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1.
Bryophytes have been screened for lectins. From the liverwortMarchantia polymorpha (Marchiantiales) a lectin could be purified to homogeneity using a combination of ultrafiltration, size exclusion chromatography and ion exchange chromatography. SDS polyacrylamide gel electrophoresis, size exclusion chromatography and electrospray mass spectroscopy showed that the lectin is a monomeric protein with a Mr of 16,134.64 ± 2.93.Marchantia polymorpha lectin agglutinates erythrocytes of different mammalia and exhibits carbohydrate specifity against complex carbohydrate structures. This is the first report of a lectin isolated from liverworts.This article forms Publication No. 71 of the Arbeitskreis Biologie und Chemie der Moose.  相似文献   

2.
Summary BacteriaVibro sp. isolated from the spongeDysidea sp. were shown to biosynthesize brominated diphenyl ethers. We identified one of the bacterial brominated metabolites using gas liquid chromatography and mass spectrometry to compare this product with standard 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol. The latter has been isolated from ethanol extracts of the spongeDysidea sp.  相似文献   

3.
Summary The structures of the metabolites formed upon incubation of 17-estradiol with the ovaries of silkworm,Bombyx mori, have been determined as 17-estradiol 3-(-D-glucopyranoside) (1) and 17-(-D-glucopyranoside) (2) by spectroscopic means.  相似文献   

4.
Summary The-endotoxin fromBacillus thuringiensis subspecieskurstaki strain HD1-9 is almost 400 times more potent than the-endotoxin from strain HD-73 as a gypsy moth larvicide. The two-endotoxins compete for a high-affinity binding site on the brush border membrane of larval gypsy moth midguts. The affinity for the-endotoxin from strain HD-73 is much greater than the affinity for the-endotoxin from strain HD1-9.  相似文献   

5.
Summary By means of closed-loop-stripping and subsequent GC analyses the diel periodicity of release of (Z)-11-hexadecenyl acetate, (E)-8-dodecenyl acetate, and (Z)-9-tetradecenyl acetate, the main constituents of the respective sex pheromone blends ofMamestra brassicae, Cryptophlebia leucotreta andSpodoptera sunia females, was determined.Pheromones, 64. For the 63rd contribution we have taken from: Szöcs, G., Toth, M., Bestmann, H. J., Vostrowsky, O., Heath, R. R., and Tumlinson, J. H., Z. Naturforsch.42c (1987) 165; Pheromones, 62: Bestmann et al.13.  相似文献   

6.
Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.  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.
Highly active metabolites have been detected in the hemolymph of the lepidopteranSpodoptera exigua infected with the mycopathogen,Beauveria bassiana. A combination of phenyl sepharose and CM ion exchange chromatography was utilized to extract the active metabolites from infected hemolymph samples. The active in vivo metabolites, having a molecular mass greater than 10 KDa, were thermolabile and were inactivated by proteinase K. These metabolites were characterized by their ability to disrupt metamorphosis, killing treated larvae at the wandering or pupal stage. Additionally, injection ofS. exigua larvae with active samples caused a reduction in the number of filopodial-producing hemocytes. The biological activities and biochemical properties suggest that novel compounds are produced duringB. bassiana mycosis.  相似文献   

9.
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   

10.
Summary The amino acid sequence was compared among the three allelic variants (allozymes) ofsn-glycerol-3-phosphate dehydrogenase inD. virilis, which are detected by one-dimensional electrophoresis. The GPDHf variant was different from the GPDHm by only one substitution of 68-lysine for asparagine; GPDHs differed from GPDHm by substitution of 127-glycine for arginine. No electrophoretically silent substitutions were found in a total of 352 amino acid residues.  相似文献   

11.
Summary The lectin receptor-site specificity of a purified galactan from snail (Achatina fulica) albumin glands has been studied by precipitin reactions in agar-gel double diffusion experiments with different lectins. Most lectins were found to be specific for terminal -D-galactose structures. Some findings suggest, that the structure DGal13DGal may be one of the receptor sites on the polysaccharide.  相似文献   

12.
Two new cytotoxic antitumor diterpenoids of the cembrane class, named 14-deoxycrassin (3) and pseudoplexaurol (4), have been isolated from the Caribbean gorgonian octocoralPseudoplexaura porosa. The structure of lactone3, possessing the infrequently encountered -methylene--lactone ring, has been established from spectral and chemical data and that of alcohol4 has been established from spectral data.  相似文献   

