Bioefficacy of Mentha piperita essential oil against dengue fever mosquito Aedes aegypti L

Objective:To assess the larvicidal and repellent potential of the essential oil extracted from the leaves of peppermint plant,Mentha piperita(M.piperita) against the larval and adult stages of Aedes aegypti(Ae.Aegypti).Methods:The larvicidal potential of peppermint oil was evaluated against early fourth instar larvae of Ae.aegypti using WHO protocol.The mortality counts were made after 24 and 48 h,and LC_(50) and LC_(90) values were calculated.The efficacy of peppermint oil as mosquito repellent was assessed using the human-bait technique.The measured area of one arm of a human volunteer was applied with the oil and the other arm was applied with ethanol.The mosquito bites on both the arms were recorded for 3 min after every 15 min.The experiment continued for 3 h and the percent protection was calculated.Results:The essential oil extracted from M.piperita possessed excellent larvicidal efficiency against dengue vector. The bioassays showed an LC_(50) and LC_(90) value of 111.9 and 295.18 ppm,respectively after 24 h of exposure.The toxicity of the oil increased 11.8%when the larvae were exposed to the oil for 48 h.The remarkable repellent properties of M.piperita essential oil were established against adults Ae.aegypti.The application of oil resulted in 100%protection till 150 min.After next 30 min, only 1-2 bites were recorded as compared with 8-9 bites on the control arm.Conclusions:The peppermint essential oil is proved to be efficient larvicide and repellent against dengue vector. Further studies are needed to identify the possible role of oil as adulticide,oviposilion deterrent and ovicidal agent.The isolation of active ingredient from the oil could help in formulating strategies for mosquito control.

Identification of EST–SSRs and molecular diversity analysis in Mentha piperita

EST sequences of Mentha piperita available in the public domain(NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were found to contain 130 SSRs, with a frequency of1 SSR/3.4 kb. Dinucleotide repeat SSRs were most frequent(72.3%) with the AG/CT(43.8%)repeat motif followed by AT/AT(16.2%). Primers were successfully designed for 68SSR-containing sequences(62.0%). The 68 primers amplified 13 accessions of M. piperita and 54 produced clear amplicons of the expected size. Of these 54, 33(61%) were found to be polymorphic among M. piperita accessions, showing from 2 to 4 alleles with an average of2.33 alleles/SSR, and the polymorphic information content(PIC) value varied between 0.13 and 0.51(average 0.25). All the amplified SSRs showed transferability among four different species of Mentha, with a highest in Mentha arvensis(87.0%) and minimum in Mentha citrata(37.0%). The newly developed SSRs markers were found to be useful for diversity analysis, as they successfully differentiated among species and accessions of Mentha.

Antibacterial Activity and Phytochemical Analysis of <i>Mentha piperita</i>L. (Peppermint)—An Important Multipurpose Medicinal Plant

Mentha piperita L. (Peppermint) is a perennial glabrous and strongly scented herb belonging to family Lamiaceae. The plant is aromatic, stimulant and used for allaying nausea, headache and vomiting. Its oil is one of the most popular widely used essential oils in food products, cosmetics, pharmaceuticals, dental preparations, mouthwashes, soaps and alcoholic liquors. The antibacterial potential of six extracts from leaf, stem and root of Mentha piperita against pathogenic bacteria such as Bacillus subtilis, Streptococcus pneumonia, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Klebsiella pneumonia were evaluated by agar well diffusion method. The organic (ethanol, methanol, ethyl acetate, chloroform, hexane and petroleum ether) extracts of the leaves were found to possess strong antibacterial activity against a range of pathogenic bacteria. The ethyl acetate leaf extract of Mentha piperita showed pronounced inhibition than chloroform, petroleum ether and hexane. The leaf extract activity being more on Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris than Escherichia coli, Streptococcus pneumonia and Klebsiella pneumonia. In the present study, we also evaluated the phytochemical analysis for the presence of various secondary metabolites. The analysis revealed the presence of alkaloids, flavonoids, steroids, tannins, and phenols.

Studies on free-radical scavenging activity and identification of active ingredients of different plant crude extracts of Mentha piperita collected from Sur,Sultanate of Oman

Objective:To determine free radical scavenging activity and active chemical ingredients of different plant crude extracts of Mentha piperita(M.piperita).Methods:The dried powder leaves of M.piperita were extracted with polar organic solvent by Soxhlet extractor.The crude extract and its fractions of hexane,chloroform,ethyl acetate and butanol crude extracts were prepared.The antioxidant activity of different crude extracts from M.piperita was carried out by DPPH method with minor modification,and the active chemical ingredients of different plant crude extracts of M.piperita were analyzed by gas chromatography-mass spectrometry(GC-MS).Results:Qualitative analysis of different polarities crude extracts by GC-MS found different types of active organic compounds.The antioxidant activity of different crude extracts were found to be in the order of chloroform extract>butanol extract>ethyl acetate extract>hexane extract>methanol extract.Majority identified compounds in the plant crude extracts by GC-MS were biologically active.Conclusions:Therefore,the isolation,purification,identification and characterization of bioactive compounds from various crude extracts of M.piperita might have ecological significance.

