Browsing by Author "Nidhi Pandey"

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Alginate lyase immobilized chitosan nanoparticles of ciprofloxacin for the improved antimicrobial activity against the biofilm associated mucoid P. aeruginosa infection in cystic fibrosis
(Elsevier B.V., 2019) Krishna Kumar Patel; Muktanand Tripathi; Nidhi Pandey; Ashish Kumar Agrawal; Shilpkala Gade; Md. Meraj Anjum; Ragini Tilak; Sanjay Singh
Dense colonization of mucoid Pseudomonas aeruginosa within the self-secreted extracellular matrix (mainly alginate), called biofilm, is a principal reason for the failure of antimicrobial therapy in cystic fibrotic patients. Alginate is a key component in the biofilm of mucoid P. aeruginosa and responsible for surface adhesion and stabilization of biofilm. To overcome this problem, alginate lyase functionalized chitosan nanoparticles of ciprofloxacin were developed for the effective treatment of P. aeruginosa infection in cystic fibrosis patients. The developed nanoparticles were found to have desired quality attributes and demonstrated sustained release following the Higuchi release kinetics. Drug compatibility with the chitosan was confirmed by FTIR while powder X-ray diffraction analysis confirmed the entrapment of drug within the nanoparticle matrix. Lactose adsorbed NPs showed promising aerodynamic property. Nanoparticles showed prolonged MIC and significant reduction in biofilm aggregation and formation in planktonic bacterial suspension. Nanoparticles exhibited significantly higher inhibitory effect against biofilm of P. aeruginosa and reduced the biomass, thickness and density confirmed by confocal microscopy. Furthermore, developed nanoparticles were haemocompatible and did not exhibit any toxicity in vitro MTT assay and in vivo on lungs male Wistar rats. The data in hand collectively suggest the proposed strategy a better alternative for the effective treatment of cystic fibrosis infections. © 2019
An extract of Pueraria tuberosa tubers attenuates diabetic nephropathy by upregulating matrix metalloproteinase-9 expression in the kidney of diabetic rats
(John Wiley and Sons Inc., 2017) Yamini B. Tripathi; Rashmi Shukla; Nidhi Pandey; Vivek Pandey; Mohan Kumar
Background: Currently, no drug is available to directly target the signaling molecules involved in the pathogenesis of diabetic nephropathy (DN); only antihypertensive and antidiabetic drugs are in clinical use. In the present study, the therapeutic effects of a active fraction of tubers from Pueraria tuberosa (hereafter referred to as PTY-2) were investigated in streptozotocin (STZ)-diabetic rats with DN, with particular emphasis on its effects on extracellular matrix (ECM) accumulation and matrix metalloproteinase (Mmp)-9 expression in kidney tissue. Methods: Rats were injected with 55 mg/kg, i.p., STZ. After 40 days, rats were divided into groups as follows (n = 6 per group): Group 1, age-matched rats not injected with STZ (non-diabetic control); Group 2, STZ-diabetic DN rats; and Group 3, PTY-2 (30 mg/100 g, p.o.)-treated DN rats. After 20 days treatment, the effects of PTY-2 on serum urea and creatinine concentrations, urinary levels of glucose, creatinine, protein, and ketone bodies, and urine pH were determined. Kidney tissue was evaluated for Mmp-9 expression and histological changes. Results: Blood glucose, serum urea, creatinine, and urine protein levels were significantly higher, and creatinine clearance was significantly lower, in Group 2 versus Group 1 rats. There was a higher degree of glomerulosclerosis, expansion of the mesangial matrix, and excess ECM deposition and eosinophilic casts in kidneys from Group 2 versus Group 1 rats. Furthermore, Mmp-9 activity and expression were significantly reduced in kidney homogenate of Group 2 versus Group 1 rats. Interestingly, PTY-2 treatment significantly reversed all these changes in DN rats. Conclusion: Treatment of DN rats with PTY-2 significantly attenuated the severity of DN by increasing the expression and activity of Mmp-9, consequently degrading the ECM accumulated in kidney tissue. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd
