微胶囊双水相法提取罗汉松挥发油及GC-MS分析

本研究对罗汉松总黄酮提取工艺进行了研究，经过筛选确认了以β-环糊精-硫酸钠体系，单因素基础上通过四因素三水平响应面实验得出对罗汉松枝叶挥发油的最佳条件为萃取时间35min，β -环糊精浓度40%，硫酸钠浓度15%，萃取温度30℃，在此条件下罗汉松枝叶挥发油得率为1.372%。在质谱图中共鉴定出其中22个化合物约占色谱面积93.72 %。萜烯及其含氧衍生物18种，占总含量的73.74 %，其中萜醇类化合物4种，萜醛类化合物2种，脂肪族化合物4种，占含量的19.98 %，其中酯类化合物2种，酸类化合物2种。取得到的挥发油中主要成分为石竹烯、α -蒎烯和β -蒎烯，含量分别为17.62%、9.78%和7.47%。     

GC/MS分析鸡毛松枝精油的化学成分

为了促进罗汉松科植物鸡毛松在医药、农药和精细化工等领域中的应用,本研究利用水蒸气蒸馏法提取鸡毛松枝精油,进一步采用气相色谱-质谱联用(GC/MS)方法对其化学成分进行分析,分离鉴定出18种化学成分,主要有β 石竹烯(2 03%)、大根香叶烯(61 39%)、γ 榄香烯(12 14%)、β 杜松烯(2 14%)和rimuene(7 66%)。已鉴定化合物占总离子流出峰面积的92 69%,其中大部分是萜烯类化合物。     

罗汉松种子总黄酮提取工艺优化及抗氧化活性

目的 采用响应面法优化罗汉松种子总黄酮超声提取工艺，并考查总黄酮的抗氧化活性。方法 基于单因素试验，以料液比、超声时间、超声温度为自变量，以总黄酮得率和DPPH自由基的清除率为因变量，采用三因素三水平的响应面分析法，确定最佳提取工艺条件。结果 得到最佳工艺参数：在超声频率为40 kHz、超声功率为200 W时，料液比（g/mL）为1∶50、超声温度为70℃、超声时间为2.7 h，其理论预测值总黄酮得率为27.54mg/g(n=3，相对标准偏差为1.63%)。当添加稀释10倍的总黄酮提取液0.50mL时，对DPPH自由基的清除率达到87.2%、对Ce（Ⅳ）还原率达到84.2%；当添加稀释10倍的总黄酮提取液0.90mL时，对OH自由基的清除率为88.1%。结论 采用响应面法优化得到的超声波辅助提取工艺稳定、可靠，可用于罗汉松种子总黄酮的提取。罗汉松种子总黄酮可作为优良的天然抗氧化剂资源。     

响应面法优化闪式提取罗汉松总黄酮及抗氧化活性研究

本研究对罗汉松总黄酮提取工艺及其抗氧化活性进行了研究,采用闪式提取法提取罗汉松总黄酮,并通过单因素法和响应面优化方法,同时考察了罗汉松总黄酮对DPPH•、O2-•和•OH自由基清除作用。结果表明,闪式提取罗汉松总黄酮最佳工艺条件为：乙醇浓度71 %、料液比1:36 (g·mL-1)、提取时间53 s、提取电压为75 V时,罗汉松总黄酮提取率为8.147 %。罗汉松总黄酮对DPPH•、O2-•和•OH具有明显的清除能力,最大清除率分别达到87.13%、58.24%和67.56%,为罗汉松的综合开发利用提供了参考。     

Sequestration of host plant-derived compounds by geometrid moth, Milionia basalis, toxic to a predatory stink bug, Eocanthecona furcellata

A predatory stink bug, Eocanthecona furcellata, died after feeding on Milionia basalis larvae. The compounds toxic to E. furcellata were isolated from the hemolymph of M. basalis larvae and identified as inumakilactone A, nagilactone C, and nagilactone C glucoside. The concentrations of inumakilactone A, nagilactone C, and nagilactone C glucoside in the hemolymph of the final instar larvae were 130, 50, and 770 g/ml, respectively. Nagilactone C showed the highest insecticidal activity against second-instar nymphs of E. furcellata, while nagilactone C glucoside showed the lowest, one twentieth of that of nagilactone C. When mixed compounds were given at the same concentrations as those in hemolymph of M. basalis, all nymphs of E. furcellata died with in three days. Inumakilactone A and nagilactone C were found to be in the leaves of podocarp, Podocarpus macrophyllus, the only host plant of M. basalis, at concentrations of 13 and 175 g/g fresh weight, respectively. However, no nagilactone C glucoside was detected in the leaves of this species. These results suggested that M. basalis may transform nagilactone C to its glucoside.     

