活性中间体芳香羟胺的研究进展

芳香羟胺是合成农药、医药等的重要中间体,其有诸多制备方法。文章着重介绍国内外以金属为还原剂,选择还原芳香硝基化合物制备芳香羟胺的研究进展,并分析此方法的优缺点,以期推动此方面的研究及应用。     

Effect of nitrogen limitation on antioxidant qualities is highly associated with genotypes of lettuce (Lactuca sativa L.)

Antioxidants are highly beneficial to human health, and their accumulation in lettuce, one of the most popular leafy vegetables, depends on both genetic and environmental factors. Nitrogen(N) availability plays an essential role in regulating antioxidant accumulation, but the influence of genotype × N interactions on the antioxidant qualities of lettuce is poorly understood. Therefore, the present study investigated the variation of growth and antioxidant qualities of 20 lettuce(Lactuca sativa L.) genotypes(10 green lettuce genotypes and 10 red lettuce genotypes) under limited N(low N, LN) conditions and standard N(high N, HN) conditions. For all 20 genotypes, LN conditions reduced shoot(i.e., leaf) growth, but increased plant concentrations of vitamin C,glutathione, and phenolic compounds, with the exception of carotenoids, compared with HN conditions. Because of reduced biomass under LN conditions, not all lettuce genotypes exhibited increased antioxidant yields or total antioxidant capacity yield. The variation in antioxidant quality was primarily genetically determined. Generally, the green lettuce genotypes exhibited more pronounced increases in antioxidant yields and total antioxidant capacity yield than the red lettuce genotypes under LN conditions. These results suggest that even though LN conditions generally tend to improve the antioxidant qualities of lettuce, the extent of this effect is highly dependent on genotype. Therefore, genotype should be given priority in future studies that aim to improve antioxidant qualities in lettuce through N management.     

Low molecular phytochemicals of Indian dwarf (Triticum sphaerococcum Percival) and Persian wheat (T. carthlicum Nevski) grain

Ancient wheat grain is considered by consumers to be more natural, pro-healthy and better tolerated, so these genotypes are being steadily reintroduced to cultivation. This study presents the content and composition of phenolic acids, alkylresorcinols, sterols, tocols and carotenoids in the grain of Indian dwarf and Persian wheats, extended by characteristics of their kernels (weight, dimensions and colour). To compare these features, four other wheat species (bread, spelt, durum and einkorn wheats) were used. It was found that the grain of Indian dwarf and Persian wheat is similar in weight and dimensions to grain of einkorn wheat, while in colour to bread wheat. Among the tested samples, grain of both new genotypes was the richest source of total low molecular phytochemicals, especially phenolic acids and alkylresorcinols, while being the weakest source of carotenoids. For these wheats, an enhanced share of ferulic acid (93–95%) was found, accompanied by higher quantitative and qualitative variability of homologues within sterols, tocols and carotenoids. In turn, the alkylresorcinol composition was related to wheat ploidy level.     

小分子化合物单克隆抗体的制备及其在动物医学领域的应用

农药、兽药、重金属、生物毒素等残留物质的痕量检测在医学诊断、食品安全、环境监测等领域均具有重要意义，其中基于抗原-抗体特异性识别的免疫分析技术具有特异性强、灵敏度高、稳定性好、操作简便快捷等优点，但如何获得小分子化合物的特异性抗体是研制免疫分析技术的关键。作者介绍了基于杂交瘤技术制备小分子化合物单克隆抗体的方法，分析了影响杂交瘤技术制备小分子化合物单克隆抗体的因素，然后综述了小分子化合物单克隆抗体在兽药残留、药物开发、环境保护等动物医学领域的应用，最后展望了小分子化合物单克隆抗体生产和应用的发展趋势，为小分子化合物单克隆抗体的制备与应用相关研究提供指导。     

亚临界流体萃取油脂及微量成分研究进展

亚临界流体萃取（subcritical fluid extraction, SFE）作为一种高效提取技术，在油脂加工中的应用备受关 注。本文介绍了国内外学者关于SFE用于油脂萃取的研究成果，详细综述了SFE在不同来源油脂及微量成分提取 领域的研究进展，并就目前研究状况对其前景进行了展望。      