Anacardic acid encapsulated solid lipid nanoparticles for Staphylococcus aureus biofilm therapy: chitosan and DNase coating improves antimicrobial activity
(Springer, 2021) Md Meraj Anjum; Krishna Kumar Patel; Deepa Dehari; Nidhi Pandey; Ragini Tilak; Ashish Kumar Agrawal; Sanjay Singh
Biofilm mediated bacterial infections are the key factors in the progression of infectious diseases due to the evolution of antimicrobial resistance. Traditional therapy involving antibiotics is not adequate enough for treatment of such infections due to the increased resistance triggered by biofilm. To overcome this challenge, we developed anacardic acid (Ana) loaded solid lipid nanoparticles (SLNs), further coated with chitosan and DNase (Ana-SLNs-CH-DNase). The DNase coating was hypothesized to degrade the e-DNA, while chitosan was coated to yield positively charged SLNs with additional adhesion to biofilms. The SLNs were developed using homogenization method and further evaluated for particle size, polydispersity index, zeta potential, and entrapment efficiency. Drug excipient compatibility was confirmed by using FT-IR study, while encapsulation of Ana in SLNs was confirmed by X-ray diffraction study. The SLNs demonstrated sustained release for up to 24 h and excellent stability at room temperature for up to 3 months. The developed SLNs were found non-toxic against human immortalized keratinocyte (HaCaT) cells while demonstrated remarkably higher antimicrobial efficacy against Staphylococcus aureus. Excellent effect of the developed SLNs on minimum biofilm inhibition concentration and minimum biofilm eradication concentration further confirmed the superiority of the developed formulation strategy. A significant (p < 0.05) reduction in biofilm thickness and biomass, as confirmed by confocal laser scanning microscopy, was observed in the case of developed SLNs in comparison with control. Cumulatively, the results suggest the enhanced efficacy of the developed formulation strategy to overcome the biofilm-mediated antimicrobial resistance. [Figure not available: see fulltext.] © 2020, Controlled Release Society.
Antioxidant activity of tuberosin isolated from Pueraria tuberose Linn
(2010) Nidhi Pandey; Yamini B. Tripathi
Antioxidant activity of Pueraria tuberose DC, (PT) Leguminosae (Fabaceae) has already been reported by us and here an active compound has been isolated and its action on expression of iNOS protein has been explored by using LPS induced changes in attached rat peritoneal macrophage cell culture. The pure compound was isolated by column chromatography and its structure was characterized by spectral studies, which was identified as tuberosin (5 hydroxy 3,4,7,3',4' pentamethoxy flavone). Its antioxidant capacity was determined and compared with alcoholic extract as EC50value for scavenging potential towards pre-generated monocation ABTS* radical, superoxide radicals, hydroxyl radicals, metal chelation property and on lipid peroxidation. Further, rat peritoneal macrophages were isolated, cultured and the attached macrophages were exposed to lipopolysaccharide (LPS) with different concentrations of tuberosin (pretreatment for 30 min). After 17 h the released NO content, in culture supernatant, was indirectly estimated as accumulated nitrite by Griess reagent. To understand the mechanism of action, the extent of expression of inducible nitric oxide synthase genes, the iNOS protein was assessed in macrophage lysate by using its antibody on western blot analysis. Tuberosin significantly scavenged all the species of FRs, described above and it also inhibited the LPS induced release of NO and amount of iNOS protein in macrophages. All the changes were significant and concentration dependent. Thus it could be suggested that tuberosin, is one of the active principles of Pueraria tuberose, which directly scavenges various species of Free radicals (FRs) and also inhibits LPS induced inflammatory changes in macrophages. © 2010 Pandey and Tripathi; licensee BioMed Central Ltd.
