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1.
Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C6 and C8 (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.  相似文献   

2.
Racemic 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA) has been synthesized and shown to inhibitAvena coleoptile elongation. (S)-(+)-TFIBA (fig. 1), which was prepared by an enzymatic method and markedly promotes root growth of Chinese cabbage, lettuce and rice plants, is a novel fluorinated plant growth regulator. Activity of the (S)-(+)-enantiomer of TFIBA was 10-fold greater than that of the (R)-(–)-enantiomer in the first two plant species and 5-fold greater in rice.  相似文献   

3.
Summary The synthesis and antischistosome properties of 5-(hydroxyimino)-4-methoxy-2-(pivaloylimino)thiazolidine-3-acetamide (1) are described. The compound was prepared by reduction of the nitrothiazoline (2) with stannous chloride in methanol, and represents the first example of a reduced nitroheterocyclic compound showing potent schistosomicidal properties. The possible relationship of compounds such as1 to the as yet unidentified reduced active but toxic entities formed in vivo from nitroheterocyclics like metronidazole is discussed.Acknowledgments. The authors are grateful to Dr A. J. Everett and his staff for the physical chemistry measurements, and to Mr G. Dickerson for the antischistosome testing.  相似文献   

4.
(E)-3-tridecen-2-one, the major volatile component of interdigital gland extracts from the black-tailed deer,Odocoileus hemionus columbianus, inhibited the growth of gram-positive bacteria and fungi. The bacteria,Propionibacterium acnes, and the fungi,Trichophyton mentagrophytes had a minimum inhibitory concentration (MIC) of 12.5 g/mL and 25 g/mL, respectively.  相似文献   

5.
Summary 1-(Substituted)benzyl-5-aminoimidazole-4-carboxamides are potent orally active inhibitors ofTrypanosoma cruzi infections in mice. The most active compounds are the 1-(4-chlorobenzyl)- and 1-(3,4-dichlorobenzyl)-analogs (L-153,094 [2] and L-153,153 [4], resp.) which are approximately 7-fold more potent upon oral administration than nifurtimox (Lampit) in suppressing parasite levels in the blood of mice with acuteTrypanosoma cruzi infections.  相似文献   

6.
The mechanism by which a new naphthoquinone derivative, the 2-hydroxy-N-(3,4-dimethyl-5-isoxazolyl)-1,4-naphthoquinone-4-imine (INQI-E) has antibacterial effect againstStaphylococcus aureus was studied. The interaction of INQI-E with the bacteria was followed by absorption spectroscopy at 323 and 490 nm. The absorption band of INQI-E at 490 nm undergoes a hypochromic shift with a decrease of intensity. This effect was found to be reversible by oxygenation during the first hours of incubation. The participation of an oxidation-reduction process related to the respiratory chain was demonstrated by oxygen consumption. An increase in O2 uptake and inhibition ofS. aureus growth was observed. Experiments with three inhibitors of the respiratory chain demonstrated that the pathway induced by INQI-E was antimycin-resistant and KCN- and salicylhydroxamic acid (SHAM)-sensitive, which suggests that INQI-E is capable of diverting the normal electron flow to an alternate superoxide-producing route. On the other hand, experiments with Tiron, a specific scavenger of superoxide, hindered the effect of INQI-E againstS. aureus, indicating that the inhibitory growth effect of this quinone-imine is mainly due to the production of the cytotoxic superoxide radical.  相似文献   

7.
Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by1H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.  相似文献   

8.
Zusammenfassung 3-[4-(p-Fluorphenyl)-1,2,3,6-te-trahydro-1-pyridyl]-1-[1-(2-hydroxyaethyl)-5-methyl-4-pyrazolyl]-1-propanon (I, CIBA 4416/B-Go) senkt bei normotonischen und hypertonischen Tieren den Blutdruck. Die Drucksenkung kann hauptsächlich auf die periphere Vasodilatation sowie auf die Vasomotorenzentren bezogen werden. Ausserdem wirkt CIBA 4416/B-Go adrenolytisch.
Previous paper:V. P. Arya, R. S. Grewal, C. L. Kaul, S. P. Ghate, D. V. Mehta andT. George, J. Pharm. Sci.58, 432 (1969).Contribution No. 243 from CIBA Research Centre.  相似文献   

