Browsing by Author "Santosh Kumar Singh"

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Advancements in Modeling-Based Therapeutics and Technology for Chronic Diseases
(Elsevier, 2025) Sachchida Nand Rai; Santosh Kumar Singh; Veer Singh
Advancements in Modeling-Based Therapeutics and Technology for Chronic Diseases delves into the crucial role of animal and cellular models in comprehending the intricate mechanisms of chronic diseases. The book emphasizes the importance of these models in predicting disease progression, testing new therapeutic approaches, and understanding how environmental and genetic factors interplay in the development of long-term health conditions. With a multidisciplinary approach, it bridges the gap between experimental research and clinical applications, offering insights into not only disease management but also the future of personalized medicine. The book also sheds light on emerging technologies, including bioinformatics tools and in silico modeling, which further enhance our ability to tackle chronic diseases. It explores how these advancements are transforming research methodologies and providing novel solutions for diagnosis and treatment. Additionally, it highlights collaborative strategies between researchers, clinicians, and technologists, stressing the importance of integrated efforts in addressing global health challenges effectively. © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
An Update of Fungal Endophyte Diversity and Strategies for Augmenting Therapeutic Potential of their Potent Metabolites: Recent Advancement
(Springer, 2025) Chandrabhan Prajapati; Sachchida Nand Rai; Anurag Kumar Singh; Balu Ananda Chopade; Yashveer Singh; Santosh Kumar Singh; Shafiul Haque; Miguel A. Prieto; Ghulam Md Ashraf
Endophytic fungi represent a significant renewable resource for the discovery of pharmaceutically important compounds, offering substantial potential for new drug development. Their ability to address the growing issue of drug resistance has drawn attention from researchers seeking novel, nature-derived lead molecules that can be produced on a large scale to meet global demand. Recent advancements in genomics, metabolomics, bioinformatics, and improved cultivation techniques have significantly aided the identification and characterization of fungal endophytes and their metabolites. Current estimates suggest there are approximately 1.20 million fungal endophytes globally, yet only around 16% (190,000) have been identified and studied in detail. This underscores the vast untapped potential of fungal endophytes in pharmaceutical research. Research has increasingly focused on the transformation of bioactive compounds by fungal endophytes through chemical and enzymatic processes. A notable example is the anthraquinone derivative 6-O-methylalaternin, whose cytotoxic potential is enhanced by the addition of a hydroxyl group, sharing structural similarities with its parent compound macrosporin. These structure-bioactivity studies open up new avenues for developing safer and more effective therapeutic agents by synthesizing targeted derivatives. Despite the immense promise, challenges remain, particularly in the large-scale cultivation of fungal endophytes and in understanding the complexities of their biosynthetic pathways. Additionally, the genetic manipulation of endophytes for optimized metabolite production is still in its infancy. Future research should aim to overcome these limitations by focusing on more efficient cultivation methods and deeper exploration of fungal endophytes’ genetic and metabolic capabilities to fully harness their therapeutic potential. © The Author(s) 2025.
Analysis and control of enhanced switched boost inverters for wide duty cycle operation
(Institute of Electrical and Electronics Engineers Inc., 2019) Avneet Kumar; M. Raghuram; Santosh Kumar Singh; Xiaogang Xiong; Motiur Reza
Switched boost inverter (SBI) is a high gain converter that uses the concept of Z-source inverter but with a reduced number of passive elements. The analysis and operation of SBI are already reported for continuous and discontinuous input current but these converters operate in the restricted range of duty cycle and load variation. In a certain duty cycle situation, the converter shows inadvertent behavior and the inductor current tends to become equal to the AC load current. This phenomenon creates a ripple in dc link voltage which causes increased THD at the output AC voltage. Moreover, the DC link capacitor undergoes higher voltage stress. In this paper, the duration for which this peculiar phenomenon lasts is termed as non-zero discontinuous current mode (NZ-DCM) of operation. The analytical expression during NZ-DCM is derived and analyzed in terms of peak to peak ripple inductor current. To overcome NZ-DCM, the authors propose a modified SBI which consists of an extra active switch antiparallel across the diode. The simulation and experimental results pertaining to the adverse effect of NZ-DCM and its mitigation in the form of the conventional and modified SBI are presented in this paper. © 2013 IEEE.
