Compositions and antimicrobial activities of the essential oils of two Hypericum species from Turkey

The chemical compositions of essential oils obtained from Hypericum hyssopifolium var. microcalycinum and Hypericum lysimachioides var. lysimachioides were analysed by using GC and GC-MS. Caryophyllene oxide was found to be the major component. The essential oils of both Hypericum species showed antimicrobial activity against nine microorganism at a concentration of 60 to 80 microg/ml.     

Antimicrobial and antiplasmid activities of essential oils

The antimicrobial and antiplasmid activities of essential oils (orange oil, eucalyptus oil, fennel oil, geranium oil, juniper oil, peppermint oil, rosemary oil, purified turpentine oil, thyme oil, Australian tea tree oil) and of menthol, the main component of peppermint oil, were investigated. The antimicrobial activities were determined on the Gram (+) Staphylococcus epidermidis and the Gram (-) Escherichia coli F'lac K12 LE140, and on two yeast Saccharomyces cerevisiae 0425 delta/1 and 0425 52C strains. The antiplasmid activities were investigated on E. coli F'lac bacterial strain. Each of the oils exhibited antimicrobial activity and three of them antiplasmid action. The interaction of peppermint oil and menthol with the antibiotics was studied on the same bacterial strain with the checkerboard method. Peppermint oil and menthol displayed additive synergy with oxytetracycline. A new mechanism of plasmid curing was established for one of the oil components.     

Chemical variability of essential oils of Protium colombianum from two tropical life zones and their in vitro activity against isolates of Fusarium

There is considerable interest in finding replacements for the synthetic fungicides and preservatives that are currently used to control fungal pathogens; however, any alternative compounds must be safe and must prevent the development of microbial resistance. In this regard, essential oils have received special attention. Protium colombianum Cuatrecasas is an endemic tree found in tropical rainforests and possesses aromatic and resinous characteristics. To date, there have been no reports concerning the chemistry of this species, which belongs to a genus that represents an interesting source of essential oils that are occasionally used as antimicrobial agents. Therefore, the chemical composition of the essential oils found in P. colombianum collected from two life zones over a five-month period was analyzed using gas-chromatography/mass-spectrometry. A total of 92 components, comprising 97.7–99.9 % of the total composition, were identified based on their mass spectra and the retention indices. Precedence markers were identified for each life zone, and seasonality affected the samples from one life zone when rainfall was maximum. The in vitro activity against Fusarium oxysporum isolates from carnation and chrysanthemum, as well as a Fusarium solani isolate from chrysanthemum, was tested by determining the minimum inhibitory concentration. Assays using essential oils and control substances showed that terpenoid and phenolic compounds are mainly responsible for the observed anti-fungal activity. These results suggest that P. colombianum essential oils exhibit cytotoxicity against Fusarium isolates and that the search for new sources of anti-fungal essential oils should include sources that contain different ratios of terpenoid and phenolic compounds.     

Chemical composition,antimicrobial and antioxidant activities of anethole-rich oil from leaves of selected varieties of fennel [Foeniculum vulgare Mill. ssp. vulgare var. azoricum (Mill.) Thell]

The chemical composition and biological activity of the essential oils obtained from the leaves of two different cultivars of Florence fennel cropped under three different fertilization treatments (Control not fertilized; Mineral Fertilization; Compost from Municipal Solid Wastes) have been analyzed. All the oils were characterized by high anethole concentration and some showed also a good percentage of limonene.Thus, the leaves of Florence fennel, which are agricultural wastes, could be used for the recovery of anethole to be used for its flavoring and biomedical properties. The antimicrobial activity expressed by assays on the examined oils indicates an appreciable effect, generally higher on Gram-positive bacteria. The various samples of Florence fennel analyzed did not show any results with FRAP test. The DPPH test showed a weak capacity of the samples to catch the free radicals from the solution, attributable to their content in anethole.     

防治木材变色的植物精油优选

为了开发木材变色防治用的天然环保产品,选用19种植物精油,依据精油的挥发速率及其对培养基中变色菌的抑菌效力,筛选综合性能较优的精油产品。结果表明,植物精油的挥发速率为7.9~550.8g·m^-2·h^-1,迷迭香和丝柏精油挥发较快,而雪松、肉桂和安息香精油挥发较慢。随着植物精油的体积分数由0.01%提高至0.05%,其对可可球二孢和串珠镰刀菌的平均抑菌效力分别由19%和21%增加至50%和59%,抑菌性能明显增强。以抑菌效力为变量的聚类分析表明,肉桂、丁香花、柠檬草和百里香4种植物精油对两种变色菌表现出较优的抑菌特性,其在体积分数0.05%条件下的抑菌效力达到100%。综合考虑抑菌效力和作用持久性,肉桂、丁香花和柠檬草精油是防治可可球二孢和串珠镰刀菌的较优品种。     

