茶树精油组合物抗空气霉菌活性及对空气消毒效果研究

探讨茶树精油组合物通过挥发对室内空气霉菌抑制效果,并观察其对室内空气消毒的效果。采用气相扩散法比较茶树精油组合物和常用化学消毒剂过氧乙酸对黄青霉、青霉菌、烟曲霉和黄曲霉的抑制作用,并按国家消毒技术规范要求进行空气消毒试验。结果发现,茶树精油组合物对室内空气中的两种常见的青霉属、曲霉属菌有抑制作用,而过氧乙酸仅对青霉属菌有抑制作用,当茶树精油组合物用量在1 mL/m~3时,0.5 h后其杀菌率达99.9%。因此,茶树精油组合物可作为有效的室内霉菌消毒剂。     

新型复方苍术空气消毒剂的研制与应用

介绍了新型复方苍术空气消毒剂的制备方法,并采用空气沉降法对其消毒效果进行了考察。结果表明,新型复方苍术空气消毒剂具有消毒作用发挥快,抑菌、杀菌作用强,无毒无刺激、作用时效长、使用便捷等优点,是一种效果显著的空气消毒剂,非常适合疫情期间在医院、商场超市、餐饮、铁路、客运、民航、中小学校、家庭等多种场所使用。     

花椒精油的挥发性化学成分及其香气进展

以花椒精油的挥发性化学成分及其香气组分为出发点,综述了花椒精油的香气差异。香气的表征方法有气相色谱法、液相色谱法、气相色谱—质谱法、感官香气评价法、电子鼻技术等。精油香气的应用主要为微胶囊香精、空气清新剂、香水等领域。利用易降解、环境友好型纤维素气凝胶的吸附性能制备花椒精油/纤维素气凝胶是有待研发的一个方向。     

盲孔快速镀铜添加剂对填孔效果的影响及其作用过程

介绍了一种快速填盲孔电镀铜工艺,镀液组成和工艺条件是:CuSO_4·5H_2O 210 g/L,H_2SO_4 85 g/L,Cl~-50 mg/L,润湿剂C(环氧乙烷与环氧丙烷缩聚物)5~30 mL/L,整平剂L(含酰胺的杂环化合物与丙烯酰胺和烷基化试剂的反应产物)3~16 mL/L,加速剂B(苯基聚二硫丙烷磺酸钠)0.5~3.0 mL/L,温度23℃,电流密度1.6 A/dm~2,阴极摇摆15回/min或空气搅拌。研究了湿润剂C、整平剂L和加速剂B对盲孔填孔效果的影响。结果表明,润湿剂C与加速剂B用量对填孔效果的影响较大,而整平剂L用量的影响较小。最优组合添加剂为:整平剂L 8 mL/L,湿润剂C 15 mL/L,加速剂B 1.5 mL/L。采用含该添加剂的镀液对孔径100~125μm、介质厚度75μm的盲孔进行填孔电镀时,填孔率大于95%,铜镀层的延展性和可靠性满足印制电路板技术要求。此外,对添加剂填孔过程的研究表明,爆发期在起镀后的20~30 min,爆发期孔内的沉积速率是表面沉积速率的11倍以上。     

桉叶素-松油醇型复合精油对6种霉菌的抑制作用研究

采用平板试验并以丙酸为对照研究桉叶素-松油醇型重整复合精油对轮枝镰刀菌、黄曲霉、桔青霉、枯草芽孢杆菌、酵母菌和副干酪乳杆菌6种菌的抑菌作用。试验结果表明,复合精油在一定浓度范围对6种菌具有较好的抑菌作用,对黄曲霉、桔青霉、酵母菌和副干酪乳杆菌的抑制效果优于丙酸,对轮枝镰刀菌和枯草芽孢杆菌的抑制效果稍差于丙酸,对这6种菌有明显抑制效果的应用体积比范围为0.075~0.240μL/m L,丙酸的有效抑菌体积比范围为0.045~0.263μL/m L,复合精油的有效浓度范围处于丙酸有效浓度范围之内,具有很好的抑菌效果。     