Antibacterial Activity of Extract of Endophytic Fungi of Gymnema sylvestre
(Springer India, 2016) Amit Ranjan; Jyoti Shankar Tripathi; Santosh Kumar Singh
Endophytic fungi were isolated from Gymnema sylvestre, a known medicinal plant for hypoglycemic activity. Isolated endophytes were screened for their antibacterial activity against an array of pathogenic bacteria. The systemic study was made on endophytic fungi of medicinal plant, G. sylvestre growing in different natural habitats of India. A total of 25 fungal isolates were recovered from different parts of G. sylvestre and they were grouped in 11 fungal genera. Potato dextrose agar medium yielded the highest number of isolates with the greatest species richness. The fungi were identified as Fusarium sp., Alternaria sp., Phomopsis sp., Pestalotia sp., Xylaria sp., Phyllosticta sp., Gleomastix sp., Acrimonium sp., Aspergillus sp., Cladosporium sp. and Scytalidium sp. The secret of this medicinal plant was revealed by the evaluation of the extract of its endophytic fungi having antibacterial activity. Traditionally this plant is being used since long in diabetic treatment, however it is also effective against the infection. The extracts of five fungal isolates among 25 isolates were found effective inhibitors against human pathogenic bacterial strains Escherichia coli (ATCC 25922) a gram negative and Staphylococcus aureus (ATCC 25323) a gram positive bacteria. © 2014, The National Academy of Sciences, India.
Antibacterial activity of seed extracts of Argemone mexicana L. on some pathogenic bacterial strains
(2009) Santosh Kumar Singh; Vidya Dhar Pandey; Aradhana Singh; Chandan Singh
Antibacterial activity of seed extracts of Argemone mexicana L. (Papaveraceae) was evaluated against some pathogenic bacterial strains. Chloroform extract of seeds exhibited varying level of antibacterial activity, with minimum inhibitory concentrations (MIC) of 2.0 - 5.0 mg/ml, against both Gram-positive and Gram-negative bacteria. The chloroform extract was found to be more active than the other extracts against all the test bacteria. MIC values were 2.0 and 3.0 mg/ml, respectively, for Staphylococcus aureus and Pseudomonas aeruginosa and their respective drug-resistant strains. The sensitivity of the test bacteria varied with the species and strains. The study provides basis for the isolation and purification of antibacterial compound(s) from the seeds of A. mexicana L. © 2009 Academic Journals.
Assessment of Biological Activities of Fungal Endophytes Derived Bioactive Compounds Isolated from Amoora rohituka
(MDPI, 2022) Ashish Verma; Priyamvada Gupta; Nilesh Rai; Rajan Kumar Tiwari; Ajay Kumar; Prafull Salvi; Swapnil C. Kamble; Santosh Kumar Singh; Vibhav Gautam
Fungal endophytes have remarkable potential to produce bioactive compounds with numerous pharmacological significance that are used in various disease management and human welfare. In the current study, a total of eight fungal endophytes were isolated from the leaf tissue of Amoora rohituka, and out of which ethyl acetate (EA) extract of Penicillium oxalicum was found to exhibit potential antioxidant activity against DPPH, nitric oxide, superoxide anion and hydroxyl free radicals with EC50 values of 178.30 ± 1.446, 75.79 ± 0.692, 169.28 ± 0.402 and 126.12 ± 0.636 µg/mL, respectively. The significant antioxidant activity of EA extract of P. oxalicum is validated through highest phenolic and flavonoid content, and the presence of unique bioactive components observed through high-performance thin layer chromatography (HPTLC) fingerprinting. Moreover, EA extract of P. oxalicum also displayed substantial anti-proliferative activity with IC50 values of 56.81 ± 0.617, 37.24 ± 1.26 and 260.627 ± 5.415 µg/mL against three cancer cells HuT-78, MDA-MB-231 and MCF-7, respectively. Furthermore, comparative HPTLC fingerprint analysis and antioxidant activity of P. oxalicum revealed that fungal endophyte P. oxalicum produces bioactive compounds in a host-dependent manner. Therefore, the present study signifies that fungal endophyte P. oxalicum associated with the leaf of A. rohituka could be a potential source of bioactive compounds with antioxidant and anticancer activity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Beyond the synthetic drugs: Fungal endophytes derived bioactive compounds in the management of neurodegenerative disorders
