玉米赤霉烯酮对人正常肝细胞(LO_2)和人胚肾细胞(HEK293)的毒性作用研究

以体外培养的人正常肝细胞(LO2)和人胚肾细胞(HEK293)为模板,用MTT比色法研究了玉米赤霉烯酮对以上两种细胞株的毒性作用,结果表明,在所测浓度范围内,玉米赤霉烯酮对这两种细胞的抑制率随其作用浓度的增加而增强,而其作用浓度到达一定程度时,玉米赤霉烯酮对这两种细胞的抑制率保持在一定的范围内不再增加。实验结果证明在2.50μg/mL和1.25μg/mL的最高浓度下,玉米赤霉烯酮对人正常肝细胞(LO2)和人胚肾细胞(HEK293)的抑制率分别为86.61%和67.06%,可见其肝毒性和肾毒性明显。     

计算机分子对接(MD)与分子动力学方法(ADMET)技术在模拟呕吐毒素降解中的应用

计算机分子对接是模拟受体和底物之间通过能量匹配和几何匹配而相互识别的过程。其被广泛运用于虚拟筛选活性物质以及初步判断分子活性和毒性等领域,并对我们进行实体分子活性毒性试验起到了重要的指导作用。分子动力学方法ADMET(吸收,分配,代谢,排泄和毒性)是当代药物设计和药物筛选中十分重要的方法。早期ADMET性质研究主要以人源性或人源化组织功能性蛋白质为"药靶",体外研究技术与计算机模拟等方法相结合,研究目标分子与体内生物物理和生物化学屏障因素间的相互作用。在本实验中我们利用计算机分子对接以ADMET分析软件,对脱氧雪腐镰刀菌烯醇(呕吐毒素)以及其降解产物进行计算机分子模拟分析,初步模拟呕吐毒素及其降解产物的毒性强弱,对呕吐毒素降解研究有重要的辅助作用。     

利用计算机模拟分子对接技术探究粮食中黄曲霉毒素的毒理效应

黄曲霉毒素是一类化学结构类似的小分子化合物,均为二氢呋喃香豆素的衍生物,主要存在于土壤、动植物和各种坚果中,是霉菌毒素中毒性最大,对人类健康危害极为突出的一类霉菌毒素,而黄曲霉毒素的毒理机制始终不是很明确。计算机分子对接是模拟受体和底物之间通过能量匹配和几何匹配而相互识别的过程,其被广泛运用于虚拟筛选活性物质以及初步判断分子活性和毒性等领域,并对我们进行实体分子活性毒性试验起到了重要的指导作用。利用计算机分子对接软件Discovery Studio 3.1client,将6种常见黄曲霉毒素分子B1、B2、M1、M2、G1、G2与其具有强亲和性的蛋白进行虚拟对接实验,而这些蛋白在细胞凋亡、激素代谢、免疫抑制以及消化系统功能方面有重要的作用。通过本实验能够初步模拟黄曲霉毒素分子毒性作用位点,对于其毒理机制研究有重要的辅助作用。     

免疫亲和柱净化—HPLC法测定植物油中玉米赤霉烯酮

建立了免疫亲和柱净化-高效液相色谱荧光法检测植物油中玉米赤霉烯酮的分析方法.方法的定量检出限为9.5μg/kg,相对标准偏差低于7.2％,回收率为89.2％～111.5％.该方法简便快速、灵敏准确、重现性好,可以用于植物油中玉米赤霉烯酮的定量检测.     

免疫亲和柱净化—HPLC法测定植物油中玉米赤霉烯酮

建立了免疫亲和柱净化—高效液相色谱荧光法检测植物油中玉米赤霉烯酮的分析方法。方法的定量检出限为9.5μg/kg,相对标准偏差低于7.2%,回收率为89.2%～111.5%。该方法简便快速、灵敏准确、重现性好,可以用于植物油中玉米赤霉烯酮的定量检测。     

小麦中呕吐毒素与玉米赤霉烯酮相关性探讨

呕吐毒素又称脱氧雪腐镰刀菌烯醇(DON),化学名为3a 7a 15-三羟基草镰孢菌-9-烯-8-酮,属单端孢霉烯族化合物.玉米赤霉烯酮(ZEN)又称F-2毒素,化学名为6-(10-羟基-6氧基-1-碳烯基)β-雷琐酸-μ-内酯,是由玉米赤霉菌、禾谷镰刀菌(F.graminearum)、三线镰刀菌(F.tricinctu...     