Insecticidal activity of some essential oils against larvae of Spodoptera littoralis

Thirty-four essential oils were tested for insecticidal activity (fumigation or topical application) against larvae Spodoptera littoralis. Twenty essential oils applied by fumigation were highly toxic to the third instar of S. littoralis larvae. Two essential oils Nepeta cataria and Thuja occidentalis were highly toxic, with LC50< or =10.0 ml/m3. Five essential oils Salvia sclarea, Thymus mastichina, Origanum majorana, Pogostemon cablin and Mentha pulegium were toxic with LC50 between 10.1 and 20.0 l ml/m3. Twenty-three essential oils were highly toxic to the third instar of S. littoralis larvae after topical application. Eight essential oils Mentha citrata, N. cataria, S. sclarea, O. vulgare, O. compactum, Melissa officinalis, T. mastichina, and Lavandula angustifolia were highly toxic with LD50 < or =0.05 microl/larvae.     

Thymoquinone vapor significantly affects the results of Staphylococcus aureus sensitivity tests using the standard broth microdilution method

The broth microdilution (BMD) method is widely used for the determination of minimum inhibitory concentrations of antimicrobial agents, including volatile oils and their components. In this series of various experiments, we have demonstrated the influence of thymoquinone (TQ) vapor on the results of the BMD test performed with Staphylococcus aureus as a model organism. The spread of vapor from the TQ containing wells (32–512 μg/mL) caused the complete inhibition of staphylococcal growth in adjoining wells initially containing bacterium-inoculated pure Mueller–Hinton broth only and thus produced false positive results of the test. The ability of TQ to pass into the adjoined wells was subsequently confirmed by gas chromatography–mass spectrometry, whereas TQ at concentrations up to 84 μg/mL was detected in these wells after five hours. Based on these results, we suppose that vapors of TQ as well as of other naturally occurring volatile compounds and their mixtures (for example essential oils and plant extracts) can significantly influence results of the standard BMD assay. These observations, therefore, call for development of new appropriate BMD method suitable for assessment of antimicrobial activity of volatile substances.     

Antimicrobial activities of essential oil from Artemisiae argyi leaves

Introduction Artemisia species, widespread throughout the world, are important medicinal plants, which are receiving phytochemical attention due to the biological and chemical diversities (Tan et al. 1998). Artemisias (Compositae) are one of the most popu…     

植物精油对木材霉变菌的抑菌效力研究

【目的】植物精油是一类安全环保且具有抑菌特性的天然产物,在木材霉变防治领域的应用潜力很大。开展植物精油对我国常见木材霉菌及变色菌的综合抑菌效力的研究,可为天然环保型木材霉变防治剂的开发提供重要依据。【方法】配制经植物精油修正的马铃薯葡萄糖琼脂培养基,通过评价霉变菌在培养基中的生长状况,对比分析19种植物精油对6种木材霉变菌的抑菌效力。【结果】在体积分数为0.05%的条件下,19种植物精油对黑曲霉Aspergillus niger、桔青霉Penicillam citrinum、绿色木霉Trichoderma viride、可可球二孢Botryodiplodia theobromae、串珠镰刀菌Fusarium moniliforme和链格孢霉Alternaria alternata的抑菌效力分别为0~100%、0~100%、0~100%、0~100%、11%~100%和20%~100%。聚类分析表明,肉桂、丁香花和百里香精油的综合抑菌效力最高,在体积分数0.05%的条件下对6种霉变菌的抑菌效力均达到100%,而尤加利、甜橙和松树精油的综合抑菌效力最低。相关分析表明,植物精油对6种霉变菌的抑菌效力之间均表现出显著相关性(P=0.01),其Pearson相关系数为0.777~0.959。【结论】不同植物精油的抑菌效力之间表现出较大差异,肉桂、丁香花和百里香精油是可以用于木材霉变防治的较优品种。     

杉木心材精油对黑胸散白蚁的触杀毒性研究

以水蒸汽蒸馏法提取杉木心材精油,其精油得率为0.73％～0.79％.用毒土法进行杉木心材精油对黑胸散白蚁的触杀毒性试验,结果表明:杉木心材精油对黑胸散白蚁具有较强的触杀毒性,且其毒性的大小与处理时间和浓度有关;当其浓度为160m/L时,72 h内白蚁死亡率为100％.     