(Bentham Science Publishers, 2023) Ashish Verma; Nilesh Rai; Swapnil C. Kamble; Pradeep Mishra; Suvakanta Barik; Rajiv Kumar; Santosh Kumar Singh; Prafull Salvi; Vibhav Gautam
Fungal endophytes are a group of fungi that reside in plant tissues and show a symbiotic relationship with the host plants. They protect against pathogens and increase food availability without causing any harmful effects on the host plant. Fungal endophytes are known to produce a wide range of bioactive compounds with several biological activities, including neuroprotective effects. Neurodegenerative disorders lead to miscommunication between nerve cells, damage or loss in structure and function of the central nervous system (CNS) or peripheral nervous system (PNS). Reactive oxygen species, neuroinflammation, protein degradation or aggregation, familial history, mutation in mitochondrial genes, and aging contribute to neurodegenerative disorders. Plant-associated fungal endophytes produce bioactive compounds, which show anti-neuroinflammatory, antioxidant, and anti-cholinesterase activities. Several pro-inflammatory (TNF-α and NF-κB) and depressant (serotonin, dopamine, and noradrenaline) molecules or neuronal signaling pathways leading to neurodegenerative disorders are known to be inhibited or down-regulated by fungal endophyte-derived bioactive compounds. Therefore, bioactive compounds produced from fungal endophytes could be a promising approach to treating various health ailments. The present chapter discusses selected fungal endophyte-derived potential bioactive compounds with neuroprotective effects for managing neurodegenerative disorders. © 2023 Bentham Science Publishers. All rights reserved.
Biological potential of bioactive metabolites derived from fungal endophytes associated with medicinal plants
(Springer Science and Business Media Deutschland GmbH, 2021) Priyanka Kumari Keshri; Nilesh Rai; Ashish Verma; Swapnil C. Kamble; Suvakanta Barik; Pradeep Mishra; Santosh Kumar Singh; Prafull Salvi; Vibhav Gautam
Endophytes are endosymbiotic fungi or bacteria that invade and colonize the plant tissue without harming their respective host. Since fungal endophytes live inside the host tissues, their effective isolation and identification is an important step. Endophytic fungi produce bioactive metabolites with unique chemical structures, which may help in improving the physiological condition of both the plants and endophytes. Endophytic fungi are a potent source of all major classes of secondary metabolites including terpenoids, non-ribosomal peptides, polyketides, and alkaloids. With the increase in the number of diseases and human health problems, an intensive search for new sources and effective metabolites is now in progress. The bioactive metabolites produced by the fungal endophytes are competent and effective against various diseases such as cancer, diabetes, infectious diseases, immunological disorders, and cardiovascular diseases. The present review summarizes the efficient approaches used for the screening of fungal endophytes, extraction, and purification of bioactive metabolites along with OMICS based study of endophytes. Along with this, the pharmaceutical importance of novel bioactive metabolites and their efficient production from fungal endophytes using various approaches like genetic engineering, use of elicitors, and precursor feeding are also discussed. © 2021, German Mycological Society and Springer-Verlag GmbH Germany, part of Springer Nature.
