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1.
The GC-MS and GC-EAD analyses of sex-gland components and sex-gland-released volatiles have identified (E)- and (Z)-11-tetradecenal (9010) and (E)- and (Z)-11-tetradecenyl acetate (8515) as components of the sex pheromone chemical communication system ofCroesia curvalana (Kearfott). The aldehyde-to-acetate ratio of 91 was found in the gland-released components. This blend at a 0.1–1 g/day release rate from PVC lures was shown to be as effective as virgin females in the trapping of maleC. curvalana.  相似文献   

2.
The mahogany shoot borer, Hypsipyla grandella, is one of the most economically important Neotropical forest pest insects because it attacks valuable timber of the Meliaceae. Despite detailed information on the life cycle of H. grandella, factors influencing attack by the shoot borer are not well known. Electroantennogram studies of borer antennae indicate that both female and male moths elicited significant antennal responses to essential oil of the terminal shoots, mature and senescent leaves, in three concentrations. -Himachalene, germacrene D, germacrene A, cadina-1,4-diene, hexadecanoic acid, and ethyl hexadecanoate appeared in all essential oils from Swietenia macrophylla. Germacrene-D and -himachalene were also present in the active essential oil of Cedrela odorata and Toona ciliata. These findings suggest that these compounds play a role in attracting H. grandella to oviposit on the leaves of these plants. The GC-EAD of essential oil from S. macrophylla mature leaves to female H. grandella antennae led to the identification of -caryophyllene as the main constituent responsible for the antennae response.  相似文献   

3.
Eight eudesmane and eremophilane sesquiterpenes administered to Tribolium castaneum larvae caused different allelochemical effects. Topical application of 3-oxo--costic acid produced the greatest lengthening in the duration of the pupal stage. Morphological deformities were found, specifically when ilicic, costic, and -costic acids and costic aldehyde were used. Ilicic acid exhibited the major toxicity 72 hr following topical application. All compounds were significantly toxic at the end point of the experiment (60 days). Treated surface toxicity was lower than when topical assays were carried out. Responses to tessaric acid in choice bioassays had the highest attractive effect. Maximum repellency was caused by the 3-oxo--costic acid. However, experimental series carried out using -costic acid, eremophilan-1(10),2,11(13)-trien-12-oic acid, costic aldehyde, and ilicic aldehyde showed no clear response.  相似文献   

4.
In a study aimed at the chemical characterization of constituents of the ventral gland secretion of the male dwarf hamster, Phodopus sungorus sungorus, 48 compounds, including saturated alcohols, saturated and unsaturated ketones, saturated and unsaturated straight-chain carboxylic acids, iso- and anteisocarboxylic acids, 3-phenylpropanoic acid, hydroxyesters, 2-piperidone, and some steroids were identified in the secretion. The position of the double bonds in -icosadienyl--butyrolactone and -henicosadienyl--butyrolactone, and the position of methylbranching in seven C16–C21saturated ketones could not be established. Several constituents with typically steroidal mass spectra also remained unidentified. The female dwarf hamster's ventral gland either does not produce secretion or produced so little secretion that it was impossible to collect enough material for analysis.  相似文献   

5.
As a first step in a study of the role of the secretion of the supplementary sacculi (buccal secretion) of the dwarf hamster, Phodopus sungorus sungorus, almost complete chemical characterization of the secretion was achieved. The 35 compounds identified include carbon dioxide, hydrogen sulfide, a large number of carboxylic acids (representing the bulk of the organic volatile fraction of the secretion), phenol, 2-piperidone, indole, two long-chain hydroxyesters, cholestrol, desmosterol, and lanosterol. The position of the double bonds in -icosadienyl--butyrolactone and -henicosadienyl--butyrolactone could not be determined, and these two compounds remained only partially characterized. Large variations were found in the relative concentrations in which the short-chain carboxylic acids are present in the secretions of individual animals, and although this aspect was not investigated in sufficient detail in the present investigation, the difference in the carboxylic acid profiles of the secretions of individual animals could play a role in individual recognition in this animal.  相似文献   

6.
H. He  H.X. Dai  K.Y. Ngan  C.T. Au 《Catalysis Letters》2001,71(3-4):147-153
The physico-chemical properties of passivated -Mo2N have been investigated. The material showed high activities for NO direct decomposition: nearly 100% NO conversion and 95% N2 selectivity were achieved at 450C. The amount of O2 taken up by -Mo2N increased with temperature rise and reached 3133.9 molg–1 at 450C; we conclude that there formation of Mo2OxNy occurred. This oxygen-saturated -Mo2N material was catalytically active: NO conversion and N2 selectivity were 89 and 92% at 450C. We found that by means of H2 reduction at 450C, Mo2OxNy could be reduced back to -Mo2N and the oxidation/reduction cycle is repeatable; such a behaviour and the high oxygen capacity (3133.9 molg–1) of -Mo2N suggest that -Mo2N is a promising catalytic material for automobile exhaust purification.  相似文献   

