Antimycobacterial natural products from Moroccan medicinal plants: Chemical composition, bacteriostatic and bactericidal profile of Thymus satureioides and Mentha pulegium essential oils

Objective: To evaluate the susceptibility of Mycobacterium aurum and Mycobacterium smegmatis in vitro to the essential oils obtained from two medicinal plants: Thymus satureioides(T. satureioides) and Mentha pulegium(M. pulegium), and to study their chemical composition.Methods: The aerial parts of T. satureioides and M. pulegium(leaves and stems) were hydro-distillated using a Clevenger-type apparatus and essential oils were analyzed and identified by gas chromatography-mass spectrometry. Antimycobacterial screening of essential oils was performed on the basis of the inhibition zone diameter by disc diffusion method against two mycobacterial strains whereas the minimal inhibitory concentration and minimal bactericidal concentration were determined by using the micro-dilution method.Results: Chemical analysis of their aerial part's essential oils gave as major compounds,borneol(34.26%), carvacrol(31.21%) and thymol(3.71%) for T. satureioides and R(+)-pulegone(75.48%), carvone(6.66%) and dihydrocarvone(4.64%) for M. pulegium.Thereafter their antimycobacterial effect evaluation, using the micro-dilution method,indicated that minimal inhibitory concentration values of T. satureioides essential oil ranged from 0.062% to 0.015%(v/v) and from 0.125% to 0.031%(v/v) for M. pulegium respectively against Mycobacterium aurum and Mycobacterium smegmatis.Conclusions: It is clearly evident from the results obtained that the Moroccan medicinal plants have great potential to be used as anti-tuberculosis agents. These findings may help scientists to undertake several research projects to discover useful natural product as new anti-tuberculosis drug.

Nanoemulsified Mentha piperita and Eucalyptus globulus oils exhibit enhanced repellent activities against Anopheles stephensi

Objective:To formulate nanoemulsion from essential oils of Mentha(M.)piperita L.and Eucalyptus(E.)globulus L.and to compare their repellant activity with normal essential oils and N,N-diethyl-m toluamide(DEET)as a standard chemical compound.Methods:In this study,protection time of essential oils and DEET was evaluated on four human subjects using test cage,and their values were determined against Anopheles stephensi.Furthermore,ED50 values for the above essential oils were determined using the ASTM E951-94 method.The compositions of essential oils were determined using GC-MS,and droplet size and zeta potential of the nanoemulsion were measured with dynamic light scattering.Results:The results(expressed as mean±SD)showed that protection time of M.piperita 50%,M.piperita Nano 50%,E.globulus 50%,E.globulus Nano 50%,and DEET 25%was(2.89±0.45)h,(4.17±0.28)h,(0.96±0.27)h,(5.51±0.02)h,and(6.10±0.47)h,respectively.ED50 values were 29.10(95%CI:23.36-36.06)μg/cm^2 for Mentha,19.39(15.35-23.99)μg/cm^2 for Mentha Nano,36.10(28.70-48.01)μg/cm^2 for Eucalyptus,18.50(14.65-23.23)μg/cm^2 for Eucalyptus Nano,and 3.62(2.68-4.55)μg/cm^2 for DEET,respectively.E.globulus Nano and M.piperita Nano provided significantly longer protection than normal essential oils E.globulus and M.piperita(P<0.01).Conclusions:The preparation of nanoemulsion from the essential oils of M.piperita and E.globulus,significantly increases the protection time and reduces ED50 values of these essential oils,hence,M.piperita Nano and E.globulus Nano can be good alternatives to DEET and other chemical compounds.

Chemical composition of Mentha suaveolens and Pinus halepensis essential oils and their antibacterial and antioxidant activities

Objective: To determin the chemical compounds of Mentha suaveolens(M. suaveolens) and Pinus halepensis(P. halepensis) essential oils(Eos) and evaluate their antioxidant and antibacterial activities. Methods: The chemical composition of P. halepensis and M. suaveolens EOs was determined by GC-MS analysis. The antioxidant activity was evaluated using DPPH,ABTS and FRAP assays. The antibacterial effect was tested against 6 bacterial strains using the well diffusion method and micro-dilution assay. Results: The major components of P. halepensis EOs were β-caryophyllene(28.04%),myrcene(23.81%) and α-pinene(12.02%). However,piperitenone oxid(56.28%),piperitenone(11.64%) and pulegone(6.16%) were the major components of M. suaveolens EOs. M. suaveolens EOs showed remarkable antioxidant activities compared with P. halepensis EOs,showing antioxidant capacity values of IC50=(64.76±2.24) μg/mL,IC50=(82.73±3.34) μg/mL,and IC50=(93.35±4.45) μg/mL,revealed by DPPH,ABTS and FRAP assays,respectively. However,P. halepensis EOs showed interesting antibacterial effects against all bacterial strains. The most sensible strains to P. halepensis EOs were Staphylococcus aureus [(34.00±0.50) mm],Listeria monocytogenes [(31.00±1.50)] mm and Proteus mirabilis [(29.00±2.25)mm]. Furthermore,the lowest minimal inhibitory concentration(MIC) and minimal bactericidal concentration(MBC) values were revealed by P. halepensis EOs against Staphylococcus aureus [MIC=MBC=0.125%(v/v)] and Listeria monocytogenes [MIC=MBC=0.25%(v/v)]. Conclusions: P. halepensis and M. suaveolens EOs contain bioactive compounds that could have potential applications against bacterial infections and oxidative stress related diseases as well as for food conservation. However,further investigations are necessary to isolate and investigate the action mechanisms of these bioactive compounds.

