罗布麻茎叶粗提物及脱胶纤维的抑菌活性分析

文章研究了罗布麻茎叶粗提物对大肠杆菌、金黄色葡萄球菌和黄曲霉的抑菌活性和最小抑菌浓度,并定性分析了脱胶后的罗布麻纤维对上述类型微生物的抑制效果。结果表明,罗布麻茎叶粗提物对黄曲霉和金黄色葡萄球菌的抑制效果较为明显,对大肠杆菌抑制效果稍差,其中,罗布白麻和罗布红麻对黄曲霉菌的最小抑菌浓度分别为5、7.5 mg/mL,对金黄色葡萄球菌最小抑菌浓度均为7.5 mg/mL,而对大肠杆菌的最小抑菌浓度分别为10、15 mg/mL;定性分析发现,经脱胶后的罗布麻纤维仍对细菌类的金黄色葡萄球菌和大肠杆菌具有一定的抑制作用,但对霉菌类的黄曲霉无明显抑制作用。     

杂交棉多目标性状间关系的统计研究

 对2009-2010年河南省棉花区试的49个杂交种（组合）的4组15个性状进行了主成分分析和典型相关分析,主成分分析表明：取5个主成分就可以使方差累计贡献率达85.18％;按特征向量由大到小的顺序,育种时应选择果枝数多、单株结铃性强、子指大、纤维强度大的杂交种。典型相关分析表明：4组性状间相关均达到极显著水平,表明在形态性状中选择生育期长、植株高大的杂交种,可以提高产量,同时也可以提高对黄萎病的抗性、纤维整齐度和纤维强度。即由易选择的形态性状,可间接对黄萎病、纤维整齐度、纤维强度等抗病性和纤维品质性状选择。     

新型含茶抗菌纤维的加工技术研究

茶叶具有天然抗菌性能。新型茶纤维纺织产品以茶叶中的天然茶色素、茶多酚、儿茶素等物质为功能性成分,具有抗菌除臭、改善人体微循环等功能。本文主要阐述茶叶抗菌功能,对其新型抗菌纤维的生产工艺进行综述。     

印楝种仁5种活性成分纯化与定量分析

印楝(Azadirachta indica.A.juss)种仁中含有印楝素A(azadirachtin)等活性成分,主要为四环三萜类化合物,对害虫具有显著的忌避拒食作用和生长抑制作用。本研究通过硅胶柱层析和TLC法对印楝活性物质进行分离纯化,得到印楝素A等5种高纯度印楝素同系物,采用LC-MS对其进行定性分析,鉴定5种物质分别为azadirachtin、salannin、nimbin、6-deacetylnimbin、6-deacetylsalannin,并使用HPLC对5种化合物进行定量分析。     

猴耳环多酚的大孔树脂纯化工艺及其组分分析

建立并优化猴耳环多酚的纯化工艺并对其组分进行定性分析。本研究以猴耳环多酚粗提物为原料,以吸附及解吸附效果筛选了最优大孔树脂,再以吸附、解吸附和纯度为评价指标,考察各工艺参数对AB-8树脂纯化多酚的影响,最后采用超高效液相色谱-四级杆-飞行时间串联质谱（UPLC-Q-TOF-MS）法进行多酚组成定性分析。结果表明：优选 AB-8树脂,粗提物以质量浓度3 mg/mL、流速1 mL/min上样10 BV（柱体积：1 BV=10 mL）,水洗后,用60%乙醇5 BV以1 mL/min的流速洗脱。在此工艺条件下,多酚纯度达到58.64%。UPLC-Q-TOF-MS定性分析了纯化后猴耳环多酚14种组分。建立的猴耳环多酚的纯化工艺稳定可行,实现了其组分定性分析,为进一步研究提供了依据。     

