A significant increase in the incidence of fungal infections and drug resistance has been observed in the past decades due to limited availability of broad-spectrum antifungal drugs. Nanomedicines ...have shown significant antimicrobial potential against various drug-resistant microbes. Silver nanoparticles (AgNps) are known for their antimicrobial properties and lower host toxicity; however, for clinical applications, evaluation of their impact at cellular and molecular levels is essential. The present study aims to understand the cellular and molecular mechanisms of AgNp-induced toxicity in a common fungal pathogen,
.
AgNps were synthesized by chemical reduction method and characterized using UV-visible spectroscopy, X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence, and zeta potential. The anti-
activity of AgNps was assessed by broth microdilution and spot assays. Effects of AgNps on cellular and molecular targets were assessed by monitoring the intracellular reactive oxygen species (ROS) production in the absence and presence of natural antioxidant, changes in surface morphology, cellular ultrastructure, membrane microenvironment, membrane fluidity, membrane ergosterol, and fatty acids.
Spherical AgNps (10-30 nm) showed minimum inhibitory concentration (minimum concentration required to inhibit the growth of 90% of organisms) at 40 μg/mL. Our results demonstrated that AgNps induced dose-dependent intracellular ROS which exerted antifungal effects; however, even scavenging ROS by antioxidant could not offer protection from AgNp mediated killing. Treatment with AgNps altered surface morphology, cellular ultrastructure, membrane microenvironment, membrane fluidity, ergosterol content, and fatty acid composition, especially oleic acid.
To summarize, AgNps affected multiple cellular targets crucial for drug resistance and pathogenicity in the fungal cells. The study revealed new cellular targets of AgNps which include fatty acids like oleic acid, vital for hyphal morphogenesis (a pathogenic trait of
). Yeast to hypha transition being pivotal for virulence and biofilm formation, targeting virulence might emerge as a new paradigm for developing nano silver-based therapy for clinical applications in fungal therapeutics.
Asymmetric desymmetrization through the selective reduction of one double bond of prochiral 2,5-cyclohexadienones is highly challenging. A novel method has been developed for synthesizing chiral ...cyclohexenones by employing an ene-reductase (
Bacillus subtilis
YqjM) enzyme that belongs to the OYE family. Our strategy demonstrates high substrate scope and enantioselectivity towards substrates containing all-carbon as well as heteroatom (
O
,
N
)-containing quaternary centers. The mechanistic studies (
k
H/D
= ∼1.8) indicate that hydride transfer is probably the rate-limiting step. Mutation of several active site residues did not affect the stereochemical outcomes. This work provides a convenient way of synthesizing various enantioselective γ,γ-disubstituted cyclohexanones using enzymes.
Asymmetric desymmetrization through the selective reduction of one double bond of prochiral 2,5-cyclohexadienones is highly challenging.
•Simple, rapid, sensitive and efficient method for amino acids analysis.•Simultaneous derivatization and extraction of amino acids in single step.•In-matrix derivatization in aqueous media without ...lyophilization and pre-purification.•A total of 20 amino acids were determined in both biological and food matrices.•Both protein amino acids and free amino acids can be analyzed by using this method.
A rapid and economical method for the simultaneous determination of 20 amino acids in complex biological and food matrices (hair, urine and soybean seed samples) has been developed using ultrasound assisted dispersive liquid–liquid micro extraction (UA-DLLME). The method involves simultaneous derivatization and extraction followed by gas chromatography–mass spectrometric (GC–MS) analysis of amino acids. The parameters of UA-DLLME were optimized with the aid of design of experiments approach. The procedure involves the rapid injection of mixture of acetonitrile (disperser solvent), trichloroethylene (TCE) (extraction solvent) and ethylchloroformate (derivatization reagent) into the aqueous phase of sample extract containing pyridine. The Plackett–Burman design has indicated that, the factors such as volume of disperser and extraction solvents and pH were found to be significantly affects the extraction efficiency of the method. The optimum conditions of these factors based on central composite design were found to be 250μL of acetonitrile, 80μL of TCE and pH of 10. The limit of detection and limit of quantification were found to be in the range of 0.36–3.68μgL−1 and 1.26–12.01μgL−1 respectively. This is the first application of DLLME for the analysis of amino acids in any matrices. The advantages like (i) in situ derivatization and extraction of amino acids without any prior lyophilization and cleanup of sample, (ii) low consumption of extraction solvent, (iii) fast and simple, (iv) cost-effective and (iv) good repeatability make the method amenable for the routine analysis of amino acids in clinical, toxicological, nutritional and quality control laboratories.