13.
Mhc organization and polymorphism have previously been studied26 in the four chromosomal species of theSpalax ehrenbergi superspecies in Israel, serologically, and at the DNA, RFLP and sequence levels of class I and class II genes. Here we demonstrate that the observed heterozygosity ofMhc class II genesP1 with 11 alleles, andQ, with at least 14 alleles, is positively and significantly correlated with infectivities of ectoparasites (gamasid mites)17 and endoparasites (helminths)18.Mhc heterozygosity is highest in the most infected area, which is in the most humid-warm region of the superspecies range, or where two zoogeographic regions overlap. We conclude that the evolutionary forces responsible for theMhc class II two-gene polymorphisms include selection for increased heterozygosity as a defense strategy against ecto- and endoparasite infections.  相似文献   

14.
Malaria, caused by members of the genusPlasmodia, is still the most prevalent parasitic disease in the world. In an attempt to understand genetic factors conferring resistance to malaria, mouse models of thalassemia, sickle trait, and ankyrin and spectrin deficiency were studied during infection with species of malaria infectious to rodents. Although growth ofP. falciparum is not inhibited in thalassemic erythrocytes in culture, mice carrying a -thalassemia mutation were protected fromPlasmodium chabaudi adami, supporting epidemiologic findings. Transgenic mice expressing s hemoglobin were also significantly protected from two species of rodent malaria. Importantly, a significant role for the spleen in protection in the s transgenic mice was found. Finally, mice deficient in spectrin and ankyrin were studied with respect to their ability to support the growth of malaria. It was found that spectrin deficient mice were almost completely refractory toP. chabaudi adami andP. berghei. These models will allow further study of host factors in resistance to malaria.  相似文献   

15.
(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   

16.
As part of a study to clarify the origins of biologically active substances in marine sponges, the carotenoids produced by two species of marine bacteria,Flexibacter sp. strain number DK30213 and DK30223, associated with the marine sponge,Reniera japonica, were investigated. Both bacteria were found to produce zeaxanthin [(3R, 3R)-dihydroxy-,-carotene] which is widely distributed in marine organisms. This carotenoid was also detected in the host sponge, suggesting the transport of zeaxanthin from the microorganisms to the host. As zeaxanthin plays the role of a quencher and scavenger for active species of oxygen, it is presumed that the sponge accumulates the bacterial product as a defense substance against the active oxygen species produced under irradiation by strong sunlight. It is thought that the bacteria are symbionts of the host sponge and act by obtaining the solid substrate and medium needed for settlement and growth from the host, and by producing and transmitting the biologically active substance to the host. Zeaxanthin-producing bacteria are also considered to have potential for practical uses by the aquacultural, pharmaceutical and food industries.  相似文献   

17.
Summary Brianolide (1), a new antiinflammatory diterpenoid of the briarein class, possessing a substituent at C-12 (R), has been isolated from the Okinawan gorgonianBriareum sp. Its structure has been established from spectral data in conjunction with a single crystal X-ray analysis.  相似文献   

18.
To study the origins of biologically active substances in marine sponges, a carotenoid produced by a marine bacterium,Pseudomonas sp. strain number KK10206C, which was associated with a marine sponge,Halichondra okadai, was investigated. A visible absorption spectrum-guided isolation procedure led to the isolation of a novel C50-carotenoid, okadaxanthin. Its structure, 2,2-bis(4-hydroxy-2-methyl-2-butenyl)-,-carotene, was elucidated mainly by spectroscopic methods. Okadaxanthin turned out to be a potent singlet oxygen quencher, approximately 10 times as strong as -tocopherol.  相似文献   

19.
In a survey of antifungal stress compounds induced by cupric chloride we found that leaves ofChenopodium album exuded a highly fungitoxic metabolite mucondialdehyde (trans-2,trans-4-hexadienedial), which was associated with 13-oxo-9,11-tridecadienoic acids (cis-9,trans-11 andtrans-9,trans-11 isomers) presumably resulting from -scission of 13-hydroperoxy-octadecadi(tri)enoic acid. The biogenesis and role as a general defensive agent in plants are briefly discussed.  相似文献   

20.
The Saccharomyces cerevisiae TPT1 gene plays a role in removing the 2-phosphate from ligated tRNA during the maturation of pre-tRNA. Here we reported the cloning and characterization of the human TRPT1 gene as a homolog of yeast TPT1. The TRPT1 gene is located at human chromosome 11q13 and encodes a polypeptide of 253 amino acids. BLAST searches with its amino acid sequence revealed the ubiquitous occurrence of TRPT1 homologs and their functional relationships with the presence of the DUF60/KptA domain. Northern analysis demonstrated that the gene is primarily expressed in heart and skeletal muscle, with lower or undetectable levels in other tissues studied. A plasmid-shuffling experiment showed that the human TRPT1 gene could complement the tpt1 mutation in S. cerevisiaeReceived 19 March 2003; received after revision 25 April 2003; accepted 22 May 2003  相似文献   

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