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1.
Summary Growth responses of Ashmouni and Karnak cotton variety seedlings toRhizoctonia solani, the damping-off fungus, or toBacillus subtilis (two different strains),Aspergillus terreus andAspergillus flavus isolated from the rhizosphere of cotton, and all antagonistic to the pathogen, were expressed in terms of growth-vigour criteria.The presence ofR. solani in the soil inhibited the growth vigour of both cotton variety seedlings. However, Karnak seedlings were more sensitive to the pathogen than Ashmouni seedlings. One of the strains ofB. subtilis andA. terreus generally increased the vigour of both cotton variety seedlings.A. flavus lowered most of the growth criteria of Karnak or Ashmouni cotton seedlings.
Zusammenfassung Rhizoctonia solani, der Parasiet von Baumwolle-Keimlingen, wurde isoliert.Sowohl Bacillus subtilis als auchAspergillus terreus und Aspergillus flavus wurden von der Rhizosphere der Baumwolle-Pflanzen isoliert. Diese Organismen wurden als antagonistisch gegenRhizoctonia solani erkannt. Die Wirkung dieser Organismen auf das Wachstum von Keimlingen der Baumwolle sorten Ashmouni und Karnak wurde untersucht. R. solani hemmt das Wachstum der Keimlinge beider Baumwolle-Sorten. Es wurde festgestellt, dass Karnak empfindlicher ist als Ashmouni. Einer der Stämme vonB. subtilis undA. terreus erwiesen sich als Wachstum förderend bei beiden Baumwolle-Sorten.A. flavus dagegen vermindert das Wachstum von Karnak und Ashmouni.
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2.
Summary Small pieces of fetal rat brain selected to contain a high number of noradrenaline (NA), dopamine (DA), or 5-hydroxytryptamine (5-HT) neuroblasts were transplanted to the anterior chamber of the eye of adult rats. The sympathetic ground plexus of the host iris was removed by superior cervical ganglionectomy so that transmitter mechanisms of the different central monoamine fibers innervating the iris could be selectively studied after intraocular maturation. Such irides, containing NA, DA, or 5-HT nerve terminals were incubated with radiolabelled transmitters and then stimulated by an electrical field while superfused, to investigate the spontaneous and stimulation-induced release of amine, both in drug-free buffer and buffer containing drugs acting on monoamine receptors.The central monoamine neurons of all three types were able to take up exogenous amines and release them upon stimulation by an electrical field, in much the same way as corresponding nerves in situ in slices of cerebral cortex (NA, 5-HT) or olfactory tubercle (DA).The -adrenergic receptor blocking agent phentolamine increased the stimulation-induced release of 3H-NA from central NA fibers on the iris significantly. The dopamine receptor stimulating agent apomorphine decreased the stimulation-induced release of 3H-DA from central DA fibers on the iris. Pimozide, a DA receptor blocking drug tended to increase the 3H-DA release. The 5-HT receptor stimulating agent ergocornine tended to reduce the stimulation-induced release of 3H-5-HT from central 5-HT fibers on the iris. It was concluded that all three types of central monoamine nerve fibers develop essentially normal transmitter storage and release mechanisms also in an environment completely devoid of normal postsynaptic receptors. The drug experiments add strong support to the view that there are presynaptic monoamine receptors (autoreceptors) able to modulate transmitter release present on the monoamine nerve terminals.Supported by the Swedish Medical Research Council (04X-3185 and 04X-2330) and by grants from Magnus Bergvalls Stiftelse and Karolinska Institutets Fonder, we thank Miss Ingrid Strömberg and Miss Ulla Enberg for skilful technical assistance.  相似文献   

3.
Summary The histochemical fluorescence method of Falck and Hillarp for the demonstration of catecholamines and certain tryptamines, e.g. 5-hydroxytryptamine is based on the principle that these amines can be condensed with formaldehyde to yield strongly fluorescent 6,7-dihydroxy-3,4-dihydroisoquinolines and 6-hydroxy-3,4-dihydro--carbolines respectively. The investigation here reported presents the fluorescence characteristics and relative fluorescence yields for formaldehyde treated biogenic monoamines and certain related compounds enclosed in a dried protein layer. The fluorescence properties of some synthetic 6,7-substituted-3,4-dihydroisoquinolines and 3,4-dihydro--carbolines are given, and the fluorescence characteristics in relation to the molecular structure are discussed.Abbreviations used A adrenaline - DA dopamine - DOPA 3,4-dihydroxyphenylalanine - DOPS 3,4-dihydroxyphenyl-serine - 5-HT 5-hydroxytryptamine - 5-HTP 5-hydroxytryptophan - 5-MT 5-methoxytryptamine - -m-DA -methyl-dopamine - -m-DOPA -methyl-3,4-dihydroxyphenylalanine - -m-NA -methyl-noradrenahne - MTA 3-methoxy-tyramine - NA noradrenaline - NM normetanephrine - T Tryptamine - Try Tryptophan  相似文献   