Bioprospecting of fungal endophytes from Oroxylum indicum (L.) Kurz with antioxidant and cytotoxic activity
(Public Library of Science, 2022) Nilesh Rai; Priyanka Kumari Keshri; Priyamvada Gupta; Ashish Verma; Swapnil C. Kamble; Santosh Kumar Singh; Vibhav Gautam
Oroxylum indicum (L.) Kurz, a medicinal plant, shows numerous pharmacological properties which may be attributed to the bioactive compounds produced by O. indicum or due to associated endophytes. In the present study, leaf of O. indicum was evaluated for the presence of associated fungal endophytes, and antioxidant and cytotoxic activities of bioactive compounds produced from them. Using culture-dependent approach, eight fungal endophytes belonging to five different genera were identified. Two endophytes Daldinia eschscholtzii and Ectophoma multirostrata have been reported for the first time from the leaf of O. indicum plant. High-performance thin-layer chromatography (HPTLC) of ethyl acetate (EA) extract of isolated fungal endophytes showed a distinct fingerprinting profile in EA extract of Colletotrichum gloeosporioides. Among identified endophytes, EA extract of C. gloeosporioides showed significant antioxidant activity against DPPH free radical, superoxide anion radical, nitric oxide radical and hydroxyl radical with EC50 values of 22.24±1.302 μg/mL, 67.46 ±0.576 μg/mL, 80.10±0.706 μg/mL and 61.55±1.360 μg/mL, respectively. EA extract of C. gloeosporioides exhibited potential cytotoxicity against HCT116, HeLa and HepG2 cancer cell lines with IC50 values of 76.59 μg/mL, 176.20 μg/mL and 1750.70 μg/mL, respectively. A comparative HPTLC fingerprinting and the antioxidant activity of C. gloeosporioides associated with two different hosts (leaf of O. indicum and dead twigs of other plant) showed that C. gloeosporioides produces bioactive compounds in a host-dependent manner. Copyright: © 2022 Rai et al.
Challenges in liver cancer and possible treatment approaches
(Elsevier B.V., 2020) David Anwanwan; Santosh Kumar Singh; Shriti Singh; Varma Saikam; Rajesh Singh
Globally, liver cancer is the most frequent fatal malignancy; in the United States, it ranks fifth. Patients are often diagnosed with liver cancer in advanced stages, contributing to its poor prognosis. Of all liver cancer cases, >90% are hepatocellular carcinomas (HCCs) for which chemotherapy and immunotherapy are the best options for therapy. For liver cancer patients, new treatment options are necessary. Use of natural compounds and/or nanotechnology may provide patients with better outcomes with lower systemic toxicity and fewer side effects. Improved treatments can lead to better prognoses. Finally, in this review, we present some of the problems and current treatment options contributing to the poor outcomes for patients with liver cancer. © 2019 Elsevier B.V.
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).
Chemical modification of poly(vinyl chloride) for blood and cellular biocompatibility
(Royal Society of Chemistry, 2015) Monika; Sanjeev Kumar Mahto; Snehashish Das; Amit Ranjan; Santosh Kumar Singh; Partho Roy; Nira Misra
Poly(vinyl chloride) (PVC) was modified with three different ionomers including thiosulphate, thiourea and sulphite for improving the biocompatibility of the polymer. All ionomers were prepared by nucleophilic substitution using a phase transfer catalyst method. The modified forms of PVC were characterized using ultraviolet-visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). They were found to be less stable thermally compared to the untreated polymer. The biocompatibility of the polymers was evaluated by assessing their wettability via contact angle measurements and by performing hemolysis and thrombogenicity assays. Their cellular biocompatibility was evaluated by assessing their adhesion and proliferation, and by carrying out cytotoxicity assays and nuclear staining. The results reveal that modification of the polymer with the specified ionomers significantly enhances the bio- and blood-compatibility properties. This journal is © The Royal Society of Chemistry.