超滤膜技术组合工艺对饮用水氯消毒的生物稳定性试验

以某水库微污染水源水为试验水样,比较了以超滤为核心的不同组合工艺的净水效果,考察了各组合工艺出水氯消毒对异养菌的灭活效果、持续消毒能力,研究了余氯的衰减、消毒副产物的生成以及对水质生物稳定的影响,从生物安全性和化学安全性两个方面对不同超滤组合工艺出水氯消毒安全性进行综合评价。结果表明,混凝沉淀-粉末活性炭-超滤组合工艺具有最佳的净水效果:该工艺能100%的去除水中的细菌总数、大肠杆菌;持续消毒能力强,72 h后水中余氯量为0.5 mg/L,对细菌总数、大肠杆菌的去除率仍为100%,且HPC小于100 CFU/mL,符合生活饮用水卫生标准;消毒副产物的生成量控制在10μg/L以下;出水AOC含量低于100μgac-C/L,符合氯化消毒生物稳定性的要求。     

杀菌干燥剂的研究现状及进展

干燥剂是在食品药品包装中常用的延长保质期的制品,然而以往所使用的干燥剂,如硅胶干燥剂、氯化钙干燥剂等,虽然被广泛使用,在性能方面却存在着不足,针对这些不足,很多新型干燥剂应运而生。本文将综述蒙脱石干燥剂、新型硅胶复合干燥剂以及氧化钙干燥剂的优缺点和作用机理,并分析其与植物精油型空气杀菌清新剂结合的可能性,探寻能否研制出新型杀菌干燥剂。新型杀菌干燥剂将同时具备杀菌和干燥的功效。     

甜橙精油抑制酪氨酸酶的机理研究

研究甜橙精油对酪氨酸酶活性的影响及其抑制动力学,试验结果表明:甜橙精油对酪氨酸酶具有明显的抑制作用,表现出良好的剂量-效应关系,其半数抑制浓度(IC_(50))约为627.52μg/mL。Lineweaver-Burk双倒数图表明甜橙精油对酪氨酸酶的作用表现为非竞争性抑制,米氏常数K_m为0.357。     

天然空气清新剂制备及其防腐和吸收CO_2性能研究

从蒜、姜、茶叶和橘子皮中提取有效成分,经复配后溶解于溶剂得到天然空气清新剂,考察了该天然空气清新剂对水果防腐以及CO2吸收情况,研究表明:所制备空气清新剂对CO2吸收是其对照组(酒精水溶液)的2.5倍,能有效保住水果表面水分、延缓水果变质腐烂。     

四种植物精油对草莓致病菌的协同抑制作用研究

通过研究肉桂、山苍子、芳樟及丁香四种植物精油及复合精油对草莓致病菌的抑菌效果,筛选出对草莓致病菌优化的复合精油组合.采用直接接触法和熏蒸法、常量稀释法、棋盘稀释法对草莓致病菌进行抑菌评价,并计算FICI指数.实验表明肉桂-山苍子复合精油对沙门氏菌、灰葡萄孢霉具有一定的协同抑菌效果,其FICI均为0.5,MIC分别为0.156、0.625 μL/mL.肉桂-山苍子(V∶V=1∶1)精油处理沙氏菌和灰葡萄孢霉的抑菌圈直径最大.通过复合精油处理沙门氏菌、灰葡萄孢霉在内容物泄露、电导率变化及菌体形态扫描电镜(SEM)的实验,复合精油严重破坏菌体结构,细胞膜渗透性增加,破坏胞内离子稳态,核酸等内容物泄露,菌体形态发生皱缩、扭曲,表明复合精油对供试菌具有损伤作用.复合精油之间的协同作用具有更好的抑菌效果,能够减少精油用量,在草莓保鲜应用上前景良好.     

