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1.
Male feral pigeons were dosed with ring-labeled and the tissues and droppings analyzed for total 14C, extractable 14C, and metabolites. Only 16% of an intraperitoneal dose of 1.5–2.2 mg kg?1 was voided in the droppings over 28 days; the rate of loss reached a maximum on the 14th day and then fell quickly away. The rate of removal of 14C in droppings was low in comparison to that found in the rat and the Japanese quail. When pigeons were dosed with 32–38 mg kg?1 DDT per bird, and killed after 77 days, 5.4% of the dose was eliminated in droppings and 87% was recovered in the body. The tissues and droppings from this experiment were analyzed for DDT and its metabolites. Of the 14C remaining in tissues 88% was accounted for as the apolar compounds DDE, DDT, and DDD. Approximately half of the 14C in droppings was present as DDE, DDT, and DDD, whereas 27–35% was apparently in conjugated form, extractable from aqueous solutions by ethyl acetate after prolonged acid hydrolysis. Two polar metabolites were isolated from the acid-released material. One was p,p′-DDA; the other was extractable from aqueous solution at pH 8 and was tentatively identified as a monohydroxy derivative of p,p′-DDT. DDE accounted for 93% of the 14C present as metabolites in tissues and droppings, clearly indicating the importance of this intermediate in this study. The metabolism of DDT in the feral pigeon is discussed in relation to its metabolism by other species. 相似文献
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In the present study, the in vivo effects of λ-cyhalothrin and cypermethrin on the activity of acetylcholinesterase (AChE, EC 3.1.1.7) were evaluated for 96 h in brain, muscle and gills of Channa punctatus. Both compounds exhibited tissue specific as well as dose dependent decrease in the activity of AChE. The treated fish showed a significant decrease in the activity of AChE in brain and a lesser inhibition in muscle and gills in response to the increasing concentrations of λ-cyhalothrin as well as cypermethrin. Our results indicated that the brain was the main target organ for both insecticides, followed by muscle and gills, as determined by AChE inhibition study. However, these organs showed variations in the degree of AChE inhibition for separate treatments of both insecticides. The λ-cyhalothrin was a more potent AChE inhibitor as compared to cypermethrin. These findings indicated that apart from the established mechanism of delayed closure of sodium ion channels, these pyrethroids inhibit the activity of AChE in C. punctatus which could further aggravate their neurotoxic effects. 相似文献
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Smriti Priya 《Pesticide biochemistry and physiology》2010,98(2):231-4821
Rhyzopertha dominica causes extensive damage to stored wheat grains. α-Amylase, the major insect digestive enzyme, can be an attractive candidate to control the insect damage by inhibiting the enzyme through α-amylase inhibitors. R. dominica α-amylase (RDA) was purified to homogeneity by differential ammonium sulphate fractionation, Sephadex G-25 and Sephadex G-100 column chromatography. The homogenous α-amylase has a molecular weight of 52 kDa. The pH optima was 7.0 and temperature optima was 40 °C. Activation energy of RDA was 3.9 Kcal mol−1. The enzyme showed high activity with starch, amylose and amylopectin whereas dextrins were the poor substrates. The purified enzyme was identified to be α-amylase on the basis of products formed from starch. The enzyme showed Km of 0.98 mg ml−1 for starch as a substrate. Citric acid, oxalic acid, salicylic acid, HgCl2, tannic acid and α-amylase inhibitors from wheat were inhibitors whereas; Ca2+ and Mg2+ were the activators of RDA. Ki values calculated from Dixon graphs with salicylic acid, citric acid, oxalic acid and wheat α-amylase inhibitors were 6.9, 2.6-8.2, 3.2 mM and 0.013-0.018 μM, respectively. The Lineweaver-Burk plots with different inhibitors showed mixed type inhibition. Wheat α-amylase inhibitor showed mainly competitive inhibition with some non-competitive behaviour and other inhibitors showed mainly non-competitive inhibition with some un-competitive behaviour. Feeding trials with salicylic acid, citric acid, oxalic acid and wheat α-amylase inhibitor showed significant effect of salicylic acid and oxalic acid along with wheat α-amylase inhibitor in controlling the multiplication of R. dominica. 相似文献
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Qing-Li Shang 《Pesticide biochemistry and physiology》2009,93(1):1-7
The full-length cDNA sequence of γ-aminobutyric acid (GABA) receptor alpha2 subunit gene was cloned from Spodoptera exigua, an economically important pest species in China, through rapid amplification of cDNA ends (RACE) and polymerase chain reaction using primers based on the 5′ and 3′-ends of the mRNA. The gene (named as SeGABARα2) was 1620 bp long, with an open reading frame of 1500 bp encoding a predicted GABA receptor protein of 499 amino acids with a molecular weight of 55 kDa. The predicted GABA receptor protein shared 96.19%, 82.16%, 74.30%, 73.95%, 73.42%, 71.40%, 67.11% and 65.13% identity with other GABA receptors proteins isolated from Heliothis virescens, Plutella xylostella, Aedes aegypti, Laodelphax striatellus, Lucilia cuprina, Musca domestica, Drosophila simulans and Drosophila melanogaster, at amino acid level, respectively. The developmental changes and tissue-specificity of the relative mRNA expression levels of SeGABARα2 gene were investigated in S. exigua. The highest expression level was observed in adult and lowest was in the first instar, there was a stable expression level during the developmental period from the second instar to the adult. Expression levels were 1.41-, 1.57-, 1.45-, 1.80-, 1.82- and 1.93-fold higher in the second instar, third instar, fourth instar, fifth instar, pupa and adult than in the first instar larva, respectively. The relative mRNA expression levels of SeGABARα2 gene were 3.51-fold higher in head and 1.77-fold higher in thorax than in abdomen 相似文献
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以(E)-2-[2'-(bromo-methyl)phenyl]3-甲氧基丙烯酸甲酯和2(1H)-喹啉酮类化合物为原料,通过醚化等反应,合成了11个新型含2(1H)-喹啉酮结构的甲氧基丙烯酸酯类化合物,其结构经红外、电喷雾串联质谱(ESI-MS)和核磁共振氢谱确证。初步生物活性测试结果表明:在100 mg/L质量浓度下,部分目标化合物对烟草赤星病菌Alternaria alternata等6种病原菌具有一定的抑菌活性,其中5a对水稻稻瘟病菌Pyricularia grisea的抑菌率达100%。 相似文献
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我国西南烟区桃蚜Myzus persicae (Sulzer)的抗药性水平 总被引：3，自引：0，他引：3
