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1.
Microorganisms which can assimilate 2-phenylethanol were screened from soil for oxidation of various alcohols into carbonyl compounds. One strain, identified as Brevibacterium sp. KU1309, had high oxidative activity towards ArCH(CH(3))CH(2)OH and Ar(CH(2))(n)OH. When the substrate concentration was 0.1 approximately 0.4% (w/v), the oxidation reaction proceeded smoothly (6 approximately 96 h), and the corresponding carboxylates were obtained in good yields (68 approximately 87%).  相似文献   

2.
As a continuation of our efforts to discover and develop the apoptosis inducing 4-anilino-2-(2-pyridyl)pyrimidines as potential anticancer agents, we explored replacing the 2-pyridyl group by other aryl groups. SAR studies showed that the 2-pyridyl group can be replaced by a 3-pyridyl, 4-pyridyl and 2-pyrazinyl group, and that the SAR for the anilino group was similar to that of the 2-pyridyl series. However, replacement of the 2-pyridyl group by a phenyl group, a 3,5-dichloro-4-pyridyl group, or a saturated ring led to inactive compounds. Several potent compounds, including 2f, 3d, 3j and 4a, with EC50 values of 0.048–0.024 μM in the apoptosis induction assay against T47D cells, were identified through the SAR studies. In a tubulin polymerization assay, compound 2f, which was active against all the three cell lines tested (T47D, HTC116 and SNU398), inhibited tubulin polymerization with an IC50 value of 0.5 μM, while compound 2a, which was active against T47D cells but not active against HTC116 and SNU398 cells, was not active in the tubulin assay at up to 50 μM.  相似文献   

3.
<正>Dear Editor,Noroviruses are positive-sense, single-stranded RNA viruses belonging to Caliciviridae and account for more than 50%of all acute gastroenteritis (AGE) outbreaks worldwide and cause an estimated 200,000 deaths per year among children\5 years of age, primarily in developing countries (Hall et al. 2012; Glass et al. 2009). The norovirus genome contains three open reading frames (ORFs).  相似文献   

4.
The individual influence of sulfate reducing and brown phototrophic sulfur bacteria from Lake Kinneret on the metalimnetic redox conditions was investigated by simulating the hydrochemical and microbiological conditions in a specially designed chemostat. The results show a strong correlation between measured redox values and the prevailing hydrogen sulfide concentration leading to a linear relationship. Changes in this relationship allowed differentiation between the on-going microbial processes, sulfate reduction and sulfide oxidation. The comparison ofin vitro andin situ redox values shows that the results of the simulation experiments agree with the data previously measured in the metalimnion of Lake Kinneret.  相似文献   

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We report the synthesis and biological evaluation of a series of novel α-branched pyrazinoyl quaternary amines for their ability to block ion transport via the epithelial sodium channel (ENaC) in human bronchial epithelial cells (HBECs). Compound 12 g has an IC(50) of 30 nM and is highly efficacious in the Guinea-pig tracheal potential difference (TPD) model of ENaC blockade with an ED(50) of 1 μg kg(-1) at 1h. In addition the SAR results demonstrate for the first time the chiral nature of the binding site of human ENaC. As such, pyrazinoyl quaternary amines represent a promising new class of ENaC blockers for the treatment of cystic fibrosis that are structurally distinct from the pyrazinoyl guanidine chemotype found in prototypical ENaC blockers such as amiloride.  相似文献   

8.
The species described asLipomyces anomalus Babjeva & Gorin shows significant genetic and phenotypic divergence from the type speciesLipomyces starkeyi Lodder & Kreger-van Rij in terms of rRNA base sequence substitution and ascosporal and septal ultrastructure. The species is consequently reclassified in the new, unispecific genusBabjevia, asBabjevia anomala.  相似文献   

9.
A novel dimer of an inositol glycoside was isolated from the mycelial extracts of Streptomyces sp. AJ 9463. Its structure was assigned as a disulfide of 2-(N-acetyl-L-cysteinyl)amido-2-deoxy-α-D-glucopyranosyl-(1→1)-1D-myo-inositol (1).  相似文献   