Chemical Compositions, Antioxidant and Antimicrobial Activities of Essential Oils of Piper caninum Blume

Chemical composition, antioxidant and antimicrobial activities of the fresh leaves and stems oils of Piper caninum were investigated. A total of forty eight constituents were identified in the leaves (77.9%) and stems (87.0%) oil which were characterized by high proportions of phenylpropanoid, safrole with 17.1% for leaves and 25.5% for stems oil. Antioxidant activities were evaluated by using β-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. Stems oil showed the highest inhibitory activity towards lipid peroxidation (114.9 ± 0.9%), compared to BHT (95.5 ± 0.5%), while leaves oil showed significant total phenolic content (27.4 ± 0.5 mg GA/g) equivalent to gallic acid. However, the essential oils showed weak activity towards DPPH free-radical scavenging. Evaluation of antimicrobial activity revealed that both oils exhibited strong activity against all bacteria strains with MIC values in the range 62.5 to 250 μg/mL, but weak activity against fungal strains. These findings suggest that the essential oils can be used as antioxidant and antimicrobial agents for therapeutic, nutraceutical industries and food manufactures.     

GC and GC/MS Analysis of Essential Oil Composition of the Endemic Soqotraen Leucas virgata Balf.f. and Its Antimicrobial and Antioxidant Activities

Leucas virgata Balf.f. (Lamiaceae) was collected from the Island Soqotra (Yemen) and its essential oil was obtained by hydrodistillation. The chemical composition of the oil was investigated by GC and GC-MS. Moreover, the essential oil was evaluated for its antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria, and one yeast species by using broth micro-dilution assay for minimum inhibitory concentrations (MIC) and antioxidant activity by measuring the scavenging activity of the DPPH radical. The investigation led to the identification of 43 constituents, representing 93.9% of the total oil. The essential oil of L. virgata was characterized by a high content of oxygenated monoterpenes (50.8%). Camphor (20.5%) exo-fenchol (3.4%), fenchon (5.4%), and borneol (3.1%) were identified as the main components. Oxygenated sesquiterpenes were found as the second major group of compounds (21.0%). β-Eudesmol (6.1%) and caryophyllene oxide (5.1%) were the major compounds among oxygenated sesquiterpenes. The results of the antimicrobial assay showed that the oil exhibited a great antibacterial activity against the tested S. aureus, B. subtilis, and E. coli. No activity was found against P. aeruginosa and C. albicans. Moreover, the DPPH-radical scavenging assay exhibited only a moderate antioxidant activity (31%) for the oil at the highest concentration tested (1 mg/mL).     

Chemical Composition and Antimicrobial Activity of the Essential Oil of Kumquat (Fortunella crassifolia Swingle) Peel

The aim of this study was to determine the main constituents of the essential oil isolated from Fortunella crassifolia Swingle peel by hydro-distillation, and to test the efficacy of the essential oil on antimicrobial activity. Twenty-five components, representing 92.36% of the total oil, were identified by GC-MS analysis. The essential oil showed potent antimicrobial activity against both Gram-negative (E. coli and S. typhimurium) and Gram-positive (S. aureus, B. cereus, B. subtilis, L. bulgaricus, and B. laterosporus) bacteria, together with a remarkable antifungal activity against C. albicans. In a food model of beef extract, the essential oil was observed to possess an effective capacity to control the total counts of viable bacteria. Furthermore, the essential oil showed strongly detrimental effects on the growth and morphological structure of the tested bacteria. It was suggested that the essential oil from Fortunella crassifolia Swingle peel might be used as a natural food preservative against bacteria or fungus in the food industry.     