Antioxidant properties of different fractions of tubers from Pueraria tuberosa Linn
(2007) Nidhi Pandey; J.K. Chaurasia; O.P. Tiwari; Yamini B. Tripathi
Pueraria tuberosa Linn. (PT), Leguminosae, is a perennial climber, growing throughout tropical parts of India. In the Ayurvedic system of medicine, it is used as a drug of choice to manage pain, inflammation and other related diseases. The antioxidant potency of P. tuberosa was investigated for the first time. Total antioxidant capacity was determined using an ABTS*+ assay. Lipid peroxidation was assessed in terms of thiobarbituric acid-reactive substances by using egg-yolk homogenates as lipid-rich media. Superoxide radical-scavenging was measured using riboflavin-light-nitro blue tetrazolium (NBT) assay. Hydroxyl radical trapping potential was determined by evaluating hydroxyl radical induced deoxyribose degradation using thiobarbituric acid method. In order to assess the metal chelation property, hydroxyl radical induced deoxyribose degradation was evaluated in the absence of ethylenediaminetetraacetic acid. Both hexane and methanol fractions inhibited lipid peroxidation and also chelated the iron, showing potent antioxidant property. © 2007 Elsevier Ltd. All rights reserved.
Carbimazole inhibits TNF-α expression in Fat-induced hypothyroidism
(BioMed Central Ltd., 2014) Yamani B. Tripathi; Nidhi Pandey
The effect of the carbimazole on expression of tumor necrosis factor (TNF-α) in liver, was investigated in an experimental model of high fat diet (HFD) induced obesity. The HFD (orally given for 4 months) induced TNF-α in liver tissue along with raised serum triglyceride (TG), cholesterol and high TSH (62%) In carbimazole (1 mg/100gbw) treatment, the induction of TNF-α was significantly inhibited, without affecting other parameters. It also improved the liver function, which was raised due to HFD in experimental control rats. © 2014 Tripathi and Pandey; licensee BioMed Central Ltd.
Combined experimental and theoretical studies on the diorganotin(IV) complexes of sparfloxacin: Synthesis, spectroscopic and DFT studies, and biological activity
(Elsevier B.V., 2018) Rachana Joshi; Swatantra Kumar Yadav; Nidhi Pandey; Hirdyesh Mishra; Ragini Tilak; Sandeep Pokharia
New diorganotin(IV) derivatives of sparfloxacin having general formula R2SnCl(L), (where L = monoanion of sparfloxacin (HL) and R = n-Bu (1)/Ph (2)) have been synthesized and structurally characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn), HMQC, ESI-MS, UV–Vis and emission spectroscopy. These investigations suggest that, in these 1:1 monomeric derivatives the sparfloxacin ligand acts as monoanionic bidentate coordinating through the Ocarboxylate and Opyridone, and the polyhedron around tin is intermediate between pseudotetrahedral and cis-trigonal bipyramidal. The proposed structures have been validated by density functional theory (DFT) based electronic structure calculations at B3LYP/6-31G(d,p)/Def2-SVP(Sn) level of theory through the calculation of the atomic charges at the selected atoms, molecular electrostatic potential (MEP) map to assign sites on the surface of the molecules, the selected conceptual-DFT based global reactivity descriptors to obtain an insight into the structure and reactivity behaviour, and the frontier molecular orbital analysis to analyze the nature of frontier orbitals. A comparative analysis of the experimental vibrational frequencies and simulated harmonic frequencies indicates good correlation between them. The simulated UV–Vis spectrum was obtained with time dependent-DFT method in gas phase and in the solvent field with IEFPCM model. The simulated 1H and 13C NMR spectra were obtained by gauge-independent atomic orbital (GIAO) method and the results were in good agreement to the experimental results. The complexes were screened for their in vitro antibacterial activity against two Gram-positive and five Gram-negative bacterial strains. Both the complexes exhibited promising antibacterial activity against all the chosen strains (MIC: 0.062–0.125 μg ml−1). © 2018
Development of Anacardic Acid/hydroxypropyl-β-cyclodextrin inclusion complex with enhanced solubility and antimicrobial activity
(Elsevier B.V., 2019) Md Meraj Anjum; Krishna Kumar Patel; Nidhi Pandey; Ragini Tilak; Ashish Kumar Agrawal; Sanjay Singh
