Genetic substructure and host-specific natural selection trend across vaccine-candidate ORF-2 capsid protein of hepatitis-E virus.

Hepatitis E virus is a primary cause of acute hepatitis worldwide. The present study attempts to assess the genetic variability and evolutionary divergence among HEV genotypes. A vaccine promising capsid-protein coding ORF-2 gene sequences of HEV was evaluated using phylogenetics, model-based population genetic methods and principal component analysis. The analyses unveiled nine distinct clusters as subpopulations for six HEV genotypes. HEV-3 genotype samples stratified into four different subgroups, while HEV-4 stratified into three additional subclusters. Rabbit-infectious HEV-3ra samples constitute a distinct cluster. Pairwise analysis identified marked genetic distinction of HEV-4c and HEV-4i subgenotypes compared to other genotypes. Numerous admixed, inter and intragenotype recombinant strains were detected. The MEME method identified several ORF-2 codon sites under positive selection. Some selection signatures lead to amino acid substitutions within ORF-2, resulting in altered physicochemical features. Moreover, a pattern of host-specific adaptive signatures was identified among HEV genotypes. The analyses conclusively depict that recombination and episodic positive selection events have shaped the observed genetic diversity among different HEV genotypes. The significant genetic diversity and stratification of HEV-3 and HEV-4 genotypes into subgroups, as identified in the current study, are noteworthy and may have implications for the efficacy of anti-HEV vaccines.

Computational exploration and molecular dynamic simulation for the discovery of antiviral agents targeting Newcastle disease virus.

Newcastle disease virus (NDV) is a highly infectious viral disease that impacts birds globally, especially domestic poultry. NDV is a type of avian paramyxovirus which poses a major threat to the poultry industry due to its ability to inflict significant economic damage. The membrane protein, Hemagglutinin-Neuraminidase (HN) of NDV is an attractive therapeutic candidate. It contributes to pathogenicity through various functions, such as promoting fusion and preventing viral self-agglutination, which allows for viral spread. In this study, we used pharmacophore modeling to identify natural molecules that can inhibit the HN protein of NDV. Physicochemical characteristics and phylogenetic analysis were determined to elucidate structural information and phylogeny of target protein across different species as well as members of the virus family. For structural analysis, the missing residues of HN target protein were filled and the structure was evaluated by PROCHECK and VERIFY 3D. Moreover, shape and feature-based pharmacophore model was employed to screen natural compounds' library through numerous scoring schemes. Top 48 hits with 0.8860 pharmacophore fit score were subjected towards structure-based molecular docking. Top 9 compounds were observed witihin the range of -8.9 to -7.5 kcal/mol binding score. Five best-fitting compounds in complex with HN receptor were subjected to predict biological activity and further analysis. Top two hits were selected for MD simulations to validate binding modes and structural stability. Finally, upon scrutinization, A1 (ZINC05223166) emerges as potential HN inhibitor to treat NDV, necessitating further validation via clinical trials.

Natural products from Streptomyces spp. as potential inhibitors of the major factors (holoRdRp and nsp13) for SARS-CoV-2 replication: an in silico approach.

The COVID-19 pandemic caused unprecedented damage to humanity, and while vaccines have been developed, they are not fully effective against the SARS-CoV-2 virus. Limited targeted drugs, such as Remdesivir and Paxlovid, are available against the virus. Hence, there is an urgent need to explore and develop new drugs to combat COVID-19. This study focuses on exploring microbial natural products from soil-isolated bacteria Streptomyces sp. strain 196 and RI.24 as a potential source of new targeted drugs against SARS-CoV-2. Molecular docking studies were performed on holoRdRp and nsp13, two key factors responsible for virus replication factor. Our in silico studies, K-252-C aglycone indolocarbazole alkaloid (K252C) and daunorubicin were found to have better binding affinities than the respective control drugs, with K252C exhibiting binding energy of - 9.1 kcal/mol with holoRdRp and - 9.2 kcal/mol with nsp13, and daunorubicin showing binding energy at - 8.1 kcal/mol with holoRdRp and - 9.3 kcal/mol with nsp13. ADMET analysis, MD simulation, and MM/GBSA studies indicated that K252C and daunorubicin have the potential to be developed as targeted drugs against SARS-CoV-2. The study concludes that K252C and daunorubicin are potential lead compounds that might suppress the inhibition of SARS-CoV-2 replication among the tested microbial compounds and could be developed as targeted drugs against COVID-19. In the future, further in vitro studies are required to validate these findings.

