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Background: White Velvet bean (Mucuna pruriens) is a very valuable plant due to its medical potential. Different parts of the plant have been studied by various researchers. However, the seeds, which contain a lot of bioactive compounds, have been considered of substantial medicinal importance. Methods: The total phenolic content, total flavonoid content, antioxidant and trypsin inhibition properties in the methanol extract of white Velvet bean (WVB) seeds and its fractions (methanol, n-hexane, ethyl acetate, n-butanol and aqueous) were studied. Result: The highest total phenolic content was recorded in the methanol extract (206.3 mg GAE g-1). The highest total flavonoid content was in the n-hexane fraction (7.75 mg rutin g-1). The methanol extract showed the highest total antioxidant potential (261.5 mg AAE g-1). The methanol extract also had the strongest DPPH radical scavenging activity and the highest level of trypsin inhibitory activity compared to the other fractions with an IC50 value (35.3 µg mL-1). [ABSTRACT FROM AUTHOR]

This study aimed to isolate a novel agarase-producing soil bacterium and characterize its agarose, which is known to produce biofunctional agarooligosaccharides or neo-agarooligosaccharides. A novel agar-degrading bacterium, namely AT2, was isolated from the agricultural soil and the enzyme activity was identified on a specific medium. The 16S rRNA nucleotide sequence represented 99% identity with that of the members of the Flavobacterium genus; hence, the isolated bacterium was named as Flavobacterium sp. AT2. The extracellular agarase reached maximum activity at 22.79 U/mL under the following culture conditions: 10% (v/v) inoculum size, shaking rate 210 rpm after 72 h incubation. The optimum conditions of the agarase activity were pH 7.0 and 60°C in 50 mM sodium phosphate buffer. The molecular mass of the purified agarase was 180 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The extracellular agarase hydrolyzed seaweed with the highest yield of 423.58 ± 33.75 µg/mL reducing sugar released after 24 h. Thus, Flavobacterium sp. AT2 and its enzyme could be practical for applications in food, cosmetic, and medical studies. [ABSTRACT FROM AUTHOR]

The fragmentation of doubly charged gas-phase methionine (HO2CCH(NH2)CH2CH2SCH3) is systematically studied using the self-consistent charge density functional tight-binding molecular dynamics (MD) simulation method. We applied graph theory to analyze the large number of the calculated MD trajectories, which appears to be a highly effective and convenient means of extracting versatile information from the large data. The present theoretical results strongly concur with the earlier studied experimental ones. Essentially, the dication dissociates into acidic group CO2H and basic group C4NSH10. The former may carry a single or no charge and stays intact in most cases, whereas the latter may hold either a single or a double charge and tends to dissociate into smaller fragments. The decay of the basic group is observed to follow the Arrhenius law. The dissociation pathways to CO2H and C4NSH10 and subsequent fragmentations are also supported by ab initio calculations. [ABSTRACT FROM AUTHOR]

Photofragmentation of thymine and 5-bromouracil into cation and neutral fragments following the core ionization by soft x-rays using photoelectron-photoion-photoion coincidence technique has been studied. The fragment ion mass spectra were recorded in coincidence with the C 1s photoelectron spectra. In the case of thymine, deuterated samples were used to identify fragments. Deuteration or bromination allowed us to study not only the main fragmentation channels of these pyrimidine bases, but also to investigate if replacement of an exocyclic functional group affects molecular fragmentation. We found that the dominant fragmentation channels involve only one starting geometry, and the base ring and other bond cleavages, leading to the detected fragments, are essentially identical between thymine and 5-bromouracil. In addition, the relative intensities of the strongest fragmentation channels were determined and compared with calculated appearance energies using ab initio unrestricted Hartree-Fock theory. [ABSTRACT FROM AUTHOR]

Dissociation of acrylonitrile into pairs of cations and neutral fragments following molecular core ionization was investigated using the photoelectron-photoion-photoion coincidence (PEPIPICO) technique. The fragment ion mass spectra were recorded in coincidence with the carbon 1s photoelectrons. Deuterated and 13C-substituted samples were used for resolving fragment mass ambiguities. Slope analysis of the PEPIPICO patterns was used in determining the fragment separation sequences in case of multiparticle processes. The results show that there are several fragmentation channels producing a wide range of charged coincident fragments. The dynamics of the dominant fragmentation processes is investigated in detail. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflicts of interest: none declared.

