肥牛木根化学成分研究

从肥牛木(Cephalomappa sinensis)根的乙醇提取物中分离得到了7个化合物,经波谱分析确定其结构分别为:羽扇豆-20(29)-烯-2α,3β-二醇(1),苏门树脂醇酸(2),油桐酸(3),3-βstigmast-5-en-3-O--βD-xylopyranoside(4),东莨菪内酯(5),香草酸(6),油酸(7)。以上化合物均为首次从该植物中分离得到。     

南海脆灯蕊柳珊瑚中西松烷型二萜和甾醇类化学成分研究

从南海水域脆灯蕊柳珊瑚的乙醇-二氯甲烷提取物中分离鉴定了6个西松烷型二萜和3个甾醇,经波谱分析确定其结构分别为:junceellin A(1),praelolide(2),junceellolides A~D(3~6),24-αmethylcholest-7,22-dien-3β,5α,6-βtriol(7),cholestan-3-ol(8),cholesterol(9);其中化合物1,2,7,8均为首次从该海洋动物中分离得到。     

小花清风藤的化学成分研究

利用Sephadex LH-20,硅胶柱色谱和硅胶制备薄层色谱等分离方法反复分离纯化,从小花清风藤（Sabia parviflora Wall．ex Roxb）中分离得到9个化合物,通过波谱数据分析分别鉴定它们为二十五烷酸（1）、木栓酮（2）、5-氧阿朴菲碱（3）、3-氧化齐墩果酸甲酯（4）、齐墩果酸（5）、羽扇豆-20（29）-烯-3-酮（6）、羽扇豆醇（7）、β-谷甾醇（8）、脱镁叶绿甲酯酸（9）。化合物2,6、7、9首次从该植物中分离得到。     

宽叶大戟化学成分的研究

对宽叶大戟(Euphorbia latifolia)的化学成分进行研究。从其乙醇提取物的石油醚、乙酸乙酯部位分离得到10个化合物,经理化常数和波谱分析,分别鉴定为:山萘酚(kaempferol,1)、槲皮素(quercetin,2)、山萘酚-3-O-β-D-葡萄吡喃糖苷(kaempferol-3-O--βD-glucopyranoside,3)、槲皮素-3-O--βD-葡萄吡喃糖苷(quercetin-3-O--βD-glucopy-ranoside,4)、白桦酯酸(betulinic acid,5)、白桦酯醇(betulin,6)、齐墩果酸(oleanolic acid,7)、胡萝卜苷(daucosterol,8)、β-谷甾醇(-βsitosterol,9)、正二十八烷醇(1-octacosanol,10)。化合物1~10均是首次从该植物中获得。     

连钱草化学成分研究

从连钱草(Glechoma longituba)分离并鉴定了10个化合物,分别为β-谷甾醇(1)、齐敦果酸(2)、熊果酸(3)、2α,3α-二羟基乌苏-12-烯-28-酸(4)2、α,3β-二羟基乌苏-12-烯-28-酸(5)、胡萝卜苷(6),3,6-二甲氧基-6″,6″-二甲基苯并吡喃-(7,8,2″,3″)-黄酮(7)、芫花素(8)、芹菜素-7-O--βD-葡萄糖苷(9)、木犀草素-7-O-β-D-葡萄糖甙(10)。其中化合物2,4~8首次从该植物中分离得到。     

云前胡的萜类成分研究

从云前胡(Peucedanum rubricauleSheh et Shan)的乙醇提取物中首次分离并鉴定了4个萜类化合物,分别为sinodielides A(1)、B(2),积雪草酸(asiatic acid,3)和乌苏酸(ursolic acid,4)。     

聚乙二醇对菠萝蛋白酶的化学修饰

方法:用琥珀酸酐法活化的聚乙二醇对菠萝蛋白酶进行化学修饰,得到菠萝蛋白酶的修饰酶,对比研究三种菠萝蛋白酶:修饰酶、混合酶、天然酶的热稳定性及酸碱稳定性,考察金属离子对三种菠萝蛋白酶的影响。结果:当在55℃水浴保温100min后天然酶活力只保留20%,混合酶活力保留37%,修饰酶活力保留58%;在pH3.0-4.5及pH6.0-7.0的条件下,修饰酶活力高于天然酶活力。当Ca2 的浓度达到0.05mg/mL时,修饰酶的活力高达257.66%;当Mg2 的浓度达到0.035mg/mL时,修饰酶的活力高达147.25%。一价离子Na 对三种菠萝蛋白酶无明显影响。结论:修饰的菠萝蛋白酶对温度和pH值的稳定性均比天然酶有很大程度的提高。混合酶的活力介于天然酶和修饰酶之间说明聚乙二醇对菠萝蛋白酶有一定的保护作用。二价离子Ca2 、Mg2 对三种菠萝蛋白酶活力均有不同程度的激活作用。     

