山苍子天然种群叶片和种实性状的表型多样性

为揭示山苍子(Litsea cubeba)天然种群叶片和种实性状的表型变异程度及其变异规律,调查了长江以南7个省份共10个天然种群的叶片和种实性状,并对其多样性进行分析。结果表明:1)山苍子的叶片和种实性状在种群间和种群内存在极其丰富的多样性,各性状表型分化系数(Vst)均值为60.19%,种群表型性状分化以种群间变异为主;2)果实形态、叶片形态、果实重和种子重4类性状的Vst均值分别为51.27%、66.66%、54.57%和72.29%;平均变异系数(CV)分别为6.60%、16.91%、19.71%和13.40%;果实形态的表型分化系数和变异系数最小,表明其性状最为稳定;3)10个表型性状间多数呈显著或极显著相关,性状与地理气候因子的相关性较差;4)系统聚类将10个种群共分为4类,种群间的分类并没有依地理距离而聚类,表型性状的Mahalanobis距离与地理距离的相关不显著(r=0.042,P=0.821),进一步表明山苍子叶片和种实性状的变异在空间上是不连续性的。研究结果为今后山苍子种质资源的保存和育种策略的制定奠定基础。     

山苍子叶内生真菌的纯化与鉴定

本研究选用PDA培养基,通过组织块分离法从山苍子叶中分离得到两株内生真菌。对照真菌鉴定手册,根据菌株和菌丝体形态学特征,并给合ITS区段的碱基序列分析,鉴定两株内生分别属于顶孢霉属和芒果球座菌属。     

柠檬醛分子蒸馏纯化新工艺与毛叶木姜子果油成分分析

利用分子蒸馏技术对毛叶木姜子果挥发油中所含柠檬醛进行了分离纯化工艺的研究。结果所得到的柠檬醛的纯度达到了 95 % ,产率为 5 3% (柠檬醛 /毛叶木姜子果油 ) ,柠檬醛的损失率仅为 15 %。从而表明 ,分子蒸馏这一现代分离技术在从毛叶木姜子果油中分离天然柠檬醛方面具有一定的可行性和工业化前景     

山苍子油的精制、分析及成份研究

本文报告一种山苍子油的精制、分析方法和成分研究.作者采用间歇精馏法从山苍子油中单离柠檬醛,可使柠檬醛含量达到90％以上;并使用毛细管气相色谱法定量测定了山苍子油中柠檬醛含量;还通过GC/ITD/COM系统从山苍子油中成功地分离出50种左右的成分,其中30多种化合物己被鉴定.     

Effects of Piper cubeba L. essential oil on methicillin‐resistant Staphylococcus aureus: an AFM and TEM study

The increasing prevalence of antibiotic‐resistant bacteria is creating a real challenge for health care systems worldwide, making the development of novel antibiotics a necessity. In addition to the development of new antibiotics, there is an urgent need for in‐depth characterization of the mechanisms of bacterial resistance toward new drugs. Here, we used essential oils extracted in our laboratory from Piper cubeba against methicillin‐resistant Staphylococcus aureus ATCC 43300, one of the most prominent antibiotic‐resistant bacteria. Effects of the essential oils extracted from P cubeba on bacteria were mainly evaluated using 2 powerful microscopy techniques: atomic force microscopy and transmission electron microscopy. High‐resolution atomic force microscopy images of the cells were obtained close to their native environment by immobilizing the cells on porous Polyether sulfone membranes, which were prepared in our laboratory with a wide range and distribution of pore sizes and depth. Inhibition zones (mm) and minimum inhibitory concentrations were determined. Two different concentrations of the oil were used to treat the cells: 50 μg/mL minimum inhibitory concentration and 25 μg/mL. The 50 μg/mL oil solution caused severe damage to the bacterial cells at microscopic levels while the 25 μg/mL solution showed no effects compared to the control. However, at nanoscopic levels, the 25 μg/mL oil solution caused significant changes in the cell wall, which could potentially impair bacterial activities. These results were also confirmed by transmission electron microscopy micrographs. Our results indicate that the extract has a good biological activity against methicillin‐ and oxacillin‐resistant S aureus and that it acts on the cell wall and plasma (cytoplasmic) membrane.     

