Sensitivity of fungi isolated from onychomycosis to Eugenia cariophyllata essential oil and eugenol

The antifungal activity of Eugenia cariophyllata essential oil and eugenol, its major constituent, on fungal strains isolated from onychomycosis was evaluated. The natural products presented prominent antifungal action with MIC of 1% and 4%, respectively.     

超临界CO2 流体萃取 - 分子蒸馏提取丁香精油的研究

用超临界CO2流体萃取技术(SCDE)萃取丁香精油,然后用分子蒸馏技术(MD)进行精制,所得精油经气相色谱 - 质谱(GC - MS)分析并与传统提取方法比较.正交试验分析结果显示,SCDE最佳工艺条件为:萃取温度45℃、萃取压力12MPa、解析温度50℃.SCDE得油率达到21.04%,经GC - MS分析共检测出22种成分,主要成分丁香酚GC含量为67.56%,经MD精制后,尽管丁香酚、β - 石竹烯、乙酰基丁香酚3种有效成分的总含量与水蒸气蒸馏法和有机溶剂回流法相差不大,但精油中丁香酚提高至68.75%,精油色泽和流动性明显改善,品质明显提高.SCDE - MD技术萃取丁香精油的得油率为19.18%,高于水蒸气蒸馏法(11.38%)和正己烷回流法(17.40%),而且萃取时间短,色素、树脂含量低.     

丁香酚在生物质半焦催化下的转化行为

以不同热解温度下制备的生物质半焦作为催化剂,在二段固定床反应器中考察木质素模型化合物(丁香酚)的转化行为,利用气相色谱质谱仪分析液体产物的成分及含量,进而考察催化反应过程中的转化路径;通过对催化反应前后的半焦结构表征,探究其结构变化对催化作用的影响。结果表明,热解温度400℃时制备的半焦(400BC)能够显著促进丁香酚向异丁香酚转化,其相对含量占热解产物的66.7%,而600℃的半焦(600BC)催化效果明显较弱。通过X射线光电子能谱和傅里叶变换红外光谱表征分析发现:400BC表面含氧官能团—OH和—COO含量高于600BC,表明半焦表面含氧官能团对丁香酚异构化反应起重要作用,且—OH的催化效果优于—COO。拉曼光谱分析则表明:生物质半焦中小芳环结构与大芳环结构I(GR+VL+VR)/ID比值从400BC的1.64下降到600BC的1.46,且催化反应后其比值进一步变小,说明半焦炭结构中的小芳环具有一定的催化活性,随着半焦制备温度的升高及催化反应的进行,半焦中小芳环逐级向大芳环转化,石墨化程度增大,从而导致活性降低。此外,笔者构建出生物质半焦对丁香酚的催化机理,即半焦表面含氧官能团与丁香酚中羟基/苯环形成氢键,以及半焦炭结构中小芳环与丁香酚苯环通过π-π堆积效应相互作用。     

Chemical variation during daytime of constituents of the essential oil of Ocimum gratissimum leaves

Variation of chemical composition of the essential oil of Ocimum gratissimum eugenol type was studied for 11 h during the daytime. Microwave oven technique was used for the serial extraction and the obtained oils were analysed by GC/MS. A considerable variation was observed in the eugenol yield, 98% at 12.00 am. to 11% at 05.00 p.m. These results show the influence of the solar light on eugenol production and can be useful to indicate the optimal time for collection of the plant.     

Inhibitory components from the buds of clove (Syzygium aromaticum) on melanin formation in B16 melanoma cells

In the course to find a new whitening agent, we evaluated the methanol extract from bud of clove (Syzygium aromaticum) on melanin formation in B16 melanoma cells. Eugenol and eugenol acetate were isolated as the active compounds and showed melanin inhibition of 60% and 40% in B16 melanoma cell with less cytotoxicity at the concentration of 100 and 200 μg/mL, respectively. Furthermore, an essential oil prepared from the bud of clove, which contain eugenol and eugenol acetate as dominant components, showed melanin inhibition of 50% and 80% in B16 melanoma cells at the concentration of 100 and 200 μg/mL, respectively.     