红松不同部位精油的成分分析及抑菌活性

[目的]植物精油是安全并有良好抑菌效果的天然产物,在食品防腐剂领域潜力巨大.本研究通过对红松不同部位精油成分与抑菌活性的研究,能为开发安全绿色的食品防腐剂及为其在食品、化妆品等领域的应用提供理论基础.[方法]采用水蒸气蒸馏法从红松的松针、松塔、松壳中制备精油,采用气相色谱-质谱(GC-MS)联用技术结合保留指数(RI)...     

Composition and biological activity of essential oil of Achillea ligustica All. (Asteraceae) naturalized in central Italy: Ideal candidate for anti-cariogenic formulations

Essential oil from flowers (FL) and vegetative parts (VP) of Achillea ligustica (Asteraceae), naturalized after cultivation in central Italy, was investigated by GC–FID and GC–MS. The most abundant components were linalool, viridiflorol, β-pinene, 1,8-cineole and terpinen-4-ol. The antioxidant assays (DPPH and ABTS radical scavenging assays, and β-carotene bleaching test) demonstrated a moderate activity of essential oils. The antimicrobial activity was evaluated by the broth micro-dilution method on 6 microbial strains and showed to be quite strong against the cariogenic Gram-positive Streptococcus mutans, suggesting that this essential oil could be a valid candidate for anti-cariogenic formulations. Moderate cytotoxic activity was observed in assays on four tumour cell lines by MTT assay.     

Chemical analysis of essential oils of Eupatorium adenophorum and their antimicrobial,antioxidant and phytotoxic properties

Essential oils from inflorescences and roots of Eupatorium adenophorum Spreng (Asteraceae) have been investigated for their antimicrobial, phytotoxic and antioxidant activities. Based on GC–MS, the oil from inflorescences is dominated by sesquiterpenes (55.9 %) with γ-cadinene (18.4 %), γ-muurolene (11.7 %), 3-acetoxyamorpha-4,7(11)-diene-8-one (7.4 %) and bornyl acetate (6.3 %) as the major constituents. The oil obtained from the roots contained both sesquiterpenes (34.3 %) and monoterpenes (32.5 %) in almost equal proportions with E,E-cosmene (19.9 %), γ-muurolene (10.1 %), isothymol (7.5 %), β-cadinene (7.0 %) and α-phellandren-8-ol (5.9 %) as the major constituents. Both oils exhibited significant antifungal activity against five phytopathogenic fungi. The inflorescence oil showed higher antibacterial activity against Klebsiella pneumoniae, while the root oil was more effective against Staphylococcus aureus. The oils strongly inhibited or delayed germination and seedling growth of the weed Phalaris minor in a dose-dependent manner. As evidenced by a DPPH assay, the essential oils also exhibited significant free radical scavenging activity.     

杨梅树叶、皮、根部精油成分及其抗氧化活性物质

采用GC-MS技术结合Kovats保留指数(KI)对比法分析鉴定了采自南岭自然保护区的乌杨梅(Myrica rubravar.astropureaTsen.)叶、皮和根部芳香精油的成分,同时运用薄层层析(TLC)筛分法对其抗氧化活性物质进行了对比分析。杨梅树根和树皮精油的主要成分为5-羟基菖蒲烯(相对含量分别为74.66%和60.32%)和油酸(7.74%和11.39%),而树叶精油的主体成分为5-羟基菖蒲烯(30.44%)、石竹烯(11.61%)、异石竹烯(10.17%)、(E)-橙花叔醇(9.57%)和油酸(4.40%)。树根、树皮到树叶部位的次生代谢物明显出现越来越复杂的分化特性。5-羟基菖蒲烯是3个部位精油的主要抗氧化活性物质,但叶部精油中的倍半萜烯类物质也表现出一定的二苯代苦味酰(DPPH)自由基清除活性。     

龙脑樟叶部精油在不同蒸馏时段的出油率和化学成分

考察龙脑樟叶在不同蒸馏时段的出油率和化学成分。采用水蒸汽蒸馏的方法、水中蒸馏的方式,将2 h的蒸馏过程分成4个阶段,收集相应的馏分,分别进行计量和GC-MS分析,结果表明,总出油率达到2.81%,蒸馏一开始就产生大量的馏分,96.53%的馏分集中在前60 min内蒸出。通过GC-MS分析鉴定,发现龙脑樟叶挥发油中主成分为右旋龙脑（天然冰片）,其含量高达81.78%,其余还有樟脑、1,8-桉叶油素、黄樟油素、α-蒎烯、芳樟醇、乙酸龙脑酯等31个化学成分。     

Antibacterial properties of Thymus pubescens and Thymus serpyllum essential oils

Antibacterial properties of essential oils of Thymus pubescens and Thymus serpyllum collected at pre and flowering stages were studied. The oils were found to possess bactericidal activities.     

