绿玉树茎皮脂溶性成分及其抗氧化活性研究

运用气相色谱-质谱联用技术（GC-MS）对绿玉树茎皮脂溶性成分进行分析，为绿玉树的综合利用提供科学依据及数据支持。应用色谱峰面积归一化法定量分析各成分的相对百分含量，共分离鉴定出32个化合物，占其总量的96.01％。含量较高的分别是羊毛甾醇（29.86％）、13, 27-环乌苏-3-酮（8.45％）、9, 19-环羊毛甾-7-烯-3-醇（5.31％）。并运用DPPH法对绿玉树茎皮脂溶性成分进行抗氧化活性测定结果表明：其具一定的抗氧化活性，IC50为263.70 μg/mL。     

蕊木茎皮脂溶性成分及抗氧化活性研究

首次运用气相色谱-质谱联用技术(GC-MS)对蕊木(Kopsia lancibracteolata Merr.)茎皮脂溶性成分进行分析，应用色谱峰面积归一化法定量分析各成分的相对百分含量，共分离鉴定出43个化合物，占其总量的80.45%。含量较高的分别是反式-2-癸烯醛(10.29%)、β-香树脂醇(10.04%)、2-十一烯醛(8.61%)、异大戟二烯醇(5.49%)、软脂酸(5.30%)等。同时采用清除DPPH自由基能力的方法对蕊木茎皮脂溶性成分进行抗氧化活性测定，结果显示一定的抗氧化活性，其IC50值为0.83 mg/mL。     

牛筋果脂溶性成分及其抗氧化活性的研究

应用气相色谱-质谱联用技术(GC-MS)对牛筋果[Harrisonia perforata (Blanco) Merrill)]果实的石油醚萃取部分脂溶性成分进行了初步研究。结果显示,石油醚萃取部分共鉴定了29种脂溶性成分,占总峰面积的69.67%,并确定其相对含量;其中含量较高的成分依次是顺-9,12-十八碳二烯醇(12.35%)、棕榈酸(9.67%)、Z-9,17-十八碳烯醛(8.97%)、亚油酸(7.97%)、油酸乙酯(5.81%)、β-谷甾醇(4.88%)、亚油酸乙酯(4.10%)。在此基础上,采用清除DPPH自由基能力的方法测定了醇提物、乙酸乙酯萃取物及石油醚萃取物的抗氧化活性,结果均显示出较强的抗氧化活性,其IC50值分别为40、22和288 μg/mL,由于石油醚萃取物的抗氧化活性远远大于其它萃取物,因此笔者等先行对其进行了研究。     

油绿苦瓜种质种子脂溶性成分的GC-MS分析

以农艺性状差异显著的2份油绿苦瓜种质(Y41和Y63)为材料,采用气相色谱-质谱(GC-MS)联用技术对其种子脂溶性成分和相对含量进行分析。结果表明,2份苦瓜种质分别鉴定出14和19种脂溶性化学成分,脂溶性成分主要为γ-生育酚、环阿屯醇、维生素E、Ela甾醇、β-香树素、24-亚甲基环木菠萝烷醇、钝叶醇。其中2种脂溶性化学成分为Y41特有,7种脂溶性化学成分为Y63特有,γ-生育酚在2份苦瓜材料中含量均较高,分别为18.388%和22.240%。可见,不同苦瓜材料间种子脂溶性成分及含量存在一定程度的差异。     

茸果鹧鸪花不同部位脂溶性成分研究

为研究茸果鹧鸪花[Trichilia sinensis Bentv.]叶与根的脂溶性成分,采用气相色谱-质谱联用技术(GC-MS)对其化学成分进行分离分析,通过Nist2008和Wiley275质谱库检索分别鉴定各化学成分;经面积归一化法测定各样品中化学成分的相对百分含量;用滤纸片琼脂扩散法测定其抗菌活性。结果分别从茸果鹧鸪花叶、根的脂溶性成分中分离出22、41个化合物,分别鉴定了其中的20、41个化合物,所鉴定的化合物其相对含量分别占各脂溶性成分总量的86.99%、91.33%。抗菌活性结果表明:其脂溶性成分对金黄色葡萄球菌均有抑制作用。     

脂溶性抗氧化剂酚酸酯的制备与活性研究进展

酚酸是一类天然抗氧化活性成分,酯化修饰不仅可以提高酚酸类化合物的脂溶性,而且可以有效改善其生物活性。本文综述了酚酸酯的化学和酶催化合成方法及其在化学和细胞两个方面的抗氧化活性研究进展,探讨了现有的酚酸酯合成方法存在的问题和解决方案,以及不同抗氧化活性评价方法的特点,并展望其未来发展方向,为高效脂溶性抗氧化剂的开发及其在食品、药品、化妆品等领域的广泛应用提供参考。     

牛角瓜根脂溶性成分的GC-MS分析

采用气相色谱-质谱(GC-MS)联用技术对牛角瓜根脂溶性成分进行分析。结果表明,从牛角瓜根中共鉴定出62个化学成分,占色谱总馏分出峰面积的60.43%。根的脂溶性成分主要为α-香树脂醇(4.18%),棕榈酸乙酯(3.49%),1,7-二甲基-萘(3.06%)。     

脂溶性茶多酚中的主要活性组分及对人卵巢癌HO-8910细胞株的体外抑制活性

利用高速逆流色谱对脂溶性茶多酚中的主要活性组分进行分离和纯化,获得了一种新的单取代的长碳链脂溶性儿茶素表没食子儿茶素-3-O-没食子酸-4'-棕榈酸酯,并对其分子结构进行了元素分析、IR、MS和1H-NMR等表征。药理学实验考察并比较了脂溶性的表没食子儿茶素-3-O-没食子酸-4'-棕榈酸酯、水溶性的绿茶多酚和脂溶性茶多酚对人卵巢癌HO-8910细胞株的体外抑制活性。结果表明,单取代的EGCG棕榈酸酯的活性比脂溶性茶多酚强,而与绿茶多酚相当。     

芝麻抗氧化物质的种类、检测方法和含量变异

芝麻种子含多种天然抗氧化成分,本文从其种类和化学结构、提取和检测方法、含量和活性影响因素等方面进行了综述.     

猪屎豆提取物的化感作用研究

[目的]探究猪屎豆是否具有化感作用。[方法]采用种子萌发法(培养皿滤纸法),评价猪屎豆提取物对玉米、萝卜、莴苣和鬼针草的化感作用。[结果]猪屎豆乙醇提取物对鬼针草种子萌发、幼苗根长、苗高和萝卜根长具有化感抑制作用,对玉米、莴苣种子萌发、幼苗根长、苗高和萝卜种子萌发、苗高及莴苣幼苗根长表现为“低促高抑”现象。猪屎豆乙醇提取物的石油醚、正丁醇萃取物对玉米种子萌发、幼苗苗高具有化感抑制作用;而石油醚、乙酸乙酯、正丁醇和水相萃取物对玉米幼苗根长生长均具有促进作用,乙酸乙酯和水相萃取物对玉米幼苗苗高具有促进作用。[结论]猪屎豆提取物对不同植物的种子萌发和幼苗生长均有不同程度的影响,具有一定的化感作用。     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.