Browsing by Author "Rajnish Bharti"

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Advances in extraction technologies: Isolation and purification of bioactive compounds from biological materials
(Elsevier, 2020) Nishi Srivastava; Arti Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Monika Yadav; Rajnish Bharti; Dharmendra Kumar; Ravindra N. Kharwar
Natural bioactive compounds (NBCs) are receiving more popularity because of their various medicinal properties and huge exploitation in various commercial sectors such as food, chemical, and pharmaceutical industries. The extraction of NBCs begins with the selection of a suitable protocol, sample preparation, and extensive literature survey. During the extraction of NBCs from biological materials, the major concern of researchers is on minimizing the interference of unwanted compounds that may coextract with the focused compounds. Numerous extraction procedures have been introduced along with existing classical extraction methodology (conventional extraction methodology), but still, scientists are in search of the development of a standard single method for extracting NBCs from biological materials. There are several critical parameters such as understanding the nature of the plant matrix and chemistry of bioactive compounds and scientific expertise that impact efficiencies of conventional and nonconventional extraction. This chapter focuses on the mechanism of different extraction techniques, extraction instrumentation, and common problems encountered and their elimination. For efficient extraction of NBCs from biological materials, there is an urgent need for advancement in selective extraction procedures, from extraction to fractionation and subsequent purification that will speed up and scale up the isolation of purified compounds from biological materials. © 2021 Elsevier Inc.
Colletotrichum gloeosporioides (endophytic fungi) mediated biosynthesis of TiO2 nanoparticles for high-performance dye-sensitized solar cell
(Elsevier B.V., 2025) Sakshi Singh; Shubham Sharma; Rajnish Bharti; Ravindra Nath Kharwar; Pankaj Kumar Srivastava
This work reports an environmentally friendly protocol for synthesizing TiO2 nanoparticles (NPs) by utilizing endophytic fungi, Colletotrichum gloeosporioides (C. gloeosporioides). The fungi isolated from Thevetia peruviana, worked as a bio-capping agent to regulate the growing TiO2 NPs morphology and agglomeration behavior. The formation of TiO2 NPs was validated by surface plasmon resonance, observed using UV–vis spectroscopy. Using XRD and HRTEM, the structure, size, and shape of the as-synthesized anatase TiO2 NPs were characterized. BET analysis was used to examine the surface area and porosity. EIS revealed the greater charge collection efficiency and enhanced electron lifetime for the TiO2 obtained with N-3 (endophytic fungal extract). The dye-sensitized solar cell (DSSC) fabricated with bio-capped TiO2 (N-3) photoanode exhibited greater light-to-current conversion efficiency, 3.50 %; much enhanced compared to 0.98 % obtained with un-capped TiO2 NPs (N-1) based cell. The study demonstrated that the endophytic fungus C.gloeosporioides played a vital role in enhancing the cell performance. © 2024 The Authors
Effect of the Histone Methyltransferase Specific Probe BRD4770 on Metabolic Profiling of the Endophytic Fungus Diaporthe longicolla
(Frontiers Media S.A., 2021) Jay Hind Nishad; Arti Singh; Rajnish Bharti; Priyanka Prajapati; Vijay Kumar Sharma; Vijai Kumar Gupta; Ravindra Nath Kharwar
The endophytic fungus Diaporthe longicolla was isolated from the stem of Saraca asoca (Roxb.) Willd., commonly known as Ashok plant in India and Sri Lanka. Since no reports are available regarding epigenetic modulations by BRD4770 in microbial entities, D. longicolla was treated with different concentrations of BRD4770 for this purpose and evaluated for its antioxidant and antibacterial potential against five human pathogenic bacteria, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Shigella boydii, Klebsiella pneumoniae, and Escherichia coli. The crude extract obtained from cultures treated with 100 nM concentration of BRD4770 showed increased antioxidant activity and inhibition zone against S. aureus and MRSA, compared to the non-treated control. The composition of the non-treated and treated crude extract was analyzed, and induced compounds were identified with the help of Gas chromatography–mass spectrometry (GC-MS) and LC-ESI-MS/MS. LC-ESI-MS/MS analysis showed that berberine (antibacterial)-, caffeine-, and theobromine (antioxidant)-like compounds were induced in the BRD4770-treated crude extract. The presence of particular absorbance at a wavelength of 346.5 nm for berberine, 259.4 nm for caffeine, and 278.4 nm for theobromine in the reverse-phase high-performance liquid chromatography (HPLC) analysis of both BRD4770-treated crude metabolites and standard solution of the above compounds strongly supported the increased antibacterial and antioxidant activities that may be due to inducing the alterations in bioactivities of the BRD4770-treated culture. © Copyright © 2021 Nishad, Singh, Bharti, Prajapati, Sharma, Gupta and Kharwar.
Evaluation of Congo red dye decolorization and degradation potential of an endophyte Colletotrichum gloeosporioides isolated from Thevetia peruviana (Pers.) K. Schum.