OBJECTIVES: To assess the performance of the GenoType MTBDR sl v1, a line-probe assay (LPA), to exclude baseline resistance to fluoroquinolones (FQs) and second-line injectables (SLIs) in the Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB 1 (STREAM 1) trial. METHODS: Direct sputum MTBDR sl results in the site laboratories were compared to indirect phenotypic drug susceptibility testing (pDST) results in the central laboratory, with DNA sequencing as a reference standard. RESULTS: Of 413 multidrug-resistant TB (MDR-TB) patients tested using MTBDR sl and pDST, 389 (94.2%) were FQ-susceptible and 7 (1.7%) FQ-resistant, while 17 (4.1%) had an inconclusive MTBDR sl result. For SLI, 372 (90.1%) were susceptible, 5 (1.2%) resistant and 36 (8.7%) inconclusive. There were 9 (2.3%) FQ discordant pDST/MTBDR sl results, of which 3 revealed a mutation and 5 (1.3%) SLI discordant pDST/MTBDR sl results, none of which were mutants on sequencing. Among the 17 FQ- and SLI MTBDR sl- inconclusive samples, sequencing showed 1 FQ- and zero SLI-resistant results, similar to frequencies among the conclusive MTBDR sl . The majority of inconclusive MTBDR sl results were associated with low bacillary load samples (acid-fast bacilli smear-negative or scantily positive) compared to conclusive results ( P < 0.001). CONCLUSION: MTBDR sl can facilitate the rapid exclusion of FQ and SLI resistances for enrolment in clinical trials.

Several strains of moderately halophilic and mesophilic bacteria were isolated at the head of an oil-producing well on an offshore platform in southern Vietnam. Cells were Gram-negative, non-spore-forming, rod-shaped and motile by means of a polar flagellum. Growth occurred at NaCl concentrations between 0 and 20%; the optimum was 5% NaCl. One strain, which was designated VT8T, could degrade n-hexadecane, pristane and some crude oil components. It grew anaerobically in the presence of nitrate on succinate, citrate or acetate, but not on glucose. Several organic acids and amino acids were utilized as sole carbon and energy sources. The major components of its cellular fatty acids were C12:0 3-OH, C16:1, omega 9c, C16:0 and C18:1 omega 9c. The DNA G + C content was 55.7 mol%. 16S rDNA sequence analysis indicated that strain VT8T was closely related to Marinobacter sp. strain CAB (99.8% similarity) and Marinobaster hydrocarbonoclasticus (99.4% similarity). Its antibiotic resistance, isoprenoid quinones and fatty acids were similar to those of Marinobacter hydrocarbonoclasticus and Pseudomonas nautica. However, the whole-cell protein pattern of VT8T differed from that of other halophilic marine isolates, including P. nautica. DNA-DNA hybridization indicated that the level of relatedness to Marinobacter hydrocarbonoclasticus was 65% and that to P. nautica was 75%. Further differences were apparent in Fourier-transformed IR spectra of cells and lipopolysaccharide composition. It is proposed that VT8T should be the type strain of a new species and should be named Marinobacter aquaeolei. P. nautica may have been misclassified, as suggested previously, and may also belong to the genus Marinobacter.

Four petroleum-degrading bacterial strains, 2TN-NB, 6TBX-CL, MVK2-5, and XCK, were isolated from various oil-contaminated sites in Vietnam. Determination of the nucleotide sequence of the gene encoding 16S rRNA allowed 2TN-NB to be identified as Acinetobacter sp. and the other three stains as Pseudomonas sp. Among the four isolates, 2TN-NB was most effective in degrading crude oil: in 1 d, it degraded 95% of the crude oil in the culture medium (5%, v/v). The isolated strains could also degrade a sulfur-containing aromatic hydrocarbon, dibenzothiophene (DBT), with low efficiency. Except for MVK2-5, which degraded crude oil least efficiently, the isolates produced biosurfactants in amounts sufficient for structural analysis. FT-IR measurement suggested that strains 6TBX-CL and XCK produced glycolipid-type biosurfactants while that produced by 2TN-NB was of the polysaccharide type.