Browsing by Author "Saumya Khare"

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Characterization and evaluation of mycosterol secreted from endophytic strain of Gymnema sylvestre for inhibition of α-glucosidase activity
(Nature Research, 2019) Amit Ranjan; Rajesh Kumar Singh; Saumya Khare; Ruchita Tripathi; Rajesh Kumar Pandey; Anurag Kumar Singh; Vibhav Gautam; Jyoti Shankar Tripathi; Santosh Kumar Singh
Endophytic fungi produce various types of chemicals for establishment of niche within the host plant. Due to symbiotic association, they secrete pharmaceutically important bioactive compounds and enzyme inhibitors. In this research article, we have explored the potent α-glucosidse inhibitor (AGI) produced from Fusarium equiseti recovered from the leaf of Gymnema sylvestre through bioassay-guided fraction. This study investigated the biodiversity, phylogeny, antioxidant activity and α-glucosidse inhibition of endophytic fungi isolated from Gymnema sylvestre. A total of 32 isolates obtained were grouped into 16 genera, according to their morphology of colony and spores. A high biodiversity of endophytic fungi were observed in G. sylvestre with diversity indices. Endophytic fungal strain Fusarium equiseti was identified through DNA sequencing and the sequence was deposited in GenBank database (https://ncbi.nim.nih.gov) with acession number: MF403109. The characterization of potent compound was done by FTIR, LC-ESI-MS and NMR spectroscopic analysis with IUPAC name 17-(5-ethyl-6-methylheptan-2-yl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a] phenanthren-3-ol. The isolated bioactive compound showed significant α-amylase and α-glucosidase inhibition activity with IC50 values, 4.22 ± 0.0005 µg/mL and 69.72 ± 0.001 µg/mL while IC50 values of acarbose was 5.75 ± 0.007 and 55.29 ± 0.0005 µg/mL respectively. This result is higher in comparison to other previous study. The enzyme kinetics study revealed that bioactive compound was competitive inhibitor for α-amylase and α-glucosidase. In-silico study showed that bioactive compound binds to the binding site of α-amylase, similar to that of acarbose but with higher affinity. The study highlights the importance of endophytic fungi as an alternative source of AGI (α-glucosidase inhibition) to control the diabetic condition in vitro. © 2019, The Author(s).
Enzymes and Its Nano-scaffold for Remediation of Organic Matter in Wastewater: A Green Bioprocess
(Springer International Publishing, 2022) Saumya Khare; Shikha
In the past few decades, remediation and management of water resources has been a major challenge. Global increase in population and industrialization has burdened the water resources. The organic pollutants discharged in wastewater from industries and anthropogenic activities have been major driving force that causes a threat to water resources. By 2050, around 5.7 billion people are expected to have a residence in the area with water scarcity for more than a month in a year. The urge is to achieve environmental sustainability by adopting sustainable alternatives for treating and managing organic pollutants using clean and eco-friendly alternatives. Enzymatic bioremediation is a green bioprocess that provides efficient detoxification of organic waste using myriad of enzymes. In this context, chapter gives an overview of organic pollutants present in wastewater and its impact on the environment and human health. This encompasses enzymatic bioremediation strategies to detoxify organic pollutants with an attempt to highlight the role of diverse range of enzymes, and the key challenges of enzymatic bioremediation. The emerging role of nanotechnology integrated with conventional bioprocess is amalgamated to provide sustainable, green, and energy-efficient bioremediation. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.