采用毛细管点滴法测定了我国西南烟区云南和贵州省的10个桃蚜Myzus persicae（Sulzer）种群对氰戊菊酯、氧化乐果、灭多威和吡虫啉的抗性。结果表明，云南楚雄种群对氰戊菊酯的抗性高达26．87倍，对氧化乐果、灭多威、吡虫啉的抗性分别为敏感种群的10．02、6．00和5．83倍。云南大理、丽江、石林和曲靖4个种群对氰戊菊酯的抗性分别达24．98、14．94、11．11和10．33倍，抗性水平也较高，但对氧乐果、灭多威和吡虫啉仍较为敏感，应尽早实施抗性治理措施。贵州省的5个种群仍然处在敏感阶段。 相似文献
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Semi-thin sectioning and transmission electron microscope techniques were employed to investigate the cuticle thickness, integument structure, and fat body of larvae from susceptible and resistant strains of Bactrocera dorsalis. The results showed that the cuticle of β-cypermethrin-resistant strains (25.96 ± 1.00 μm) was thicker than that of susceptible strains (19.36 ± 0.82 μm). The number of chitin layers in the endocuticle of β-cypermethrin-resistant strains (98.00 ± 3.61 layers) was more than that in susceptible strains (75.67 ± 2.40 layers). Compared with susceptible strains, the laminated structure of the chitin layers in the endocuticle of resistant strains revealed higher density and more distinctive structure, and the interspace of epidermal cells was thicker. Fat body in the resistant insects contained more fat granules than those in susceptible insects. Moreover, HPLC analysis showed that the cuticular penetration of β-cypermethrin into larvae of resistant strains was slower than that of susceptible strains. In addition, the metabolism of β-cypermethrin in resistant strains was faster than that in susceptible strains, indicating that the resistant strains could enhance detoxification metabolism. These results indicated that cuticle thickness, fat body, laminated structure of the chitin layers, and interspace of epidermal cells might be correlated with cuticular penetration between susceptible and resistant strains, suggesting that the resistant strains could decrease the rate of penetration of insecticide into the internal cavity. 相似文献
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为进一步从核酸水平上研究亚洲玉米螟Pgi基因相关特性,采用反转录PCR及RACE等技术对该基因编码序列及DNA全序列进行了测定,与Gen Bank中其它昆虫Pgi基因相关信息进行比较分析,并构建了系统发育树。结果表明:亚洲玉米螟Pgi基因编码区序列长为1 671 bp,共编码556个氨基酸;其DNA序列全长为10 078 bp(短序列为9 311 bp),由12个外显子与11个内含子镶嵌而成;各外显子长度与鳞翅目大部分昆虫相同,介于95~188 bp之间,内含子序列总长度为8 407 bp(短序列为7 640 bp),各内含子长度介于418~1 547 bp之间,且在内含子3、4、5、11上均发现杂合现象。系统发育结果显示,大部分昆虫Pgi基因c DNA严格按物种聚类,除了双翅目的家蝇Musca domestica与黑森瘿蚊Mayetiola destructor出现一定的交叉现象外,其余没有出现交叉现象。 相似文献
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Pigeons, Bengalese finches, and Japanese quail were dosed with pure pp′DDT, and their tissues were examined for residues immediately after death, or following storage. DDD residues in livers extracted immediately after death were always low (<5% DDT concentration) and sometimes undetectable. Reductive dechlorination of DDT to DDD occurred postmortem, relatively repidly at 20°C (90% after 8 hr), but more slowly at ?10 and ?20°C. The conversion could not be attributed to bacterial action and was evidently due to processes operating within the cell under anaerobic conditions. During storage at ?12 to ?15°C, reductive dechlorination occurred in brain and in embryos, but did not occur to any significant extent in depot fat or in eggs without embryos. These findings raise questions about the importance of DDD as an in vivo metabolite in birds and other vertebrates. The interpretation of DDD residues in tissues from laboratory and field studies is discussed. 相似文献
