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The rapid proliferation of antibiotic-resistant microbes has imposed an urgent need for development of novel antimicrobial agents with diverse mechanisms. This study reports a novel extraction method with salting-in and salting-out method for obtaining potential bacteriocin from Bacillus subtilis (MK733983) of ethnomedicinal origin. This technique extracted bacteriocin with desired antimicrobial peptide moieties that showed creditable minimum inhibitory concentrations, thermostability and efficacy compared to all other extraction protocols attempted. Further study used a unique scheme of steps in RP-HPLC purification process using methanol-water as solvents for the bacteriocin that achieved an outstanding antimicrobial activity against Staphylococcus aureus (MTCC 737). The bacteriocin is sensitive to proteases, confirming its proteinaceous nature and showed promising heat stability up to 70 °C for 10 min. Bacteriocin extracted from a series of ammonium sulphate precipitation showed MIC values 350 µg and 300 µg for Mycobacterium smegmatis and Staphylococcus aureus respectively. On the other hand, bacteriocin extracted by using chloroform showed MIC values 400 µg and 300 µg for M. smegmatis and Staphylococcus aureus. All the results implicate the efficacy of bacteriocin and future prospect as an effective antimicrobial agent.

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In this study, the anti-biofilm compound of 2,6-Di-tert-butyl, 1,4-benzoquinone was purified from Nocardiopsis synnemataformans (N. synnemataformans) RMN 4 (MN061002). To confirm the compound, various spectroscopy analyses were done including ultraviolet (UV) spectrometer, Fourier transform infrared spectroscopy (FTIR), analytical high-performance liquid chromatography (HPLC), preparative HPLC, gas chromatography-mass spectroscopy (GC-MS), liquid chromatography-mass spectroscopy (LC-MS), and 2D nuclear magnetic resonance (NMR). Furthermore, the purified compound was shown 94% inhibition against biofilm-producing Proteus mirabilis (P. mirabilis) (MN396686) at 70 µg/mL concentrations. Furthermore, the metabolic activity, exopolysaccharide damage, and hydrophobicity degradation results of identified compound exhibited excellent inhibition at 100 µg/mL concentration. Furthermore, the confocal laser scanning electron microscope (CLSM) and scanning electron microscope (SEM) results were shown with intracellular damages and architectural changes in bacteria. Consecutively, the in vivo toxicity effect of the compound against Artemia franciscana (A. franciscana) was shown to have a low mortality rate at 100 µg/mL. Finally, the molecular docking interaction between the quorum sensing (QS) genes and identified compound clearly suggested that the identified compound 2,6-Di-tert-butyl, 1,4-benzoquinone has anti-quorum sensing and anti-biofilm activities against P. mirabilis (MN396686).

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Gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) can be used to detect the synthetic forms of endogenous anabolic androgenic steroids (EAAS) by comparing the 13C/12C ratios of the endogenous reference compound to that of the target compound. Isolation and enrichment of the target compound from urinary matrices is an essential prerequisite for the GC/C/IRMS confirmation procedure in doping control analysis. Boldenone (Bo) is a natural anabolic androgenic steroid (AAS) and a derivative of testosterone. The GC/C/IRMS confirmation procedure for Bo and its main metabolite 5ß-androst-1-en-17ß-ol-3-one (BoM) is extremely complicated due to the low concentrations and the enormously complex matrices in urine. The present study demonstrated a sample purification procedure for GC/C/IRMS by using online 2D-HPLC to purify Bo and BoM in urine samples. Bo and BoM with concentrations as low as 2 ng/mL were isolated and enriched with superior purity and selectivity. The validity of the method was verified with the technical document issued by the world anti-doping agency. The online 2D-HPLC purification procedure featured high selectivity for the analytes and no isotopic fractionation in the collection process. The present method can be used as a routine method allowing doping control laboratories to perform Boldenone confirmation.

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Objective: Based on the Tracerlab FXF-N platform, a synthesis program and preparative high-performance liquid chromatography (HPLC) purification program edited by us can stably and repeatedly produce [18F] AV-45 without changing the process. The [18F] AV-45 produced meets the main indexes of radiopharmaceutical intravenous preparations. Methods: The O-toluene sulfonated precursor (1 mg) was subjected to nucleophilic radiofluorination at 115°C in anhydrous dimethyl sulfoxide (DMSO), then the protective group was hydrolyzed by acid. The neutralized reaction mixture was purified through a preparative HPLC then formulated for injection using a C18 purification cartridge. This method yielded a relatively pure [18F] AV-45 product with high specific activity. Results: Four consecutive radiochemical synthesis operations were carried out in this experiment; the average production time of [18F] AV-45 preparation was 60 min, the radiochemical yield was 14.8 ± 2.1% (n = 4), the radiochemical purity was greater than 95%, and the other important quality control indexes met the requirements of radioactive drugs for intravenous administration. Conclusion: This experiment was based on the Tracerlab FXF-N platform with the synthesis program and preparative HPLC purification program edited by us. Through screening and optimization of the separation and purification system and the separation and analysis system, as well as automatic radiochemical synthesis and preparation quality control, intravenous [18F] AV-45 was successfully prepared.