Effects of eugenol on hepatic glucose production and AMPK signaling pathway in hepatocytes and C57BL/6J mice

Eugenol is a phenylpropanoid with many pharmacological activities, but its anti-hyperglycemic activity is not yet fully explored. For in vitro study, HepG2 cells and primary rat hepatocytes were used, and glucose production was induced by adding 100 nM of glucagon in the presence of gluconeogenic substrates. In animal study, hyperglycemia was induced by high fat diet (HFD) in male C57BL/6J mice, and eugenol was orally administered at 20 or 40 mg per kg (E20, E40) for 15 weeks. Eugenol significantly inhibited glucagon-induced glucose production and phosphorylated AMPK in the HepG2 and primary rat hepatocytes, and these effects were reversed in the presence of compound C (an AMPK inhibitor) or STO-609 (a CAMKK inhibitor). In addition, the protein and gene expression levels of CREB, CRTC2 · CREB complex, PGC-1α, PEPCK and G6Pase were all significantly suppressed. Moreover, inhibition of AMPK by over-expression of dominant negative AMPK prevented eugenol from suppressions of gluconeogenic gene expression and hepatic glucose production. In animal study, plasma glucose and insulin levels of the E40 group were decreased by 31% and 63%, respectively, when compared to those of HFD control. In pyruvate tolerance tests, pyruvate-induced glucose excursions were decreased, indicating that the anti-hyperglycemic activity of eugenol is primarily due to the suppression of hepatic gluconeogenesis. In summary, eugenol effectively ameliorates hyperglycemia through inhibition of hepatic gluconeogenesis via modulating CAMKK-AMPK-CREB signaling pathway. Eugenol or eugenol-containing medicinal plants could represent a promising therapeutic agent to prevent type 2 diabetes.     

Behaviour-modifying activity of eugenol on Thrips tabaci Lindeman

A series of observational bioassays were conducted to investigate the behavioural responses of the onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), to an application of a secondary plant compound to two different host plants with dissimilar leaf surface characteristics. Eugenol, a phenylpropanoid compound known to deter feeding and oviposition of the onion thrips, was applied to leek (Allium porrum L.) and cucumber (Cucumis sativus L.) at 1% concentration. Using a video system and special software for computing observational data, influences of this plant compound on the behaviour of T. tabaci females were evaluated. Eugenol treatment significantly prolonged the time periods thrips spent being inactive and moving across the treated leek or cucumber surface. The feeding periods on leek leaves treated with eugenol were clearly shorter compared to periods on untreated leek. The behaviours related to oviposition on leaves from both host species treated with eugenol were slightly reduced. T. tabaci females avoided direct contact with eugenol particularly when applied to leek, showing significantly lower contact duration compared to an untreated surface. This shows that behaviour-modifying secondary compounds such as eugenol may be used in various strategies and may contribute to the enhancement of current biological control measures and/or form novel components of Integrated Pest Management strategies.     

Effect of citral,eugenol, nerolidol and α-terpineol on the ultrastructural changes of Trichophyton mentagrophytes

The antifungal effects of citral, eugenol, nerolidol and α-terpineol on Trichophyton mentagrophytes were investigated. Citral over 0.1 mg/ml strongly inhibited the hyphal growth of T. mentagrophytes, and the antifungal activity of α-terpineol was less effective. The morphological changes of the fungus exposed to the terpenes were observed by electron microscopy. The hyphae were distorted and collapsed at 0.2, 0.4 and 1 mg/ml of eugenol, nerolidol and α-terpineol respectively, and cell membrane and organelles were irreversibly damaged at 0.2 mg/ml citral.     

Herbicidal activity of eugenol towards some grassy and broad-leaved weeds

Journal of Pest Science - The present study investigated the phytotoxic potential of eugenol, a major component from the essential oil of clove [Syzygium aromaticum (L.) Merrill and Perry], towards...     

Eugenol and thymol, alone or in combination, induce morphological alterations in the envelope of Candida albicans

The envelope of Candida albicans, with its outermost array of macromolecules protruding towards the environment, is pivotal to the expression of major virulence factors such as adhesiveness, and the morphological transition to hyphal form. We tested the anticandidal activity of eugenol, main component of clove oil, and thymol, main component of thyme oil, alone or in combination, by investigating their ability to interfere with the architecture of the envelope of C. albicans. Both molecules alterated the morphogenesis of the envelope, but the effects of thymol were more pronounced than those of eugenol. Certain combinations of the two molecules led to a synergistic effect, which is interesting in the view of potentiating their inhibition of C. albicans colonisation and infectiousness.     