新鲜椰衣纤维表面半纤维素含量的测定及去除

新鲜椰衣纤维表面粘附有一定量结构疏松的椰糠,椰糠的主要成分为半纤维素和木聚糖类,既不利于椰衣纤维的改性,也不利于用做固定化酶的载体材料,必须将其除去。采用稀硫酸加热水解,使新鲜椰衣纤维表面粘附的半纤维素转化为可溶的木糖和低聚木糖,以木糖为标准,3,5-二硝基水杨酸(DNS)为显色剂,采用分光光度法间接测定新鲜椰衣纤维中半纤维的含量,以考察椰衣纤维表面半纤维去除的效果。结果表明,当硫酸溶液浓度1.3 mol/L、水解温度102℃、水解时间2 h,固液比为1∶50时,半纤维素的去除效果最佳,新鲜椰衣纤维表面粘附的半纤维素量为14.58%,通过红外光谱和扫描电镜等可观察椰衣纤维表面的变化,重现性试验及标准回收试验证明该方法效果良好。      

微波辅助萃取测定苎麻果胶含量的方法

介绍了一种微波辅助萃取测定苎麻果胶含量的方法,通过单因素实验,确定了其最佳工艺条件,并采用红外光谱法对所萃取果胶进行了定性分析。实验结果表明,最佳工艺为：以草酸铵（5g/L）为萃取剂,苎麻纤维的长度为1.0 cm,液料比为20 mL/g,苎麻浸泡20 min后在450 W微波功率下辐照6 min,连续萃取两次后可达到GB5889—86国标法苎麻中果胶的测定效果。微波辅助萃取不仅大大缩短了果胶的萃取时间,而且其萃取物的红外光谱亦与标准果胶结构相符。     

利用能源植物斑茅纤维固态发酵产纤维素酶及其糖化的研究

以能源植物斑茅(Erianthus arundinaceus)为材料,对其纤维成分、产酶条件和糖化条件进行了分析。结果表明:斑茅含有纤维素43.77%、半纤维素28.57%、木质素11.01%;对斑茅进行预处理后,纤维中纤维素的含量提高至72.54%,半纤维素含量降低至13.02%,木质素的含量降低至3.34%。利用预处理的斑茅纤维进行固态发酵产酶,其最佳的产酶条件为:茅麸比1∶3,固液比1∶2,氮源(脲)0.75%,初始pH 5.0,32℃发酵培养72 h;相对于利用未经预处理的斑茅纤维为原料,其FPA酶活提高210.9%,达到20.74 U/g,CMC酶活提高239.1%,达到218.26 U/g。以纤维素酶对斑茅纤维进行糖化,糖化率达到40.60%。     

黄麻纤维的形态结构及组分研究现状

对黄麻纤维的形态、微观结构和化学成分的研究现状进行了综述,介绍了黄麻工艺纤维中木质素和半纤维素对工艺纤维力学性质作用机理的猜测以及细胞间质成分的争论.并讨论了黄麻工艺纤维加工中的主要影响因素之一 --细胞间质成分,及其他尚未解决的问题.     

咖啡果皮与不同来源可溶性膳食纤维结构及性质比较研究

本研究以咖啡果皮可溶性膳食纤维（CPSDF）与大豆、菊粉、大枣、燕麦、芹菜5种市售可溶性膳食纤维为原料，系统分析了6种可溶性膳食纤维的粒径、单糖组成、微观结构、理化性质及功能特性。结果表明：CPSDF的粒径分布较宽，均一性弱于其余5种可溶性膳食纤维，共检测出10种单糖组分；红外光谱和扫描电镜结果表明，不同来源可溶性膳食纤维具有相似的光谱分布，但特征波段的强度略有不同，且微观结构也有差异。X-射线衍射和热重分析表明，6种样品结晶度不同，CPSDF结晶度最小（38.84%），但其热稳定性优于其他5种样品。CPSDF的持油性为(2.18±0.03)mg/g，与其余5种膳食纤维样品无显著差异；CPSDF的溶解性为90.9%，低于其余5种可溶性膳食纤维样品；CPSDF的亚硝酸盐吸附能力显著优于其他5种样品，吸附量为7.93 mg/g。本研究结果可为咖啡果皮的开发利用提供理论基础，为咖啡果皮可溶性膳食纤维的高值化利用提供理论支撑。     

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.     

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.     

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.     

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.     

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).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

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).