Anacardic Acid (AnAc), a key constituent of cashew nut shell liquid (CNSL), has been reported to exhibit antibacterial activity against S. aureus but its bioactivity and clinical applicability are limited owing to its poor water solubility and physicochemical stability. The aim of the present study was to develop inclusion complex of AnAc (C15:3) and hydroxypropyl-β-cyclodextrin (HP-β-CD) to improve its aqueous solubility and antimicrobial activity. The inclusion complex was prepared using the co-evaporation method considering different molar ratios of AnAc (C15:3) and HP-β-CD. The prepared inclusion complex was characterized using FT-IR, DSC, XRD, SEM, and 1H NMR, which provided appropriate evidence to confirm the formation of the inclusion complex. The prepared inclusion complex demonstrated ~2009 times improved aqueous solubility. The developed complex maintained the antimicrobial activity of pure AnAc against S. aureus. AnAc/HP-β-CD complex exhibited excellent biofilm dispersal potential against mature biofilms. Confocal laser scanning microscopy (CLSM) demonstrated a remarkable decrease in bacterial biomass and thickness upon treatment with the inclusion complex. Conclusively, the developed inclusion complex of Anacardic Acid (C15:3) can be effectively used to overcome the poor aqueous solubility and improve the therapeutic efficacy for many other indications. © 2019
DNase-I functionalization of ciprofloxacin-loaded chitosan nanoparticles overcomes the biofilm-mediated resistance of Pseudomonas aeruginosa
(Springer Science and Business Media Deutschland GmbH, 2020) Krishna Kumar Patel; Ashish Kumar Agrawal; Md. Meraj Anjum; Muktanand Tripathi; Nidhi Pandey; Sankha Bhattacharya; Ragini Tilak; Sanjay Singh
Pseudomonas aeruginosa infection in cystic fibrosis (CF) is a major complication which aggravates the disease complexity and progression. The improvement of antimicrobial therapy against the P. aeruginosa biofilm infection in CF by dissembling the extracellular matrix is a fundamental concept of this study. Chitosan nanoparticle was successfully fabricated and characterized. Furthermore, various in vitro antimicrobial efficacy, biofilm dispersal potential, and in vitro as well as in vivo toxicity were assessed. The chitosan nanoparticles of ciprofloxacin functionalized with DNase-I had spherical shape with desired quality attributes (particle size—212.3 ± 8.9; polydispersity index—0.288 ± 0.06, zeta potential—14.6 ± 1.3, and entrapment efficiency—53.7 ± 3.8%). The developed DNase-I functionalized chitosan nanoparticles laden with ciprofloxacin demonstrated substantial and prolonged microbial inhibition, efficiently prevented the biofilm development, and possessed the excellent biofilm dispersal potential. Moreover, the confocal study demonstrated that the biofilm treated with DNase-I functionalized chitosan nanoparticles of ciprofloxacin had minimum biofilm thickness, biomass, and microbial density compared to the other treatment groups. Additionally, the developed formulation was found to be safe and had minimal in vitro as well as in vivo toxicity. Thus, the findings of this study suggests ciprofloxacin-loaded chitosan nanoparticles functionalized with DNase-I as an effective and safe treatment approach for the P. aeruginosa infection in CF. © 2019, King Abdulaziz City for Science and Technology.
Effect of extract of Pueraria tuberosa on expression of hypoxia inducible factor-1α and vascular endothelial growth factor in kidney of diabetic rats
(Elsevier Masson SAS, 2017) Rashmi Shukla; Nidhi Pandey; Somanshu Banerjee; Yamini B. Tripathi
Backgrounds Kidney hypoxia represents a unifying mechanism in the pathogenesis of diabetic nephropathy. Hypoxia-induced factor (HIF)-1α mediates the metabolic responses of renal hypoxia by modulating the expression of VEGF. In the present study, we investigated the effect of Pueraria tuberosa extract (PTY-2r) on the expression of HIF-1α, VEGF and nephrin in streptozotocin (STZ) induced diabetic nephropathy (DN). Methods The model of diabetic nephropathy (DN) was produced by intraperitoneal injection of 55 mg/kg of STZ and maintained for 60 days. These DN-rats were randomly divided into three groups, i.e., DN, DN + PTY-2r (100 mg/100 g), and DN + PTY-2r (50 mg/100 g). A normal control (NC) group was administrated with drug vehicle. Expression of HIF-1α, VEGF and nephrin were evaluated in the renal