9.
Summary The lipid fraction, 17%, of air-driedPlexaura homomalla formakükenthali, collected in the Caribbean at Puerto Rico, yielded 50% of its weight as the mammalian prostaglandin (15S)-PGA2 methyl ester. The freeze-dried gorgonian yielded (15S)-PGA2 largely as the acetate of the methyl ester. (15S)-PGA2 was also obtained from material collected at St. Croix and at South Caicos. Field observations indicate thatPlexaura kükenthali may be a species separate fromPlexaura homomalla and that it is abundant on some shallow water reefs in the Caribbean. Prostaglandins could not be detected in the lipid fraction of eggs isolated fromPlexaura homomalla (Esper) formahomomalla.Acknowledgments. We gratefully acknowledge support from the Office of Sea Grant, NOAA, Department of Commerce (Grant 047-158-44067), and the use of facilities at the Isla Mayagues Marine Laboratory of the University of Puerto Rico, Mayaguez, the West Indies Laboratory of Fairleigh Dickinson University at St. Croix, U.S.V.I., and the Marine-Biologisch Instituut at Curacao. Special thanks to Dr. F.M. Bayer, Curator, Department of Zoology, National Museum of Natural History-Smithsonian Institution for checking identity of gorgonians used in this study.  相似文献   

10.
We report here the identification of the long-range, male-produced sex pheromone of the Old house borerHylotrupes bajulus. Chemical analysis of hexane extracts obtained by surface extraction from dissected prothoracic glands and from headspace samples of the two sexes, revealed male-specific compounds: (3R)-3-hydroxy-2-hexanone, 2-hydroxy-3-hexanone, the diastereomeric diols (2R, 3R)-2,3-hexanediol and (2S, 3R)-2,3-hexanediol, 2,3-hexanedione, as well as 1-butanol.In wind tunnel bioassays we tested the influence of these male-specific compounds from the prothoracal glands on the behaviour of unmated and mated females. Specific behavioural sequences of the tested females (activity, running behaviour, searching, cleaning, flying, extension of ovipositor) were recorded. Unmated females were attracted by male beetles, headspace extracts of males, synthetic blends of the major pheromone compounds as well as by the components (3R)-3-hydroxy-2-hexanone, and the diastereomeric diols. Hexane, female beetles and 2,3-hexanedione did not attract unmated females. The reactions of mated females to male beetles and headspace samples did not differ significantly from those of the controls.The results of the bioassays show that the two-stage premating behaviour is initiated by emission of a long-range sex pheromone from the male prothoracal glands, which functions as an activator, attractant, and possibly aphrodisiac for unmated females.  相似文献   

11.
Summary The isolation and structure determination of (Z)-1,17-diaminooctadec-9-ene from several species of Coccinellidae is reported.Maître de Recherches du Fonds National de la Recherche Scientifique.We gratefully acknowledge the Fonds National de la Recherche Scientifique for financial support. We express our sincere thanks to Professor K. S. Hagen for a generous gift ofH. leis conformis.  相似文献   

12.
Summary (Z)-[11,12d 2]-11-Hexadecenoic acid was applied topically to the pheromone gland of silkworm pupa. After eclosion, the gland components were analyzed by capillary GC-MS. (Z)-11-Hexadecenoic acid, a characteristic fatty acid of the gland, was found to be a precursor of bombykol, (Z)-11-hexadecenol and bombyk acid.We are greatful to Dr Y. Tamaki and Mr H. Sugie of the National Institute of Agricultural Science for mass spectrometric analysis and Dr M. Noda of Kyoto Prefectural University for valuable discussion. This work was supported by a Grant-in-aid for Scientific Research (to K.H. No. 56112011) from the Ministry of Education, Science and Culture of Japan.  相似文献   

13.
Summary Infective stage juveniles ofNeoaplectana carpocapsae (Steinernematidae) andHeterohabditis heliothidis (Heterorhabditidae) were able to penetrate through the alimentary tract of young tadpoles ofHyla regilla (Hylidae) andXenopus laevis (Pipidae) and enter the body cavity. Some infectives ofN. carpocapsae were able to release their symbiotic bacterium,Xenorhabdus nematophilus inside the host and in two cases, the nematodes developed into adult females before they perished. Tadpole mortality was associated with foreign bacteria entering the penetration holes made by the invading nematodes. The infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's infective stage juveniles of both nematodes frequently encountered a host defense reaction upon reaching the tadpole's coelom.  相似文献   