Multichemical resistance of the coniferPodocarpus gracilior (Podocarpaceae) to insect attack

Podocarpus gracilior is resistant in nature to insect attack. Apparently, the resistance ofP. gracilior is due to a multichemical defense mechanism. Chemicals identified as potential components of the multichemical defense are four norditerpenedilactones, including nagilactones, C, D, and F, which cause insect feeding deterrent activity ultimately coupled to an insecticidal activity, and podolide, an insecticide; two nonlethal growth-inhibiting biflavones, podocarpusflavone A and 7,4-dimethylamentoflavone; and the ecdysis-inhibiting phytoecdysone, ponasterone A.     

Seasonal change in nagilactone contents in leaves inPodocarpus nagi forest

Nagilactones isolated fromPodocarpus nagi (Thunb.) Zoll. et Moritz. are known by their physiological activities as a plant growth inhibitor or antiherbivory substance. As the first step in clarifying the nagilactone dynamics in a forest canopy, the seasonal variations in nagilactone contents in leaves and mass of nagilactones accumulated in the canopy were examined at Mt. Mikasa, Nara City, central Japan. Nagilactone content in mature leaves dropped sharply in May, when new leaves flushed. The nagilactone content of new leaves was far greater than that of mature leaves, implying a translocation of nagilactones from old leaves to new leaves. The total mass of nagilactones in the canopy was 3.9 kg/ha.     

竹柏果油提取工艺优化及理化特性分析

以竹柏果仁为原料,采用单因素与响应面试验相结合的方法对超声波辅助索氏提取法提取竹柏果仁油的工艺进行优化,并考察其理化性质与脂肪酸组成。结果表明,竹柏果油最适提取工艺条件为:以正己烷为提取溶剂,提取温度75℃,料液比140(g/mL),提取时间150min。该条件下,竹柏果仁油提取率为29.32%。经GC-MS定性、定量分析可知,竹柏果油中共检出9种脂肪酸,其中不饱和脂肪酸含量达95.81%,多不饱和脂肪酸总量(76.27%)显著高于单不饱和脂肪酸(19.54%);其中亚油酸含量最高,并富含油酸、二十碳二烯酸和二十碳三烯酸。     

竹柏种仁油脂成分及其抗氧化活性分析

采用5种方法对竹柏种仁油脂进行提取,并通过核磁共振和气相色谱-质谱技术分别对其油脂成分和脂肪酸组成进行分析,同时采用DPPH自由基清除法和羟基自由基清除法对竹柏种仁油脂的抗氧化活性进行研究。结果表明,5种方法对竹柏种仁油脂的提取率存在显著差异(P 0.05),其中Folch法的提取率最高,为53. 81%。竹柏种仁油脂以甘油三酯为主,磷脂、游离脂肪酸和甾醇含量极低。竹柏种仁油脂经2 mol/L KOH-甲醇溶液室温衍生3 min,甲酯转化率即达99. 80%;且其脂肪酸以油酸(18. 65%)、亚油酸(43.49%)和花生烯酸(30.65%)为主,不饱和脂肪酸含量高达90%以上。竹柏种仁油脂对DPPH自由基和羟基自由基的IC_(50)分别为3.36 mg/mL和0. 38 mg/mL,表明竹柏种仁油脂具有较好的抗氧化能力,可作为健康植物油脂进行开发利用,具有良好的开发潜力和应用前景。本研究为竹柏种仁油脂的提取、成分分析和抗氧化活性研究提供了一定的参考。     

The Plant Growth Inhibitor Nagilactone Does Not Work Directly in a Stabilized Podocarpus nagi Forest

Nagilactones isolated from Podocarpus nagi are known for poisonous physiological activities to organisms. To clarify the allelopathic potential of nagilactone to wild plants, the seasonal changes in nagilactone contents in throughfall, leaf litter, and soil were monitored monthly in a podocarp forest at Mt. Mikasa, Nara City, central Japan. The average annual nagilactone concentrations in throughfall, leaf litter, and surface soil at 0–10 cm depth were 4.7 × 10^–12 g/ml, 3.8 × 10^–4 g/g and 3.1 × 10^–7 g/g, respectively. The nagilactone flux from canopy leaves to the forest floor via throughfall was 5.2 × 10^–2 g/ha/yr, which was far smaller than that via leaf litterfall: 765.3 g/ha/year. The disappearance of nagilactones from leaf litter and the nagilactone accumulation in the Ao layer and mineral soil were also studied. Nagilactone in leaf litter rapidly disappeared and its relative disappearance rate was 5.8/yr. Nagilactone concentration in mineral soil also decreased rapidly with an increase in soil depth and could not be detected in soil at 40–100 cm depth. The total mass of nagilactones was 177.3 g/ha in the Ao layer and 105.0 g/ha in mineral soil. These quantities in nagilactone dynamics give a very rapid turnover time of 0.37 year (4.4 months) in a soil nagilactone pool, implying the possibility of the reabsorption of nagilactone by P. nagi, while the allelopathic effects of nagilactone to other plants in the podocarp forest are questionable.