4.
Summary We report here a new human -globin gene rearrangement carrying the two normal, 2 and 1, and two hybrid, 1/2, globin genes in the order 5-2-1/2-1/2-1-3. Both the hybrid genes, subtyped with ApaI and RsaI restriction enzymes, were found to be of the uncommon anti 3.7 type II. The hybrid genes were expressed at the biosynthetic level and their interaction with the -thalassaemia IVS 1 nt 1 GA mutation caused thalassaemia intermedia. We also report a case of an -globin gene rearrangement in the twin of one of the -globin gene carriers; the duplicated gene was of the anti 4.2 type and was associated with the absence of RsaI polymorphism. The singular finding of an -anti 3.7 cluster with two identical rare hybrid genes suggests that the reciprocal unequal recombination causing the -globin gene rearrangements could be of the intra-chromosomal rather than the interchromosomal type.  相似文献   

5.
Ionic relations of aeroponically-grown olive genotypes,during salt stress   总被引:1,自引:1,他引:0  
Two olive (Olea europaea L.) genotypes, Frantoio and Leccino, were exposed to increasing concentrations of NaCl (0-30-60-120 mM) in an aeroponic cultivation system for 60 days. Dry weights and sodium and potassium contents of apical and basal leaves, new and old wood, and roots were measured to determine Na uptake rate, Na translocation rate and K-Na selectivity ratio (SK,Na). Frantoio showed a higher salt resistance than Leccino. Frantoio and Leccino had a similar Na uptake rate, but largely differed for Na translocation to the shoot. Furthermore Frantoio exhibited a higher K-Na selectivity than Leccino at both whole plant level and above all at the level of shoot system. Resistance mechanism of Frantoio is probably related to Na esclusion by roots and to the ability to maintain an appropriate K/Na ratio in actively growing tissues.Research supported by National Research Council of Italy, Special project RAISA.  相似文献   

6.
Summary Five subunits (-, -, -, - and -subunits) of the six -and -subunits) in the F1 portion (F1ATPase) of sweet potato (Ipomoea batatas) mitochondrial adenosine triphosphatase were isolated by an electrophoretic method. The - and -subunits were not distinguishable immunologically but showed completely different tryptic peptide maps, indicating that they were different molecular species. In vitro protein synthesis with isolated sweet potato root mitochondria produced only the -subunit when analyzed with anti-sweet potato F1ATPase antibody reacting with all the subunits except the -subunit. Sweet potato root poly(A)+RNA directed the synthesis of six polypeptides which were immunoprecipitated by the antibody: two of them immunologically related to the -subunit and the others to the - and -subunits. We conclude that the -subunit of the F1ATPase is synthesized only in the mitochondria and the -, - and -subunits are in the cytoplasm.  相似文献   

7.
Summary Using the histochemical method for the demonstration of DA, NA and 5-HT it has been possible to demonstrate, in reserpine treated rats, that intraventricularly administered DA, NA, -methyl-DA and -methyl-NA in doses of 1–2 g are specifically taken up by the parts of the DA and NA neurons lying close to the ventricles and the subarachnoidal space. The distribution of this uptake is described in detail. No uptake and accumulation of DA and NA was observed unless the monoamineoxidase had been inhibited whereas the -methylated compounds which are resistant to monoamineoxidase accumulated without monoamineoxidase inhibition. Intraventricularly administered 5-HT was specifically taken up and accumulated in the 5-HT neurons within the same zone provided that monoamineoxidase had been inhibited. The distribution of this uptake is described in detail. After high doses of CA (5–10 g) these amines accumulated to some extent also in the 5-HT neurons while no such accumulation was observed in the CA neurons after high doses of 5-HT. Thus, the present results indicate that there exists a specific reserpine-resistant, amine-concentrating mechanism at the nerve cell membrane of CA and 5-HT neurons. In areas where the exogenous amine concentrations probably were high there also occurred an accumulation of DA and NA in the CA neurons although the monoamineoxidase was not inhibited. Finally, in a certain area of the hypothalamus, CA was found to accumulate even after low doses (1–2 g), in nerve cell bodies which probably normally do not contain CA.This study was supported by a research grant from the Swedish Medical Research Council (12x-715-03) and by grants from M. Bergwalls stiftelse and C. Nathorsts stiftelse.  相似文献   