不同居群山苍子果实精油和柠檬醛含量及其与地理-气候因子的相关性

采用水蒸气蒸馏法和气相色谱技术对取自浙江富阳、贵州毕节和织金、湖南永州、福建永安和建瓯、云南景东、四川长宁、江西安远和分宜10个居群的山苍子[ Litsea cubeba (Lour.) Pers.]果实精油含量和柠檬醛含量进行测定,并分析了果实精油含量和柠檬醛含量与地理-气候因子的相关性;在此基础上对供试居群进行了聚类分析.测定结果表明:各居群的果实精油含量和柠檬醛含量差异显著,精油含量均值为3.60％,变异系数(CV)为1.54％～10.46％;柠檬醛含量均值为3.52％,CV为24.78％ ～40.54％;云南景东居群精油含量最高(4.56％)、江西分宜居群最低(3.14％);福建永安居群柠檬醛含量最高(7.01％)、贵州毕节居群最低(1.85％),且柠檬醛含量的表型分化系数为57.87％,说明居群间柠檬醛含量的变异幅度大于精油含量,且居群间柠檬醛含量的变异程度大于居群内.相关性分析结果显示:山苍子果实精油含量与经度和7月均温呈极显著负相关,与年降雨量呈显著负相关,与海拔呈极显著正相关;柠檬醛含量与经度和年降雨量分别呈显著和极显著正相关,说明精油含量随经度增大而降低,且受环境水分和温度变化的影响较大;而柠檬醛含量随经度增大而提高,并明显受生境中水分条件的调节.聚类分析结果表明:在欧氏距离15处,供试的10个山苍子居群主要分成3类,根据地理位置大体可划分为西南部和东南部2个种质类型,其中福建永安居群较为特殊.研究结果表明:不同居群山苍子果实精油含量和柠檬醛含量差异与遗传特性、地理分布和生境气候条件均有一定的相关性.     

山苍子油对小鼠系统性新生隐球菌感染的实验研究

目的研究山苍子油治疗小鼠系统性新生隐球菌感染的疗效。方法建立小鼠系统性新生隐球菌感染模型,观察给药后小鼠的中位生存时间,检测小鼠肾脏及肺菌落形成单位计数。结果山苍子油不仅能够显著延长感染小鼠的中位生存时间,提高其生存率,而且可显著增加感染小鼠肾脏及肺菌落清除率。结论山苍子油对系统性新生隐球菌感染小鼠具有治疗作用。     

不同工艺提取老鹰茶总黄酮含量的比较

比较不同工艺提取富集的老鹰茶中总黄酮含量,分别采用传统乙醇提取-正丁醇萃取法和水提取-大孔树脂法提取老鹰茶总黄酮,并用紫外分光光度法,以芦丁为标准品,270nm下测定总黄酮含量。水提取-大孔树脂法富集所得固体中黄酮含量较高,可达55.86%,回收率为105.6%,RSD=1.64%。水提取-大孔树脂富集的工艺操作简单,所得固体黄酮含量高,更适于老鹰茶总黄酮的提取,对进一步的工业化生产开发有较好的参考价值。     

豺皮樟和圆叶豺皮樟中的阿朴啡生物碱成分

从豺皮樟（Ｌｉｔｓｅａ ｒｏｔｕｎｄｉｆｏｌｉａ ｖａｒ．ｏｂｌｏｎｇｉｆｏｌｉａ）和圆叶豺皮樟（Ｌｉｔｓｅａ ｒｏｔｕｎｄｉｆｏｌｉａ）的茎中分离得到三个阿朴啡型生物碱成分,通过光谱解析及化学方法,三个化合物分别鉴定为降波尔定（１）、波尔定（２）和氮乙酰降波尔定（３）。其中氮乙酰降波尔定系首次直接从植物中得到。     

Chemical Composition and Antibacterial Activity of Essential Oils from Different Parts of Litsea cubeba

The composition of the essential oils obtained by hydrodistillation of different parts of Litsea cubeba, including roots, stems, leaves, alabastra (flower buds), flowers, and fruits, were investigated by GC (RI) and GC/MS. The antimicrobial activity of the oils was assessed with disc diffusion and microbroth dilution assays. The results showed large variations in the composition among the different oils. The major components in the oils from roots and fruits, from stems, leaves, and alabastra, and from flowers were citral B (neral), β‐phellandrene, and β‐terpinene, respectively. The inhibition zone (DD) and MIC values for the bacterial strains tested, which were all sensitive to the essential oil of L. cubeba, were in the range of 10.1–35.0 mm and 100–1000 μg/ml, respectively. Hence, the oils of the various parts showed moderate activity against the tested bacteria. This investigation showed that the antibacterial activity of L. cubeba was attributed to the essential oils, thus they can be a potential medicinal resource.