枇杷叶的化学成分

枇杷叶系蔷薇科（Rosaceae）枇杷属植物枇杷[Eriobotrya japonica（Thunb．）Lindl．]的干燥叶,为常用中药,收载于历版《中华人民共和国药典》中。枇杷叶归肺、胃经,具清肺止咳、降逆止呕的作用,用于治疗肺热咳嗽、气逆喘气、胃热呕逆及烦热口渴之症状。目前,已经从枇杷叶中分离出三萜酸、黄酮类、多酚、倍半萜及其苷类等成分,对其药效的研究主要集中在三萜酸的抗炎心、降血糖和抗病毒活性等方面。     

Dissolved humic substances – ecological driving forces from the individual to the ecosystem level?

1. This review focuses on direct and indirect interactions between dissolved humic substances (HS) and freshwater organisms and presents novel opinions and hypotheses on their ecological significance. Despite their abundance in freshwaters, the role of HS is still inadequately understood. These substances have been considered too large to be taken up by freshwater organisms. On the contrary, here we present evidence that dissolved HS are indeed taken up and interact directly and/or indirectly with freshwater organisms. 2. We show that dissolved HS exert a mild chemical stress upon aquatic organisms in many ways; they induce molecular chaperones (stress shock proteins), induce and modulate biotransformation enzymes and modulate (mainly inhibiting) the photosynthetic release of oxygen by freshwater plants. Furthermore, they produce an oxidative stress, which may lead to membrane oxidation. HS modulate the multixenobiotic resistance activity and probably other membrane‐bound pumps. This property may lead to the increased bioaccumulation of xenobiotic chemicals. Furthermore, they can modulate the numbers of offspring in a nematode and feminise fish and amphibians. The ecological consequences of this potential remain obscure at present. HS also have the potential to act as chemical attractants (as shown with a nematode). 3. In some macrophytes and algae we show that HS interfere with photosynthesis and growth. For instance, the presence of HS suppresses cyanobacteria more than eukaryotic algae. By applying a quantitative structure activity relationship approach, we show that quinones in the HS interfere with photosynthetic electron transport. We show that even Phragmites leachate can act as a kind of phytotoxin. HS also have the potential to suppress fungal growth, as shown with the water mould Saprolegnia parasitica and force the fungus to respond by spore production. 4. In very soft, humic freshwaters, such as the Rio Negro, Brazil, HS stimulate the uptake of essential ions, such as Na and Ca, at extremely low pH (3.5–4.0) and prevent the ionoregulatory disturbance induced by acid waters, thereby enabling fish to survive in these environments. 5. We discuss whether or not HS are directly utilised by aquatic microorganisms or via exoenzymes, which may be washed in from the terrestrial catchment. There is accumulating evidence that the quality of the HS controls microbial growth. In total, net‐heterotrophy may result from HS‐mediated suppression of primary production by the quinone structures and/or from HS‐mediated support of microbial growth. As there is also evidence that HS have the potential to support photoautotrophic growth and suppress microbial growth, the opposite community effect could result. Consequently, dissolved organic carbon (DOC) has to be chemically characterised, rather than simply measuring bulk DOC concentration. 6. In sum, dissolved HS interact with freshwater organisms in a variety of ways in unenriched humic lakes. In addition to the well known effects of HS on light regime, for example, and the direct and indirect supply with carbon (energy), other interactions may be much more subtle. For instance, HS may induce internal biochemical stress defence systems and have the potential to cause acclimatisation and even adaptation. We are just at the beginning of understanding these interactions between dissolved HS and freshwater organisms.     

药用柴胡属植物产地与化学成分相关性研究

从柴胡属植物品种入手,着重介绍药用柴胡属植物的生境分布、不同产地环境因子与柴胡化学成分研究进展,并为将来控制柴胡质量,解决柴胡资源有效途径提供方案.