8.
Predominance and tissue specificity of adenine methylation in rice   总被引:2,自引:0,他引:2  
Summary Using A and C methylation-specific restriction enzymes, namely, MboI, Sau3AI, DpnI, MspI, and HpaII, total rice cv Basmati 370 DNA, repetitive DNAs, and a specific repeat sequence indicated an abundance of adenine methylation. Although cytosine methylation in 5-CCGG-3 sequences suggested more CpC methylation than CpG, the C methylation in sequence 5-GATC-3 was comparatively less than A methylation. Furthermore, the presence of adenine methylation was tissue specific; it was predominant in rice shoot DNA as compared to embryo DNA. This pattern was also observed in two other cultivars of rice, i.e., R-24 and Sona, and was again confirmed using a cloned probe of a specific repeat sequence. Besides the changes in adenine methylation, there was also a qualitative change in 5mC from CpG to CpC dinucleotides in these two tissue systems.  相似文献   

9.
Se diferencian 5 arcos de precipitatión en la técnica de inmunoelectroforesis (IEF) luego de enfrentar sueros de 16 pacientes de paracoccidioidomicosis a la paracoccidioidina. El arco l presente en todos los sueros es asimilado a arcos presuntamente específicos descritos previamente. En immunoelectroosmoforesis-inmunodifusión (IEOF-ID) se observaron bandas anódicas y bandas catódicas en todos los casos. La comparación de los resultados obtenidos con las 2 técnicas reveló siempre un mayor número de arcos en IEOF-ID lo que se debería a la aparición de los arcos de localizatión catódica 1 y 2 del inmunoelectroforegrama, tanto en el lado anódico como en el catódico de las láminas de IEOF-ID.
Summary Immunoelectroporesis (IEF) and immunoelectroosmophoresis-immunodiffusion (IEOP-ID) (1) were comparatively used in the diagnosis of 16 patients with mycologically proved paracocidioidomycosis.In IEF, 5 different precipitin arcs were found and identified with arable numbers. Arc. 1, cathodic, present in all the patients, is assimilated to specific arcs previously described by other authors.In IEOP-ID both cathodic and anodic arcs were observed in all the sera.A high number of precipitin arcs were revealed by IEOP-ID technique in comparison to IEF in every case. This should be due to the presence of cathodic arcs 1 and 2 of the immunoelectrophoregram at both sides of the IEOP-ID preparate.
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10.
Several factors that affect the frequency of organogenesis in apple leaf explants were examined for the scion cultivars Empire, Freedom, Golden Delicious, Liberty, McIntosh, and Mutsu and for the rootstocks Malling 7A and Malling 26. The main factors affecting morphogenesis were BA concentration, basal medium, leaf explant origin and maturity, explant orientation, and photosynthetic photon flux. Depending on the genotype, optimal regeneration was obtained using either 22.2 or 31.1 M BA and the N6 basal medium, with the exception of Golden Delicious which regenerated better on MS medium. After 6 weeks, the average number of shoots per segment varied from 5 to 16, and the percentage of regeneration between 70 and 100%, depending on the genotype tested and the maturity of the explant. Regeneration capacity increased dramatically from the tip towards the base of the leaf, and was higher from the middle to the proximal end.Cefotaxime and carbenicillin, two antibiotics commonly used during transformation studies to eliminate Agrobacterium tumefaciens from plant tissue, were tested to determine their effect on morphogenesis. Cefotaxime at a dose of 250 mg 1-1 enhanced regeneration and shoot development, whereas carbenicillin at a dose of 500 mg l-1 induced abundant callus formation and inhibited regeneration. Kanamycin, a widely used selection agent for plant transformation, strongly inhibited regeneration even at very low doses. Schemes for selection and recovery of transgenic apple plants when kanamycin is used as the selection agent are discussed.Abbreviations BA benzyladenine - Cef cefotaxime - Crb carbenicillin - IBA indolebutyric acid - Kan kanamycin - LS Linsmaier and Skoog (1965) medium - M Malling - MS Murashige and Skoog (1962) medium - NAA naphthaleneacetic acid - N6 medium (Chu et al. 1975) as modified by Welander (1988) - PPF photosynthetic photon flux  相似文献   