Identification of the myxobacterial secondary metabolites Aurachin A and Soraphinol A as promising inhibitors of thymidylate kinase of the Monkeypox virus.

Thymidylate kinase (TMPK) of monkeypox virus (MPXV) has emerged as a promising target for potential therapeutics due to its significant role in pyrimidine metabolism. While smallpox drugs are advised for treating monkeypox, the European Medicine Agency has sanctioned Tecovirimat due to its potent nanomolar activity. Nonetheless, there is a need for monkeypox-specific therapeutic options. In this work, we employed docking-based virtual screening and molecular dynamics (MD) simulations to identify myxobacterial secondary metabolites as promising anti-viral natural compounds capable of inhibiting thymidylate kinase. The computational pharmacokinetics and manual curation of top-scoring compounds identified six lead compounds that were compared in terms of protein-ligand contacts and protein-essential dynamics. The study shows that among the six candidates, Aurachin A and the Soraphinol analogues such as Soraphinol A and Soraphinol C remain very stable compared to other compounds, enabling the active site integrity via a stable dynamics pattern. We also show that other compounds such as Phenoxan, Phenylnannolone C, and 8E-Aurafuron B remain unstable and have a negative impact on the active site integrity and may not be suitable binders for TMPK protein. Analyzing the Aurachin A and Soraphinol A binding, the established hydrogen bonds with Arg93 and the conserved hydrophobic interaction with Tyr101 are consistent with previous experimental interactions. Additionally, a deeper insight into the indole and the aromatic ring interaction through π-π stacking and π-cation interactions, as well as the background of Aurachin A and Soraphinol A as a bioactive compound, has significant implications not only for its potential as a promising drug but also for directing future drug discovery efforts targeting the TMPK protein.

In-silico Screening and Synthesis of Benzo[c]pyridazines Targeting N-methyl D-Aspartate Glutamate Receptor for the treatment of Seizures.

This study focuses on synthesizing novel benzopyridazine compounds with an evaluation of their anti-epileptic activity by in-silico screening and MES test. The compounds were synthesized under controlled conditions by the reaction of the substituted anilines with sodium nitrite, followed by the reaction with cyanoacetamide, substituted urea, ethanol, and water. The final compounds (5a-d; 6a-d) were tested for antiepileptic activity by in-silico screening targeting N-Methyl D-Aspartate glutamate receptor (PDB ID:5IPV). The screened compounds are also evaluated by in vivo test (MES) by taking phenytoin as a standard drug. The results of the whole study were satisfactory with the yield of the compounds in the range of 88% to 96%. The results of in- silico, screening showed that compounds 6a and 6c have far more binding energy compared with standard phenytoin (6a -7.5 Kcal/mol. ; 6c -7.6 Kcal/mol. and Phenytoin -6.5 Kcal/mol.). The TD50 values of synthesized compounds (6a-6d) are observed to be significantly higher than those of standard phenytoin. The PI values of several synthetic compounds (6a and 6c) were found to be higher (55.8% and 58.0%) than the current antiepileptic medicine phenytoin (55.6%), demonstrating the synthesized compound's safety potential.

Physicochemical Evaluation and Pharmacological Screening of Fernando Adenophylla Steenis Fruits.

The current study aimed to evaluate the physicochemical properties of Fernandoa adenophylla. Powder studies were carried out to estimate the quantitative physicochemical characteristics of the crude drug, including moisture content, ash content, and extractive values. Using a Soxhlet apparatus and different analytical grade solvents, 3 sample extracts of a crude drug were made. To evaluate the potentially toxic nature, an acute oral toxicity study was performed as per OECD guideline no. 423. Sample extracts were tested and analyzed by ANOVA for pharmacological potential (analgesic, antipyretic, and antidiabetic) using Wister-Albino rats. Where physicochemical analysis indicated purity, quality, and presence of organic/inorganic materials in crude drug extracts, no sign of mortality was found up to 2000 mg/kg of body weight of Fernandoa adenophyllas extracts. Analgesic activity was observed in all sample extracts, whereas only chloroform and ethanolic extracts expressed antipyretic and antidiabetic potential. Ethanolic extract was found to be most potent in pharmacological potential as 200 mg/kg extract dose exhibited %age pain inhibition of 55.12 % and reduced body temperature from 39.78±0.03 °C to 37.22±0.02 °C in hyperthermic rats. A decrease in blood glucose levels up to 57.88 % was observed on the 21st day of the treatment with 500 mg/kg ethanolic extract.

