琼榄提取物的抗氧化及抗菌活性初步研究

为研究琼榄的药用活性成分,更好地开发和利用琼榄资源,对琼榄根、茎、叶的5种不同溶剂提取物分别采用清除DPPH自由基法和滤纸片扩散法进行抗氧化及抗菌活性研究。结果表明,琼榄叶的乙酸乙酯提取物（L-EtOAc）清除DPPH自由基的IC50最小,为154.1μg/mL,是15组提取样品中清除自由基活性最强的部位。琼榄根、茎、叶的15组提取物对5种供试菌均具有不同程度的抑菌活性,且以琼榄叶的乙酸乙酯提取部位对5种供试菌的抑菌作用均较强,特别是对金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌的抑制作用和阳性对照品头孢他啶的抑菌作用接近。因此,琼榄叶部位的抗氧化和抗菌活性最强,且活性物质在乙酸乙酯部位,L-EtOAc为有效提取部位。     

琼榄提取物的抗氧化及抗菌活性

为研究琼榄的药用活性成分,更好地开发和利用琼榄资源,对琼榄根、茎、叶的5种不同溶剂提取物分别采用清除DPPH自由基法和滤纸片扩散法进行抗氧化及抗菌活性研究。结果表明,琼榄叶的乙酸乙酯提取物(L-EtOAc)清除DPPH自由基的IC50最小,为154.1 mg/L,是15组提取样品中清除自由基活性最强的部位。琼榄根、茎、叶的15组提取物对5种供试菌均具有不同程度的抑菌活性,且以琼榄叶的乙酸乙酯提取部位对5种供试菌的抑菌作用均较强,特别是对金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌的抑制作用和阳性对照品头孢他啶的抑菌作用接近。因此,琼榄叶部位的抗氧化和抗菌活性最强,且活性物质在乙酸乙酯部位,L-EtOAc为有效提取部位。     

反丁烯二酸桂醇甲酯的合成及抗菌活性研究

以α,β-不饱和羰基结构为母体合成对皮肤无致敏性的反丁烯二酸桂醇甲酯(CMF)。合成实验表明:顺丁烯二酸酐与肉桂醇等摩尔混合,90℃反应2.5h后加入异构化催化剂在90℃反应4h转型,甲酯化反应以甲醇与桂醇单酯的摩尔比为6:1,在90℃恒温反应4h得率较高。抗菌活性实验表明:反丁烯二酸桂醇甲酯不但杀菌谱广,而且有效作用浓度低。在食品加工、保藏中具有广阔的开发应用前景。     

壳聚糖抗菌活性研究进展

壳聚糖具有无毒、良好的生物相容性、生物可降解性、广谱抗菌性等优良性能,作为新型抗菌剂越来越受学者的青睐。本文主要综述了21世纪以来影响壳聚糖抗菌性能的因素、壳聚糖的抗菌机理以及壳聚糖衍生物抗菌性能等方面的内容。     

壳聚糖抗菌活性研究进展

壳聚糖具有无毒、良好的生物相容性、生物可降解性、广谱抗菌性等优良性能,作为新型抗菌剂越来越受学者的青睐。本文主要综述了21世纪以来影响壳聚糖抗菌性能的因素、壳聚糖的抗菌机理以及壳聚糖衍生物抗菌性能等方面的内容。     

添加动物性成分化妆品的抗菌防霉问题

介绍了含有动物性成分的化妆品的霉变原因,指出了有效的防腐剂。     

紫苏全草抗菌活性的研究

对紫苏全草分部位、分萃取段进行了抗菌活性研究。选择革兰氏阳性菌中的金黄色葡萄球菌和革兰氏阴性菌中的大肠杆菌为代表菌种,筛选出了对所选细菌的生长具有明显抑制作用的抗菌活性部分:紫苏叶的石油醚萃取物,紫苏叶、茎、根的乙酸乙酯萃取物,在LB培养基中,它们对金黄色葡萄球菌的抑菌圈半径分别为6、8、4、2mm;对大肠杆菌的抑菌圈半径分别为1 5、3、2、0mm。结果表明,紫苏叶的乙酸乙酯萃取物对两种细菌的抑菌活性最强。采用薄层色谱(TLC)预试法对抗菌活性部位进行了有效化学成分分析,结果表明,紫苏全草抗菌活性成分主要为:挥发油、黄酮、酚、有机酸、香豆素内酯等化合物。     

