首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Conformational changes of αs-casein by heating were investigated by measuring ultraviolet difference spectra. The ultraviolet difference spectra at elevated temperature against 5.5°C were measured in various ionic strengths and pHs. Thermal effects of the difference spectra were cancelled by comparing with the spectra of model compounds such as lysozyme and ribonuclease, and the blue shift of αs-casein spectra was observed at above 30°C in these all experimental conditions. This shift was considered to mean unfolding of the αs-casein molecule. The aggregation of αs-casein was observed above ionic strength of 0.4 by heating. These heat-induced changes were reversible until the aggregation was observed.  相似文献   

2.
The delta 5,9 fatty acids (5Z,9Z)-5,9-hexadecadienoic acid, (5Z,9Z)-5,9-nonadecadienoic acid, and (5Z,9Z)-5,9-eicosadienoic acid were synthesized for the first time in four steps (9-12% overall yield) starting from commercially available 2-(2-bromoethyl)-1,3-dioxolane. The synthetic approach provided enough material to corroborate the structure and stereochemistry of (5Z,9Z)-5,9-nonadecadienoic acid which was recently identified in the flowers of Malvaviscus arboreus (Malvaceae). The novel phospholipids 1-hexadecanoyl-2-[(5Z,9Z)-5,9-eicosadienoyl]-sn-glycer o-3-phosphocholine and 1-octadecanoyl-2-[(5Z,9Z)-5,9-eicosadienoyl]-sn- glycero-3-phosphocholine were also synthesized from commercially available L-alpha-phosphatidylcholine (egg yolk) and characterized by positive ion electrospray mass spectrometry. These are the first examples of unsymmetrical phospholipids with saturated fatty acids at the sn-1 position and delta 5,9 fatty acids at the sn-2 position.  相似文献   

3.
The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae), is a worldwide pest of cruciferous crops. We examined the female pheromone production and male response to various pheromone blends in two Korean populations. Gas chromatography (GC) and GC‐mass spectrometry (MS) analyses of pheromone gland extracts revealed that females produce (Z)‐11‐hexadecenal (Z11‐16:Ald), (Z)‐11‐hexadecenyl acetate (Z11‐16:OAc), and (Z)‐11‐hexadecen‐1‐ol (Z11‐16:OH) in a ratio of 8:100:18. However, (Z)‐9‐tetradecenyl acetate (Z9‐14:OAc), a previously reported component of the sex attractant of a Canadian P. xylostella population was not detected in gland extracts of the Korean one. Field tests showed that Z11‐16:Ald and Z11‐16:OAc are essential for attraction of male moths, and the highest attraction is obtained with a 10:90 blend mimicking the blend found in gland extracts. Addition of 1 or 10% of Z11‐16:OH to the 10:90 blend of Z11‐16:Ald and Z11‐16:OAc significantly increased attraction. However, attraction was strongly antagonized by the addition of as little as 0.1% of Z9‐14:OAc to the most attractive ternary blend. The ternary blend of Z11‐16:Ald, Z11‐16:OAc, and Z11‐16:OH at a ratio of 10:90:1 was more effective at catching P. xylostella males than the Japanese three‐component blend or the Canadian four‐component blend in Korea. These results suggest that there is geographical variation in the pheromone systems of this species.  相似文献   