Bioremediation of hydrocarbon by co-culturing of biosurfactant-producing bacteria in microbial fuel cell with Fe2O3-modified anode.

The most common type of environmental contamination is petroleum hydrocarbons. Sustainable and environmentally friendly treatment strategies must be explored in light of the increasing challenges of toxic and critical wastewater contamination. This paper deals with the bacteria-producing biosurfactant and their employment in the bioremediation of hydrocarbon-containing waste through a microbial fuel cell (MFC) with Pseudomonas aeruginosa (exoelectrogen) as co-culture for simultaneous power generation. Staphylococcus aureus is isolated from hydrocarbon-contaminated soil and is effective in hydrocarbon degradation by utilizing hydrocarbon (engine oil) as the only carbon source. The biosurfactant was purified using silica-gel column chromatography and characterised through FTIR and GCMS, which showed its glycolipid nature. The isolated strains are later employed in the MFCs for the degradation of the hydrocarbon and power production simultaneously which has shown a power density of 6.4 W/m3 with a 93% engine oil degradation rate. A biogenic Fe2O3 nanoparticle (NP) was synthesized using Bambusa arundinacea shoot extract for anode modification. It increased the power output by 37% and gave the power density of 10.2 W/m3. Thus, simultaneous hydrocarbon bioremediation from oil-contamination and energy recovery can be achieved effectively in MFC with modified anode.

The antibacterial efficiency of Chitosan photodynamically activated Phycocyanin, and Morinda Oleifera against S.mutans and the bonding strength between composite resin and caries-affected dentin.

Objective: Evaluation of contemporary disinfection techniques, Moringa Oleifera (M.Oleifera), Phycocyanin activated by photodynamic therapy (PDT), and Chitosan, on S.mutans survival rate and bond integrity of composite to carious-affected dentin (CAD). Methods: The in vitro study was conducted at King Saud University and concluded within three months. Sixty mandibular teeth with cavities extending to the middle third of the dentin were sterilized. S.mutans was inoculated onto the CAD surface of twenty samples. The samples were randomly divided into four groups (n: 15) based on various disinfection regimes. Group-1 received 2% CHX, Group-2 Phycocyanin activated by photodynamic therapy (PDT), Group-3 Chitosan, and Group-4 M.oleifera. S.mutans survival rate was calculated. Ten CAD samples from each group were restored using composite. The bond integrity of samples was assessed using a Universal testing machine (UTM) and failure mode using a stereomicroscope. Analysis of variance (ANOVA) and Tukey's Post Hoc test were used to calculate statistical significance (p=0.05). Results: Group-2 samples subjected to Phycocyanin activated using PDT, displayed minimal survival rate (0.24 ± 0.05 CFU/ml) of S.mutans.Group-1 samples treated with CHX exhibited the highest count of S.mutans (0.69 ± 0.12 CFU/ml). The most robust bond was observed in Group-3 (Chitosan) samples (19.33 ± 0.47 MPa). In contrast, SBS values were lowest in Group-1 (CHX) treated study samples (13.17 ± 1.88 MPa). Conclusion: Chitosan, Phycocyanin activated by PDT, and Moringa Oleifera extract exhibit potential as viable substitutes for chlorhexidine (CHX) in clinical settings, presenting the possibility of better eradication of S.mutans and greater adhesive strength to CAD.

Assessment of the Antioxidant and Anti-inflammatory Properties of Aqueous Extract of Rosa sempervirens Leaves.