Antidermatophytic Activity of Essential Oils against Locally Isolated <i>Microsporum canis</i>—Gaza Strip

There is a need for new antimicrobial drugs due to the continuous development of resistance. Natural antimicrobials are of utmost importance due to safety issue and availability. The antifungal activity of four essential oils (Mentha piperta, Thymus vulgaris, Cymbopogon citratus, and Oreganum majoranum oils) against locally isolated Microsporum canis was determined by disc diffusion method and minimum inhibitory concentration was determined using broth dilution method. Mentha piperta oil showed the highest antifungal activity among tested oils in this study. The total inhibition attached when 0.046% was used with M. piperta, the total inhibition obtained with the 0.133% of C. citratus oil, which is accounted as the second essential oils, also T. vulgaris and O. majoranum oils achieved reductions at 0.133%. The present work has revealed that all oils have been used in low concentrations and produced promising results in comparison to the positive control (Clotrimazole).

Effects of Growth Regulators on Biomass and the Production of Secondary Metabolites in Peppermint (<i>Mentha pi-perita</i>) Micropropagated <i>in Vitro</i>

The effects of plant growth regulators on peppermint (Mentha piperita) cultured in vitro were studied for the purpose of maximizing growth and essential oil production in micropropagated plants. The basal medium was experimentally supplemented with the auxin 4-indol-3-ylbutyric acid (IBA) and the cytokinin 6-benzylaminopurine (BAP) individually and in combination. Supplementation with BAP alone resulted in the highest values for root length, root dry weight, shoot length, and numbers of nodes, leaves, and ramifications. Treatment with IBA alone or with IBA + BAP resulted in a ~50% increase in shoot fresh weight. The production of secondary metabolites was affected only by the addition of cytokinin, which resulted in a ~40% increase in the total yield of essential oils (EOs). Similar trends were observed for yields of the major EO components (menthone, menthol, pulegone, and menthofuran). Our findings demonstrate that the application of growth regulators increases EO production and biomass concomitantly in an herbaceous species rich in commercially valuable terpenes.

阜阳市薄荷品种精油成分分析

[目的]筛选出地区适应性强、产量高、活性成分含量高的亚洲薄荷优良种质,推动阜阳市薄荷产业的高质量发展。[方法]以阜阳市薄荷主要种植区的30份薄荷品种资源为研究对象,对精油含量、精油成分及相对含量进行检测分析。[结果]30份薄荷品种精油含量平均值为2.14%,其中M-23品种最高,达3.50%。精油化学型主要为薄荷醇型和氧化胡椒酮型等化学型。薄荷醇型中M-1品种的薄荷醇含量最高,达77.91%。氧化胡椒酮型中M-26品种的氧化胡椒酮含量最高,达56.19%。在30份薄荷品种资源中,有25种达到了2020版《中国药典》的标准,24种达到了当地采购商的采购要求。[结论]M-1、M-3、M-19、M-27这4个薄荷品种精油含量高、薄荷醇含量高,精油品质好,适合在阜阳地区推广应用。

薄荷精油对黄曲霉生长的抑制作用研究

目的研究薄荷精油对黄曲霉生长及其毒素B1合成的抑制作用。方法在培养基中加入不同体积浓度的薄荷精油,以不加薄荷精油作为对照,通过测定其对产毒黄曲霉的最小抑菌浓度(minimum inhibitory concentration,MIC)、孢子萌发、菌丝干重、菌落直径、微观结构及黄曲霉毒素B1合成量的影响,探究薄荷精油对黄曲霉的抑制效果。结果薄荷精油对产毒黄曲霉的MIC为1.6μL/mL;2.0 MIC薄荷精油处理对黄曲霉孢子萌发抑制率、黄曲霉菌丝干重抑制率及黄曲霉毒素B1合成抑制率均达到99%以上,且扫描电镜结果表明,薄荷精油会影响黄曲霉菌丝形态;同时,通过熏蒸处理,薄荷精油能够有效抑制花生中的霉菌增长,防止霉菌侵染花生。结论薄荷精油对黄曲霉具有良好的抑制作用,在粮食储藏、食品防霉等方面具有进一步开发成安全防腐抑菌剂的潜力。