4.
Traps baited with Z11-16:Ac, Z11-16:Ald, Z11-16:OH, and Z13-18:Ac, singly or in mixtures, were tested for their attractivity for males of microlepidoptera in an apple orchard, a mixed deciduous forest, and a coniferous forest. In particular, Z11-16:Ac and Z11-16: Ald attracted some Crambinae, one Glyphipteryx species, and several species of Argyresthia, including the injurous species A. fundella (on fir), A. conjugella (on apple), A. pruniella (on cherry), and A. thuiella (on Thuja).
Attraction sexuelle de microlépidoptères des sous-familles Argyresthiinae, Glyphipteryginae et Crambinae par des hexadécènes 11Z
Résumé L'attraction de microlépidoptères par des hexadécènes 11Z a été examinée en 1982 et 1983 à l'aide de pièges sexuels placés dans différents biotopes de Hollande. Ces pièges contenaient différents mélanges synthétiques d'acétoxy-1-hexadécènes 11Z (Z11-16:Ac), d'hexadécènal 11Z (Z11-16:Ald), d'hexadécénol 11Z (Z11-16:OH) et d'acétoxyl-1-octadécène 13Z (Z13-18:Ac). Les pièges étaient placés dans un verger de pommiers, dans un bois de feuillus aux essences diverses et dans un bois de résineux. Des mâles de 10 espèces de lépidoptères ont été capturés avec ces mélanges, parmi lesquels ceux de 3 espèces de Pyralidae, d'une espèce du genre Glyphipteryx et de 6 espèces du genre Argyresthia. Parmi les Argyresthia, certaines espèces sont considérées comme des déprédateurs: A. fundella sur sapin (Abies), A. conjugella sur pommier (Malus), A. pruniella sur cerisier (Prunus) et A. thuiella sur Thuja. Enfin, un tableau fournit 28 produits contenant des hexadécènes Z11 actuellement connus comme attractifs sexuels de microlépidoptères; la majorité des espèces appartient aux sous-familles Crambinae, Argyresthiinae, Glyphipteryginae et Acrolepiinae.
  相似文献   

5.
A new heptadecatriene was isolated from the acarid mite, Caloglyphus polyphyllae, as the major characteristic component which could be used to identify the species chemo-taxonomically. Its structure was elucidated as 1,6,9-heptadecatriene by partial hydrogenation and a subsequent GC/MS analysis of the dimethyldisulfide derivative, together with evidence of the terminal vinyl group and Z-configuration of double bonds that was provided by GC-FT/IR and NMR. The triene was identified as (Z,Z)-1,6,9-heptadecatriene by its synthesis and is revealed to be a new compound as a natural product.  相似文献   

6.
Abstract:  GC-EAD and GC-MS analysis of pheromone gland extracts of sugarcane borer, Diatraea saccharalis , revealed two antennally active compounds, (9 Z ,11 E )-hexadeca-9,1-dienal and (11 Z )-hexadec-11-enal, in approximately 10 : 1 ratio. Various doses of identified compounds were investigated in wind tunnel experiments individually and in a 10 : 1 ratio. At all tested doses (9 Z ,11 E )-hexadeca-9,1-dienal alone elicited upwind orientation and source location only in a minority of tested males. An admixture of (11 Z )-hex-11-enal enhanced the attractiveness of (9 Z ,11 E )-hexadeca-9,11-dienal significantly. This two-component blend (100 pg) was as attractive as natural pheromone extracted from three female pheromone glands. The data suggest that (11 Z )-hexadec-11-enal is a part of the D. saccharalis sex pheromone.  相似文献   