放线菌发酵提取物对百合炭疽病的抗菌活性筛选

从云南不同生态环境中采集的土壤样品巾分离到334株放线菌,以百合炭疽病菌作为指示菌,通过菌株发酵提取物对孢子萌发抑制、菌丝生长抑制和温室盆栽防治效果的测定,初步筛选出对炭疽病菌分生孢子萌发有较强抑制能力的18个菌株,对炭疽病菌菌丝生长有较强抑制能力的24个菌株,离体叶片防治效果60％以上的14个菌株,其中YIM31927、YIM31047等10株发酵提取物对百合炭疽病菌孢子萌发、菌丝生长和离体叶片防治试验均表现出了一致活性,筛选到一批具有开发应用潜能的放线菌资源。     

金银花提取物在乳液化妆品中的抑菌活性及应用

【目的】研究金银花提取物在乳液化妆品中的抑菌活性及其应用、【方法】采用防腐效能测试方法研究不同用量的金银花提取物及其与乙基己基甘油的复配物在乳液化妆品中的抑菌活性、【结果】实验证明质量分数为0.5%的金银花提取物以及0.25%的金银花提取物与0.25%的乙基己基甘油复配物在受试乳液化妆品中表现出有效的抑菌效果、【结论】金银花提取物具有显著的广谱抑菌效能,是一种有研究和开发价值的植物防腐剂。     

香豆素噻唑类化合物的合成及其抗菌活性研究

以水杨醛为原料,经5步反应合成了一系列新型香豆素噻唑类化合物,其结构经1HNMR、13CNMR和元素分析证实.体外考察了所得化合物对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的抑制活性.结果表明,大部分化合物都具有较强的抗菌活性.其中,化合物(E)-N'-(3-氟4-羟基苯基亚甲基)-4-(2-氧代-2H-苯并吡喃-3-基)噻唑-2-酰肼活性最好,对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的最低抑制浓度分别为0.39、1.56和1.56 μg/mL.     

Surfactant-assisted enzymatic extraction of the flavor compounds from Zanthoxylum bungeanum

ABSTRACT

Surfactant-assisted enzymatic hydrolysis, which has been rarely involved in food industry, was used to extract the flavor compounds from Zanthoxylum bungeanum. The extraction conditions optimized through orthogonal and single-factor experiments were as follows: the amount of cellulase, neutral protease and surfactant (calcium stearyl lactylate) addition was 0.5%, 0.3% and 0.7% (w/w), respectively, the solid–liquid ratio was 1:6 (g/mL), the enzymolysis temperature was 45°C, the enzymolysis time was 3 h and the granularity was less than 60 mesh. Under these conditions, the yield of limonene, linalool and alkylamide increased from 1.02% to 7.51%, from 16.50% to 48.39%, and from 27.40% to 37.74%, respectively. The mechanism of surfactant-assisted enzymatic hydrolysis to extract the flavor compounds were also investigated. The study provides a scientific basis for the refinement and comprehensive utilization of Zanthoxylum bungeanum.     

花椒有效成分的提取

花椒中含有挥发油、植物碱、酰胺类等物质,而且花椒作为中药也被广泛应用.本实验针对我国花椒资源丰富而加工利用技术缺乏的现状,开展花椒有效成分的高效及全面提取.本实验用不同溶剂在微波辐射催化下从花椒中萃取出不同的成份：水溶性、油溶性和酯溶性.     

制备生物柴油用高游离脂肪酸花椒籽油的酯化法降酸

花椒籽油要达到制备生物柴油的要求,必须进行降酸处理。简单介绍了降酸前处理中的脱胶和脱色,甲醇酯化降酸的较优工艺为:催化剂浓硫酸浓度为2%,醇油摩尔比为30∶1,反应时间为2.5 h,反应温度为60℃。在此条件下,花椒籽油酸值可由78.91 mg KOH/g降到1.56 mg KOH/g,可以满足后期制备生物柴油要求。     

Low Temperature Affects Fatty Acids Profiling and Key Synthesis Genes Expression Patterns in Zanthoxylum bungeanum Maxim