tissue. Results Blood glucose, urine protein, serum creatinine, and urea, level were significantly raised along with decreased creatinine clearance in DN rats. Immunofluorescence and Western blot analysis showed significantly increased expression of HIF-1α & VEGF and decreased expression of nephrin in DN control rats. The PTY-2r treatment significantly reversed these changes in a dose-dependent manner. Correlation analysis showed that the expression of VEGF was positively correlated with that of HIF-1α and negatively correlated with nephrin. Conclusions The PTY-2r can improve the chronic hyperglycemic condition induced kidney damage, and may delay the development of diabetic nephropathy by inhibiting the expression of HIF-1α and VEGF, thereby restoring the expression of nephrin. © 2017
Effect of hexane fraction of leaves of Cinnamomum tamala Linn on macrophage functions
(2010) J.K. Chaurasia; Nidhi Pandey; Yamini Bhushan Tripathi
The leaves of Cinnamomum tamala Linn (Lauraceae), component of Indian spices are associated with hypoglycemic property in Ayurveda; however, no report is available towards its immunomodulation property, which has been explored here. The dried powder of CT leaves was extracted with hexane and solvent free extract (CTH) was given orally to rats for 10 days, in various doses. Its effect was studied on peritoneal macrophage functions, and was compared with ascorbic acid (1,000 mg/ kg, immune-stimulant) and cyclophosphamide (10 mg/kg, immune-suppressant). CTH significantly suppressed phagocytosis activity (EC 50 2,355 ± 52.45 mg/kg), reduced production of superoxide (EC50 275.91 ± 10.21 μg/ml) and cellular NADPH (EC 50 384.959 ± 4.85 μg/ml) content in concentration dependent manner. It also inhibited LPS induced production of nitric oxide (EC 50 143.75 ± 3.40 μg/ml) and iNOS protein expression (EC50 183.132 μg/ml). Thus, it could be suggested that non-polar hexane fraction of leaves of C. tamala possesses immunosuppressive property, which is mediated through modulation of innate immunity. © Birkhäuser Verlag, Basel/Switzerland 2010.
Effect of nigella sativa seeds extracts on inos through antioxidant potential only: Crude/total extract as molecular therapy drug
(2012) Yamini B. Tripathi; A.P. Chaturvedi; Nidhi Pandey
There is general belief that only pure phytomolecules may be used as molecular therapeutic agent through one to one action. However, the traditional systems of medicine e.g. Ayurveda, uses the crude extracts, mostly water decoctions and oils, as drug. A comparative study of hexane, ethyl acetate and methanol fractions of N. Sativa seeds has been carried out on fresh rat-peritoneal-macrophage culture with reference to their role on various targets of lipopolysaccharide induced release of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) expression. The results indicated significant antioxidant potential with methanolic extract as most effective. Its mechanism of action was proposed primarily through its antioxidant potential and not through direct inhibition of other kinases, involved in its signaling cascade.
Enhanced antilipopolysaccharide (LPS) induced changes in macrophage functions by Rubia cordifolia (RC) embedded with Au nanoparticles
(2013) Ashwani Kumar Singh; Yamini B. Tripathi; Nidhi Pandey; D.P. Singh; Deepshikha Tripathi; O.N. Srivastava
In this paper, we have shown that gold nanoparticles (Au (NPs)) embedded in Rubia cordifolia (RC) matrix (RC-Au (NPs)) exhibit a high therapeutic value relating to its anti-inflammatory characteristics. It was prepared by utilizing the reducing properties of RC to convert HAuCl4 into Au (NPs). In order to compare its effectiveness, with respect to Au (NPs), the latter was synthesized separately by reducing HAuCl4 with lemon extract. These Au (NPs) along with RC-Au (NPs) were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), and UV-visible spectroscopy. The enhancement in anti-inflammatory characteristics was assessed as its inhibitory potential for lipopolysaccharide (LPS)-induced nitric oxide (NO) release, by rat peritoneal macrophages. The RC-Au (NPs) significantly enhanced its potential to inhibit NO release, which was reported in terms of inhibitory concentration for 50% inhibition (IC50=11.98 ng/ml), as compared to either RC extract (IC50=47 × 103 ng/ml) or to Au (NPs) (IC 50=587.50 ng/ml). © 2013 Elsevier Inc.