7.
8.
(Z)-11-hexadecenal and (Z)-9-hexadecenal were ineffective lures forH. armigera males unless combined. Attraction depended upon perception of a 90%–99% combination of (Z)-11-hexadecenal with 1%–10% (Z)-9-hexadecenal. Increasing the level of (Z)-9-hexadecenal in the mixture to 26.2% reduced catches. Adding 2.3% (Z)-7-hexadecenal to the mixture did not enhance or reduce attraction, while adding 8.7% (Z)-11-hexadecenol significantly reduced male catches. The combination of (Z)-11-hexadecenal and (Z)-9-hexadecenal was effective only when released from rubber dispensers but not from polyethylene vials. A load of 2 mg of the mixture on rubber dispensers effectively attracted males for at least 31 days. TheH. zea lure which contained all the pheromonal components of that species was also effective in attractingH. armigera males. TheH. virescens lure attracted significantly fewerH. armigera males than theH. zea lure.
Résumé Les (Z)-11-hexadecenal et (Z)-9-hexadecenal sont des attractifs sexuels in efficaces pour les mâles deH. armigera. L'attraction dépend de la perception d'un mélange de 90 à 99% de (Z)-11-hexadecenal avec 1 à 10% (Z)-9-hexadecenal, L'augmentation jusqu'à 26,2% de la teneur en (Z)-9-hexadecenal réduit les captures. L'addition de 2,3% de (Z)-7-hexadecenal au mélange ne modifie pas l'attractivité, tandis que celle de 8,7% de (Z)-11-hexadecenol, réduit significativement les captures de mâles. Le mêlange de (Z)-11-hexadecenal et de (Z)-9-hexadecenal n'a été efficace qu'avec des diffuseurs en caoutchouc, par contre il a été sans effet à partir de récipients de polyéthylène. Une charge de 2 mg de mélange dans des diffuseurs en caoutchouc attire effectivement les mâles pendant ou moins 31 jours. L'attractif sexuel deH. zea qui contient tous les constituants de la phéromone de cette espèce attire aussi efficacement les mâles deH. armigera. Celui deH. virescens attire significativement moins de mâles deH. armigera que l'attractif sexuel deH. zea.
  相似文献   

9.
The sex pheromone blend of the butterbur borer, Ostrinia zaguliaevi (Lepidoptera: Pyralidae) was analyzed by means of gas chromatography-electroantennographic detection (GC-EAD), GC-mass spectrometry and a series of wind-tunnel bioassays. Four EAD-active compounds were detected in the female sex pheromone gland extract, and these were identified as tetradecyl acetate (14:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc). The average amounts ± s.d. of the four compounds in a single sex pheromone gland were 7.9±3.7 ng, 10.1±3.2 ng, 1.1±0.5 ng and 11.6±5.1 ng, respectively. In a wind-tunnel bioassay, the ternary blend of Z9-, E11- and Z11-14:OAc at a ratio found in the sex pheromone gland (45:5:50) elicited the same behavioral responses from the males as did virgin females and pheromone gland extract. Removal of any single compound from the ternary blend significantly diminished the pheromonal activity, whereas addition of 14:OAc to the ternary blend had no effect on the males' behavioral responses. Therefore, it was concluded that the sex pheromone blend of O. zaguliaevi is composed of Z9-14:OAc, E11-14:OAc and Z11-14:OAc at a ratio of 45:5:50.  相似文献   

10.
Female-tip washings of the leafroller moth, Pandemis cerasana, were found to contain (E)-11-tetradecenyl acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenol, (Z)-11-tetradecenol and tetradecyl acetate, based on chemical analysis and electroantennogram tests. The relative amounts of these compounds in the gland were ca. 64:21:10:3:2 in the order named. Only (E)-11 and (Z)-11-tetradecenyl acetate were required for attraction of males to trap dispensed in the ratio 3:1, respectively.  相似文献   

11.
Abstract  The sex pheromone gland extracts of the Oriental tobacco budworm, Helicover assulta Guenée, collected from North China in Beijing area, were analyzed by capillary gas chromatograph(GC) and 6 components from the extracts were identified by capillary GC—MS as hexadecanal (16:Ald), (Z)9-hexadecenal (Z9–16:Ald), (Z)-11-hexadecenal (Z11–16:Ald), (Z)-9-hexadecen-1-ol (Z9–16:OH), Z11-hexadecen-1-ol (Z11–16:OH), Z-9-hexadecenylacetate (Z9–16:OAc) at a ratio of 10. 9: 58. 7: 3. 9: 14. 7: 1.1: 10. 7. Field studies indicated that an optimum blend of Z9–16:Ald and Z11–16:Ald was 100: 7. Addition of 16: Ald or Z9–16:Ac to the two aldehyde blend showed no significant effect on attractiveness. However presence of Z9–16:OH in the blends significantly reduced male captures.  相似文献   