Control of fruit-flies (Dacus spp.) by attractants of plant origin

Four dominating species of fruit-fliesDacus zonatus, D. cucurbitae, D. dorsalis andD. ciliatus are widely distributed throughout Pakistan. They cause heavy damage to ripe and semi-ripe fruits and vegetables annually in our country. A natural attractant of plant origin, i.e., from Tulsi (Ocimum sanctum L.) was isolated and extracted in PCSIR Laboratories Complex, Karachi, with a view to applying for the control of fruit-flies. Different extracts of roots, stems, flowers, seeds, bark, and leaves were prepared in chloroform, acetone, ethylene chloride, ethanol, and ethyl acetate; and were tested for trapping fruit-flies in specially designed traps under different field conditions. A cotton pad (0.3 mg) treated with 0.25 ml of leaves extract in ethyl acetate is found to be a potent attractant for luring and trapping the fruit-flies (Dacus spp.) from a distance of 0.8 km. Methyl eugenol used as a standard attractant also gave the same results.     

滇产艾纳香叶挥发油化学成分的GC-MS分析

用水蒸气蒸馏法提取滇产艾纳香叶的挥发油成分,经分离纯化后,采用GC-MS进行化学成分分析,共鉴定出有效组分56个,经鉴定其中相对含量 0.11%～0.50%有44个,0.51%～1.00%有6个,大于1.01%有6个.其主要成分有樟脑17.76%、龙脑52.42%,其他主要成分为异龙脑、松油醇、石竹烯、丁子香酚、愈创木醇、库贝醇等.     

Anthelmintic activity of essential oil of Ocimum sanctum and eugenol.

The essential oil of Ocimum sanctum and eugenol, tested in vitro, showed potent anthelmintic activity in the Caenorhabditis elegans model. Eugenol exhibited an ED(50) of 62.1 microg/ml. Eugenol being the predominant component of the essential oil, is suggested as the putative anthelmintic principle.     

Direct and admixture toxicity of diatomaceous earth and monoterpenoids against the storage pests <Emphasis Type="Italic">Callosobruchus</Emphasis><Emphasis Type="Italic">maculatus</Emphasis> (F.) and <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> (L.)

We investigated the effects of two commercial diatomaceous earth based insecticides (DE), Protect-It^® and SilicoSec^®, the nano-structured silica product AL06, developed by the section for Urban Plant Ecophysiology at Humboldt University Berlin, and the monoterpenoids, eugenol, and cinnamaldehyde on two stored product pests, Callosobruchus maculatus and Sitophilus oryzae. Protect-It^® was more effective than SilicoSec^® against C. maculatus while the reverse was true for S. oryzae. Generally C. maculatus was more sensitive towards DE and silica treatment than S. oryzae. Mortality rate of both pest species increased when DE’s were applied to food commodities previously treated with a monoterpenoid. In admixture experiments, the toxicity of SilicoSec^® + cinnamaldehyde (LD₅₀ = 42.73 ppm), SilicoSec^® + eugenol (LD₅₀ = 24.30 ppm), and Protect-It^® + eugenol (LD₅₀ = 2.60 ppm) was increased over DE alone against S. oryzae. Both substances showed a synergistic effect considering their co-toxicity coefficient relative to the LD₅₀-value. In contrast, we could not find any synergistic effects in experiments with C. maculatus. Here only Protect-It^® + cinnamaldehyde (LD₅₀ = 20.84 ppm) showed an additive effect while all other combinations of monoterpenoid and DE indicated antagonistic effects. In addition to contact insecticidal effects both monoterpenoids showed a strong fumigant action. The presented results indicate that the natural product DE has great potential to replace synthetic pesticides commonly used in stored product pest management. Efficacy of DE can be improved by adding certain monoterpenoids against certain insect pests.     

桔小实蝇的发生为害规律及防治

桔小实蝇是为害水果及瓜类蔬菜的重要检疫性害虫.经3 a多观察试验,初步确定该虫在上海每年发生6～7代.每年9月为发生高峰期.采用悬挂含甲基丁香酚为性息素的引诱器进行诱杀,配合化学药剂,降低虫口密度,直至无法造成较大的危害,控制损失在经济阈值以下.     