玉米赤霉烯酮与冬小麦的生长与发育

实验采用酶联免疫法分析了冬小麦（燕大1817）（Triticum aestivum L.Yan Da 1817）在不同条件（低温、短日或长日）下内源玉米赤霉烯酮（Zearalenone, 以下简称ZEN）的动态变化,并通过在不同时期外施ZEN探讨外源ZEN对冬小麦生长发育的影响。结果表明,ZEN可能是冬小麦生长与发育的重要调节物质之一。短日诱导可以代替低温春     

浅谈霉菌毒素及对养猪业的危害

正一、霉菌毒素概述霉菌毒素是霉菌产生的高毒性次级代谢产物。目前,霉菌主要分为作物在收获前产生的田间霉菌和作物收获后产生的仓储霉菌,产生霉菌毒素的霉菌不仅损害饲粮作物,还会对各种饲料和食物生产造成巨大损失,直接影响人和动物的健康,甚至引发疾病和死亡。霉菌毒素根据不同霉菌产生的毒素可分为黄曲霉毒素、单端孢霉烯旋毒素、烟曲霉毒素、玉米赤霉烯酮、     

杀青前后烤烟叶片中性香气物质变化研究

定量测定了杀青前后烤烟叶片中性香气物质的变化。结果表明:杀青前后不同中性致香成分的含量不同,杀青后含量降低的中性致香成分有3-己烯-1-醇、苯甲醇、芳樟醇、壬醛、5-甲基正糠醛、癸醛、茄酮、β-紫罗兰酮、巨豆三烯酮、十四醛、2-十四烯-1-醇、新植二烯、邻苯二甲酸二丁酯,其中壬醛、5-甲基正糠醛、癸醛、β-紫罗兰酮、巨豆三烯酮、2-十四烯-1-醇、邻苯二甲酸二丁酯、十四醛等中性致香物质均以痕量存在。杀青后含量升高的中性致香物质有糠醛、对二甲苯、苯乙醛、香叶基丙酮、巨豆三烯酮混合物、二氢猕猴桃内酯等,其中二氢猕猴桃内酯为杀青过程新增加的中性致香产物。随杀青过程变化较小的中性致香物质有邻二甲苯、β-二氢大马酮等。     

陕西地区玉米生霉粒、小麦病斑粒与真菌毒素关系的探讨分析

通过样品采集和制备,对5个样本的呕吐毒素、玉米赤霉烯酮、黄曲霉毒素B1含量进行检测和分析。实验结果表明,同一玉米样品同一生霉粒其含量与呕吐毒素、玉米赤霉烯酮、黄曲霉毒素B1含量呈正相关;同一地区玉米真菌毒素整体侵染程度基本相同,不同地区三种真菌毒素侵染程度不同,不同生霉粒包含的真菌毒素类型不同,真菌毒素具有地域性;陕西地区2017年黄曲霉毒素B1污染基本为零;同一小麦样品不同梯度病斑粒含量与呕吐毒素呈正相关,不同地区小麦呕吐毒素可能差别很大,赤霉病粒对小麦呕吐毒素的影响非常大。因此,不能简单由玉米、小麦的外观或者生霉粒、病斑粒含量判断真菌毒素含量的高低,但是根据同一样品中同一生霉粒、病斑粒其含量与真菌毒素呈正相关性,可以在收获季节,分地区采集样品,检测完好粒与生霉粒或者病斑粒真菌毒素的侵染情况,寻找合理控制点,通过收购质量指标指导对相关监测卫生指标的把控,辅助粮食质量安全的监测,尽力解决目前现场收购时的质量安全风险漏洞。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...