Zanthoxylum bungeanum is one of the most important medicinal and edible homologous plants because of its potential health benefits and unique flavors. The chemical components in compositions and contents vary with plant genotype variations and various environmental stress conditions. Fatty acids participate in various important metabolic pathways in organisms to resist biotic and abiotic stresses. To determine the variations in metabolic profiling and genotypes, the fatty acid profiling and key differential genes under low temperature stress in two Z. bungeanum varieties, cold-tolerant (FG) and sensitive (FX), were investigated. Twelve main fatty acids were found in two Z. bungeanum varieties under cold stress. Results showed that the contents of total fatty acids and unsaturated fatty acids in FG were higher than those in FX, which made FG more resistant to low temperature. Based on the result of orthogonal partial least squares discriminant analysis, palmitic acid, isostearic acid, linolenic acid and eicosenoic acid were the important differential fatty acids in FG under cold stress, while isomyristic acid, palmitic acid, isostearic acid, stearic acid, oleic acid, linolenic acid and eicosenoic acid were the important differential fatty acids in FX. Furthermore, fatty acid synthesis pathway genes fatty acyl-ACP thioesterase A (FATA), Delta (8)-fatty-acid desaturase 2 (SLD2), protein ECERIFERUM 3 (CER3), fatty acid desaturase 3 (FAD3) and fatty acid desaturase 5 (FAD5) played key roles in FG, and SLD2, FAD5, 3-oxoacyl-[acyl-carrier-protein] synthase I (KAS I), fatty acyl-ACP thioesterase B (FATB) and acetyl-CoA carboxylase (ACC) were the key genes responding to low temperature in FX. The variation and strategies of fatty acids in two varieties of Z. bungeanum were revealed at the metabolic and molecular level. This work provides a reference for the study of chemical components in plant stress resistance.     

火炭母提取物抑菌活性的初步研究

对药用植物火炭母（Polygonum chinense Linn.）提取物的抑菌活性进行了研究。结果表明：（1）不同部位提取物中,叶和茎均含有抑菌活性物质,但叶提取物的抑菌效果更强、更明显;（2）不同溶剂提取物中,65%乙醇提取物具有最佳抑菌效果;（3）不同提取方法提取物中,超声提取物抑菌效果较索氏提取物抑菌效果强,但差异不是很大;（4）不同溶剂萃取物的抑菌实验表明,火炭母提取物中的抑菌活性物质易溶于乙醚、石油醚等非极性溶剂;（5）火炭母提取物对金黄色葡萄球菌、痢疾杆菌、枯草杆菌、藤黄球菌、白色念珠菌的最小抑菌浓度（MIC）分别为0.6g.mL-1、0.6g.mL-1、0.8g.mL-1、1.0g.mL-1、0.6g.mL-1,最小杀菌浓度（MBC）均为1.0g.mL-1。为开发新型、安全、高效的临床药物及扩大药源提供了科学依据。     

凤眼草抑菌活性成分的研究

对苦木科臭椿属植物臭椿的果实凤眼草(Ailanthus altissima)的95％乙醇提取液的抑菌活性进行了研究.利用系统溶剂萃取法得到了石油醚提取物、氯仿提取物、乙酸乙酯提取物和正丁醇提取物,重点研究了4种提取物对枯草芽孢杆菌、大肠杆菌和金黄色葡萄球菌的抑菌性和最低抑菌浓度.结果表明,乙酸乙酯提取物和正丁醇提取物均...     

Comparison and optimization of two extract methods (atmospheric pressure and pressurized pretreatment) of pectin from Zanthoxylum bungeanum Maxim. seeds by response surface methodology

In this study, the extract methods of pectin from Zanthoxylum bungeanum Maxim. seeds under atmospheric pressure and pressurized pretreatment were investigated and compared. Response surface methodology was applied to optimize the extraction conditions for obtaining the maximum yield of pectin. The optimum extraction conditions under atmospheric pressure were as follows: pH 2.5, 84.8°C, 81.0 min, and liquid-to-solid ratio 14.2:1 (ml/g). The optimum extraction conditions under pressurized pretreatment were as follows: pH 6.1, 117.7°C, and 95.4 min. In contrast, the optimal extraction yield under pressurized pretreatment was 76.52% above that of extraction under atmospheric pressure.