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。

4种新疆地产芳香植物精油抗氧化作用比较研究

采用体外研究方法比较新疆地产玫瑰、迷迭香、椒样薄荷和罗马甘菊4种芳香植物精油的抗氧化活性。测定4种精油对1,1-二苯基苦基苯肼(DPPH)自由基、羟自由基和超氧阴离子自由基的清除能力,同时用硫代巴比妥酸(TBA)法测定4种挥发油对脂质过氧化反应的抑制作用。结果表明:4种精油均可清除DPPH自由基、羟自由基和超氧阴离子自由基,并可抑制卵黄不饱和脂肪酸过氧化,且清除各类自由基及抑制脂质过氧化作用与样品挥发油质量浓度正向相关。4种精油抗氧化活性顺序为玫瑰>迷迭香>椒样薄荷>罗马甘菊。

薄荷提取物对朱砂叶螨体内几种酶活性的影响

研究经2mg.mL^-1薄荷活性成分处理后朱砂叶螨的症状表现和处理24h后的透射电镜亚细胞结构,采用生化方法测定薄荷活性成分对朱砂叶螨体内的单胺氧化酶(MAO)、谷胱甘肽-S-转移酶(GSTs)、乙酰胆碱酯酶(AchE)和蛋白酶活性的影响。结果表明:薄荷提取物处理朱砂叶螨后,成螨经历了静止、活跃、痉挛和死亡4个时期。与对照组相比,处理后螨体内MAO活性增强,12h和24h时活性差异显著(P<0.05);GSTS亦被激活,24h内酶活性呈上升趋势;AchE活性受抑制,处理后12h时酶活性最低,处理组与对照组酶活性24h内变化趋势相同;蛋白酶活性整体处于被抑制状态。薄荷提取物对朱砂叶螨有毒害作用,并引起了螨体内GSTs的解毒,来维持正常的生理功能。AchE的活力受到一定程度的抑制并可能造成神经递质积累、传递阻断。MAO活性被激活,单胺在螨体内没有积累,因而并非通过此途径导致成螨死亡。蛋白酶活性受到抑制表明该物质对消化系统有破坏。透射电镜观察发现对照组颈部体壁亚细胞结构完整且规律,而处理组结构完全溶解,无法辨认。初步推测薄荷提取物通过破坏神经系统及消化系统,对朱砂叶螨产生毒害作用。薄荷提取物可以作为新型植物源农药,且具有一定的开发价值。

薄荷中杀螨活性物质的分离与鉴定

为测定薄荷中杀螨活性物质的毒力,分离鉴定该物质的分子结构,利用甲醇、氯仿和石油醚3种溶剂在常温下进行提取后,用液-液萃取法萃取,并用硅胶层析和薄层层析(TLC)结合碘显色法进行分离纯化,同时用玻片浸渍法对活性物质跟踪;最后采用紫外分光光度法(UV)、液相色谱法(HPLC)、红外色谱(RI)和质谱(MS)等技术对该物质进行鉴定。研究发现薄荷地上部分的石油醚粗提物对朱砂叶螨具有很强的毒杀作用,当浓度为1mg.mL-1时,24h内对成螨的致死率为87.05%,卵为93.16%。经Duncans检验,3种不同溶剂的粗提物对成螨及卵的致死率差异显著(P<0.05)。同时发现薄荷地上部的甲醇、氯仿提取物杀螨效果相对较差,24h致死率仅为28.51%与10.73%。用甲醇对石油醚粗提物进行液液萃取后发现,杀螨活性物质主要集中在极性较弱的石油醚中,其对成螨24h的触杀率高达93.75%。对石油醚萃取物进行分离,共得到8段流分。利用生物活性跟踪,得到一种具有较高杀螨活性的样品V,其对成螨触杀的LC50值为0.5464mg.mL-1,95%置信区间为0.3268～0.9134mg.mL-1。经紫外和高压液相色谱分析,该样品纯度达到89.16%;质谱检测该物质的分子离子峰为414,数据库显示该物质为甾醇环状结构。红外分析显示该物质在1160,1450,1380,1700cm-1等处有明显特征峰,初步确定该化合物为β-谷甾醇。