Identification of Compounds in the Essential Oil of Nutmeg Seeds (Myristica fragrans Houtt.) That Inhibit Locomotor Activity in Mice

The present study was designed to evaluate the inhibitory effect of nutmeg (Myristica fragrans Houtt.) seed essential oil on the locomotor activity of mice in a wheel cage. Active compounds in the essential oil were identified by off-line solid phase extraction (SPE-C18) and GC/MS analysis. The essential oil was administered by inhalation at doses of 0.1, 0.3, and 0.5 mL/cage. The results showed that inhalation of nutmeg seed essential oil at a dose of 0.5 mL/cage decreased locomotion by 68.62%; and inhalation of 0.1 and 0.3 mL/cage inhibited locomotion by 62.81% and 65.33%, respectively. Generally, larger doses and longer administrations of nutmeg seed essential oil exhibited greater locomotor inhibition. Subsequently, the plasma concentrations of essential oil compounds were measured. The most concentrated compound in the plasma was myristicin. Half an hour after the addition of 1 mL/cage of nutmeg seed oil, the plasma concentration of myristicin was 3.7 μg/mL; one and two hours after the addition, the blood levels of myristicin were 5.2 μg/mL and 7.1 μg/mL, respectively. Other essential oil compounds identified in plasma were safrole (two-hour inhalation: 1.28 μg/mL), 4-terpineol (half-hour inhalation: 1.49 μg/mL, one-hour inhalation: 2.95 μg/mL, two-hour inhalation: 6.28 μg/mL) and fatty esters. The concentrations of the essential oil compounds in the blood plasma were relatively low (μg/mL or ppm). In conclusion, the volatile compounds of nutmeg seed essential oil identified in the blood plasma may correlate with the locomotor-inhibiting properties of the oil when administered by inhalation.     

Pharmacological Assessment of the Medicinal Potential of Acacia mearnsii De Wild.: Antimicrobial and Toxicity Activities

Acacia mearnsii De Wild. (Fabaceae) is a medicinal plant used in the treatment of microbial infections in South Africa without scientific validation of its bioactivity and toxicity. The antimicrobial activity of the crude acetone extract was evaluated by both agar diffusion and macrobroth dilution methods while its cytotoxicity effect was assessed with brine shrimp lethality assay. The study showed that both bacterial and fungal isolates were highly inhibited by the crude extract. The MIC values for the gram-positive bacteria (78.1-312.5) μg/mL, gram-negative bacteria (39.1-625) μg/mL and fungal isolates (625-5000) μg/mL differ significantly. The bacteria were more susceptible than the fungal strains tested. The antibiosis determination showed that the extract was more (75%) bactericidal than bacteriostatic (25%) and more fungicidal (66.67%) than fungistatic (33.33%). The cytotoxic activity of the extract was observed between 31.25 μg/mL and 500 μg/mL and the LC(50) value (112.36 μg/mL) indicates that the extract was nontoxic in the brine shrimp lethality assay (LC(50) > 100 μg/mL). These results support the use of A. mearnsii in traditional medicine for treatment of microbial infections. The extract exhibiting significant broad spectrum antimicrobial activity and nontoxic effects has potential to yield active antimicrobial compounds.     

Synthesis of Chimeric Thiazolo-Nootkatone Derivatives as Potent Antimicrobial Agents

Nootkatone, an approved insecticide, is a well-known natural product from grapefruit. A series of fused-thiazole derivatives of nootkatone have been synthesized, and these new compounds were tested against several strains of bacteria. Some of these compounds are found to be potent antimicrobial agents against Staphylococcus aureus and Enterococcus faecium with minimum inhibitory concentration (MIC) values as low as 1.56 μg/mL. The lead compound is bactericidal and very potent against S. aureus persisters. These compounds are nontoxic to human cancer cell lines at 10 μm concentration.     