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20-(S)-喜树碱7-C-取代衍生物的合成及杀松材线虫活性研究 总被引：1，自引：1，他引：0
为研究喜树碱(CPT)类化合物的杀线虫活性,以喜树碱为原料,经烷基化、氧化、酯化等步骤合成了13个7-C-取代的20-(S)-喜树碱衍生物,其中化合物 14 未见文献报道,所有衍生物的结构经红外光谱(FT-IR)、核磁共振氢谱(1H NMR)和液-质联用(LC-MS)等分析手段进行了表征。采用浸渍法测定了化合物对松材线虫Bursaphelenchus xylophilus的毒杀活性。结果表明:与母体化合物喜树碱相比,7-C-取代的20-(S)-喜树碱衍生物具有更强的杀线虫活性,其中化合物7-苄基喜树碱、7-甲酰基喜树碱、7-苯甲酰氧甲基喜树碱在24 h的致死中浓度(LC50值)分别为2.28、2.21和1.37 mg/L,明显高于母体化合物喜树碱的LC50值12.18 mg /L。 相似文献
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通过研究光活化杀虫活性成分 α -三联噻吩( α -T)对红火蚁 Solenopsis invicta Buren工蚁觅食行为和触角识别功能的影响,探讨了光活化成分用于控制红火蚁的可行性。用Potter喷雾法将100 μg/mL的 α -T丙酮水溶液喷施于红火蚁中型工蚁体表,再经紫外(UVA)光照射30 min,在处理后5、10、15、20和30 min时,试蚁对火腿肠的识别率分别为20.00%、25.00%、38.33%、40.00% 和41.67%,对杀虫剂饵料的识别率分别为3.33%、0、0、3.33%和0,聚集率分别为17.50%、38.33%、 32.50%、45.00%和48.33%;经100 μg/mL的 α -T涂抹试蚁触角再经紫外光照处理30 min后,触角对丙酮反应的电位值为-0.177 mV,可正常行走的工蚁比率为75.00%;以100 μg/mL的 α -T涂抹试蚁触角并经紫外光照射30 min后10 h,红火蚁的死亡率为27.50%;上述结果均与 α -T黑暗处理、对照(CK)光照处理和CK黑暗处理结果差异显著。 α -T对红火蚁工蚁食物识别和探路行走能力均具有良好的光活化抑制作用,以其防治红火蚁具有良好可行性。 相似文献
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A new pigment, 3,3′-biflaviolin (3,3′-bi-2,2′,5,5′,7,7′-hexahydroxy-1,1′,4,4′-naphthoquinone), was identified from agar cultures of the fungus Thielaviopsis basicola treated with the fungal melanin inhibitor, tricyclazole. An albino mutant of T. basicola that does not form melanin or colored melanin shunt products, synthesized 3,3′-biflaviolin when treated with flaviolin. The dimerization reaction appeared to be enzymatic. 相似文献
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为了确定生防菌新月弯孢菌Culvularia lunata菌株J15(2)的安全性及防除稗草的潜力,研究了该菌株的寄主范围,接种孢子时稗草叶龄、接种后保湿时间、接种浓度对该菌株致病力的影响,土壤带菌对稗草出苗的影响,以及与化学除草剂的相互作用.结果显示,菌株J15(2)只能在稗草上侵染并扩展;接种孢子后保湿24 h,对2叶期稗草抑制率可达55.6%,对1.5叶期稗草抑制率可达100%;保&48h,对2叶期稗草防效提高至91.6%;接种孢子量需达1012孢子/hm2才能较好地抑制稗草生长;土壤带菌亦可抑制稗草生长.该菌与化学除草剂精噁唑禾草灵或二氯喹啉酸混用能显著提高除稗效果,菌株J15(2) 3.3 × 1012孢子//hm2分别与精噁唑禾草灵有效剂量3.83g/hm2二氯喹啉酸有效剂量250.00g/hm2混用,对稗草防效分别为99.5%和88.6%,远高于这两个除草剂单用时的药效.该试验结果表明,菌株J15(2)具有作为微生物除草剂的开发潜力. 相似文献
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利用粉纹夜蛾(Trichoplusia ni)围食膜蛋白多克隆抗体,从已构建的华北大黑鳃金龟 Holotrichia oblita 中肠cDNA表达文库中筛选得到1个编码羧酸酯酶的cDNA克隆 HoCL1 ,其开放阅读框(ORF)长1 599 bp,编码532个氨基酸,推导的蛋白质分子质量为59.5 kDa,等电点(p I)为4.5。 HoCL1蛋白具有羧酸酯酶的保守结构域:1个二硫键形成的位点和1个丝氨酸活性中心,三联体催化活性中心位于Ser207、Asp333和His422上,不含有氮联糖基化位点和氧联糖基化位点,只含有3 个半胱氨酸残基。依据氨基酸序列同源性分析和保守结构域分析,HoCL1属于B类酯酶,与赤拟谷盗 Tribolium castaneum 羧酸酯酶相似性最高,为35.2%。通过与其他昆虫羧酸酯酶序列比对及构建系统发育树,发现HoCL1羧基端的氨基酸序列保守性低,但靠近N端的活性中心处的氨基酸序列则高度保守,可与赤拟谷盗、异色瓢虫 Harmonia axyridis 羧酸酯酶聚类在一起。羧酸酯酶 HoCL1 基因的克隆鉴定为进一步研究该基因在华北大黑鳃金龟体内的表达及功能奠定了基础。 相似文献
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为明确苹果炭疽叶枯病病原菌围小丛壳Glomerella cingulata的侵染致病特征,在分离获得该病原菌的基础上,采用形态学观察、ITS序列分析和致病性测定对其进行了鉴定,并利用光学和扫描电子显微镜对病原菌在嘎啦苹果叶片上的侵染过程进行了研究.结果表明,在陕西咸阳地区分离获得的9株病原菌均为围小丛壳G.cingulata.25 ℃下接种9 h后,分生孢子中间产生隔膜,双胞化,并萌发产生芽管和附着胞;24 h后分生孢子的2个细胞均可萌发并形成芽管及附着胞,部分芽管顶端可产生次级分生孢子;48 h后次级分生孢子萌发形成附着胞;72 h后,附着胞下形成的侵染钉可直接入侵寄主,在表皮细胞内形成初生菌丝和次生菌丝,此时叶片表面已出现褐色斑点.接种7 d后叶片病斑处出现分生孢子盘和子囊壳.表明陕西省近年出现的苹果炭疽叶枯病病原菌为围小丛壳G.cingulata,该病菌在嘎啦叶片上的一些特殊侵染行为可能是导致该病害易在短时间内暴发的重要原因. 相似文献
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Rachel McFadyen 《中国生物防治》1998,14(2):94
ＩＯＢＣ／ＳＥＡＲＳ（东南亚地区分部）介绍ＲａｃｈｅｌＭｃＦａｄｙｅｎ（ＩＯＢＣ／ＳＥＡＲＳ主席,澳大利亚）东南亚地区分部（ＴｈｅＳｏｕｔｈａｎｄＥａｓｔＡｓｉａｎＲｅｇｉｏｎａｌＳｅｃｔｉｏｎ,简称ＳＥＡＲＳ）成立于１９７７年。１９８９～１９９２年... 相似文献