Influence of some synthesized pyrimidine derivatives on corrosion inhibition of mild steel in hydrochloric acid medium

The influence of four newly synthesized pyrimidine derivatives on the corrosion inhibition of mild steel in 0.5 M HCl solution is studied using mass loss and electrochemical techniques. The corrosion rate was found to depend on concentration and temperature of the medium. Adsorption of all the four inhibitors obeys Langmuir isotherm model. Polarization curves indicated that the studied inhibitors are of mixed type. Electrochemical impedance spectroscopy explains the mechanism of inhibitor’s action. Various activation and adsorption thermodynamic parameters were calculated and discussed. The results obtained from weight loss and electrochemical studies are in good agreement with each other. The variation in inhibitive efficiency mainly depends on the type and nature of the substituents present in the inhibitor molecule

Phylogenetic tree derived from NJ analysis showing the evolutionary relationship of <i>Emericella variecolor</i> CLB38 with its closest BLAST hits.

<p>Bootstrap values (1000 replications) based on multiple sequence alignment using the MEGA-5 software. Asterisk indicates the isolate obtained in this study.</p

Application of Bioassay-Guided Fractionation Coupled with a Molecular Approach for the Dereplication of Antimicrobial Metabolites

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.A systematically delineated dereplication approach was described based on genome mining and bioassay-guided fractionation using endophytic fungus Xylaria psidii FPL-52(S) isolated from leaves of Ficus pumila Linn., (Moraceae). A polyketide synthase gene-based molecular screening strategy by a degenerate oligonucleotide primer polymerase chain reaction technique coupled with a bioinformatic phylogenomic approach revealed the presence of an iterative polyketide synthase gene within the genome of Xylaria psidii FPL-52(S). Chemical dereplication of ethyl acetate extract derived from a submerged fermentation culture broth of Xylaria psidii FPL-52(S) by bioassay-guided chromatographic and hyphenated analytical spectroscopic techniques led to the identification of polyketide mycoalexin 3-O-methylmellein. Antimicrobial profiling and minimal inhibitory concentration values for 3-O-methylmellein were determined by disc diffusion and microbroth dilution techniques. Gram-positive bacteria, dermatophytic and phytopathogenic fungi were susceptible in terms of inhibition zone and minimum inhibitory concentration values when compared to co-assayed standards. Herein, we highlight and demonstrate an improved approach which facilitates efficient dereplication and effect-guided fractionation of antimicrobial metabolite(s). The present work flow serves as a promising dereplication tool to survey the biosynthetic potential of endophytic fungal diversity, thereby identifying the most promising strains and prioritizing them for novel polyketide-derived antimicrobial metabolite discovery

PCR amplification of rDNA from <i>Emericella variecolor</i> CLB38 using ITS1 and ITS4 universal primers.

<p>Lane: M—100 bp DNA ladder; CLB38 –~575 bp amplicon representing ITS region of rDNA; C–control.</p

Minimum inhibitory concentration (MIC in μg/ml) of purified compound Emerimidine A from endosymbiotic <i>E</i>. <i>variecolor</i> CLB38 against test microorganisms.

<p>Minimum inhibitory concentration (MIC in μg/ml) of purified compound Emerimidine A from endosymbiotic <i>E</i>. <i>variecolor</i> CLB38 against test microorganisms.</p

Application of Bioassay-Guided Fractionation Coupled with a Molecular Approach for the Dereplication of Antimicrobial Metabolites

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.A systematically delineated dereplication approach was described based on genome mining and bioassay-guided fractionation using endophytic fungus Xylaria psidii FPL-52(S) isolated from leaves of Ficus pumila Linn., (Moraceae). A polyketide synthase gene-based molecular screening strategy by a degenerate oligonucleotide primer polymerase chain reaction technique coupled with a bioinformatic phylogenomic approach revealed the presence of an iterative polyketide synthase gene within the genome of Xylaria psidii FPL-52(S). Chemical dereplication of ethyl acetate extract derived from a submerged fermentation culture broth of Xylaria psidii FPL-52(S) by bioassay-guided chromatographic and hyphenated analytical spectroscopic techniques led to the identification of polyketide mycoalexin 3-O-methylmellein. Antimicrobial profiling and minimal inhibitory concentration values for 3-O-methylmellein were determined by disc diffusion and microbroth dilution techniques. Gram-positive bacteria, dermatophytic and phytopathogenic fungi were susceptible in terms of inhibition zone and minimum inhibitory concentration values when compared to co-assayed standards. Herein, we highlight and demonstrate an improved approach which facilitates efficient dereplication and effect-guided fractionation of antimicrobial metabolite(s). The present work flow serves as a promising dereplication tool to survey the biosynthetic potential of endophytic fungal diversity, thereby identifying the most promising strains and prioritizing them for novel polyketide-derived antimicrobial metabolite discovery

Bioactivity-guided isolation of antimicrobial metabolite from Xylaria sp.

Symbiotic plant-microbe metabolic interactions not only have beneficial effects on plants but also contribute to rich, unmatched and complex chemical biodiversity with biological potential. Systematic delineated bioprospecting of fungal diversity associated with Ficus pumila Linn (Moraceae) for antimicrobial metabolite revealed Xylaria sp. FPL-25(M). The present study describes bioactivity guided fractionation prioritized for antimicrobial potential. Thus, chemical investigation of culture broth of Xylaria sp. FPL-25(M) by bioactivity guided fractionation with spectroscopic techniques revealed bioactive metabolite xylobovide-9-methyl ester. The xylobovide-9-methyl ester exhibited broad-spectrum antimicrobial activity. However, Gram-positive bacteria and fungi were more susceptible than Gram-negative bacteria. The present study results represent bioassay-based screening strategy which facilitates rapid, efficient and reliable approach for endophytic strain prioritization for novel bioactive molecules

Determination of antimicrobial activity of ethyl acetate fraction of endosymbiotic <i>Emericella variecolor</i> CLB38 (100 μg/disc) against test microorganisms.

<p>Determination of antimicrobial activity of ethyl acetate fraction of endosymbiotic <i>Emericella variecolor</i> CLB38 (100 μg/disc) against test microorganisms.</p

Nano-Zirconium Dioxide Catalyzed Multicomponent Synthesis of Bioactive Pyranopyrazoles That Target Cyclin Dependent Kinase 1 in Human Breast Cancer Cells

Small molecules are being used to inhibit cyclin dependent kinase (CDK) enzymes in cancer treatment. There is evidence that CDK is a drug-target for cancer therapy across many tumor types because it catalyzes the transfer of the terminal phosphate of ATP to a protein that acts as a substrate. Herein, the identification of pyranopyrazoles that were CDK inhibitors was attempted, whose synthesis was catalyzed by nano-zirconium dioxide via multicomponent reaction. Additionally, we performed an in-situ analysis of the intermediates of multicomponent reactions, for the first-time, which revealed that nano-zirconium dioxide stimulated the reaction, as estimated by Gibbs free energy calculations of spontaneity. Functionally, the novel pyranopyrazoles were tested for a loss of cell viability using human breast cancer cells (MCF-7). It was observed that compounds 5b and 5f effectively produced loss of viability of MCF-7 cells with IC50 values of 17.83 and 23.79 µM, respectively. In vitro and in silico mode-of-action studies showed that pyranopyrazoles target CDK1 in human breast cancer cells, with lead compounds 5b and 5f having potent IC50 values of 960 nM and 7.16 μM, respectively. Hence, the newly synthesized bioactive pyranopyrazoles could serve as better structures to develop CDK1 inhibitors against human breast cancer cells