基于山苍子精油的复配筛选及协同抗菌性能

为解决单一植物精油在抗菌应用时,用量相对较大、气味单一且浓郁刺激、易引起人们感官不适及过敏反应等问题。通过研究13种单一植物精油对大肠杆菌和金黄色葡萄球菌的抑菌效果,以山苍子精油为基调,采用棋盘稀释法、抑菌圈法、感官评价等方法筛选出具有协同抗菌效果的芳香复配精油,并以大肠杆菌为供试菌探究了其抑菌机理。结果表明,当V(山苍子精油) ∶V(肉桂精油)=2∶1时制备的复配精油对大肠杆菌和金黄色葡萄球菌具有优异的协同抗菌性,抑菌圈直径分别为（21.12±0.17）mm和（40.26±0.61）mm,且香气较愉悦、舒适、易接受。与单一山苍子精油和肉桂精油相比,复配精油对大肠杆菌的抑制效果更为明显,且可以破坏菌体细胞膜,影响细胞膜通透性,导致细胞内离子、核酸等成分泄露,使得菌液相对电导率明显增加,细菌细胞内容物泄露程度与单一山苍子精油和肉桂精油相比分别提升140%和20%。     

基于山苍子精油的复配筛选及协同抗菌性能

为解决单一植物精油在抗菌应用时用量相对较大、气味单一且浓郁刺激、易引起人们感官不适及过敏反应等问题。通过研究13种单一植物精油对大肠杆菌和金黄色葡萄球菌的抑菌效果，以山苍子精油为基调，采用棋盘稀释法、抑菌圈法、感官评价法筛选出具有协同抗菌效果的芳香复配精油，并以大肠杆菌为供试菌探究了其抑菌机理。结果表明，当V(山苍子精油)∶V(肉桂精油)=2∶1时制备的复配精油对大肠杆菌和金黄色葡萄球菌具有优异的协同抗菌性，抑菌圈直径分别为（21.12±0.17）和（40.26±0.61）mm，且香气较愉悦、舒适、易接受。与单一山苍子精油和肉桂精油相比，复配精油对大肠杆菌的抑制效果更为明显，且可以破坏菌体细胞膜，影响细胞膜通透性，导致细胞内离子、核酸等成分泄漏，使菌液相对电导率明显增加，细菌细胞内容物泄漏程度与单一山苍子精油和肉桂精油相比分别提升140%和20%。     

几种植物精油对桔青霉菌的抑菌活性测定

采用气相抑菌法测定了香茅油、松节油、桉叶油、珊瑚姜油、椒样薄荷油、青花椒油和迷迭香油7种植物精油对桔青霉菌（penicillium citrinum Thorn．）的抑制效果。结果表明,松节油和香茅油抑菌效果最好,在体积比浓度为1μL／mL时可完全抑制桔青霉菌生长,桉叶油和珊瑚姜油效果次之,分别在2和4μL／mL时完全抑制桔青霉菌生长,椒样薄荷油和花椒油效果较差,在4μL／mL时仍有少量霉菌生长,而迷迭香油在4μL／mL时仍有较多菌落生长。     

水溶性壳聚糖稀土配合物的合成、表征及其抑菌性研究

以水溶性壳聚糖(CS)与稀土离子La3+, Nd3+, Sm3+, Eu3+和Dy3+在常温和pH值为4~5的条件下制备了水溶性壳聚糖稀土配合物CS-La, CS-Nd, CS-Sm, CS-Eu和CS-Dy. 并运用FT-IR, UV和TG-DTA对其配合物进行表征,并研究了配体和配合物的热稳定性及配合物的抑菌活性. 结果表明,5种配合物均有选择性抑菌性能;其对大肠杆菌和金黄色葡萄球菌均有很好的抑菌作用;其对5种菌的最小抑菌浓度(MIC)为120~500 mg/mL,低于800 mg/mL,且抑菌效果明显优于单独的壳聚糖和稀土硝酸盐. CS-Sm对大肠杆菌的抑菌性最好,MIC为125 mg/mL;而CS-Nd和CS-Sm对金黄色葡萄球菌的抑菌性最强,MIC均为120 mg/mL.