Evaluation of antioxidant and antimicrobial potential of a novel Himalayan plant Reinwardtia indica dumort: Scientifically unexplored
(Academic Press, 2019) Prabhat Upadhyay; Sunil Kumar Mishra; Awadhesh Kumar Mishra; Pradeep Kumar; Nidhi Pandey; Kavindra Nath Tiwari; Ragini Tilak; Suresh Purohit; G.P. Dubey
Reinwardtia indica (Lineceae) is a medicinal plant cultivated in the Himalayan region. It is effectively used in folk medicines for the treatment of various health complications. In the present study, the shade dried leaves and stem were extracted in three different solvents such as ethyl acetate, ethanol, and hydro-alcoholic. The antioxidant efficacy of these extracts was confirmed by using different in vitro assays: DPPH free radical scavenging, superoxide radical scavenging, lipid peroxidation, metal ion chelating capability and reducing power determination. Total phenol content was maximum in hydro alcoholic extract of leaf (540.37 mg per g of gallic acid equivalents) and stem (330.51 mg per g of gallic acid equivalents) while flavonoid content was maximum in ethanolic extract of leaf (305 mg per gram of rutin equivalents) and ethyl acetate extract of stem (170.6 mg per gram of rutin equivalents). The antioxidant activity of these extracts was positively correlated with their total phenol and flavonoid content. Among all tested extracts, ethanolic extract of leaf exhibit maximum zone of inhibition against all tested clinical isolates of bacterial (E. coli 11.00 ± 1.73 mm, P. aeurogenosa 11.67 ± 0.58 mm and S. aureus 10.33 ± 1.53 mm) and fungal (C. albicans 11.33 ± 1.10 mm) pathogens, while ethyl acetate extracts of the leaf and stem showed minimum inhibitory concentration against all tested microorganisms. Thus, R. indica extracts can be used as potent natural antioxidant having antifungal and antibacterial action. © 2018 Elsevier Ltd
Green synthesis of silver nanoparticles by root extract of Premna integrifolia L. and evaluation of its cytotoxic and antibacterial activity
(Elsevier Ltd, 2023) Chandrashekhar Singh; Sumit Kumar Anand; Richa Upadhyay; Nidhi Pandey; Pradeep Kumar; Deepjyoti Singh; Punit Tiwari; Rajesh Saini; Kavindra Nath Tiwari; Sunil Kumar Mishra; Ragini Tilak
An efficient, reproducible, and eco-friendly protocol has been developed for the green synthesis of silver nanoparticles using an aqueous root extract of Premna integrifolia (PE-AgNPs). The synthesized nanoparticles were characterized by different techniques to determine their formation, stability, and morphology. Nanoparticles were tested for cytotoxicity against the HepG2 cancer cell line and antibacterial activity against clinical isolates of bacteria. The cytotoxic potential of PE-AgNPs was analyzed using MTT assay, Hoechst and AO/EtBr staining, ROS measurement, mitochondrial membrane potential, clonogenic, and wound healing assays. PE-AgNPs were found strongly cytotoxic against Hep G2 cell lines during all assays. A disc diffusion assay confirmed that Pseudomonas aeruginosa was most susceptible to PE-AgNPs than Staphylococcus aureus and E. coli. It was further confirmed by MIC, MBC values, and TEM microphotographs. As a result, our findings indicate that biosynthesized silver nanoparticles could be useful as cytotoxic and antimicrobial candidates. © 2023 Elsevier B.V.