12.
北京地区的烟青虫(Helicover Pa asslta Cucn(?)e)的性信息素腺体提取物经毛细管柱气相色谱分析及GC MS分析,鉴定了6种组分.这6种组分为:十六醛(16:Ald)、顺 9—十六烯醛(Z9—16:Ald)、顺11—十六烯醛(Zll 16:Ald)、顺9—十六烯醇(Z9-16:OH)、顺11—十六烯醇(Zll-16:OH)、顺9—十六烯基乙酸酯(Z9 16:OAc),比例为10.9:58.7:3.9:14.7:1.1:10.7.田间试验表明,只有16:Ald、Z9 16:Ald和Zll 16:Ald(比例为15.3:79.2:5.5)组成的三组分诱芯和Z9—16:Ald和Zll—16:Ald(比例为93.4:6.6)组成的两组分诱芯对于雄蛾有强烈的引诱活性.在3种醛为组分的诱芯中加入Z9 16:OH明显地降低引诱活性.  相似文献   

13.
Two active fractions were found during the isolation of contact sex pheromone of female elytra of the white‐spotted longicorn beetle, Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae), in addition to fraction of hydrocarbons that had previously been identified. One fraction was essential to evoke a series of precopulatory behaviors of males toward a glass dummy when coated together with the hydrocarbon blend. The other fraction enhanced this activity when added to the mixture. From the latter synergistic fraction, we isolated five novel compounds and identified them as 10‐heptacosanone, (Z)‐18‐heptacosen‐10‐one, (18Z,21Z)‐heptacosa‐18,21‐dien‐10‐one, (18Z,21Z,24Z)‐heptacosa‐18,21,24‐trien‐10‐one, and 12‐heptacosanone by GC‐MS and NMR analyses. A blend of four of these synthetic ketones, without 12‐heptacosanone, in the ratio and concentration found in female elytra extract (250 : 400 : 1000 : 180 ng FE?1) showed greater synergistic effect than the natural fraction containing the ketones. This effect was canceled out by further addition of 12‐heptacosanone (100 ng FE?1), which was still comparable to the effect of the natural ketone fraction.  相似文献   

14.
Incubation of peripheral blood leukocytes with arachidonic acid (and ionophore A23187) led to the formation of leukotriene B4, Δ6-trans-leukotriene B4, Δ6-trans-12-epi-leukotriene B4, 5-hydroxy-icosatetraenoic acid, 12-hydroxy-icosatetraenoic acid and of 5S,12S-dihydroxy-6,8,10,14-(E,Z,E,Z)-icosatetraenoic acid (5S,12S-DiHETE). Incubation of leukocytes with leukotriene A4 resulted in the formation of leukotriene B4 and of its two Δ6-trans-isomers but not of the 5S,12S-DiHETE. 18O2 labeling experiments have shown that the hydroxyl groups at C5 and C12 in the 5S,12S-DiHETE are derived from molecular oxygen. The tetraacetylenic analog of arachidonic acid was found to be a potent inhibitor of the formation of the 5S,12S-DiHETE whereas it potentiated the synthesis of the 5-hydroxy acid and of leukotriene B4. Addition of the 12-hydroxy-icosatetraenoic acid to leukocytes, or of the 5-hydroxy-icosatetraenoic acid to a suspension of platelets caused the formation of the 5S,12S-DiHETE. It is concluded that the 5S,12S-DiHETE is not derived from leukotriene A4 but is a product of the successive reactions of arachidonic acid with two lipoxygenases of different positional specificities.  相似文献   