新疆留兰香挥发油成分GC-MS分析及其抑菌活性研究

基于GC-MS技术对新疆和田产地种植的留兰香的挥发油成分进行分析,并进行体外抑菌活性研究。采用水蒸气蒸馏法提取留兰香地上部分的挥发油,应用GC-MS技术,分析、鉴定其挥发油的化学成分。采用肉汤稀释法和平板菌落计数法检测留兰香挥发油的体外抑菌活性。结果表明留兰香的挥发油产率是0.36%,密度是0.941 g/mL。从中鉴定出36种化学成分,其主要成分是左旋香芹酮(58.33%)、柠檬烯(24.28%)、1-石竹烯(5.48%)、左旋-β-蒎烯(1.94%)。抑菌实验表明,留兰香挥发油对金黄色葡萄球菌、大肠埃希菌、白色念珠菌均具有一定的抑菌作用。本方法用于留兰香挥发油的化学成分分析稳定可靠,初次揭示了新疆和田地区留兰香挥发油的化学成分及其抑菌活性,可作为具有抑菌剂开发价值的潜在天然植物。

薄荷油β-环糊精包合物的制备

目的优选薄荷油β-环糊精包合物的制备工艺。方法采用L9(34)正交实验设计,以薄荷油的包合率为指标,考察薄荷油与β-环糊精的比例、包合温度、搅拌时间、β-环糊精与水的比例对制备工艺的影响,并用TLC与IR光谱验证包合物的形成。结果最佳的工艺条件为薄荷油∶β-环糊精为1∶8,包合温度为45℃,搅拌时间为2 h,β-CD与水的比例为1∶10。结论此法可用于薄荷油β-环糊精包合物的制备。

应用微渗析技术在大鼠中考察2种促渗剂对美洛昔康的渗透促进作用

目的考察薄荷油(MO)和azone 2种促渗剂对美洛昔康的渗透促进作用。方法用大鼠为实验动物,采用微渗析技术进行在体取样,以HPLC法测定样品中的药物浓度;应用反向渗析法测定探针的在体回收率,以计算药物在皮肤中的浓度。结果在实验条件下微渗析探针的体外回收率主要受灌注液流速的影响,为(50.16±2.34)%;反向渗析法测得探针的在体回收率为(14.096±0.58)%;MO的体积分数为3%和5%时,增渗倍数分别为3.8、17.6;azone的体积分数为3%和5%,增渗倍数分别为9.2、24.8。结论不同体积分数的MO和azone均可显著增加美洛昔康经皮渗透稳态流量,azone的体积分数为5%时,大鼠角质层的屏障作用可能受到了较大程度的破坏。

薄荷油治疗肠易激综合征的基础和临床研究进展

肠易激综合征(IBS)是一种常见的消化系统疾病,其发病机制目前尚未完全阐明。IBS的治疗方法,如改变生活方式和饮食习惯、药物治疗、心理治疗等疗效均不甚理想。目前研究发现薄荷油是治疗IBS的有效药物,能显著改善IBS的症状,提高患者生活质量。本文就薄荷油治疗IBS的基础和临床研究进展作一综述。

两种植物精油对粮食中玉米象的熏蒸效果研究

采用三角瓶密闭熏蒸法研究了薄荷油、留兰香油对小麦中玉米象的熏蒸效果及熏蒸毒力。结果表明:在0%,30%,50%,70%的小麦装满度下,2种精油对玉米象成虫均具有较好的熏蒸效果。在小麦装满度70%时,薄荷精油用300μL/L浓度,留兰香精油用350μL/L浓度熏蒸,处理7 d后玉米象成虫的校正死亡率分别达到76.67%和84.17%,LC50值分别为231.50、268.71μL/L。不同粮食装满度时,随着粮食的增加,熏蒸所需要的精油浓度也逐渐增加。小麦对不同精油的吸附率不一样,但小麦占空间体积越大,对精油的吸附就越大。

薄荷油不同提取方法的比较

目的比较不同提取方法对薄荷挥发油得率和薄荷醇得率的影响。方法分别采用水蒸气蒸馏法、冷浸法、超声波法和超临界CO_2法提取薄荷油,通过气相色谱测定薄荷醇含量。结果超临界CO_2法提取薄荷油得率和薄荷醇得率分别为2.43%和1.77%,超声波法分别为1.34%和1.09%,冷浸法分别为1.27%和1.02%,水蒸气蒸馏法分别为1.15%和0.90%。结论薄荷油的4种提取方法中以超临界CO_2法最优。