7.
Soldier defense secretions from samples of Reticulitermes collected in California, Nevada, Arizona, New Mexico, and Georgia were characterized and correlated with cuticular hydrocarbon phenotypes. Twenty-seven cuticular hydrocarbon phenotypes have been defined, and soldier defense secretion (SDS) phenotypes have been described for 25 of these. Forty-five terpenoid compounds were found, including monoterpenes, sesquiterpenes, and a few diterpenes. The monoterpenes include (–)--pinene, (–)--pinene, (–)-camphene, myrcene, (Z)- and (E)-ocimene, and (–)-limonene. The major sesquiterpenes produced are (+)--cadinene, (+)--cadinene aldehyde, (–)-germacrene A, germacrene B, -himachalene, and -bisabolene. Some SDS phenotypes pair with more than one cuticular hydrocarbon phenotype; however, with two exceptions, each hydrocarbon phenotype is associated with only one SDS phenotype. These chemical characterizations lend support to the conclusion that there are numerous undescribed species of Reticulitermes in North America.  相似文献   

8.
Sixteen terpene compounds were isolated from the soldier defensive secretions of seven European termite taxa of the genus Reticulitermes (Isoptera, Rhinotermitidae). We describe species-specific mixtures of monoterpenes (-pinene, -pinene, limonene), sesquiterpenes (germacrene C, germacrene A, germacrene B, -selinene, -selinene, -selinene, (E)--farnesene, -cadinene, nerolidol), diterpenes (geranyl linalool, geranyl geraniol, geranyl geranial), and one sesterterpene (geranyl farnesol). Compounds were purified by HPLC and their structures determined by means of MS spectrometry, or 1D and 2D NMR spectroscopy. Comparison of two different analytical approaches, GC-MS and HPLC with subsequent NMR spectroscopy, revealed Cope rearrangement of germacrene A, germacrene B, and germacrene C to the respective -elemene, -elemene, and -elemene under GC conditions, thus demonstrating the limits for this analytical approach. The species-specific compound composition provides insight into taxonomy and species origin of European Reticulitermes. The biological significance of the species-specific composition of Reticulitermes defensive secretions is briefly discussed.  相似文献   

9.
Gas chromatographic-mass spectrometric analysis of whole body extracts of Platynothrus peltifer, a desmonomatan oribatid mite that belongs to the family Camisiidae, exhibited a basic profile of seven compounds, comprising the monoterpenes neral, geranial, and nerylformate; the aromatics 3-hydroxybenzene-1,2-dicarbaldehyde (= -acaridial) and 2-formyl3-hydroxybenzyl formate (= rhizoglyphinyl formate), and two unsaturated C17-hydrocarbons, 6,9-heptadecadiene and 8-heptadecene. Neryl formate, -acaridial, and rhizoglyphinyl formate were the main components and amounted to 80% of the extracts. With the exception of -acaridial (relative abundance varied considerably among samples), this chemical profile was consistently present in extracts of P. peltifer from nine different localities in SE-Austria. In addition, two further components, 2,3-dihydroxy benzaldehyde and 7-hydroxyphthalide, both probably of non-oil gland origin, infrequently were detected in the extracts. The aromatic compound rhizoglyphinyl formate, also known from Astigmata, was found for the first time in extracts of Oribatida, whereas all other compounds have already been reported from other oribatid species. The hydrocarbons are generally considered to represent plesiomorphic characters of mite oil gland secretions, whereas the monoterpenes and -acaridial form a part of the so-called astigmatid compounds that are thought to be characteristic for middle-derivative Mixonomata and all more highly derived oribatid groups (including Astigmata).  相似文献   

10.
Adult male Ithomiinae feed at plants containing pyrrolizidine alkaloids. Certain species secrete on hairs of the costal fringe, a specialized organ on their hindwings, a novel -lactone structurally related to the unusual branched-chain acids that are unique to these alkaloids.  相似文献   