Important role of the position of a functional group in isomers for photophysical and antibacterial properties: A case study with naphthalenemaleonitrile positional isomers
(Royal Society of Chemistry, 2020) Monika; Abhineet Verma; Supriy Verma; Nidhi Pandey; Ragini Tilak; Satyen Saha
The naphthalenemaleonitrile positional isomers, (1N: 2-amino-3-(((E)-naphthalene-1-ylmethylene)amino)maleonitrile) and (2N: 2-amino-3-(((E)-naphthalene-2-ylmethylene)amino)maleonitrile), were synthesized and then studied comparatively. Their molecular configurations exhibit an extraordinary ability to affect photophysical properties such as aggregation induced emission (AIE) and aggregation caused quenching (ACQ) properties and an unexpected structural dependence of antibacterial activity in biological cells. The 2N (naphthalene and aminomaleonitrile moieties are planar to each other) shows interesting AIE photophysical behaviours, whereas 1N (the naphthalene and aminomaleonitrile moieties are twisted around each other) exhibits the usual ACQ. The answer to the apparent contradiction of the general conception that planar molecules show ACQ in aggregates is hidden in the packing of molecules and the interactions present therein. Furthermore, 1N shows antimicrobial activity in a biological cell, whereas 2N does not. Although, the presence of a particular functional group such as imine is reported to be a determinant factor for a molecule to show antimicrobial activity, as far as is known, functional group position-dependent biological activities in aminomaleonitrile group containing molecules are not yet reported. Therefore, this report demonstrates that just the presence is not enough; the position of the functional group, which affects the structure of the molecule, is equally important. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Interaction of triorganotin(IV) moiety with quinolone antibacterial drug ciprofloxacin: Synthesis, spectroscopic investigation, electronic structure calculation, and biological evaluation
(Wiley-Blackwell, 2018) Rachana Joshi; Swatantra K. Yadav; Hirdyesh Mishra; Nidhi Pandey; Ragini Tilak; Sandeep Pokharia
New triorganotin(IV) derivatives of ciprofloxacin (HL) with general formula R3Sn(L) (where R = Me (1)/Cy (2) and L is the monoanion of ciprofloxacin) have been synthesized and structurally characterized on the basis of elemental analysis, IR, Raman, multinuclear (1H-, 13C- and 119Sn-) NMR, ESI-MS, UV-Visible, and emission spectroscopy. A distorted trigonal bipyramidal geometry around tin has been tentatively proposed for these triorganotin(IV) derivatives in which the ligand may act as monoanionic bidentate coordinating through the Ocarboxylate and Opyridone. The proposed structure has been validated by density functional theory (DFT)-based electronic structure calculations at B3LYP/6-31G(d,p)/Def2-SVP(Sn) level of theory. The atomic charges have been calculated at the selected atoms, and the reactive sites have been assigned on the surface of the molecules through molecular electrostatic potential map. The frontier molecular orbitals and selected conceptual-DFT-based global reactivity descriptors have been calculated to obtain an insight into the structure and reactivity behavior of the complexes. A comparative analysis of the experimental vibrational frequencies and simulated harmonic frequencies indicates good correlation between them. The complexes were screened for their in vitro antibacterial activity against two Gram-positive and five Gram-negative bacterial strains. The results revealed that both the complexes exhibited promising antibacterial activity against the chosen strains (MIC: 0.062-0.125 μg/mL). © 2018 Wiley Periodicals, Inc.
Mesoporous x[Cu(II)O] nanoclusters dispersed and immobilized on y [SiO 2] matrix: structure and effective controlled biocidal activity against Pseudomonas aeruginosa and Bacillus subtilis
(Springer, 2020) Dhiman Banik; S. Chennakesavulu; Monika Singh; Nidhi Pandey; Ragini Tilak; Aramati Bindu Madhava Reddy; Pradip Paik
Herein we report the synthesis of mesoporous nanostructures comprising copper (II) oxide { x[Cu (II) O] } immobilized on silica y[SiO 2] template for release of copper ions by precipitation via sol–gel technique. Three different specimens with increasing amount of Cu in the matrix with amount of Si being the same in all the samples, viz. ‘6Cu:5Si’, ‘4.5Cu:5Si’ and ‘3Cu:5Si’ where the numbers refer to the respective molar ratios of their respective domains, were prepared. Increase of crystallinity in the mesoporous material with increase in incorporation of copper domains consisting of CuO in SiO 2 matrix has been established. The average size of the CuO nanoparticle (NP) (domain) is 20–30 nm. The BET surface area has been found to be 276–390 m2g-1 and Langmuir surface area has been found to be 422–605.9 m2g-1 for the samples 5Si:3Cu–5Si:6Cu, respectively, having pore size of 4–6.5 nm. The cytotoxicity data show that the NPs are less toxic below concentration of 125μgml-1. A steady increase in percentage of bacterial-‘Escherichia coli’, ‘Pseudomonas aeruginosa’ and ‘Bacillus subtilis’ cell death (indicated by decrease in optical density) due to increase in concentrations of NPs after incubation for 14 h, showing sensitivity even at very low concentrations (5–20 μ g), has been observed. A comparative antibacterial activity test among the three prepared specimens has been reported, which shows better antibacterial activity with the lowest copper concentration. Better antibacterial sensitivity when compared with equivalent amount of commercial CuO is established. © 2020, Indian Academy of Sciences.