15.
A simple and one-pot approach for the synthesis of highly functionalized novel (E)-2-benzylideno-(Z)-carbazolylideno cyanoacetamide derivatives from different 2-(2′,3′,4′,9′-tetrahydro-carbazol-1′-ylidene)-propanedinitriles and aryl/heteroaryl carbaldehydes via vinylogous aldol reaction. The structures of the molecules were designated by FT-IR, 1H NMR, 13C NMR studies, elemental and X-ray crystallographic analysis. The synthesized pure products have been screened for in vitro antibiofilm inhibitory activity towards antibiotic-resistant pathogenic organisms. All the synthesized compounds showed biofilm inhibition. Promisingly, the moieties 3a, 3d and 3h showed higher antibiofilm activity at biofilm inhibitory concentration (BIC) (200?μg/mL) against bacterial pathogens. Among the three moieties, 3a showed high prospective against E. coli biofilm with minimal and maximal BIC percentage of 32% (10?μg/mL) and 89% (100?μg/mL) and chosen lowest BIC for further evaluation. Also, the 3a generate ROS two fold at 1?h treatment in E. coli biofilm. The 3a exhibited no toxic effect on cell viability upto 75?μg/mL in HEK293 cell lines. The results of the present study reveal that among (E)-2-benzylideno-(Z)-carbazolylideno cyanoacetamides, (E)-2-benzylideno-6-methyl-2,3,4,9-tetrahydro-1H-carbazol-(Z)-α-carbamino-α-cyano-1-ylidene (3a) could be exploited as an excellent antibiofilm agent against carbapenem-resistant E. coli bacteria strains.  相似文献   

16.
不同配方信息素诱芯对二化螟的诱捕效果比较研究   总被引:3,自引:0,他引:3  
2004年和2005年夏季在江淮稻区二化螟Chilo suppressalis性诱剂诱捕的结果表明:一种新型诱芯(其中顺-11-十六碳烯醛∶顺-9-十六碳烯醛为2∶1)对第1代二化螟的日平均诱捕量相当于二化螟标准诱芯的5倍左右,而在越冬代和第2代成虫发生期则分别相当于后者的1.5839倍和1.7474倍。二化螟诱捕量取决于顺-11-十六碳烯醛和顺-9-十六碳烯醛的比例,而与其各自的剂量或信息素总剂量无明显关系,且它们的最佳配比可能因世代夜间温度的不同而不同,二化螟标准诱芯在第1代诱捕效果下降的原因可能是两种不饱和十六醛比例不适。  相似文献   

17.
The female‐produced sex pheromone of the Durra stem borer, Sesamia cretica (Lederer) (Lepidoptera: Noctuidae), had been previously characterized as a 75:25 blend of (Z)‐9‐tetradecenol (Z9‐14:OH) and (Z)‐9‐tetradecenyl acetate (Z9‐14:OAc) based on field trapping experiments. The low attraction of this blend in the field led us to further investigate the sex pheromone of this pest. Coupled gas chromatography with electroantennographic detection (GC‐EAD) analysis of female pheromone gland extracts consistently revealed three EAD‐active compounds. According to their GC retention times, mass spectra, and comparative EAG analyses with authentic standards, two of these compounds were found to be the previously reported components Z9‐14:OH and Z9‐14:OAc, whereas a third compound was identified as (Z)‐11‐hexadecenol (Z11‐16:OH). In wind tunnel experiments, the highest male responses were elicited by ratios of Z9‐14:OH, Z9‐14:OAc, and Z11‐16:OH, ranging from 90:1:9 to 90:5:5. In field tests, the 90:1:9 ratio of the blend loaded onto rubber septum dispensers was significantly more effective than single‐component, two‐component, and any other ratio of the three‐component blend. The greater effectiveness of this blend resulted in a more accurate detection of S. cretica flight activity compared with the previously reported two‐component blend.  相似文献   