The antioxidant and anti-inflammatory properties of an aqueous natural extract obtained from Rosa sempervirens leaves were assessed. The ability of the extract to scavenge DPPH, •OH, and H2O2 radicals, chelate ferrous ions, reduce ferric ions, and protect ß-carotene-linoleic acid in emulsion from peroxidation was investigated in vitro. Furthermore, the anti-inflammatory activity of the extract was evaluated by measuring the stability of the membrane of human red blood cells against different hypotonic concentrations of NaCl and heat, as well as by inhibiting the denaturation of albumin. A high total phenolic content (278.38± 11.07 mg GAE/g) and flavonoid content (34.22± 0.12 mg QE /g) were found in the extract. The extract exhibited significant scavenging activity of DPPH (IC50 6.201 ± 0.126 µg/ ml), •OH (IC50 = 894.57 ± 21.18 µg/ml), and H2O2 (IC50= 107±09.58 µg/ml) radicals, and good antioxidant activity by chelating ferrous ions (IC50 = 2499.086 ± 28.267µg/ml), reducing ferric ions (IC50=141.33±2.34 µg/ml), exhibiting total antioxidant capacity (IC50 465.65 ± 9.71 µg/ml), and protecting ß-carotene-linoleic acid against peroxidation (I% = 90.05 ± 1.65% at 1000µg/ml). R. sempervirens displayed anti-inflammatory activity in aqueous extract by inhibiting heat-induced albumin denaturation and stabilizing the membrane of human red blood cells. It was suggested from the results that R. sempervirens aqueous extract could help prevent oxidative and inflammatory processes due to its good antioxidant and anti-inflammatory properties.

New Insight into Mechanisms of Cardiovascular Diseases: An Integrative Analysis Approach to Identify TheranoMiRNAs.

MiRNAs regulate both physiological and pathological heart functions. Altered expression of miRNAs is associated with cardiovascular diseases (CVDs), making miRNAs attractive therapeutic strategies for the diagnosis and treatment of heart diseases. A recent publication defined, for the first time, the term theranoMiRNA, meaning the miRNAs that may be used both for diagnosis and treatment. The use of in silico tools may be considered fundamental for these purposes, clarifying several molecular aspects, suggesting future directions for in vivo studies. This study aims to explore different bioinformatic tools in order to clarify miRNA interactions with candidate genes, demonstrating the need to use a computational approach when establishing the most probable associations between miRNAs and target genes. This study focused on the functions of miR-133a-3p, miR-21-5p, miR-499a-5p, miR-1-3p, and miR-126-3p, providing an up-to-date overview, and suggests future lines of research in the identification of theranoMiRNAs related to CVDs. Based on the results of the present study, we elucidated the molecular mechanisms that could be linked between miRNAs and CVDs, confirming that these miRNAs play an active role in the genesis and development of heart damage. Given that CVDs are the leading cause of death in the world, the identification of theranoMiRNAs is crucial, hence the need for a definition of in vivo studies in order to obtain further evidence in this challenging field of research.

Phytochemical characterization and anti-arthritic potential of Croton bonplandianus leaves extract: In-vivo and in-silico approach.

Croton bonplandianus, a natural source traditionally used for treating various illnesses, including rheumatoid arthritis, was evaluated in this study. The effects of ethanolic extracts (CBEE) and aqueous fractions (CBAF) of C. bonplandianus leaves on arthritis-induced inflammation were studied using an albino rat model of inflammation induced by Freund's complete adjuvant. Eight test groups (n = 5 per group) and one vehicle control were used to evaluate the antiarthritic effects of different doses of CBEE and CBAF (125 mg.kg-1, 250 mg.kg-1, and 500 mg.kg-1) on days 5, 10, 15, and 20 compared to arthritic and vehicle controls. Arthritis severity was assessed using macroscopic arthritis grading, histological analysis, body weights, and paw thickness. CBEE and CBAF were found to reduce the prevalence of arthritis, increase body weight, and decrease paw inflammation compared to the vehicle control group by the 23rd day. In addition, they showed no effect on biochemical parameters, but a significant difference (p < 0.05) in hematological parameters compared to the arthritic control group. The study identified Hentriacontane compound as a potential contributor to the anti-inflammatory effect of C. bonplandianus, as it showed the lowest dock score for IL-1ß and IL-6. Palmitoylethanol amide was identified as a potential contributor to the anti-inflammatory effect of TNF-α. Gene expression of IL-6, IL-1ß, and TNF-α was down-regulated significantly (p < 0.05) in a dose-dependent manner in all treatment groups compared to the arthritic control group. In conclusion, this study validated the anti-arthritic and anti-inflammatory properties of CBEE and CBAF in a time and dose-dependent manner.

Enzyme mediated transformation of CO2 into calcium carbonate using purified microbial carbonic anhydrase.