竹叶挥发油化学成分及其抗氧化特性

采用水蒸气蒸馏法从黄金间碧竹、孝顺竹、毛竹和麻竹4种竹叶中提取挥发油,用气相色谱-质谱联用技术对4种竹叶挥发油化学成分进行分析和鉴定,共获得168个色谱峰,鉴定其中132种化学成分,并运用气相色谱面积归一化法确定各组分的相对含量;以TBHQ为对照品,采用DPPH法研究4种竹叶挥发油对自由基的清除作用.结果表明:采用水蒸气蒸馏法黄金间碧竹竹叶挥发油的得率最高(0.827%),而毛竹竹叶挥发油的得率仅为0.391%.4种竹叶挥发油的化学成分在含量和组成上不同,竹叶挥发油主要化学成分是3-甲基-2-丁醇,麻竹竹叶挥发油含量最高达到46.25%;其他主要化学成分有4-乙烯基-2-甲氧基-苯酚、己-2-烯醛、橙花叔醇、植物醇、苯乙醛、天竺葵醛、植酮、二氢猕猴桃内酯和异植物醇.4种竹叶挥发油均有较强的抗氧化活性,竹叶挥发油的抗氧化活性与挥发油的浓度呈正相关(r=0.91),其中黄金间碧竹竹叶挥发油的抗氧化活性最强(IC50=2.705mg·mL-1),孝顺竹竹叶挥发油抗氧化活性较低(IC50=3.442mg·mL-1).综合研究结果表明,竹叶挥发油具有较高的应用价值,可作为食品和药品的功能性组分进一步开发和利用.     

Toxicity and antitermite activity of the essential oils from Cinnamomum camphora, Cymbopogon nardus, Melaleuca cajuputi and Dipterocarpus sp. against Coptotermes curvignathus

Efficacy of four different essential oils against the subterranean termite, Coptotermes curvignathus Holmgren, was assessed in various bioassays. Laboratory results indicate that the highest termite mortality was found in Dipterocarpus sp. essential oil after 24 h (LC₅₀ = 1.62 %) and the lowest in Melaleuca cajuputi (LC₅₀ = 4.60 %). The wood consumption in the filter paper treated with Dipterocarpus sp. oil is also smaller than for the other three essential oils tested. However, the other three essential oils also inhibited termite susceptibility of the specimens. Dipterocarpus sp. (keruing oil) was the most effective insect antifeedant and repellent against C. curvignathus. The results suggest that essential oils might have some beneficial activity of economic value and are considered good candidates for the development of new chemicals (repellents or antifeedants) for termite control.     

不同采收期单叶蔓荆子挥发油成分的分析比较

采用水蒸气蒸馏法提取不同采收时期(早、中、晚)的单叶蔓荆子挥发油,得率分别为0.35%、0.41%和0.39%。气相色谱-质谱联用分析结果表明:从3种采收期蔓荆子挥发油中分别分离鉴定得到19、22和29种成分;虽然仅有5种相同成分:1,8-桉油精(1,8-环氧对薄荷烷)、反-水合桧烯、β-葑基乙醇、β-荜澄茄油烯和τ-萘醇等(在早、中、晚期样中这5种成分总质量分数分别为13.778%、12.871%和15.097%),但主体成分均为单萜及倍半萜类化合物(3个时期样中的质量分数分别为99.6%、90.2%和94.1%)。不同采收期的蔓荆子挥发油主要成分各有特征:早期呈高蒎烷型,中期呈高乙酰氧基-对-薄荷烷型,晚期呈高对-薄荷烷(二烯)型;具代表性的首要成分分别为α-蒎烯(34.994%)、1-乙酰氧基-对-薄荷烷-4(8)-烯(63.943%)和dl-柠檬烯(4-薄荷烷-1,8-二烯,31.819%)。早期挥发油中质量分数较高的还有1-乙酰氧基-对-薄荷烷-4(8)-烯(22.972%)、β-水芹烯(10.753%)、1,8-桉油精(8.151%)和桧烯(7.842%)等,而晚期有β-蒎烯(15.798%)、β-石竹烯(10.043%)和1,8-桉油精(5.927%)。此外,中期出现4种脂肪族化合物(占总质量的6.08%);晚期不含有1-乙酰氧基-对-薄荷烷-4(8)-烯,而出现一些沸点较高的三环倍半萜类如δ-古芸烯(3.584%)、β-荜澄茄油烯(6.774%)。