Allelopathic effect of phenolic acids from humic solutions on two spruce mycorrhizal fungi:Cenococcum graniforme andLaccaria laccata

The aim of this investigation was to determine the impact ofp-hydroxyacetophenone,p-hydroxybenzoic acid, catechol, and protocatechuic acid on respiration of two spruce mycorrhizal fungi:Laccaria laccata andCenococcum graniforme. These phenols are produced byVaccinium myrtillus,Athyrium filixfemina, andPicea abies, predominant species of spruce forests in the Alps, and they are also present in humic solutions at 10^–10 M or 10^–5 M. Respiration of the two fungi was inhibited by the four phenolic acids, even at concentrations ranging from 10^–5 M to 10^–7 M. These data show phenolic acids from humic solutions have biological activity at extremely low concentrations, suggesting a contribution ofV. myrtillus, A. filixfemina, andP. abies to allelopathic inhibition of mycorrhizal fungi.     

兰香草挥发油化学成分的研究

采用常压水蒸气蒸馏法提取了兰香草挥发油,得油率为 0.35 ~ 0.52%。其相对密度(20℃/4℃)0.9980 ~0.9900,折射率(20℃)1.4608,比旋光度+0.51°;酸值1.5。并用毛细管气相色谱、红外光谱、核磁共振谱和色-质联机等对该挥发油进行了系统的成分分析。在分出的112个色谱峰中,共鉴定出 71 个化合物,占挥发油总量的 94.6%。其主要成分为芳樟醇、紫苏醇、香芹酮、荠苎烯、4-甲基-6-庚烯-3-酮、葎草烯、马鞭草烯酮、左旋松香芹酮、2-壬烯-4-炔等。     

Studies on the response of ‘Tifblue’ and ‘Woodard’ rabbiteye blueberries to fertilizers

A field study was conducted to investigate the effects of three fertilizer placement methods and 11 fertilizer formulations on plant survival, economics of replanting, yield, and fruit size of two rabbiteye blueberry (Vaccinium ashei Reade) cultivars Tifblue and Woodard. Fertilizer rates were either mixed with the soil under plants (before planting), sidedressed, or half-rate was placed under plants with the other half sidedressed. Fertilizers at planting caused a total of 34% Woodard and 12% Tifblue plants to die as compared to 6% for Woodard and none for Tifblue when no fertilizer was applied. Fertilizer formulas 2-1-1 and 5-10-10 oxide ratios placed under Woodard plants caused 100% mortality whereas Tifblue fertilized with oxide ratios 2-2-2 and 5-10-10 under plants reached the maximum 50% mortality. Splitting fertilizer placement under the side of the plants resulted in less Woodard plant mortality (30%) than placing all the fertilizer under plants (54%). However, plant mortality for the side/under group was not different than sidedressing all fertilizer (23%). A planted hectare in this experiment consisted of 1852 Tifblue and 926 Woodard plants, providing one Woodard plant to pollinate two Tifblue plants. Based on the results obtained, the 5-10-10 fertilizer placed under plants would be expected to cause half the Tifblue (926 plants) and all the Woodard (926 plants) to be replanted. Plant costs alone was estimated to be $2315 with additional replanting costs of $93 for Tifblue and much higher for Woodard. Sidedressing 5-10-10 fertilizer eight weeks after planting would have prevented plant mortality. Placement of various fertilizers under Woodard or Tifblue plants resulted in a significant increase in plant mortality as compared to side placement of fertilizers. Yield loss due to plant mortality increased linearly with the N level of the fertilizers (ranging from 0 to 2) for both cultivars. Woodard fruit size was not affected by fertilizer placement but placing fertilizers under Tifblue plants produced smaller yields with larger fruit than sidedressed plants. Blueberry plants in a virgin acidic soil may experience no reduction in yield if fertilization is completely eliminated.     

闪蒸-气相色谱应用于鱼腥草挥发性组分研究

本文用一种新的分析方法闪蒸-气相色谱（FE—GC）来研究中药鱼腥草的挥发性组分，用质谱鉴定了其挥发性物质的化学组成，并和传统的水蒸气蒸馏法进行了对比。结果表明：该方法简单、快速、可靠，样品粉末可直接用于分析，不需要复杂费时的前处理过程，且样品需要量少。这对鱼腥草化学成分整体性研究和有效成分提取方法的开发具有非常重要的意义。     

GC—MS结合HEIP分析茅苍术中挥发油成分

分析茅苍术挥发油中的化学成分。利用气相色谱一质谱（GC—MS）联用技术对其进行分离检测,结合直观推导式演进特征投影法（HELP）对重叠色谱峰进行分辨解析,从而对挥发油成分进行准确的定性定量分析,同时利用程序升温保留指数辅助定性。共分辨出52个色谱峰,鉴定出其中50个组分,其含量占茅苍术挥发油总量的97．44％,其主要化学成分为：2-（2-甲氧基）苯甲氧基苯酚,其相对含量达29．22％,其次还有2,3-二氢-7-甲氧基-4-甲基-1H-1,5一苯并二氮卓-2-酮（3．72％）、甘香烯（3．64％）、丁子香烯（3．60％）、β-丁子香烯（3．54％）、6S-2,3,8,8-四甲基-三环[5．2．2．0（1,6）]十一（2）烯（3．37％）、雅槛蓝树油烯（2．63％）等,它们占总挥发油的49．72％,而其它43个组分只占47．72％。结合使用直观推导式演进特征投影法解析重叠色谱峰,比单独使用GC-MS法能更真实、全面地反映茅苍术中的挥发油化学成分。     

白英化学成分及生物活性研究进展

综述了近年来自英的化学成分和药理作用的研究概况.到目前为止,从白英中分离出的化合物有皂甙类、有机酸类、萜类、多酚类、黄酮类、甾醇类、香豆素类、多糖类和其他类型的化合物;白英具有良好的抗癌、抗菌、抗过敏等作用,在临床上具有广泛的应用价值.     

中华苦荬菜总黄酮和总三萜提取工艺优化研究

以中华苦荬菜的总黄酮和总三萜为筛选指标,分别对索氏提取、超声波提取、微波提取设计正交试验,比较3种方法对有效成分的提取效率。每种方法得到优化整合方案,最后进行得率比较,优选最佳提取工艺。结果表明超声波提取法对总黄酮和总三萜提取得率最高,单次提取即可同时达到2种物质提取率的较好方法。其最佳条件为80%乙醇,在45℃条件下提取40 min。该法简便,提取率高,可用于快速提取中华苦荬菜中的有效成分。     

超声波法提取鱼腥草中的绿原酸

利用超声波效应提取鱼腥草中的绿原酸。对乙醇浓度、超声作用时间、料液比等因素进行研究,并与传统的提取方法相比。结果表明,该法提取率高,提取时间短,较佳的工艺条件为:乙醇浓度为60％,超声作用时间为40 min,料液比为1:30。     

淮山的化学成分和药理作用研究进展

淮山具有多种生物活性物质,为了更好地开发和利用中国丰富的淮山资源,本文对近年来国内外淮山的化学成分、药理作用的研究概况进行综述,并提出了今后的研究方向,旨在为淮山生物活性物质的开发利用提供参考。