留兰香总黄酮提取工艺研究

目的 优化留兰香(Mentha spicata L.)总黄酮的提取工艺.方法 以留兰香总黄酮得率为指标,采用单因素试验和L.(34)正交试验设计,研究乙醇体积分数、固液比、提取时间3个因素对总黄酮得率的影响:在此基础上,通过改变温度进一步研究静态提取和动态提取对留兰香总黄酮得率的影响.结果 留兰香总黄酮最佳提取工艺条件为:乙醇体积分数50％,提取温度(动态提取)90 ℃,料液比1∶12(首次提取需多加入2倍溶媒),提取2次,每次提取1.5 h,总黄酮得率为6.50％.结论 该提取工艺经济、稳定、可行,为留兰香进一步开发利用提供了依据.     

Assessment of Lithium,Macro- and Microelements in Water,Soil and Plant Samples from Karst Areas in Romania

Lithium is a critical element for the modern society due to its uses in various industrial sectors. Despite its unequal distribution in the environment, Li occurrence in Romania was scarcely studied. In this study a versatile measurement method using ICP-MS technique was optimized for the determination of Li from various matrixes. Water, soil, and plant samples were collected from two important karst areas in the Dobrogea and Banat regions, Romania. The Li content was analyzed together with other macro- and microelement contents to find the relationship between the concentration of elements and their effect on the plants’ Li uptake. In Dobrogea region, half of the studied waters had high Li concentration, ranging between 3.00 and 12.2 μg/L in the case of water and between 0.88 and 11.1 mg/kg DW in the case of plants, while the Li content in the soil samples were slightly comparable (from 9.85 to 11.3 mg/kg DW). In the Banat region, the concentration of Li was lower than in Dobrogea (1.40–1.46 μg/L in water, 6.50–9.12 mg/kg DW in soil, and 0.19–0.45 mg/kg DW in plants). Despite the high Li contents in soil, the Li was mostly unavailable for plants uptake and bioaccumulation.     

Effect of Plant Polyphenols on Ischemia‐Reperfusion Injury of the Isolated rat Heart and Vessels

In the present study, we investigated the potential protective effect of selected natural substances in a rat model of heart and mesenteric ischemia‐reperfusion (I/R). Experiments were performed on isolated Langendorff‐perfused rat hearts, subjected to 30‐min global ischemia, followed by 30‐min reperfusion. Arbutin, curcumin, rosmarinic acid and extract of Mentha x villosa were applied in the concentration of 1 × 10^?5 mol/l 10 min before the onset of ischemia and during reperfusion, through the perfusion medium. Mesenteric ischemia was induced by clamping the superior mesenteric artery (SMA) for 60 min, subsequent reperfusion lasted 30 min. Production of reactive oxygen species (ROS) by SMA ex vivo was determined by luminol‐enhanced chemiluminiscence (CL). The effect of the substances was tested after their incubation with tissue. Curcumin and extract of Mentha x villosa were found to be the most effective in reducing reperfusion‐induced dysrhythmias ‐ ventricular tachycardia and fibrillation. This effect was accompanied by bradycardic effect. The mesenteric I/R induced an increase in CL in vascular tissue which was dampened by substances tested. All substances tested were found to have antioxidant properties, as demonstrated by a reduction in ROS production in mesenteric vessels. This effect was confirmed in curcumin and extract of Mentha x villosa which reduced reperfusion dyshythmias. Copyright © 2012 John Wiley & Sons, Ltd.     

留兰香水溶性部分化学成分的分离与鉴定

目的对唇形科薄荷属植物留兰香(Mentha spicataL.)的水溶性部分的化学成分进行研究。方法采用甲基化的方法处理水溶性部分样品,采用硅胶柱色谱等方法进行分离纯化,根据理化性质和NMR波谱数据进行结构鉴定。结果分离得到5个化合物,分别鉴定为柠檬酸三甲酯(trimethyl citrate,1)、原儿茶酸甲酯(methyl protocatechuate,2)、香草酸甲酯(methyl vanillate,3)、次黄嘌呤核苷(inosine,4)、尿苷(uridine,5)。将它们还原为甲基化前的结构,依次为柠檬酸(citricacid,1′)、原儿茶酸(protocatechuic acid,2′)、香草酸(vanillic acid,3′)、次黄嘌呤核苷(inosine,4)、尿苷(uridine,5)。结论化合物4、5为首次从薄荷属植物中分离得到,化合物1′为首次从留兰香中分离得到。     

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-( 30.0m×0.53mm×1.00 μm)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...     

湖北栽培薄荷挥发油化学成分气相色谱-质谱分析

目的 分析湖北栽培的唇型科植物薄荷挥发油化学组成.方法 采用水蒸气蒸馏法提取挥发油,用GC-MS进行成分分析.结果 利用GC-MS法对湖北栽培薄荷挥发油进行了化学组分的定性和定量分析,共分离出89个峰,并且确认了其中60个化合物.主要成分为薄荷醇(15.43%),其次为2-氰基-2-异丙基-3-甲基丁酸(9.81%),...     

Modulatory effects of Mentha piperita on lung tumor incidence, genotoxicity, and oxidative stress in benzo[a]pyrene-treated Swiss albino mice

Mentha piperita or peppermint is currently used for alleviating nausea, flatulence, and vomiting. In the present investigation, we evaluated the chemopreventive, antigenotoxic, and antioxidative effects of an aqueous extract of Mentha piperita leaves. One-day-old Swiss albino mice were treated with a single subcutaneous injection of 0.5 mg benzo[a]pyrene (BP) and then given either water or a Mentha extract (ME; 1 g/kg body weight) by gavage starting at 3 weeks of age (weaning). The mice were killed at 9 weeks of age and tested for lung tumor incidence (chemoprevention); bone marrow micronucleus and chromosome aberration frequency (antigenotoxicity); and levels of liver and lung sulfhydral groups, superoxide dismutase (SOD) and catalase (CAT) activity, and lipid peroxidation (LPO) (antioxidative properties). The ME treatment resulted in a significant reduction in the number of lung adenomas from an incidence of 67.92% in animals given only BP to 26.31%, an inhibition of 61.26%. Tumor multiplicity was 1.22 in the BP-alone group and 1.15 in the BP + ME group. In addition, compared with the animals in the BP-alone group, ME reduced the frequency of chromosomal aberrations and micronuclei in bone marrow cells and decreased the levels of LPO and increased reduced glutathione content, and SOD and CAT activities in liver as well as lung. The results of this study indicate that ME is chemopreventive and antigenotoxic when given subsequent to an initiating dose of BP in newborn Swiss albino mice. The chemopreventive action and antigenotoxic effects observed in the present study may be due to the antioxidative properties of ME.