椒样薄荷对NaCl胁迫的生理响应

[目的]探讨椒样薄荷耐盐生理特性,为其在盐渍地的开发利用提供理论基础。[方法]分别用0、0.3%、0.5%、0.8%、1.0%、1.2%NaCl溶液处理椒样薄荷植株,研究薄荷对NaCl胁迫的生理生化响应。[结果]随着NaCl浓度的升高,薄荷叶片含水量、CAT酶活性呈现先升高后降低的变化,而渗透势、电导率、MDA含量、Na+含量呈现持续升高的趋势。[结论]椒样薄荷能耐受0.8%NaCl胁迫,在该浓度下,薄荷植株能正常生长,并维持较高的含水量、较低的渗透势、较低的电导率和MDA含量以及较高的CAT酶活性,而在遭受更高的Na-Cl胁迫时会受到一定程度的伤害。

薄荷的快速繁殖与栽培技术的研究

研究了薄荷的组培与快繁。适宜培养基为:诱导,MS;增殖,MS+6BA2.0mg/L+NAA0.2mg/L;生根培养基为1/2MS+6BA1.0mg/L+NAA0.2mg/L。首先,诱导丛生芽,然后诱导生根。将生根小苗从瓶中移于蛭石和细砂各半的基质上,最后移于培养土中。重视各环节练苗,成活率可达98%以上。笔者还叙述了薄荷的特征、特性、类型及品种与栽培技术及其广泛用途等。

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。

椒样薄荷试管苗生根的影响因素分析

The factors of effect on rooting of Mentha piperita L.plantlets are investigated.The results show that basic medium types and phytohormone concentrations are effective factors on rooting.The optimizing medium for rooting of tube plantlets of M.piperita is 1/2 MS containing 0.5 mg·L-1 6-BA and 0.3 mg·L-1 NAA.The better conditions for rooting of transferring plantlets are soaking shoots in solution containing 100 mg·L-1 6-BA and 50 mg·L-1 NAA for 30 min or in solution containing 50 mg·L-1 6-BA and 25 mg·L-1 NAA for 60 min.

UV-B辐射对薄荷药用成分质量分数的影响

目的:探讨增强UV-B辐射对胡椒薄荷氨基酸及药用次生代谢物质量分数的影响.方法:人工模拟生长环境中紫外辐射增强处理胡椒薄荷,用分光光度法测胡椒薄荷内黄酮质量分数,氨基酸采用日立L-8800型全自动氨基酸分析仪测定,薄荷挥发油中主要药用成分质量分数测定采用Agilent 6820气相色谱仪(配氢火焰检测器FID,美国安捷伦公司)测定.结果:0.15W/m2紫外胁迫下胡椒薄荷体内黄酮质量分数显著升高,Glu,Lys,Gly,薄荷醇、薄荷酮、胡薄荷酮质量分数均显著降低,Leu,Phe质量分数变化呈先降低后升高的趋势,蛋白质质量分数在UV-B胁迫后20d和30d显著降低;0.35W/m2紫外胁迫下黄酮质量分数先升高后降低,在30d时达到峰值,Glu,Gly,Leu,Tyr,Phe,Arg质量分数及9种药用氨基酸之和均在前40d明显下降,蛋白质质量分数在处理的后20d显著降低,而薄荷醇、薄荷酮、胡薄荷酮质量分数显著上升.结论:低强度UV-B辐射促进了芳香族氨基酸Phe和支链氨基酸Leu的合成,而高强度UV-B胁迫降低了胡椒薄荷中药用氨基酸的质量分数,UV-B胁迫增强下胡椒薄荷可以通过增加黄酮、薄荷醇、薄荷酮、胡薄荷酮等药用次生代谢产物来提高对UV-B辐射的适应性.

GC-MS法分析瑞丽椒样薄荷精油化学成分

采用水蒸气蒸馏法从瑞丽市种植的椒样薄荷鲜样中提取精油,利用气相色谱-质谱联用仪(GC-MS)对精油的挥发性化学成分进行分析鉴定,各挥发性化学成分经质谱扫描后得到的色谱图通过质谱工作站Xcalibur3.0进行定性和定量分析,结合NIST08标准质谱图数据库对比检索,并对图谱进行综合分析,鉴定出43种主要的挥发性化学成分,按峰面积归一化法计算各成分在精油中的相对质量分数。43种挥发性化学成分占挥发油总量的97.30%,其中含量较高的7个成分分别是薄荷酮(14.01%)、薄荷醇(53.80%)、月桂醛(4.83%)、肉豆蔻醇(3.05﹪)、α-甲基戊醛(2.66%)、红樟油(2.54%)和4-乙酸基-1-萜品烯(2.58%),占挥发油总量的83.47%。这些主要成分的种类和含量差异因地域和种植条件的不同,决定了椒样薄荷精油的香气品质差异。该研究为进一步研究和开发瑞丽本地种植的椒样薄荷提供了科学依据。