不同萎凋方式和碰青工艺对红茶挥发性成分的影响

为探明萎凋方式和碰青工艺对红茶香气形成的影响,以金萱为材料,采用顶空固相微萃取和气相色谱—质谱联用分析技术(HS-SPME-GC-MS)结合茶叶感官审评,研究红茶可挥发性成分和香气前体物的变化规律。结果表明,改变萎凋方式或引入碰青工艺对金萱红茶主要挥发性成分并没有很大作用,但可引起挥发性成分相对含量变化,导致茶叶香型发生改变。日光和鼓风萎凋对金萱红茶香型差异性有积极作用。抽湿萎凋和碰青工艺则增强香气的丰富度和持久性。鉴定的48种挥发性化合物中主要为醇类,占香气总量的71.58%~74.19%。反-β-罗勒烯是区别于其他红茶的主要成分之一。茶叶前体物产生的挥发性成分呈规律性变化,日光萎凋有利于苯丙氨酸和法呢基焦磷酸/牻牛儿基焦磷酸为前体的挥发性成分产生;鼓风和抽湿萎凋则以不饱和脂肪酸降解的挥发性成分为主。碰青工艺对来自苯丙氨酸和类胡萝卜素的挥发性成分有积极作用,但与静置时间成负相关。本研究结果为乌龙茶品种改制红茶提供理论参考。     

Phenolic compounds in raw and cooked rice (Oryza sativa L.) and their inhibitory effect on the activity of angiotensin I-converting enzyme

Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes.     

Comparison of sorghum and maize raw distillates: Factors affecting ethanol efficiency and volatile by-product profile

The potential of sorghum grain in the production of bioethanol was determined in comparison to maize and as an alternative to it. The effects of the raw materials, the raw material cultivars, and the fermentation process on ethanol efficiency and volatile compound profile of the raw distillates were investigated. The ethanol yield proved to be strongly determined by the variety of the raw material and by the fermentation method. The SSF method with a weight to water ratio of 1:4 proved to be the most effective for ethanol production in the case of both maize and sorghum. The highest ethanol yield at 86.94% of the theoretical value, was obtained from maize; the value from sorghum was 80.15%. The fermentation method, though not the grain cultivar, had a significant effect on the volatile compound profile of the raw distillates. The raw distillates obtained using the SSF method at a ground grain to water ratio of 1:4 had the lowest concentration of esters and aldehydes. The average content of volatile compounds in the sorghum distillates was lower than in the maize distillates. This study emphasizes the great potential of sorghum, a maize alternative, as an energy plant in the distillery.     

一种光合细菌复合制剂对草鱼的生长及非特异性免疫功能的影响

在基础饲料中添加一种光合细菌复合制剂持续饲喂草鱼30 d和60 d,探讨草鱼的生长及非特异性免疫指标的变化。结果表明,饲喂30 d时,添加光合细菌复合制剂的处理组草鱼白细胞吞噬百分比、血清总超氧化物歧化酶(SOD)活力、血清和肝脏谷胱甘肽过氧化物酶(GSH-Px)活力极显著高于饲喂基础饲料的对照组草鱼(P<0.01);饲喂60 d时,处理组草鱼血清抗菌活力、血清和肝脏总SOD活力较对照组极显著升高(P<0.01),血清丙二醛(MDA)含量显著升高(P<0.05)。结论为所选光合细菌复合制剂持续饲喂草鱼30 d或60 d,对草鱼生长量有促进作用,能提高草鱼的非特异性免疫功能。     

Marine antitumor drugs: status, shortfalls and strategies

Cancer is considered as one of the deadliest diseases in the medical field. Apart from the preventive therapies, it is important to find a curative measure which holds no loopholes and acts accurately and precisely to curb cancer. Over the past few decades, there have been advances in this field and there are many antitumor compounds available on the market, which are of natural as well as synthetic origin. Marine chemotherapy is well recognized nowadays and profound development has been achieved by researchers to deal with different molecular pathways of tumors. However, the marine environment has been less explored for the production of safe and novel antitumor compounds. The reason is a number of shortfalls in this field. Though ample reviews cover the importance and applications of various anticancerous compounds from marine natural products, in the present review, we have tried to bring the current status of antitumor research based on marine inhibitors of cancer signaling pathways. In addition, focus has been placed on the shortfalls and probable strategies in the arena of marine antitumor drug discovery.