Clinical implication of metformin in relation to diabetes mellitus and ovarian cancer
(MDPI AG, 2021) Santosh Kumar Singh; Tejumola Apata; Shriti Singh; Melayshia McFadden; Rajesh Singh
Since multiple reports established an association between diabetes mellitus and various cancers, emerging studies have surfaced to understand the effects of metformin as an anti-cancer agent. Although there was previous, but conflicting evidence, of a relationship between diabetes and ovarian cancer (OvCa), recent studies have supported this association. The mechanism of cancer development in patients with diabetes is likely to involve hyperglycemia, hyperinsulinemia, chronic inflammation, reactive oxygen species, regulation of cellular homeostasis, and activation of various pathways that lead to tumor cell proliferation. Preclinical evidence indicating that metformin, a medication commonly used to treat type 2 diabetes mellitus, may protect against OvCa. Metformin exerts anti-cancer properties by activating the MAPK pathway, inhibiting the PI3K/AKT/mTOR pathway, increasing tumor suppressor genes, inducing G2/M cycle arrest, and various other processes. Several studies have shown the efficacy of metformin as an adjunct with standard chemotherapeutic agents due to its synergistic effects on OvCa cells. This review highlights the epidemiologic evidence supporting a link between diabetes and OvCa, the fundamental molecular mechanism underlying carcinogenesis in patients with diabetes, the anti-cancer effects of metformin, and the need for further clinical investigations on combination therapies with metformin and standard chemotherapeutic agents for OvCa. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Clinical Prediction of Type 2 Diabetes Mellitus (T2DM) via Anthropometric and Biochemical Variations in Prakriti
(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Shriti Singh; Neeraj Kumar Agrawal; Girish Singh; Sangeeta Gehlot; Santosh Kumar Singh; Rajesh Singh
Type 2 Diabetes Mellitus (T2DM) is a complicated multifactorial illness involving hereditary and external environmental variables. The symptoms typically appear gradually over a number of years without realizing it. This viewpoint is further supported by the Ayurvedic constitution concept (Prakriti). Prakriti explains the biological variability that is observed in different individuals. This study was conducted a retrospective investigation to examine if there was a link between type 2 diabetes and an individual’s constitution based on anthropometric and biochemical characteristics. Physical and mental characteristics and anthropometric and biochemical markers were used to determine reported cases’ prevailing Dosha Prakriti (constitution). Based on biochemical and anthropometric data, significant differences in Prakriti were found between the case (T2DM patients) and control (person without diabetes) groups. The incidence of numerous secondary problems linked with T2DM patients was also evaluated according to their Prakriti types, which revealed a positive relationship. The three primary contributing parameters, such as waist-hip ratio, postprandial blood sugar, and serum creatinine, were correctly classified all person with or without diabetes subjects to 90.6% of the time, whereas the constitution-wise study classified person with diabetes and without diabetes individuals of Pitta and Kapha Prakriti to 94.3% and 90%, respectively. A discriminant function was created to predict a person with diabetes and without diabetes based on these three contributing factors. The primary contributing biochemical parameters discovered by Prakriti in the current study could be used as a biochemical disease diagnostic for predicting type 2 diabetes susceptibility. © 2022 by the authors.
Comparative study of connexins expression in diabetic and nondiabetic wounds
(Inst Materials Physics, 2010) Surabhi Bajpai; Manish Mishra; Hemant Kumar; Kamlakar Tripathi; Santosh Kumar Singh; Rakesh Kumar Singh
Wound healing is the synchronized interplay of interaction of several cellular and biochemical components. In case of diabetes this normal course of wound healing is delayed. The mechanism behind the delayed wound healing in diabetes remains unexplored. The passage of various apoptotic and inflammatory signals via gap junctions play an important role in tissue remodeling during diabetic wound healing. In this study, we compared the expression of the following connexins (Cx) namely Cx26, Cx30.3, Cx31, Cx31.1, Cx37, Cx40, Cx43 in diabetic and non-diabetic wounds. A significant increase in the levels of Cx26, Cx30.3, Cx31, Cx31.1, Cx43 with the commencement of wound repair was observed in diabetic wounds as compared to non-diabetic wounds. In contrast, Cx37 and Cx40 were not expressed in either in diabetic or non diabetic wounds. The results of this study suggest that cellular cross talking via gap junctions is as much vital during proper wound healing, and an up regulated connexin expression might leads to improper gap junctions formation attributing to the passage of various, apoptotic and inflammatory signals thereby resulting in delayed healing of chronic diabetic ulcers.