Imidazoquinoline gallamide is a toll‐like receptor 7/8 agonist, belongs to the imidazoquinoline class, has the potential to activate antigen‐presenting cells, and enhances immune response, primarily ...Th1 response. The COVAXIN is a whole virion inactivated Coronavirus disease 2019 vaccine formulated with this novel adjuvant called, aluminum hydroxide gel Imidazoquinoline gallamide, wherein, Imidazoquinoline gallamide is chemisorbed onto aluminum hydroxide gel. Herein, an analytical method based on liquid chromatography‐tandem mass spectrometry was developed to identify and quantify Imidazoquinoline gallamide in aluminum hydroxide gel Imidazoquinoline gallamide and COVAXIN. The multiple reaction monitoring transitions were optimized for Imidazoquinoline gallamide quantification are M+H
+
ions with 512.24→343.19 m/z (quantifier ion) and 512.24→360.22 m/z (qualifier ion). The developed method was validated as per the international conference on harmonization quality2 revison1 guidelines. The method was linear in the range of 0.025–10 µg/mL with a coefficient of determination of 0.9985 and the limit of quantification is 0.025 µg/mL. The accuracy was in the range of 82–121 % and intra‐ and inter‐day precision was less than 7.1% and 5.39%, respectively. The expanded uncertainty results are 9.2% for Imidazoquinoline gallamide in the sample. The validated method was successfully applied to evaluate Imidazoquinoline gallamide concentration in every batch of COVAXIN.
Mangifera indica L. (mango) is said to be the king of fruits due to its rich nutritional properties and mainly originates from the Indian sub‐continent. The consumption pattern of the mangoes has ...increased drastically, due to which, many ripening practices/agents were used to make it ready‐to‐eat fruit or juice for the consumers. The fruit quality and metabolic composition are said to be altered due to different ripening agents/practices. The present communication mainly deals to understand the metabolic perturbations in mango fruits due to different ripening practices/agents (room temperature ripening, ethylene, and calcium carbide) using gas chromatography ‐ mass spectrometry based metabolomics. The partial least square‐discriminant analysis has found 16 differential metabolites for different ripening agents/practices which are belong to the classes of amino acids, fatty acids, sugars, and polyols. Four metabolic pathways were found to alter in the fruit metabolome due to different ripening agents/practices. Fructose, glucose, and galactose were found to be significantly up‐regulated due to calcium carbide ripening in comparison to other ripening agents/practices. Overall findings from the present study advocates that mass spectrometry based metabolomics can be valuable tool to understand the fruit quality and safety with respect to consumer health.
Biosynthesis of nanoparticles has gained great attention in making the process cost-effective and eco-friendly, but there are limited reports which describe the interdependency of physical parameters ...for tailoring the dimension and geometry of nanoparticles during biological synthesis. In the present study, gold nanoparticles (GNPs) of various shapes and sizes were obtained by modulating different physical parameters using Trichoderma viride filtrate. The particles were characterized on the basis of visual observation, dynamic light scattering, UV-visible spectroscopy, transmission electron microscopy, fourier transform infrared spectroscopy, and X ray diffraction. While the size varied from 2-500 nm, the shapes obtained were nanospheres, nanotriangles, nanopentagons, nanohexagons, and nanosheets. Changing the parameters such as pH, temperature, time, substrate, and culture filtrate concentration influenced the size and geometry of nanoparticles. Catalytic activity of the biosynthesized GNP was evaluated by UV-visible spectroscopy and confirmed by gas chromatography-mass spectrometric analysis for the conversion of 4-nitrophenol into 4-aminophenol which was strongly influenced by their structure and dimension. Common practices for biodegradation are traditional, expensive, require large amount of raw material, and time taking. Controlling shapes and sizes of nanoparticles could revolutionize the process of biodegradation that can remove all the hurdles in current scenario.
Vegetables are considered good food for the management of hyperglycemia. Bombax ceiba L. (family: Bombacaceae) calyces are part of traditional vegetables. This study evaluated its usefulness on ...various parameters responsible for the development of hyperglycemia and conducted phytometabolomic analysis to identify phytochemicals responsible for the observed activities. It was found that the aqueous methanol extract of its calyces (B. ceiba calyx extract, BCE) reduced (12.4%) significantly (p < 0.05) the development of sucrose‐induced postprandial hyperglycemic load in rats. In‐vitro studies revealed that BCE improved glucose‐stimulated insulin secretory activity in MIN6 cells plausibly by decreasing ADP/ATP ratio. BCE also augmented concentration‐dependent (5 µg, 10 µg, and 20 µg) increase in glucose uptake in hyperglycemic L6 myotubes both by non‐insulin‐dependent manner (35%, 68%, and 132%, respectively) and insulin‐dependent manner (42%, 59%, and 172%, respectively). The insulin‐stimulated GLUT4 translocation was compromised (34%) significantly (p < 0.05) under hyperglycemic condition; however, it was improved by 23% and 72% (p < 0.001) when L6 myotubes were primed with 10 and 20 µg of BCE, respectively. Hyperglycemia aggravated reactive oxygen species (ROS) generation in L6 myotubes. The ROS generation was significantly (p < 0.001) reduced by priming myotubes with BCE before challenging myotubes to hyperglycemic environment, possibly by preserving cellular antioxidant enzymes catalase, glutathione peroxidase, and reduced glutathione levels. Phytometabolomic analysis disclosed a number of phytochemicals present in B. ceiba calyces known to display these activities. This is the first study reporting antihyperglycemic activity in B. ceiba calyces, its mechanisms of action, and phytometabolomic profile applying UPLC‐QTof‐MS/MS technique.