11.
Headspace extracts obtained from agar plate cultures of two marine bacteria from the North Sea (Germany), Loktanella strain BIO-204 and Dinoroseobacter shibae strain DFL-27, were analyzed by GC-MS. Several -lactones and one -lactone were identified, besides pyrazines and some sulfur compounds. The absolute configuration of the major lactone (R,Z)-dodec-5-en-4-olide, known as buibuilactone, a pheromone of several scarab beetles, was determined by a new catalytic enantioselective synthesis and GC on a chiral stationary phase. Unsaturated lactones in the extracts included (E)-dodec-5-en-4-olide and the regioisomer (Z)-dodec-6-en-4-olide, previously identified as a component of black-tailed deer urine. The pyrazines 2-butyl-3,6-dimethylpyrazine and 2-isopentyl-3,6-dimethylpyrazine were identified by comparison with synthesized material. The latter compound is a known ant pheromone, as is another identified pyrazine, 2-ethyl-3,6-dimethylpyrazine. The striking similarity between insect pheromones and these bacterial volatiles is discussed, suggesting the possibility of more widespread occurrence of symbiosis between microorganisms and insects than previously thought.  相似文献   

12.
An incorporation model has been proposed and used to discuss the interaction between various metal oxides and -alumina. The dispersion capacities of various metal oxides are predicted and the surface hydroxyl group density on -alumina estimated, based on the assumption that the (110) plane is preferentially exposed on the surface of -alumina. These results are in good agreement with the available experimental data.  相似文献   

13.
Two polyoxygenated fatty acids with antifungal activity have been isolated from aerial parts ofAeollanthus parvifolius (Labiatae) using bioassay-guided isolation procedures. Spectroscopic analysis was used to identify the compounds as (Z)-4,9-diacetoxy-6,7-epoxy-5-hydroxy-8-oxododeca-2-enoic acid and (Z)-4,6,7,9-tetraacetoxy-5-hydroxy-8-oxododeca-2-enoic acid. Both of these compounds inhibited spore germination ofCladosporium cucumerinum. Minimum inhibitory doses were 1 µg and 5 µg, respectively, but only the former inhibited germination ofAspergillus niger at a dose of 5 µg. Neither compound exhibited antibacterial activity. (Z)-4,9-Diacetoxy-6,7-epoxy-5-hydroxy-8-oxododeca-2-enoic acid reduced the hyphal growth ofPythium ultimum. The mode of action was not resolved but did not involve either the disruption of the cell wall membrane or the inhibition of extracellular enzymes. Application of (Z)-4,6,7,9-tetraacetoxy-5-hydroxy-8-oxododeca-2-enoic acid to seedling plants did not give any protection against fungal attack, and indeed the compound appeared to be phytotoxic.  相似文献   

14.
Fresh leaves and volatile oil of the important weed Ageratum conyzoides in south China were highly inhibitory to seedling growth of various cultivated crops, especially in an adverse habitat. The constituents of the volatile oil were analyzed by GC-MS. Eleven components were identified and six main components, precocene I, precocene II, 3,3-dimethyl-5-tert-butylindone, -caryophyllene, -bisabolene, and fenchyl acetate, were isolated by means of column chromatography. Precocene I, precocene II, -caryophyllene, and 3,3-dimethyl-5-tert-butylindone inhibited seedling growth of acceptor plants. Inhibitory activity of the volatile oil was more intense than that of the pure components. Fenchyl acetate and -bisabolene have no inhibitory activity, but when mixed with precocene II, they increased the inhibitory activity to growth of acceptor seedling plants. Experiments show that allelopathic synergism exists among allelochemicals of Ageratum conyzoides.  相似文献   

15.
F. Gracia  W. Li  E.E. Wolf 《Catalysis Letters》2003,89(3-4):235-242
From EXAFS (extended X-ray absorption fine structure) analysis, gold was found to have mainly oxygen in its nearest coordination shell in the fresh Au/-Al2O3 catalyst prepared by AuCl3 impregnation and vacuum drying at room temperature. After thermal treatment under helium, chlorine appeared within the nearest neighbors of gold and more chlorine showed up as the treatment temperature was increased from 323 to 473K. No reduced Au species was observed up to 473K under He. However, the gold became reduced during CO oxidation at 373K and above. The precursor AuCl3 was found to deposit on -Al2O3 via bonding to surface hydroxyl groups. This catalyst showed nearly 100% CO conversion at 573K, but a very low activity at 373 K under the conditions used in this study. Neither the residual chlorine nor the extent of reduction can explain the low activity at lower temperatures.  相似文献   