11.
Summary This work deals with the ability of phage 80 to provide defective mutants of with their missing functions. Functions Involved in Recombination. As shown by others, the Int mechanism of 80 cannot excise prophage . However, 80 efficiently excises recombinants from tandem dilysogens, using its Ter mechanism. Likewise, the nonspecific mechanism Red is interchangeable between 80 and . Maturation of DNA by 80. The Ter recombinants excised by 80 from tandem dilysogens are packaged into a 80 protein coat. This contrasts with the fact, already mentionned by Dove, that 80 is extremely inefficient for packaging phage superinfecting a -lysogen. The latter result is also found when the helper phage is a hybrid with the left arm of (80hy4 or 80hy41 — see Fig. 1). However, the maturation of the superinfecting is much more efficient if the 80hy used as a helper has the att-N region of (like 80hy1). Conversely a with the att-N region of 80 (hy6 — see Fig. 1) is packaged more efficiently by 80 or 80hy4 than by 80hy1. It is suggested that the maturation of chromosome superinfecting an immune cell requires a recombination with the helper phage. Vegetative Functions. Among the replicative functoons O and P, the latter only can be supplied by 80. That N mutants are efficiently helped by 80 does not tell that 80 provides the defective with an active N product; the chromosomes are simply packaged into a 80 coat. This shows that 80 is unable to switch on the late genes of . That neither 80 nor any of the 80hy tested can provide an active N product is shown in a more direct way by their complete failure to help N -r14; this phage carries a polar mutation which makes the expression of genes O and P entirely N-dependant. The maturation of a N - by 80 contrasts with the fact that mutants affected in late genes (A, F or H) are not efficiently helped by 80. This suggests that the products coded by these genes are not interchangeable between 80 and , and that packaging of DNA into 80 coats is possible but inhibited when late proteins are present in the cell. Activation of the Late Genes. Among the im 80 h + hybrids tested, only 80hy41 is able to switch on the late genes of a N defective mutant. This hybrid differs from the other hybrids studied here, by the fact that it has the Q-S-R region of (see Fig. 1). The results are consistant with the view that the product of Q gene is sufficient for activating the late genes of a DNA. N would thus control the expression of late genes only indirectly by controlling the expression of gene Q (Couturier & Dambly have independantly reached the same conclusion, 1970). Furthermore the failure of 80 and of the 80hy1 and 80hy4 to activate the late genes of would imply that these phages are unable to provide an Q product active on the chromosome Reciprocally, switches on the late genes of prophage 80hy41, but not of prophages 80hy1 and 80hy4. This suggests that the initiation of late genes expression takes place at a main specific site located in the Q-S-R region of the chromosome. The expression of the late genes would thus be sequential, and proceed through the left arm only when steaky ends cohere. Similar conclusions were reached independantly by Toussaint (1969) and by Herskowitz and Signer (1970).

Ce travail a été réalisé dans le cadre du contrat d'association Euratom-U. L. B. 007-61-10 ABIB et avec l'aide du Fonds de la Recherche Fondamentale Collective.  相似文献   

12.
Thirteen species of methanogenic bacteria were analyzed for corrinoids. Pseudo vitamin B12 (Co-[-(7-adenyl)]-cobamide) was the predominant cobamide of methanococcales and Methanoplanus. All other methanogens contained factor III (Co-[-(5-hydroxybenzimidazolyl)]-cobamide). Vitamin B12 (Co-[-(5,6-dimethylbenzimidazolyl)]-cobamide) was not detected in any of these archaebacteria. Their cobamide content was 100 to 1400 nmol per gram cell dry weight, indicating that abundant cobamides are essential for methanogens.  相似文献   

13.
A simple and rapid pea regeneration procedure was developed. An average of up to 20 shoots formed from hypocotyl explants of cvs. Sugar Ann and Patriot cultured on Murashige and Skoog basal medium supplemented with 0.5 or 1.0 M thidiazuron (N-phenyl-N-1,2,3-thiadiazol-5-ylurea). Hypocotyls of Puget and Sugar Daddy did not respond. Regenerated shoots rooted rapidly when cultured on Murashige and Skoog basal medium containing either 2.0 M -naphthaleneacetic acid or 1.0–2.0 M indole-3-butyric acid. Seeds were harvested from regenerated plants after only 9–11 weeks.Abbreviations BAP 6-benzyladenine - 2,4-d 2,4-dichlorophenoxy acetic acid - GA3 gibberellic acid - IBA indole-3-butyric acid - MS Murashige and Skoog (1962) medium - NAA -naphthaleneacetic acid - TDZ thidiazuron (N-phenyl-N-1,2,3-thiadiazol-5-ylurea)  相似文献   