Practical Application
B. ceiba calyces are part of traditional vegetables. Our study finds that B. ceiba calyces contain phytochemicals possessing antihyperglycemic, insulin secretory, insulin sensitization properties, and potentials for preserving hyperglycemia‐induced vitiations in cellular antioxidant defense. These observations provide foundation for exploring further possibilities of B. ceiba calyces to become valuable dietary inclusion in the diet of people suffering from metabolic disorders.
Paraquat (PQ) exposure causes degeneration of the dopaminergic neurons in an exposed organism while altered metabolism has a role in various neurodegenerative disorders. Therefore, the study ...presented here was conceived to depict the role of altered metabolism in PQ-induced Parkinson-like symptoms and to explore
Drosophila
as a potential model organism for such studies. Metabolic profile was generated in control and in flies that were fed PQ (5, 10, and 20 mM) in the diet for 12 and 24 h concurrent with assessment of indices of oxidative stress, dopaminergic neurodegeneration, and behavioral alteration. PQ was found to significantly alter 24 metabolites belonging to different biological pathways along with significant alterations in the above indices. In addition, PQ attenuated brain dopamine content in the exposed organism. The study demonstrates that PQ-induced alteration in the metabolites leads to oxidative stress and neurodegeneration in the exposed organism along with movement disorder, a phenotype typical of Parkinson-like symptoms. The study is relevant in the context of
Drosophila
and humans because similar alteration in the metabolic pathways has been observed in both PQ-exposed
Drosophila
and in postmortem samples of patients with Parkinsonism. Furthermore, this study provides advocacy towards the applicability of
Drosophila
as an alternate model organism for pre-screening of environmental chemicals for their neurodegenerative potential with altered metabolism.
•An integrated (nano-bio) technique is employed to degrade γ-HCH in soil.•Degradation efficiency of γ-HCH in integrated and individual systems is compared.•Synergistic effect was noticed on γ-HCH ...degradation in integrated system.•Integrated system was found 1.7–2.1 times more efficient than individual methods.•This technique could be exploited for other chlorinated pesticides as well.
We have evaluated the effect of an integrated (nano-bio) technique involving the use of stabilized Pd/Fe0 bimetallic nanoparticles (CMC-Pd/nFe0) and a Sphingomonas sp. strain NM05, on the degradation of γ-HCH in soil. Factors affecting degradation such as pH, incubation temperature and γ-HCH initial concentration were also studied. The results revealed that γ-HCH degradation efficiency is ~ 1.7–2.1 times greater in integrated system as compared to system containing either NM05 or CMC-Pd/nFe0 alone. The integration showed synergistic effect on γ-HCH degradation. Further, cell growth studies indicated that NM05 gets well acclimatized to nanoparticles, showing potential growth in the presence of CMC-Pd/nFe0 with respect to control system. This study signifies the potential efficacy of integrated technique to become an effective alternative remedial tool for γ-HCH contaminated soil. Further research in this direction could lead to the development of effective remediation strategies for other isomers of HCH and other chlorinated pesticides as well.
•A Rhodococus sp. able to degrade DDT and chlorobenzoate was isolated.•DDE, DDD and DDMU were identified as metabolites of DDT by the bacterium.•The bacterium possessed catechol 1,2-dioxygenase to ...form lower intermediates.•Trehalolipid was identified as the surfactant produced by the Rhodococus sp.
A 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) degrading bacterium strain IITR03 producing trehalolipid was isolated and characterized from a pesticides contaminated soil. The strain IITR03 was identified as a member of the genus Rhodococcus based on polyphasic studies. Under aqueous culture conditions, the strain IITR03 degraded 282μM of DDT and could also utilize 10mM concentration each of 4-chlorobenzoic acid, 3-chlorobenzoic acid and benzoic acid as sole carbon and energy source. The catechol 1,2-dioxygenase enzyme activity resulted in conversion of catechol to form cis,cis-muconic acid. Cloning and sequencing of partial nucleotide sequence of catechol 1,2-dioxygenase gene (cat) from strain IITR03 revealed its similarity to catA gene present in Rhodococcus sp. strain Lin-2 (97% identity) and Rhodococcus strain AN22 (96% identity) degrading benzoate and aniline, respectively. The results suggest that the strain IITR03 could be useful for field bioremediation studies of DDT-residues and chlorinated aromatic compounds present in contaminated sites.
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