Green synthesis, characterization and biocompatibility evaluation of silver nanoparticles using radish seeds
(Elsevier B.V., 2022) Saumya Khare; Rajesh Kumar Singh; Om Prakash
Green synthesis of silver nanoparticles has attained wider interest for biomedical applications owing to higher stability, and biocompatibility. Unlike the physico-chemical method, green synthesis of nanoparticles is an ecofriendly, economical and simple process. The present study aims to synthesize silver nanoparticles and evaluate its biocompatibility using radish (Raphanus sativus L.) seeds as reducing and stabilizing agent. The silver nanoparticles showed UV–vis absorption peak around 452 nm. The nanoparticles were thereafter characterized using X-ray diffractometer (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Energy Dispersive X-ray (EDX) analysis. The synthesized nanoparticles revealed crystalline nature, spherical shape, with size in the range of 5–20 nm and strong intense peak around 3 KeV corresponding to elemental silver. The biomolecules of seed extract enable the reduction of silver ions is revealed by specific bands in FTIR spectra. Further, blood compatibility of silver nanoparticles was ascertained using hemolysis assay which revealed non-toxic nature of AgNPs. The biocompatibility of silver nanoparticles was assessed with colon carcinoma cell line HCT-15 using cell viability assay. It showed higher cell compatibility under the safety framework. Hence, these preliminary studies suggest biocompatible properties of silver nanoparticles which is major prerequisite for its biomedical application as drug-carrier system for future cancer therapy. © 2022 The Author(s)
Immobilization of α-amylases and their analytical applications
(Springer International Publishing, 2019) Om Prakash; Saumya Khare
[No abstract available]
PR Toxin - biosynthesis, genetic regulation, toxicological potential, prevention and control measures: Overview and challenges
(Frontiers Media S.A., 2018) Manish K. Dubey; Mohd Aamir; Manish S. Kaushik; Saumya Khare; Mukesh Meena; Surendra Singh; Ram S. Upadhyay
Out of the various mycotoxigenic food and feed contaminant, the fungal species belonging to Penicillium genera, particularly Penicillium roqueforti is of great economic importance, and well known for its crucial role in the manufacturing of Roquefort and Gorgonzola cheese. The mycotoxicosis effect of this mold is due to secretion of several metabolites, of which PR toxin is of considerable importance, with regard to food quality and safety challenges issues. The food products and silages enriched with PR toxin could lead into damage to vital internal organs, gastrointestinal perturbations, carcinogenicity, immunotoxicity, necrosis, and enzyme inhibition. Moreover, it also has the significant mutagenic potential to disrupt/alter the crucial processes like DNA replication, transcription, and translation at the molecular level. The high genetic diversities in between the various strains of P. roqueforti persuaded their nominations with Protected Geographical Indication (PGI), accordingly to the cheese type, they have been employed. Recently, the biosynthetic mechanism and toxicogenetic studies unraveled the role of ari1 and prx gene clusters that cross-talk with the synthesis of other metabolites or involve other cross-regulatory pathways to negatively regulate/inhibit the other biosynthetic route targeted for production of a strain-specific metabolites. Interestingly, the chemical conversion that imparts toxic properties to PR toxin is the substitution/oxidation of functional hydroxyl group (-OH) to aldehyde group (-CHO). The rapid conversion of PR toxin to the other derivatives such as PR imine, PR amide, and PR acid, based on conditions available reflects their unstability and degradative aspects. Since the PR toxin-induced toxicity could not be eliminated safely, the assessment of dose-response and other pharmacological aspects for its safe consumption is indispensable. The present review describes the natural occurrences, diversity, biosynthesis, genetics, toxicological aspects, control and prevention strategies, and other management aspects of PR toxin with paying special attention on economic impacts with intended legislations for avoiding PR toxin contamination with respect to food security and other biosafety purposes. © 2018 Dubey, Aamir, Kaushik, Khare, Meena, Singh and Upadhyay.
Purification and Biochemical Characterization of α-Amylase from Radish (Raphanus sativus L.) Seeds Using Response surface methodology
(Springer, 2019) Saumya Khare; Om Prakash
The α-amylase from radish seeds has been purified to apparent homogeneity with specific activity of 821.66 U/mg of protein with 36 folds purification. The purified enzyme displayed single protein band on native PAGE (polyacrylamide gel electrophoresis) confirmed by activity staining. The SDS PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) revealed protein band of approximately 43 and 90 kDa. The calcium content of enzyme preparation was around 1.442 µg/mg of protein as analyzed by AAS (atomic absorption spectrophotometer). The energy of activation for enzyme was 3.82 kcal/moles with K m and V max values 4.8 mg/mL and 0.377, respectively, using starch as the substrate. The metal ions such as Ca 2+ and Mg 2+ showed augmented activity whereas Ni 2+ , Fe 2+ and Cu 2+ showed slight inhibition in the amylase activity. The thiol group reagents also activated the enzyme. Further, the effect of pH and temperature on α-amylase activity were analyzed and optimized utilizing response surface methodology. The value of regression coefficients was found significant (R 2 = 92.62%) showing the suitability of the proposed model. The multiple regression and analysis of variance showed the individual and cumulative effect of pH and temperature on the activity of enzyme with optimum pH of 6.5 and temperature of 60 °C. Additionally, contour plot, 3D surface plot and optimization plot were used to predict the effect of each variable with minimum set of experiments. © 2017, The National Academy of Sciences, India.