14.
Effector-target conjugates, formed by coincubation of lymphokine-activated killer (LAK) cells with either K562 or Daudi cells, were separated from single cells by Percoll sedimentation. The occurrence of various CD molecules (CD3, CD56, CD57, CD16, /-TCR) was compared in both fractions. Only LAK cells expressing the / T cell receptor (TCR) were found in a significantly increased percentage in fractions containing conjugates indicating that /-TCR+ LAK cells were preferably bound to target cells at the time of separation. In order to determine whether /-TCR+ LAK cells also show a preferred killing activity against the targets, cultures enriched with or depleted of /-TCR+ cells were established. Against K562 cells, /-TCR+-enriched cultures showed a greatly reduced killing activity compared to LAK bulk cultures or cultures depleted of /-TCR+ cells. Using Daudi cells as targets the enriched fraction revealed a slightly increased killing activity compared to bulk cultures or depleted fractions. Preincubation of /-TCR+ LAK cells with anti-/ or anti-CD3 mAb resulted in a distinct increase of the killing activity against K562 cells, but in only a slightly enhanced activity against Daudi cells. It is postulated that /-TCR+ LAK cells use the same adhesion mechanism for both targets but that only Daudi cells express a specific ligand for the /-TCR. Occupation of the /-TCR/CD3 complex by mAb, however, seems to substitute for the absent epitope on K562 cells by eliciting stimulatory signals in /-TCR+ LAK cells which, in combination with the binding stimulus, trigger cytolytic activity.This work was supported by the Hartmann-Müller Foundation, Zürich  相似文献   

15.
The bean-pod weevil (BPW), Apion godmani Wagner, often causes heavy losses in crops of common bean (Phaseolus vulgaris L.). Farmers need resistant bean cultivars to minimize losses, cut production costs, stabilize seed yield, and reduce pesticide use and consequent health hazards. To design effective breeding methods, breeders need new and better sources of resistance and increased knowledge of their modes of inheritance. We therefore: (1) compared sources of resistance to BPW, (2) studied the inheritance of resistance, and (3) determined whether the sources possess similar or different genes for BPW resistance. The following sources of resistance, originating from the Mexican highlands, were evaluated for 3 years at INIFAP-Santa Lucía de Prias, Texcoco, Mexico: Amarillo 153, Amarillo 169, Hidalgo 58, J 117, Pinto Texcoco, Pinto 168, and Puebla 36. All except Puebla 36 were crossed with the susceptible cultivar Jamapa. Amarillo 153 and Puebla 36 were crossed with another susceptible cultivar, Bayo Mex. The parents, F1 hybrids, and F2 populations were evaluated for BPW damage in 1992. Backcrosses of the F1 of Jamapa/Pinto 168 to the respective susceptible and resistant parents were also evaluated in 1992. All seven resistant accessions were crossed in all possible combinations, excluding reciprocals. The resulting 21 F1 hybrids and 21 F2 populations were evaluated for BPW damage in 1994. J 117 had the highest level of resistance to BPW. Pinto Texcoco and Puebla 36 had the highest mean damage score of all seven sources of resistance. The F1 hybrids between susceptible parents and resistant sources were generally intermediate. Two genes segregating independently controlled the BPW resistance in each accession. One gene, Agm, has no effect when present alone, whereas the other gene, Agr, alone conferred intermediate resistance. When both genes were present, resistance to BPW was higher. Based on mean BPW damage scores, all 21 F1 hybrids and their F2 populations, derived from crosses among seven resistant accessions, were resistant. However, data from individual plant damage scores in F2 populations of Amarillo 169/Pinto 168 and Pinto Texcoco/Pinto 168 suggested that at least one gene in each of the three accessions was non-allelic. Data also indicated that Amarillo 169 had a dominant gene that conferred high levels of BPW resistance, irrespective of the alleles at the other locus; and that Pinto Texcoco and Pinto 168 possessed two different genes for intermediate resistance.  相似文献   