18.
Field studies using the synthetic sex pheromone of Trichophysetis cretacea, a trinary blend of (Z)‐11‐hexadecenyl acetate (Z11‐16:OAc), (Z)‐11‐hexadecenal (Z11‐16:Ald) and (Z)‐11‐hexadecenol (Z11‐16:OH), were performed in Sichuan to determine operational parameters for detection and control, such as dispenser type, blend ratio, dosage, and trap type, height and density. Of three pheromone dispensers tested, grey halo‐butyl isoprene elastomeric septa were significantly more effective than polyvinyl chloride capillary tubing or silicone rubber septa. The ratio of the three components in the blend significantly affected moth catch. In the halo‐butyl isoprene septa, the most effective ratio was 5 : 2 : 1 Z11‐16:OAc:Z11‐16:Ald:Z11‐16:OH. Sticky wing traps caught significantly more moths than water, noctuid moth or cone funnel traps. The most effective height at which wing traps were hung was 20 cm above the jasmine plants. Optimum trap density was 45 traps per hectare. Addition of volatile jasmine compounds did not increase the attractiveness of the sex pheromone. A dosage of 50 μg Z11‐16:OAc per lure was most effective in the autumn weather conditions of Quanwei. These data provide sufficient information to develop effective protocols for using the T. cretacea pheromone to detect and monitor this pest in the jasmine fields.  相似文献   

19.
Lipoxygenases have been classified according to their specificity of fatty acid oxygenation and for several plant enzymes pH-dependent alterations in the product patterns have been reported. Assuming that the biological role of mammalian lipoxygenases is based on the formation of specific reaction products, pH-dependent alterations would impact enzymes' functionality. In this study we systematically investigated the pH-dependence of vertebrate lipoxygenases and observed a remarkable stability of the product pattern in the near physiological range for the wild-type enzyme species. Site-directed mutagenesis of selected amino acids and alterations in the substrate concentrations induced a more pronounced pH-dependence of the reaction specificity. For instance, for the V603H mutant of the human 15-lipoxygenase-2 8-lipoxygenation was dominant at acidic pH (65%) whereas 15-H(p)ETE was the major oxygenation product at pH 8. Similarly, the product pattern of the wild-type mouse 8-lipoxygenase was hardly altered in the near physiological pH range but H604F exchange induced strong pH-dependent alterations in the positional specificity. Taken together, our data suggest that the reaction specificities of wild-type vertebrate lipoxygenase isoforms are largely resistant towards pH alterations. However, we found that changes in the assay conditions (low substrate concentration) and introduction/removal of a critical histidine at the active site impact the pH-dependence of reaction specificity for some lipoxygenase isoforms.  相似文献   

20.
Helicoverpa gelotopoeon Dyar is a very important pest of economic importance on cotton in Argentina. Analysis of female pheromone gland extracts prepared from 1‐ to 2‐day‐old virgin female moths demonstrated the presence of a 1 : 0.84 blend of hexadecanal (16:Ald) and (Z)‐9‐hexadecenal (Z9‐16:Ald), with trace quantities of tetradecanal in some samples, 2.4% of 16:Ald. The average quantity of Z9‐16:Ald extracted per female was estimated to be 33 ng, with a range of 18.9–46.4 ng per female when collected 2–3 h into the scotophase. In field trials conducted in both cotton and tomato crops in Santiago del Estero, Argentina 1 : 1 blends of 16:Ald and Z9‐16:Ald caught significantly more male H. gelotopoeon than Z9‐16:Ald alone, although there was no significant difference between blends containing between a 0.2 : 1 and 2 : 1 ratio of 16:Ald and Z9‐16:Ald. There was no analytical evidence for the presence of (Z)‐11‐hexadecenal (Z11‐16:Ald) in pheromone gland extracts, although this compound has been identified in all female sex pheromones of Heliothinae to date. In field trials, the addition of Z11‐16:Ald at the 1% level to either a 1 : 1 blend of 16:Ald and Z9‐16:Ald or Z9‐16:Ald alone significantly reduced the catch of male H. gelotopoeon. Sympatric Heliothis virescens were not caught in any of the blends tested for H. gelotopoeon, but were caught in low numbers in traps baited with a 4 : 100 blend of (Z)‐9‐tetradecenal and (Z)‐11‐hexadecenal.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号