薄荷精油抗菌活性研究(英文)

采用气相色谱-质谱联用仪分析了薄荷精油的成分，在鉴定出的21种成分中，异佛尔酮（41．22％）、13．石竹烯（10．01％）、斯巴醇（2．89％）、β-蒎烯（1．45％）和桉树脑（1．13％）为主要成分。采用琼脂扩散法和微量肉汤稀释法对薄荷精油的抗菌活性进行了研究。结果表明，枯草芽孢杆菌及变形杆菌出现最大的抑菌环。MIC实验中，薄荷精油的浓度范围为5．00％-0．039％。在所选的8种菌种中，变形杆菌的MIC及MBC值最低，分别为0．625％及1．25％。结果充分证明，薄荷精油对于所选的8种病原菌都有很好的抗菌活性，在食品及制药工业中有广阔的应用前景。

薄荷油超临界CO_2萃取条件的优化和筛选

以样品中的薄荷脑含量为指标,通过单因素和正交实验对影响薄荷(M entha haplocalyxB riq.)油超临界CO2萃取的因素进行研究,筛选出薄荷油超临界CO2萃取的最佳条件。研究结果表明,影响样品中薄荷脑萃取率的因素从大到小依次为萃取压力、萃取温度、萃取时间、CO2流量。样品中薄荷脑含量最高的超临界CO2萃取条件为萃取压力10 MPa、萃取温度50℃、CO2流量30 L.h-1且萃取时间1.5 h。

水蒸气蒸馏法与超临界CO_2萃取法提取薄荷油的化学成分比较

采用水蒸气蒸馏(SD)法和超临界CO2萃取(SCDE)法从薄荷中提取挥发油,并用GC-MS技术对其化学成分进行了分析。SD法提取薄荷油的出油率为1.15%,SCDE法提取薄荷油的出油率为2.43%。GC-MS分析表明,SD法提取的薄荷油中含44种化学成分,占总挥发油的97%以上,其中薄荷醇相对含量为69.4%;SCDE法提取的挥发油中含38种化学成分,占总挥发油的92%以上,其中薄荷醇相对含量为61.8%。

薄荷精油成分和含量的影响因素综述

从薄荷的品种、产地、气候和采收时间、不同器官、栽培条件、贮藏时间以及精油提取方法等方面对影响薄荷精油成分因素的研究进展进行了综述。结果表明,薄荷属精油成分和含量种间种内差异明显;薄荷属资源精油中的主要化学成分不但与其遗传背景等有关,也与产地有关;同一种薄荷不同器官的精油成分和含量不同;薄荷精油的化学成分受采收时间等影响很大;栽培地的纬度和气象因子对薄荷精油成分和含量也有一定的影响;栽培条件如施肥量、施肥方式、氮源、矿质离子浓度、种植密度、生长激素等都对薄荷精油成分及其相对含量具有一定影响。

留兰香挥发油化学成分的研究

利用气相色谱 质谱对留兰香的挥发油成分进行了研究 ,共鉴定出了 6 6种组分 .其中主要组分为 :香芹酮、柠檬烯、二氢香芹酮、桉油素、β -蒎烯、香芹乙酸酯、α -蒎烯、反 -石竹烯、顺式香芹酮、β -水芹烯、香芹醇、β -波旁烯、α -萜品醇等。其中香芹酮的含量最高 ,占挥发油总量的 5 9.5 8% ,柠檬烯含量为 13.31% ,二氢香芹酮含量为 8.85 %。三种成分占总挥发成分的 81.74 %。检出成分占挥发油总量的 95 .4 8%。

中国新疆椒样薄荷油的化学成分分析及品质研究

采用GC/MS法,研究了中国新疆和印度椒样薄荷(MenthapiperitaL.)精油的化学组成,测定了其相对含量,并与美国出口日本的优质椒样薄荷精油进行品质对比。分别鉴定出精油中的37种化合物,包括了检测精油质量常规指标的全部15个组分。结果表明,中国新疆产的椒样薄荷精油品质优良,优于印度产精油,已基本符合出口日本的标准。

苏薄荷挥发性成分分析及其动态变化研究

目的探讨苏薄荷挥发性成分的动态积累。方法考察不同采收时间苏薄荷中薄荷油的含量,并以其中的主要成分薄荷酮和薄荷醇为指标,采用GC法考察它们的动态变化。结果不同生长期苏薄荷含油量的积累具有一定规律。结论苏薄荷中薄荷油含量积累曲线最大峰值与传统采收期一致。