16.
Oxidative injury and antioxidant responses were investigated in two banana genotypes (Musa AAA Berangan and Musa AA Mas) subjected to 40 % PEG-induced water stress. PEG treatment resulted in oxidative injury, as expressed in increased lipid peroxidation and reduced membrane stability index, in both cultivars; however, greater oxidative injury was detected in Mas. Under PEG treatment, catalase activity and glutathione reductase activity were enhanced in both cultivars, but were higher in Mas. Ascorbate peroxidase activity was enhanced in Berangan under water stress, but was unaffected in Mas. Meanwhile, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in Berangan. Higher ascorbate peroxidase and superoxide dismutase activities were associated with greater protection against water stress-induced oxidative injury.  相似文献   

17.
The taxonomic significance of the trunk limbs of the chydoridae (Cladocera)   总被引:1,自引:1,他引:0  
N. N. Smirnov 《Hydrobiologia》1966,27(3-4):337-343
Summary The differences in the structure of the trunk limbs allow to outline three sections of Chydoridae (see table I and fig. 1), coinciding with the sections distinguished according to the structure of the head pores.
Chydoridae (Cladocera)
Chydoridae (. ), , .
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18.
Primers were developed for 118 microsatellites isolated from grape (Vitis vinifera) genomic libraries enriched for (AC)n repeats. Only one microsatellite sequence matched other grape SSR-sequences in the GeneBank database. Genotyping was carried out in the parental lines and four offspring of two pseudo-test-cross populations, Cabernet Sauvignon x Seyval and Chardonnay x Bianca, and a further six other grape genotypes (V. vinifera Sultanina, Merlot, Syrah, Müller-Thurgau, Vitis Regent and V. riparia Gloire de Montpellier). A total of 108 microsatellites showed easily scorable alleles and 100 of them segregated according to a configuration suitable for mapping in either cross. A further 8 SSRs, although unsuitable for mapping in those crosses, showed polymorphism in the other genotypes tested. This set of markers was used, along with 75 microsatellites of other repeat-types, to fingerprint 46 offspring of the cross Chardonnay x Bianca. For each full-sib, individual heterozygosity and distance in repeat units between pairs of alleles at each locus (mean d2) were calculated as a tool for predicting highly outbred recombinant individuals. Six microsatellites with segregation ratios significantly distorted towards the lack of homozygous sibs were identified and mapped to linkage groups LG 3 and LG 5. Estimation of heterozygosity at genome-wide level and genotyping at loci for which homozygous sibs are discriminated against are discussed for marker-assisted background selection in outcrossing grapevines.  相似文献   

19.
Summary The carotenoid pigments of the myxobacterium Sorangium compositum were analyzed by chromatographical and chemical techniques and by visible, infra red, and mass spectroscopy. Besides -carotene, neurosporene, torulene, lycopene, and 1,2-dihydro-1-hydroxy--carotene, four new carotenoid glycosides were found. These pigments were identified as 1,2-dihydro-1-hydroxy-torulene glucoside ester (I), 1,2-dihydro-3,1-dihydroxy-torulene glucoside ester (III), 1,2-dihydro-1-hydroxy-torulene rhamnoside (II), and 1,2-dihydro-3,1-dihydroxytorulene rhamnoside (IV).Fifth communication on the carotenoids of myxobacteria. Fourth communication see Arch. Mikrobiol. 76, 364–380 (1971).  相似文献   

20.
4-Methylumbelliferyl 6-O-benzyl--d-lactoside (6Bn-MU-Lac) and some related compounds were synthesizedvia different selective reactions including phase-transfer glycosylation. Their suitability as substrates for a fluorometric assay of ceramide glycanase (CGase) was evaluated. Among others, the 6Bn-MU-Lac, which is resistant to exogalactosidase, was found to be a suitable substrate for routine assay of the CGase activity. For American leech CGase, theK m value is 0.232 mM at pH 5. Abbreviations: CGase, ceramide glycanase; Gal, galactose; Glc, Glucose; Lac, lactose; MU, 4-methylumbelliferone; MU-Lac, 4-methylumbelliferyl -d-lactoside; bBn-Lac, 6-O-benzyl-lactose; 6Bn-MU-Lac, 4-methylumbelliferyl 6-Obenzyl--d-lactoside; 46Bd-MU-Lac, 4-methylumbelliferyl 4,6-O-benzylidene--d-lactoside; MU-Cel, 4-methylumbellifery -d-cellobioside; 46Bd-MU-Cel, 4-methylumbelliferyl 4,6-O-benzylidene--d-cellobioside; TLC, thin layer chromatography;1H-NMR, proton nuclear magnetic resonance; GSL, glycosphingolipids; CSA, 10-camphorsulfonic acid. See Scheme 1 for chemical structures.  相似文献   

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