Necessity to identify candida species accurately with minimum inhibitory concentration determination in each case of bloodstream infections
(Elsevier Ltd, 2020) Nidhi Pandey; Munesh K. Gupta; Pradeep Paul; Ragini Tilak
Background: Bloodstream Candida infection is a life-threatening event among ICU admitted patients. This infection is caused by a diverse range of Candida species having varied minimum inhibitory concentrations. Objectives: To identify Candida species causing bloodstream infections with their antifungal susceptibility determination. Methods: Candida species isolated from the blood of ICU admitted patients were identified by phenotypic as well as by molecular methods including PCR-RFLP using MspI restriction enzyme and MALDI TOF MS. The minimum inhibitory concentration of fluconazole, voriconazole, amphotericin B and caspofungin was determined against isolated Candida species by CLSI M27A3 guidelines. Results: A total of 119 Candida species were isolated. Among them, C. tropicalis(n = 29) was the predominant isolate followed by C. parapsilosis(n = 18), C. glabrata (n = 12), C. krusei (n = 11) and C. albicans(n = 11). Uncommon Candida species isolated were; Wickerhamomyces anomalus(n = 15), Kodaemia ohmeri(n = 8), C. lusitaniae (n = 5) and C. auris (n = 2). A varied antifungal MIC values were observed. Caspofungin had the lowest MIC among the tested antifungals. Increased fluconazole MIC was observed against the isolated Candida species including C. tropicalis. All the isolated C. lusitaniae and C. auris strains have ≥1mcg/ml amphotericin B MIC. In comparison to fluconazole, voriconazole was more effective when tested in vitro. Conclusion: Emergence of uncommon Candida species having varied antifungal MIC warns the physicians to have a prompt, accurate identification with antifungal MIC determination in each case of bloodstream Candida infections. © 2019 The Authors
New triorganotin(IV) complexes of quinolone antibacterial drug sparfloxacin: Synthesis, structural characterization, DFT studies and biological activity
(John Wiley and Sons Ltd, 2018) Rachana Joshi; Nidhi Pandey; Ragini Tilak; Swatantra Kumar Yadav; Hirdyesh Mishra; Sandeep Pokharia
A new series of triorganotin(IV) complexes of sparfloxacin (HL) having general formula R3SnL (where L is the monoanion of sparfloxacin (HL) and R = Me (1)/n-Bu (2)/Ph (3)/Cy (4)) have been synthesized and characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn), 2D-HETCOR, ESI-MS and UV-Vis studies. These investigations suggest that, in these 1:1 monomeric derivatives the sparfloxacin ligand acts as monoanionic bidentate coordinating through the Ocarboxylate and Opyridone, and the polyhedron around tin is intermediate between pseudotetrahedral and cis-trigonal bipyramidal, with Opyridone and two organic groups in equatorial plane and the carboxylate oxygen and the third organic group in axial positions. The proposed structures have been validated by density functional theory (DFT) based quantum chemical calculations at B3LYP/6-31G(d,p)/Def2-SVP(Sn) level of theory. A detailed electronic structure calculations were performed at this level of theory to calculate atomic charges at the selected atoms, molecular electrostatic potential (MEP) map to assign sites on the surface of the molecules, the selected conceptual-DFT based global reactivity descriptors to obtain an insight into the structure and reactivity behaviour, and the frontier molecular orbital analysis to analyze the nature of frontier orbitals. All the complexes were screened for their in vitro antibacterial activity against two Gram-positive and five Gram-negative bacterial strains. All the complexes exhibited promising antibacterial activity as compared to sparfloxacin against all the chosen strains. Copyright © 2018 John Wiley & Sons, Ltd.