traditional Chinese medicine were discovered according to the hierarchical clustering analysis of the saponin fraction of these plants. 相似文献
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Shuisheng Li Wanshun Li Shoujia Jiang Yi Jing Ling Xiao Yangyang Yu Yun Liu Yanhong Li Dengdong Wang Jiang Li Cheng Peng Jiaxing Chen Danqi Lu Bin Wu Xuanmin Guang Junping Ma Xinxin You Yuqing Yang Su Liu Xiaodong Fang Qiang Gao Qiong Shi Haoran Lin Manfred Schartl Zhen Yue Yong Zhang 《Molecular ecology resources》2023,23(4):920-932
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Preparation and antimicrobial activity of hydroxypropyl chitosan 总被引:11,自引:0,他引:11
Water-soluble hydroxypropyl chitosan (HPCS) derivatives with different degrees of substitution (DS) and weight-average molecular weight (Mw) were synthesized from chitosan and propylene epoxide under basic conditions. Their structure was characterized by IR spectroscopy, NMR spectroscopy, and elemental analysis, which showed that both the OH groups at C-6 and C-3 and the NH2 group of chitosan were alkylated. The DS value of HPCS ranged from 1.5 to 3.1 and the Mw was between 2.1x10(4) and 9.2x10(4). In vitro antimicrobial activities of the HPCS derivatives were evaluated by the Kirby-Bauer disc diffusion method and the macrotube dilution broth method. The HPCS derivatives exhibited no inhibitory effect on two bacterial strains (Escherichia coli and Staphylococcus aureus); however, some inhibitory effect was found against four of the six pathogenic fruit fungi investigated. Some derivatives (HPCS1, HPCS2, HPCS3, HPCS3-1, and HPCS4) were effective against C. diplodiella and F. oxysporum. HPCS3-1 is the most effective one with MIC values of 5.0, 0.31, 0.31, and 0.16mg/mL against A. mali, C. diplodiella, F. oxysporum, and P. piricola, respectively. Antifungal effects were also observed for HPCS2 and HPCS3-1 against A. mali, as well as HPCS3 and HPCS3-1 against P. piricola. The results suggest that relatively lower DS and higher Mw value enhances the antifungal activity of HPCS derivatives. 相似文献
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Catalase from Bacillus sp. N2a (BNC) isolated from Antarctic seawater was purified to homogeneity. BNC has a molecular mass of about 230 kDa and is composed of four identical subunits of 56 kDa. The catalase showed optimal activity at 25 degrees C and at a pH range of 6-11. The enzyme could be inhibited by azide, hydroxylamine, and mercaptoethanol. These characteristics suggested that BNC is a small-subunit monofunctional catalase. The activation energy of BNC was 13 kJ/mol and the apparent kcat/Km values were 3.6 x 10(6) and 4 x 10(6) L.mol(-1).s(-1) at 4 and 25 degrees C, respectively. High catalytic efficiency of BNC at low temperatures enables this bacterium to scavenge H2O2 efficiently. BNC exhibited activation energy, catalytic efficiency, and thermostability comparable with some mesophilic homologues. Such similarity of enzymatic characteristics to mesophilic homologues, although uncommon among the cold-adapted enzymes in general, has also been observed in other psychrophilic small-subunit monofunctional catalases. 相似文献
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甲壳质脱乙酰基酶的研究概况及进展 总被引:1,自引:0,他引:1
甲壳质脱乙酰基酶(chitindeacetylase)最初是从真菌毛霉(Mucor.rouxi)分离纯化的一种乙酰基转移酶。这种酶可以催化脱去甲壳质分子中N-乙酰葡糖胺链上的乙酰基,而使之变成壳多糖[1]。除几种真菌外,在昆虫中也发现了这种酶的存在[2]。真菌的甲壳质脱乙酰基酶主要参与真菌细胞壁的形成[3],还与真菌自溶的过程中的细胞壁裂解有关[4]。最近又发现它参与植物和病原微生物的相互作... 相似文献
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一种海洋琼胶酶的分离纯化、酶学性质研究及降解产物分析 总被引:2,自引:0,他引:2
摘要:【目的】对海洋Agarivorans albus QM38菌株所产琼胶酶的纯化工艺和酶学性质进行了研究。【方法】发酵液通过离心、(NH4 ) 2SO4盐析、DEAE-Sepharose Fast Flow 阴离子交换层析、Sephacry S-100 凝胶过滤等纯化步骤得到SDS-PAGE电泳级纯酶,并用质谱对酶的降解产物进行分析。【结果】得到琼胶酶A,纯化倍数为17.6倍,收率为15.21 %,SDS-PAGE测定其分子量为127.8 kDa。对琼胶酶A进行了进一步的性质分析,其最适反应温度为35 ℃,最适反应pH为7.6,最适底物浓度为0.9 %,多数金属离子为其活性抑制剂。琼胶酶A的降解产物经质谱分析主要为四糖和六糖。【结论】从菌株QM38的发酵液中纯化得到的琼胶酶A具有降解凝胶态琼胶的能力,其分子量与以往报道过的琼胶酶不同。 相似文献