Effect of Different Bioassay Methods on Enzymatic Characteristics of Cotton Aphid,Aphis gossypfi Glover （Hemiptera：Aphididae）

In this study, the susceptibility of three populations of cotton aphid, Aph＆ gossypii Glover （Hemiptera：Aphididae） was assayed to imidacloprid （35SC） and thiametoxam （50WG）. The involvement of metabolic enzymes in the resistance strain of cotton aphid to the neonicotinoids was determined by the biochemical biomarkers and the resistance mechanism was determined as CaE. In another study, three different bioassay experiments were designed for detecting the susceptibility of cotton aphid to imidacloprid and thiametoxam and the effect of these two insecticides on the enzymatic activity of cotton aphid was assessed in the adult aphids treated with three different bioassay methods using a modified version of the FAO dip test, residue bioassay procedure and starvation method. Our findings suggested that the type of bioassay methods is very important when aphids＇ populations assess for the resistance against the neonicotinod insecticides. It has shown the starvation method is the most reliable method compared with other methods.     

核桃青皮抑真菌物质的分离鉴定与抑菌活性

[目的]分离鉴定出核桃(Juglans regiaL.)青皮中对植物病原真菌起抑制作用的化合物,并评价其抗菌活性.[方法]采用生长速率法依次测定核桃青皮乙醇粗提物,石油醚、三氯甲烷、乙酸乙酯萃取物以及石油醚相分离流分和活性化合物对葡萄蔓枯病菌(Cryptosporella viticola)等植物病原真菌的抑菌活性;结合抑菌活性追踪,采用硅胶柱层析、制备薄层层析分离纯化活性组分,核磁共振波谱(NMR)对活性物质进行结构鉴定.[结果]核桃青皮乙醇粗提物和3种萃取物以及石油醚萃取相的分离流分,分别对供试的10种、4种和3种植物病原真菌有抑制活性;流分Fr1-4和Fr1-5对葡萄蔓枯病菌(Cryptosporella viticola)、葡萄溃疡病菌(Botryosphaeria dothidea)和辣椒疫霉病菌(Phytophthora capsici)3种病原真菌的抑制率显著高于其他4个流分,流分Fr1-4对葡萄蔓枯病菌的抑制率达70.08％;分别从Fr1-4和Fr1-5鉴定出1个环状二芳基庚烷化合物胡桃素和4,8-二羟基-1-四氢萘酮(胡桃酮);胡桃素对供试的葡萄蔓枯病菌和辣椒疫霉病菌均显示出抑制活性,对其菌丝生长抑制中浓度(EC50)分别为0.060、0.124 mg/mL.[结论]核桃青皮乙醇粗提物及其石油醚、三氯甲烷萃取物均对供试的植物病原真菌有良好的抑制活性,从中分离获得的胡桃素对葡萄蔓枯病菌有显著抑菌活性,对辣椒疫霉病菌有中等的抑菌活性.     

纤维素高效降解菌群构建及产酶底物优化

为促进堆肥腐熟、缩短堆肥周期,通过平板初筛及酶活测定,从腐烂竹子、玉米秸秆中获得4株酶活性较高纤维素降解菌并混合培养,得到理想组合Cro-2/Bam-Q/Bam-3/Bam-1,其内切葡聚糖酶(CX)、外切葡糖酶(C1)、β-外切葡萄糖苷酶(CB)及纤维素全酶(FPA)活性分别为12.54、14.65、7.71、11.98 U,均高于单一菌株酶活性。对混合菌群产酶底物优化结果表明,当沼渣与水稻秸秆11混合,麸皮为氮源时,可有效提高混合菌群产酶活性。     

地鳖虫提取物对大鼠运动能力和骨骼肌抗氧化酶活性的影响

【目的】探讨补充地鳖虫提取物对大鼠运动能力、骨骼肌抗氧化酶表达水平及活性的影响,以明确其作为运动补剂的可能性。【方法】对大负荷游泳训练大鼠按各组平均体质量的0.5,1.0和1.5g/kg剂量分别补充地鳖虫提取物,在8周大负荷训练结束后测定大鼠力竭游泳时间、骨骼肌抗氧化酶活性及其原因表达水平。【结果】8周大负荷训练后,与单纯大负荷运动组相比,补充地鳖虫提取物组大鼠运动能力显著提高,其骨骼肌SOD、CAT、GST3种抗氧化酶活性均显著增加,同时3种抗氧化酶编码基因的表达水平也显著上调。【结论】补充地鳖虫提取物能够显著提高大鼠运动能力和骨骼肌抗氧化酶活性,其可能的机理是地鳖虫提取物上调了抗氧化酶编码基因的表达水平。     