栽培条件对椒样薄荷油质量的影响

本文报导椒样薄荷在不同收割期油中化学组分的变化 ,用生物化学的观点来讨论各不同收割期之间油中主要化学组分的变化关系。从椒样薄荷品种的起源 ,生长的土壤、气候、灌溉条件。

毛细管气相色谱法测定薄荷精油中薄荷醇的含量

目的：建立薄荷精油中薄荷醇的含量测定方法。方法：采用水蒸气蒸馏法提取薄荷中的薄荷精油,并采用AT.SE-30-（30.0 m×0.53 mm×1.00μm）毛细管色谱柱,以苯甲酸为内标的毛细管气相色谱法测定薄荷精油中薄荷醇的含量。结果：薄荷醇在0.0996-0.4980 mg/mL浓度范围内,峰面积与内标峰面积的比值与浓度呈良好的线性关系（r=0.9998）,平均回收率为99.17%,RSD为1.18%。结论：该方法易操作,可作为控制薄荷精油质量的一种方法。

品系及干燥方式对椒样薄荷精油成分的影响

分别采用室内阴干、自然晒干、60℃烘干对耐盐椒样薄荷"科院1号"叶片进行干燥处理,利用水蒸气蒸溜法提取精油。结果显示,室内阴干精油出油率最高(0.99%),不同品系精油出油率差异显著,其中白花系精油出油率最高,达2.50%。利用气相色谱-质谱(GC-MS)法分析椒样薄荷精油成分,不同的干燥方式获得的椒样薄荷精油都可鉴定出18种主要成分,其中影响精油品质的薄荷醇、薄荷酮、乙酸薄荷酯和薄荷呋喃4种主要成分总含量分别占挥发油总量的68.7%、67.0%和67.0%,差异不大,但每种成分的含量因干燥方式不同有显著变化,可决定椒样薄荷精油的香气品质差异,其中室内阴干处理精油品质最佳。此外,不同品系椒样薄荷精油中化学成分含量差异显著,研究结果为新品种改良及开发应用提供依据。

耐盐薄荷的离体培养与植株再生的研究

为研究耐盐薄荷的快速繁育技术,以耐盐的椒样薄荷茎段为外植体,采用正交试验L4(23)筛选其愈伤诱导培养基。研究结果表明,NAA是影响耐盐薄荷诱导愈伤能力的重要因素,其最适浓度为0.2 mg/L,愈伤诱导率达92%以上。在此基础上,通过扩大培养基中6-BA浓度进行不定芽增殖培养基筛选,最终确定增殖培养基为2/3 MS+5.0 mg/L6-BA+0.2 mg/L NAA+30 g/L蔗糖+4 g/L琼脂,pH值6.0(灭菌前);此培养基下培养,增殖系数达19.23。在诱导生根培养基的筛选中,综合分析植株生长量(株高)、生根数量(根数)及根生长量(根长),确定生根培养基为1/2 MS+0.2 mg/LNAA+30 g/L蔗糖+4 g/L琼脂,pH值6.0。

椒样薄荷和亚洲薄荷挥发油香气成分的研究

报道椒样薄荷和亚洲薄荷挥发油的ＧＣ分析结果，两种油的组分基本相似。但椒样薄荷油中，有一重要的组分——薄荷呋喃，使椒样薄荷油的香气变得园韵、温和，较亚洲薄荷油清甜优美。

增强UV-B辐射对胡椒薄荷逆境生理指标的影响

对增强UV-B辐射胁迫下(辐射强度分别为自然光对照0、0.15 W/m2、0.35 W/m2)下生长的胡椒薄荷(Mentha piperita L.)逆境生理指标的动态变化进行了研究.结果表明:薄荷对增强UV-B辐射胁迫做出了适应性生理反应.0.15 W/m2下薄荷叶片内脯氨酸、可溶性糖、MDA质量浓度及3种抗氧化酶活性升高,蛋白质质量浓度下降;0.35 W/m2下薄荷叶片内脯氨酸质量浓度和CAT活性先升高后降低,可溶性糖质量浓度和SOD活性先升高再趋于平稳,可溶性蛋白质、MDA质量浓度和POD活性先降低后升高.尽管不同强度UV-B辐射下各个指标变化趋势不同,但与自然光对照相比,经过UV-B辐射处理后,薄荷内可溶性蛋白质质量浓度降低,而其它指标均升高.