Computational Investigations on Bis-(ferrocenylmethyl)-Based Sulphur Rich Sensitizers for Dye-Sensitized Solar Cells
(John Wiley and Sons Inc, 2024) Santosh Kumar Singh; Sudip Mandal; Suman Kushwaha
In this work, a computational investigation of ferrocene (Fc)-based compounds FcCH2CS3CH2Fc (1) and FcCH2SSCH2Fc (2) sensitizer for dye-sensitized solar cells (DSSCs) has been carried out to comprehend the photophysical and photo-electrochemical properties. The density functional theory (DFT) and time-dependent DFT (TD-DFT) were employed to assess the photovoltaic parameters of the compounds. The frontier molecular orbital analysis revealed the electron density distribution at HOMO and LUMO, which clearly demonstrates the charge separation within the compounds. The electronic absorption spectra are simulated using the TD-DFT method to comprehend the ability of the compounds to harvest sunlight and efficiently act as photosensitizer. Simulation of electronic spectra of dye@TiO2 cluster exhibits that the absorption coefficient of compound 1 is higher than compound 2 due to the greater extent of charge transfer from the dye to the TiO2 cluster. These computational findings are corroborated by the reported photovoltaic performance of the compounds. © 2024 Wiley-VCH GmbH.
Computational investigations on Heteroleptic Dithiocarbimate–diamine-based metal complexes as photosensitizers in dye-sensitized solar cells
(Elsevier B.V., 2025) Santosh Kumar Singh; Aman Kumar; Sudip Mandal; Suman K. Kushwaha
In this work, nine heteroleptic complexes of the form [M(L)(L')] where L = p-tolylsulfonyldithiocarbimate (p-CH3C6H4SO2N=CS22−); M = Ni (II), L' = 2,2′-bipyridine (Bpy) (C1) or 1,10-phenanthroline (Phen) (C2) or N1,N1,N2,N2-tetramethylethylenediamine (TMEDA) (C3); M = Pd (II), L' = Bpy (C4) or Phen (C5) or TMEDA (C6); and M = Pt (II), L' = Bpy (C7) or Phen (C8) or TMEDA (C9) have been theoretically investigated as sensitizer for dye-sensitized solar cells (DSSCs). The electronic structure of the dye, i.e., spectroscopic and redox properties and its interactions with the TiO2 cluster, is widely elaborated and discussed by employing density functional theory (DFT) and time-dependent DFT (TD-DFT). Frontier molecular orbital and projected density of states analyses disclosed that the charge separation state was generated for C1, C2, C4, C5, C7 and C8 complexes. According to the energy level diagram, C4 would be the best sensitizer in terms of driving force for dye regeneration. The reorganization energy (Λtotal) calculations showed that Bpy and Phen-based complexes had lower Λtotal values, indicating that they could be used as sensitizers for better photovoltaic performance. The adsorption energy (Eads) of dye@TiO2 showed that, with the exception of C3, C6, and C9 complexes, all other sensitizers had negative Eads values, indicating an efficient charge transfer between the sensitizer and TiO2 cluster; and the photovoltaic and global reactivity parameters indicated that, in addition to C1 and C2, C4 and C7 would be viable sensitizers. © 2025 Elsevier B.V.