(Springer Science and Business Media B.V., 2023) Rajnish Bharti; Monika Yadav; Arti Singh; Puja Kumari; Jay Hind Nishad; Veer Singh Gautam; Ravindra Nath Kharwar
Decolorization and degradation of textile dye by endophytic fungi stand to be a profitable and viable alternative over conventional methods with respect to eco-friendliness, cost-effectiveness, and non-hazardous nature. One of the active fungal endophytes Colletotrichum gloeosporioides isolated from plant Thevetia peruviana (Pers.) K. Schum. was screened for laccase production and Congo red dye decolorization. Various physicochemical parameters like dye concentration, carbon sources, nitrogen sources, temperature, and pH were optimized, and the maximum decolorization (%) was achieved at 100 mg/L of dye concentration (82%), yeast extract (80%), 30 °C temp (80%), glucose (79%), and 7 pH (78%), respectively. SEM image and fungal biomass changes represent that fungus actively participated in the dye decolorization and had less significant effect on biomass. The regenerative ability of fungus C. gloeosporioides after dye decolorization indicated tolerance against the dye and was found to be more advantageous over previous reports of dye decolorization by other endophytic fungi. UV-Vis spectra, TLC, FTIR, and HPLC results confirmed the decolorization and degradation process due to absorption and biodegradation. Phytotoxicity assay depicted that degraded products are less toxic to Phaseolus mungo compared to Congo red. The overall findings showed that C. gloeosporioides possesses a good decolorization and degradation potential against Congo red and this endophyte can be profitably used for dye-containing wastewater treatment. © 2022, Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.
Metabolites Profiling, Bioactivity Assessment and Extracellular Enzymes Estimation of Pestalotiopsis sp. L12, an Endophytic Fungus Recovered from Saraca asoca (Roxb.) Willd. Leaves
(Pleiades Publishing, 2025) Jay Hind Nishad; Shubham Vishwakarma; Anil Kumar Singh; Mahendra Yadav; Rajnish Bharti; Ravindra Nath Kharwar
Abstract: The medicinal plant Saraca asoca harbors an endophytic fungal strain, which was identified as Pestalotiopsis sp. L12 by morphological and molecular analyses. It exhibited maximum amylase and cellulase production at 28°C after 72 h, releasing 41.66 µg of maltose and 35.66 µg of glucose. The crude extracts of isolate L12 showed antibacterial activity against such important pathogens as K. pneumoniae, S. aureus, and E. coli in addition to antioxidant properties. The effective concentration (EC50) of the crude extract for antioxidant activity against ABTS+ radical was 64 µg/mL. Furthermore, the GC-MS and HPLC-ESI-MS/MS analyses of the crude extracts identified six and seven compounds, respectively. Notably, one of the compounds, 6,9-dimethyltetradecan, is known for its antibacterial and antioxidant properties. Oleic acid and theophylline identified through mass fragmentation in HPLC-ESI-MS/MS analysis have also been well-recognized for antibacterial and antioxidant activities. © Pleiades Publishing, Ltd. 2025.
Phenolic and flavonoid contents and antioxidant activity of an endophytic fungus Nigrospora sphaerica (EHL2), inhabiting the medicinal plant Euphorbia hirta (dudhi) L.
(Springer Science and Business Media Deutschland GmbH, 2022) Veer Singh Gautam; Arti Singh; Puja Kumari; Jay Hind Nishad; Jitendra Kumar; Monika Yadav; Rajnish Bharti; Priyanka Prajapati; Ravindra Nath Kharwar
Since endophytic fungi are pivotal sources of various bioactive natural compounds, the present study is aimed to investigate the antioxidant compounds of the endophytic fungus Nigrospora sphaerica isolated from a pantropical weed, Euphorbia hirta L. The fungus was fermented in four different media and each filtered broth was sequentially extracted in various solvents. Crude extracts collected from different solvents were subjected to phytochemical analysis and antioxidant activity. The total phenolic content (TPC) and total flavonoid content (TFC) were maximal in ethyl acetate crude extract (EtOAcE) of endophyte fermented in potato dextrose broth (PDB) medium (77.74 ± 0.046mgGAE/g and 230.59 ± 2.0 mgRE/g) with the highest 96.80% antioxidant activity. However, TPC and TFC were absent in hexane extract of Czapek Dox broth (CDB) medium exhibiting the lowest 4.63 ± 2.75% activity. The EtOAcE (PDB) showed a positive correlation between TFC and antiradical activity (R2 = 0.762; P < 0.05), whereas a high positive correlation was noticed between TPC and antioxidant activity (R2 = 0.989; P < 0.05). Furthermore, to determine the antioxidant activity, EtOAcE (PDB) was subjected to TLC bioautography-based partial purification, while GC/MS analysis of the partial purified extract was done to confirm the presence of phenolics along with antioxidant compounds that resulted in the detection of 2,4-Di-tert-butylphenol (13.83%), a phenolic compound accountable for the antioxidant potential. Conclusively, N. sphaerica is a potential candidate for natural antioxidant. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.