10.
A survey is given on the various methods for dispersal of freshwater algae. Dispersal factors are either water or air, or organisms — from beetles, dragonflies and mammals to birds, the latter being the most important group. The question of dispersal distances is discussed, in relation to dispersal mechanisms and to the resistance of the algae to transport conditions. Man's recent importance in algal dispersal is emphasized.  相似文献   

11.
A β-d-glucan was isolated on fractionation of a 4% potassium hydroxide extract (hemi-celluloses) of immature barley plants (Hordeum distichum L.). Most of the glucose residues in the extract were found to be derived from the glucan. Methylation analysis and enzyme degradation studies showed that the glucan had (l-→3)-and (1-→4)-linked d-glucopyranosyl residues in an approximate molar ratio of 1.0:2.3. The molecular weight of the glucan was estimated to be 1.8 x 105 by gel filtration on Sepharose CL-6B.  相似文献   

12.
Abstract

Treatment of ψ-uridine (3) with α-acetoxyisobutyryl chloride in acetonitrile gave, after deprotection, a mixture of four products: 5-(2-chloro-2-deoxy-β-D-arabinofuranosyl)uracil (10a), its 3′-chloro xylo isomer (11a), 2′-chloro-2′-deoxy-ψ-uridine (9a) and 4,2′-anhydro-ψ-uridine (8a). Each component was isolated by column chromatography. Compound 9 was converted to the known 1,3-dimethyl derivative 2 by treatment with DMF-dimethylacetal. Treatment of 10 and 11 with NaOMe/MeOH afforded the same 4,2′-anhydro-C-nucleoside 8. The 1,3-dimethyl analogues of 10 and 11, however, were converted to 2′,3′-anhydro-1,3-dimethyl-ψ-uridine (13) upon base treatment. The epoxide 13 was also prepared in good yield by treatment of 10 and 11 with DMF-dimethylacetal.  相似文献   

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G&#  bor L. L&#  VEI 《生物安全学报》2021,30(1):1-2,28
The still-untamed SARS-CoV-2 pandemic underlined,again,two important facts that have been known for a long while but conveniently forgotten by humankind.One is that we are profoundly linked to other organisms and nature,and the other is that human-driven distribution chains are global and fast.  相似文献   

15.
A new high-yield synthesis of 2-pyridylferrocene (1) without formation of the 1,1′-disubstituted product has been developed. Also the corresponding ruthenocene and cymantrene derivatives [C5H4(2-C5H4N)]MLn (MLn = Ru(C5H5) (2), Mn(CO)3 (3)) were prepared and fully characterized. Ortho-lithiation of 1 followed by electrophilic halogenation yielded [C5H3X(2-C5H4N)]Fe(C5H5) [X = F (4), Cl (5), Br (6), I (7)], with 4 only being the second reported and first fully characterized fluoroferrocene. The molecular structures of 1, 4 and 6 have been determined by X-ray crystallography.  相似文献   

16.
Summary Reaction ofDl-serine and adenosine-5-phosphorimidazolide in the presence of adenosine-5-(O-methylphosphate) and imidazole resulted in the stereoselective synthesis of the aminoacyl nucleotide ester 2(3)-O-seryl-adenosine-5-(O-methylphosphate). The enantiomeric excess ofd-serine incorporated into 2(3)-O-seryl-adenosine-5-(O-methylphosphate) was about 9%. Adenylyl-(5N)-serine and an unknown product also incorporated an excess ofd-serine; however, serylserine showed an excess ofl-serine. The relationship of these results to the origin of the biological pairing ofl-amino acids and nucleotides containingd-ribose is discussed.  相似文献   