Cooperative influence of ligand frameworks in sustaining supramolecular architectures of Ni(II)/Pd(II) heteroleptic dithio-dipyrrin complexes via non-covalent interactions
(Elsevier Ltd, 2015) Vinod Kumar; Vikram Singh; Ajit N. Gupta; Santosh Kumar Singh; Michael G.B. Drew; Nanhai Singh
The impact of the ligand frameworks on the crystal stabilization of the novel heteroleptic complexes [M(bzdpm)(xant)] (M = Ni(II) 1, Pd(II) 2, xant- = 4-methoxyphenylethylxanthate, bzdpmH = 5-benzyl dipyrromethene) and [Ni(dmbzdpm)(dtc)] 3 (dmbzdpmH = 5-N,N-dimethylbenzyl dipyrromethene; dtc- = N-pyridyl-N-ferrocenylmethyl dithiocarbamate) has been investigated. In these planar complexes, the supramolecular structures of 1 and 2 are stabilized via C-H⋯O and CH⋯π interactions. The structure of 3 revealed a centrosymmetric dimer formed by two C-H...N intermolecular hydrogen bonds between the nitrogen atom of the pyridyl group and a hydrogen atom on a neighboring molecule. The dimers thus formed are held together by C-H...π (NiCS2, chelate) interactions, sustaining a 2-D supramolecular architecture and constructing an unprecedented cyclic analog of benzene. The intermolecular interaction energies for the C-H...N and C-H...π (NiCS2, chelate) interactions have been estimated to assess their nature. The palladium complex 2 shows luminescent characteristics in solution at room temperature. © 2015 Elsevier Ltd. All rights reserved.
Current perspective in research and industrial applications of microbial cellulases
(Elsevier B.V., 2024) Priya Sutaoney; Sachchida Nand Rai; Sakshi Sinha; Rachana Choudhary; A.K. Gupta; Santosh Kumar Singh; Paromita Banerjee
The natural interactions between various bacteria, fungi, and other cellulolytic microorganisms destroy lignocellulosic polymers. The efficacy of this process is determined by the combined action of three main enzymes: endoglucanases, exo-glucanases, and β-glucosidase. The enzyme attacks the polymeric structure's β-1,4-linkages during the cellulose breakdown reaction. This mechanism is crucial for the environment as it recycles cellulose in the biosphere. However, there are problems with enzymatic cellulose breakdown, including complex cellulase structure, insufficient degradation efficacy, high production costs, and post-translational alterations, many of which are closely related to certain unidentified cellulase properties. These issues impede the practical use of cellulases. A developing area of research is the application of this similar paradigm for industrial objectives. Cellulase enzyme exhibits greater promise in many critical industries, including biofuel manufacture, textile smoothing and finishing, paper and pulp manufacturing, and farming. However, the study on cellulolytic enzymes must move forward in various directions, including increasing the activity of cellulase as well as designing peptides to give biocatalysts their desired attributes. This manuscript includes an overview of current research on different sources of cellulases, their production, and biochemical characterization. © 2024 Elsevier B.V.
Cytotoxic and apoptotic inducing activity of Amoora rohituka leaf extracts in human breast cancer cells
(Elsevier B.V., 2020) Rajesh Kumar Singh; Amit Ranjan; Akhileshwar Kumar Srivastava; Monika Singh; Anil Kumar Shukla; Neelam Atri; Anurag Mishra; Anil Kumar Singh; Santosh Kumar Singh
Background: Amoora rohituka is described in Ayurveda, an Indian traditional system of medicine for management of disorders of blood, diseases of eye, helminthiasis disease, ulcer, liver disorders and splenomegaly. However, the leaves were not reported to have anticancer properties till date. Objective: This study was carried out to evaluate the cytotoxic potential of leaf extracts of Amoora rohituka. Materials and methods: The leaves powder was macerated in petroleum ether, ethyl acetate and methanol and evaluated their anticancer activities in vitro. The phytochemical constituents of the active (ethyl acetate) extract were screened by FTIR analysis and phytochemical screening methods. Results: The ethyl acetate extract (RLEA) showed the presence of alkaloids, flavonoids, steroids, tannins, saponins and terpenoids. The RLEA exhibited high cytotoxic effect against human breast cancer cells, MCF-7 (IC50 = 9.81 μg/mL) and induced apoptosis by altering nuclear morphology and DNA laddering. Wound healing assays explained the potency of extract to decrease the cell migration. Conclusion: The extract of Amoora rohituka leaves exhibited anticancer activity with less toxicity and it could be used for development of alternative drugs in the treatment of human breast cancer. © 2019 Transdisciplinary University, Bangalore and World Ayurveda Foundation