16.
Summary Molecular motions of elastomers under deformations were observed through dynamic mechanical measurements. Composite master curves of dynamic moduli E and E and loss tangent tan over a wide range of frequency and in a state of elongation were obtained by the time-temperature superposition procedure. It is found that both moduli increase with strain, . The slope of the dispersion curve of E become more gradual with the increase in , while that of E is almost unchanged. The increment of E is generally larger than that of E, which does not agree with the N. W. Tschoegl prediction, E * ()=f() E o * (), where E * () and E o * () are complex moduli at the strain of and O, respectively, and f() is the function of only . The difference in the strain dependence of E from E was found to correspond to the strain dependence of the equilibrium modulus.  相似文献   

17.
The catalytic activity and selectivity of three PdO-MoO3/-Al2O3 catalysts containing about 2% Pd and 2% Mo were studied for the reduction of NO by h2 in the presence of varying amounts of oxygen at temperatures from 50 to 550 °C. The results are compared with those for PdO/-Al2O3, PdO-MoO3/-Al2O3 containing 2% Pd and 20% Mo, and a commercial Pt-Rh catalyst. In the absence of oxygen, the conversion of NO to N2 and N2O is higher on the three catalysts than it is on PdO/-Al2O3 at 500 and 550 °C. In the presence of oxygen, the yields of N2 and N2O are generally lower on two of the PdO-MoO3/-Al2O3 catalysts than on PdO/-Al2O3.  相似文献   

18.
Summary The interaction of -cyclodextrin(-CD) with sodium 1-pyrenesulfonate(PS) was studied spectrophotometrically. -CD was found to cause much larger decrease in the absorption maxima of PS than -CD. The fluorescence spectra of PS in the presence of -CD showed excimer emission, while those of PS with -CD showed only monomer emission, indicating that -CD forms 12 (-CDPS) complexes in which two PS molecules are included in the -CD cavity in a face-to-face fashion. The binding isotherm showed a sigmoidal curve. The association constants were estimated by computer simulation of the binding curve. The 12 (CDPS) complex was found to be much more stable (K=106 M–1) than the 11 complex (K=1 M–1). At high concentration of -CD another -CD cooperates in binding two PS molecules, resulting in the formation of a 22 complex.  相似文献   

19.
The inhibition effect of gamma-pyrodiphenone (PD) on copper corrosion in near neutral sulphate solutions was investigated. Weight loss and polarization measurements show a high inhibition efficiency (>96%) of PD on copper corrosion at extremely low concentrations. PD suppresses active copper dissolution and oxygen reduction. The potentiodynamic cathodic reduction measurements showed an inhibition of oxide formation and stabilization of the Cu2O oxide in the presence of PD. XPS measurements suggested that the high inhibition effect of PD on copper corrosion is due to the adsorption of PD molecules, as a first stage, and the formation of a film with a polymer-like structure by coordination of PD with Cu2O on prolonged exposure.  相似文献   

20.
Field observations revealed that flowers of Osmanthus fragrans attract few insect species despite their strong scent and vivid coloration (yellowish orange). Floral volatiles of the plant were thus examined for suspected repellency to Pieris rapae, a potential visitor that never visits this flower. The influence of odor components on the foraging behavior of adult butterflies was assessed by two behavioral bioassays: proboscis extension reflex (PER) in response to olfactory stimuli and the frequency of visits to artificial flowers. In the PER bioassays, a binary mixture composed of a test material and 2-phenylethanol (a positive standard compound) was used, and the negative effect of test materials was appraised based on the degree of suppression caused compared with the original PER performance evoked by 2-phenylethanol alone. Isopentane extract of the flower exhibited significant deterrency in the PER test and remarkable repellency in the flower-visiting experiment, thereby suggesting the presence of a repellent(s) in the floral volatiles. Fractionation of the extract by silica gel column chromatography yielded an active fraction (based on PER performance), which, upon GC and GC-MS analyses, was found to consist of -decalactone, -ionone, and linalool oxide (LO) isomers (furanosides and pyranosides) as major components together with small amounts of linalool and -ionone. -Decalactone was strongly deterrent in the PER test, and -ionone and all LO isomers were weakly deterrent, while the other compounds exhibited no deterrency. In the flower-visiting tests, -decalactone showed notable repellency, whereas -ionone had no repellent effect. Among the LO isomers, at least furanosides (cis/trans mixture) and cis-pyranoside were found to be weakly repellent. On the other hand, the butterfly showed strong to weak EAG responses to LO furanosides, cis-LO pyranoside, -decalactone, and -ionone in decreasing order of intensity. The present results clearly indicate that the repellency of a compound is correlated with its deterrent effect on PER but not necessarily with antennal sensitivity.  相似文献   

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