14.
PF9601N, N-(2-propynyl)-2-(5-benzyloxy-indolyl) methylamine, an monoamine oxidase (MAO) B inhibitor, has shown neuroprotective properties against dopaminergic toxins. To elucidate the mechanisms involved in this protection, the effect of PF9601N on mitochondria was assessed. PF9601N prevents mitochondrial swelling, drop in the electrical potential and oxidation of sulfhydryl groups, glutathione and pyridine nucleotides induced by Ca2+. These observations demonstrate the protective effect of PF9601N on the induction of mitochondrial permeability transition. This protection is due to the interaction of the secondary protonated amino group in the molecule with pore-forming structures and to its antioxidant property, rather than to inhibition of MAO B activity. PF9601N also prevents the release of cytochrome c from mitochondria, suggesting its potential inhibitory effect on mitochondria-mediated apoptosis. The low IC50 value for this inhibition, in comparison with deprenyl, make it a more efficient compound than propargylamines and other amines in protecting the bioenergetic functions of mitochondria. Received 9 March 2006; received after revision 10 April 2006; accepted 21 April 2006  相似文献   

15.
Résumé La (Bis allylamino-4, 6 s-triazinyl-2)-I (bis p-fluorobenzhydryl)-4 pipérazine est un stimulant respiratoire à longue durée d'action et dépourvu d'action stimulante du système nerveux central.  相似文献   

16.
Summary Volatile fractions of the clover head,Hypera meles (Fab.), and alfalfa,Hypera postica (Gyllenhal), weevils contained three of four boll weevil,Anthonomus grandis (Boh.), pheromone components, (Z)-3,3-dimethylcyclohexane 1,-ethanol and (Z)- and (E)-3,3-dimethylcyclohexane-1,-acetaldehyde. Also found were eight oxygenated monoterpenes, previously identified as precursors and intermediates of the boll weevil pheromones.  相似文献   

17.
Summary A novel ether lipid, (-)-(R)-1-O-geranylgeranylglycerol (1), has been isolated from the brown alga Dilophus fasciola and its structure proved by spectroscopic methods and chemical degradation.This work was supported by CNR, Rome, Italy.  相似文献   

18.
Chemicals releasing oviposition by an Asclepiadaceae feeder,Ideopsis similis, were identified from a host plant,Tylophora tanakae. A strong positive response was evoked by a methanolic extract of the plant, which proved to contain multiple stimulants. A mixture of two phenanthroindolizidine alkaloids, (+)-isotylocrebrine and (–)-7-demethyltylophorine, isolated from organic fractions, elicited significant ovipositional responses from females.  相似文献   

19.
The degree of genetic variability and the taxonomic status of adults of 14 seed chalcid species of the genusMegastigmus was analyzed using electrophoresis on horizontal starch gel. Variability of chalcid populations with host tree was observed in 21 host species. A total of 13 enzyme loci were considered. Seven of the loci were found to be polymorphic. The electrophoretic data strongly supported the adaptation of each chalcid species to a limited number of congeneric hosts, and confirmed the morphologically-based taxonomy of the genus. The resulting dendrogram separated the chalcid species into three distinct groups, infesting 1) Pinaceae spp., 2) Cupressaceae spp., and 3) Angiosperm spp., respectively. The highest level of overall genetic similarity was observed among the chalcid populations infesting conifers of the generaPseudotsuga andAbies. The genetic identity values observed among populations infesting 5 differentAbies species tended to reflect the occurrence of conspecific populations rather than that of distinct chalcid species. Genetic identity was similarly important among the chalcid species infesting seeds of Cupressaceae. By contrast, a large genetic distance was observed between two seed chalcids attacking a same host,Rosa montana.  相似文献   

20.
The presence of a multidrug resistance (MDR) related protein, P-170, in normal and pathological lymphoid cells has been described. The present report evaluates the expression of themdr 1 gene by using the reverse Polymerase Chain Reaction (PCR) on cells obtained from the thymus and bursa of chicken embryos starting from day 12 until hatching. Results show that the thymic cells are positive from day 12 to the end of the observation period. In contrast,mdr mRNA was detected in the bursa from day 14 to day 17 of embryonic life. Possible relationships between the expression ofmdr and the development of T and B lymphocytes are discussed.  相似文献   

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