植物源血管紧张素转换酶抑制剂的研究进展

血管紧张素转换酶抑制剂(Angiotensin converting enzyme inhibitors,ACEI)通过肾素-血管紧张素系统(RAS)和激肽释放酶-肽酶系统(KKS),抑制血管紧张素II的生成,减少缓激肽的降解,从而达到降血压的目的;植物来源的天然化合物具有来源广泛、结构多样、特异性高、毒性低等特点,因而从植物中筛选安全有效的ACEI成为研究热点。在此综述了血管紧张素转换酶(ACE)的活性测定方法以及植物来源的不同结构类型的ACEI研究进展。     

黄花蒿精油对绿豆象成虫体内酶活力的影响

本试验测定了黄花蒿精油对绿豆象成虫体内几种酶活力的影响。试验结果表明:黄花蒿精油对绿豆象成虫体内多种酶均有影响。黄花蒿精油对绿豆象成虫体内乙酰胆碱酯酶活力表现出明显的抑制作用,对谷胱甘肽-S-转移酶表现出明显的诱导作用,对绿豆象成虫体内羧酸酯酶、酸性磷酸酯酶、碱性磷酸酯酶表现出一定的抑制作用。黄花蒿精油进入成虫体内后,同时作用于多靶标,提高了黄花蒿精油对绿豆象成虫的毒杀效果,也将有效延缓害虫产生抗药性。     

赤霉病菌特异抗体-防御素融合蛋白的表达和功能鉴定

选择对赤霉病菌具有高度特异性和亲合力的单链抗体,与植物防御素构建成融合蛋白基因,将融合蛋白及防御素基因分别与细菌表达载体pGEX和植物表达载体pMBL4构建成重组载体,在细菌中经IPTG诱导表达GST融合蛋白,亲和层析纯化蛋白;经根癌农杆菌介导的真空渗入法在烟草叶片中瞬间表达,提取叶片总蛋白用于鉴定。抑菌活性分析表明,烟草叶片瞬间表达的防御素和抗体-防御素融合蛋白,均对赤霉病菌有强烈的抑菌作用;从细菌中纯化的防御素蛋白,也能有效抑制赤霉病菌生长。说明赤霉病菌抗体-防御素融合蛋白基因,可作为抗赤霉病资源,用于改良植物的抗赤霉病性。     

海参皂苷的分离提取与生物活性

海参具有较高的营养价值和药用价值.海参皂苷具有抗肿瘤,抗菌等多种生物活性,具有重大的应用价值和广阔的应用前景.本文对海参皂苷的提取、分离纯化、分析方法及生物活性进行初步的介绍.     

糖蛋白的制备、结构分析及生理功能研究现状

糖蛋白广泛分布于生物体内,其糖链部分影响蛋白质的折叠和整体构象,蛋白质与糖链连接的特殊结构使其具备了各种生物活性,参与了人类许多生理功能及疾病的发生和预防。糖基或糖链与蛋白质肽链的链接方式主要有0一连接和N一连接2种。本文综述了糖蛋白的分类、分离纯化方法及其化学结构组成的分析方法,并介绍了某些糖蛋白的生理活性,对糖蛋白的开发利用具有借鉴作用。     

Insulin and IGF-I receptors and tyrosine kinase activity in carp ovaries: changes with reproductive cycle

Insulin and insulin-like growth factor I (IGF-I) receptors from carp ovaries were semipurified with wheat germ agglutinin at different moments of the reproductive cycle and their binding characteristics and tyrosine kinase activity were studied. Specific receptors for insulin and IGF-I were found. IGF-I receptors presented higher binding (23.8 ± 1.5%), number of receptors (965 ± 20fm/mg) and affinity (K_D 0.24 ± 0.03nM) than those shown for insulin receptors (4.1 ± 1%, 530 ± 85fm/mg and 0.85 ± 0.1nM, respectively). Insulin and IGF-I receptors have a tyrosine kinase activity which is not different from that found in muscle of the same species. Seasonal changes were found in binding, with maximum values for insulin and IGF-I reached at the end of pre-spawning period (June). However, while IGF-I binding was observed in all stages, insulin binding decreased in autumn and disappeared in winter, which suggests a different role for the two peptides in ovarian physiology.