17.
The dicarboxylic acid malate has long been thought to play important roles in plant physiology. In addition to being a major photosynthate in C4 and CAM plants and an intermediate of the tricarboxylic acid cycle it has been proposed to play essential roles in pH regulation and important roles in pathogen response, as a component of the root exudates and as a regulatory osmolyte affecting stomatal function. Recent years have seen the cloning and functional analysis of a wide range of enzymes and transporters associated with malate metabolism. Here we attempt to provide a synthesis of research in this field as well as re-evaluating the role of this metabolite in mediating guard cell function.  相似文献   

18.
Hourly blood samples were collected from 10 mares during 24 h of each of the preluteolytic, luteolytic, and postluteolytic periods. The autocorrelation function of the R program was used to detect pulse rhythmicity, and the intra-assay CV was used to locate and characterize pulses of prolactin (PRL) and a metabolite of prostaglandin F2α (PGFM). Rhythmicity of PRL and PGFM concentrations was detected in 67% and 89% of mares, respectively. Combined for the three periods (no difference among periods), the PRL pulses were 5.2 ± 0.4 h (mean ± SEM) at the base, 7.5 ± 1.5 h between nadirs of adjacent pulses, and 12.3 ± 1.5 h from peak to peak. The peaks of PRL pulses were greater (P < 0.05) during the luteolytic period (46 ± 14 ng/mL) and postluteolytic period (52 ± 15 ng/mL) than during the preluteolytic period (17 ± 3 ng/mL). Concentrations of PRL during hours of a PGFM pulse were different (P < 0.003) within the luteolytic period and postluteolytic period and were greatest at the PGFM peak; PRL concentrations during a PGFM pulse were not different during the preluteolytic period. The frequency of the peak of PRL and PGFM pulses occurring at the same hour (synchrony) was greater for the luteolytic period (65%, P < 0.01) and postluteolytic period (50%, P < 0.001) than for the preluteolytic period (17%). This is the first report in mares on characterization and rhythmicity of PRL pulses, synchrony between PRL and PGFM pulses, and greater PRL activity during the luteolytic and postluteolytic periods than during the preluteolytic period.  相似文献   

19.
Results of experiments on the quenching of singlet delta oxygen (SDO) O2(a 1Δ g ) in lean hydrogen-oxygen mixtures at temperatures of 500–1020 K and pressures of 26–90 Torr behind the shock front are analyzed theoretically. The processes affecting SDO quenching are simulated taking into account the temporal characteristics of the experiment and various mechanisms of energy transformation in an O2(a 1Δ g )-H2-H-HO2 system. It is demonstrated that the approximations of both fast and slow (in comparison with the vibrational relaxation time of the HO2 radical) quenching of the electronically excited state of the radical are in good agreement with the experimental data on the effective rate constant of SDO deexcitation at temperatures of up to 700 K. It is shown that the available data on the kinetics of reactions involving SDO in H2-O2-O2(a 1Δ g ) mixtures overestimate the SDO quenching rate in comparison with the experimental results obtained at temperatures above 850 K. The decrease in the rate constant of the reaction H + O2(a 1Δ g )→ products by one order of magnitude makes it possible to match the simulation results to the experimental data. The existence of the processes restoring SDO in the presence of atomic hydrogen that are not considered in the current models of the H2-O2-O2(a 1Δ g ) kinetics is supposed.  相似文献   

20.
An agar-degrading Thalassomonas bacterium, strain JAMB-A33, was isolated from the sediment off Noma Point, Japan, at a depth of 230 m. A novel -agarase from the isolate was purified to homogeneity from cultures containing agar as a carbon source. The molecular mass of the purified enzyme, designated as agaraseA33, was 85 kDa on both SDS-PAGE and gel-filtration chromatography, suggesting that it is a monomer. The optimal pH and temperature for activity were about 8.5 and 45°C, respectively. The enzyme had a specific activity of 40.7 U/mg protein. The pattern of agarose hydrolysis showed that the enzyme is an endo-type -agarase, and the final main product was agarotetraose. The enzyme degraded not only agarose but also agarohexaose, neoagarohexaose, and porphyran.  相似文献   

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