香辛料精油成分对生鲜食品中有害菌杀灭活性研究

采用平板稀释法和菌块转移法研究了百里香酚、丁香酚、肉桂醛、茴香脑、水杨醛、柠檬醛、香兰素7种食用植物精油组分对大肠杆菌、金黄色葡萄球菌、沙门氏菌、单增李斯特菌、副溶血性弧菌等生鲜食品常见5种有害菌的杀灭活性。实验结果表明,水杨醛对5种有害菌的综合杀灭能力最强,然后依次是百里香酚、肉桂醛、茴香脑、丁香酚、柠檬醛、香兰素。通过正交试验将水杨醛、肉桂醛、百里香酚、茴香脑复配,得到最佳组合是为:水杨醛、肉桂醛、百里香酚、茴香脑的质量比为2∶5∶20∶5,其杀灭所有供试菌的最低质量浓度为0.25 mg/L,仅为杀菌效果最好的单一水杨醛浓度的1/2。通过对香辛料精油成分杀菌作用协同效应分析得出,复配的香辛精油对单增李斯特菌的杀灭表现出很强的协同增效作用效果,对金黄色葡萄球菌、大肠杆菌和副溶血性弧菌的杀灭表现出相加作用,而对沙门氏菌则表现出无关作用。     

Preparation of cyclodextrin grafting wood flour and investigation of the release characteristics of eugenol

Poplar wood flour, a low-cost and abundantly available material, was modified by grafting β-cyclodextrin (β-CD) in the presence of citric acid or 1,2,3,4-Butanetetracarboxylic acid, aiming to expand the application of wood flour. The products were characterized by Fourier transform infrared spectroscopy and the technique of phenolphthalein probe. The grafting conditions of β-CD onto wood flour including curing temperature, β-CD concentration in impregnation solution and catalyst were also evaluated by the technique of phenolphthalein probe. Besides, eugenol (EG), an antibacterial fragrant guest molecule, was loaded on the modified wood flour by lyophilization, and its release characteristics were investigated by Thermo-gravimetric. The results revealed that the modified wood flour material had a thermo-protective effect on the volatilization of EG and the encapsulated EG content was reached to 1.31 %, which could demonstrate a potential application in the finishing and packing areas.     

Contact and fumigant toxicity of some essential oil constituents against a grain insect pest Sitophilus oryzae and two fungi, Aspergillus westerdijkiae and Fusarium graminearum

Bioassays were performed to determine the antifungal and insecticidal activity of clove essential oil (EO), several botanical compounds (eugenol, carvacrol, allylisothiocyanate (AITC) and ethyl formate (EtF)) against mycotoxigenic fungi (Aspergillus westerdijkiae and Fusarium graminearum) and the rice weevil, Sitophilus oryzae. Antifungal activity was quantified by measuring conidia germination inhibition and mycelial growth inhibition zone to determine the minimum inhibitory concentration (MIC). Mortality of insects was determined through either contact toxicity assay (impregnated filter paper) or fumigation toxicity assay (airtight exposure chamber). A four-parameter logistic regression of fungi inhibitory growth rate to the dose of tested substances, either by the agar diffusion assay or the micro-atmosphere test, showed that AITC had antifungal and sporicide activity. The concentration at MIC for A. westerdijkiae and F. graminearum was 24.2 and 19.8???l?l^?1, respectively, whereas clove essential oil (EO) was 755 and 352???l?l^?1 after 72?h incubation period. Bioassays with S. oryzae showed that clove EO contact insecticidal activity was similar to pure eugenol and carvacrol: LD₉₀s were 366, 385 and 442???l?dm^?2, respectively. The fumigation insecticidal activity of AITC was LC₉₅?=?10.8???l?l^?1. For EtF and clove EO, only the LC₅₀ could be accurately determined after 24?h exposure time which was observed at 41 and 210???l?l^?1, respectively (vs. 6.4???l?l^?1 for AITC LC₅₀). The combined antifungal activity on mycotoxigenic seed-borne fungi and insecticidal activity against the rice weevil demonstrated that AITC in vapour phase may be a promising active substance for the preservation grain stored in unsafe conditions with a risk of fungal growth.     

黄樟油素新资源—香楠的精油成分研究

香楠(Cinnamomum rigidissimum)是我国特有植物,其伐根材富含精油,出油率高达1.44％,含黄樟素61.72％,丁香酚甲醚28.62％。香楠资源在广东海南岛尖峰岭地区比较集中,为当地主要用材树种之一。据调查,利用现有伐根蒸油,可产50—60吨根油。为配合综合利用,本研究对叶精油也进行了成分分析,其中松油醇—4含量较多。     

Medicinal plants used for peptic ulcer in the Bangangte region, western Cameroon

Thirty-nine plant species, traditionally used to treat peptic ulcers in the Bangangte region, Western Cameroon, are reported.