In this study, a bacterial carbonic anhydrase (CA) was purified from Corynebacterium flavescens for the CO2 conversion into CaCO3. The synthesized CaCO3 can be utilized in the papermaking industry as filler material, construction material and in steel industry. Herein, the CA was purified by using a Sephadex G-100 column chromatography having 29.00 kDa molecular mass in SDS-PAGE analysis. The purified CA showed an optimal temperature of 35 °C and pH 7.5. In addition, a kinetic study of CA using p-NPA as substrate showed Vmax (166.66 µmoL/mL/min), Km (5.12 mM), and Kcat (80.56 sec-1) using Lineweaver Burk plot. The major inhibitors of CA activity were Na2+, K+, Mn2+, and Al3+, whereas Zn2+ and Fe2+ slightly enhanced it. The purified CA showed a good efficacy to convert the CO2 into CaCO3 with a total conversion rate of 65.05 mg CaCO3/mg of protein. In silico analysis suggested that the purified CA has conserved Zn2+ coordinating residues such as His 111, His 113, and His 130 in the active site center. Further analysis of the CO2 binding site showed conserved residues such as Val 132, Val 142, Leu 196, Thr 197, and Val 205. However, a substitution has been observed where Trp 208 of its closest structural homolog T. ammonificans CA is replaced with Arg 207 of C. flavescens. The presence of a hydrophilic mutation in the CO2 binding hydrophobic region is a further subject of investigation.

Association Mechanism and Conformational Changes in Trypsin on Its Interaction with Atrazine: A Multi- Spectroscopic and Biochemical Study with Computational Approach.

Atrazine (ATR) is a herbicide globally used to eliminate undesired weeds. Herbicide usage leads to various adverse effects on human health and the environment. The primary source of herbicides in humans is the food laced with the herbicides. The ATR binding to trypsin (TYP) was investigated in this study to explore its binding potential and toxicity. In vitro interaction of ATR with TYP was studied using multi-spectroscopic methods, molecular docking, and enzyme kinetics to explore the mechanism of binding for the TYP-ATR system. The TYP-ATR complex revealed binding constants (103 M-1), suggesting a moderate binding. The free energy for the TYP-ATR complexes was negative, suggesting a spontaneous interaction. Thermodynamic parameters enthalpy (ΔH) and entropy (ΔS) obtained positive values for the TYP-ATR system suggesting hydrophobic interactions in the binding process. Micro-environmental and conformational changes in TYP molecules were induced on interaction with ATR. Reduced catalytic activity of TYP was observed after interaction with ATR owing to the changes in the secondary structure of the TYP.

Interaction Characterization of a Tyrosine Kinase Inhibitor Erlotinib with a Model Transport Protein in the Presence of Quercetin: A Drug-Protein and Drug-Drug Interaction Investigation Using Multi-Spectroscopic and Computational Approaches.

The interaction between erlotinib (ERL) and bovine serum albumin (BSA) was studied in the presence of quercetin (QUR), a flavonoid with antioxidant properties. Ligands bind to the transport protein BSA resulting in competition between different ligands and displacing a bound ligand, resulting in higher plasma concentrations. Therefore, various spectroscopic experiments were conducted in addition to in silico studies to evaluate the interaction behavior of the BSA-ERL system in the presence and absence of QUR. The quenching curve and binding constants values suggest competition between QUR and ERL to bind to BSA. The binding constant for the BSA-ERL system decreased from 2.07 × 104 to 0.02 × 102 in the presence of QUR. The interaction of ERL with BSA at Site II is ruled out based on the site marker studies. The suggested Site on BSA for interaction with ERL is Site I. Stability of the BSA-ERL system was established with molecular dynamic simulation studies for both Site I and Site III interaction. In addition, the analysis can significantly help evaluate the effect of various quercetin-containing foods and supplements during the ERL-treatment regimen. In vitro binding evaluation provides a cheaper alternative approach to investigate ligand-protein interaction before clinical studies.

Determination of anticancer potential of a novel pharmacologically active thiosemicarbazone derivative against colorectal cancer cell lines.

Thiosemicarbazones have received noteworthy attention due to their numerous pharmacological activities. Various thiosemicarbazone derivatives have been reported to play a key role as potential chemotherapeutic agents for the management of cancer. Herein, we aimed to establish the anticancer efficacy of novel thiosemicarbazone derivative C4 against colon cancer in vitro. The MTT viability assay identified C4 as a promising anticancer compound in a panel of cancer cell lines with the most potent activity against colon cancer cells. Further, anticancer potential of C4 was evaluated against HT-29 and SW620 colon cancer cell lines considering the factors like cell adhesion and migration, oxidative stress, cell cycle arrest, and apoptosis. Our results showed that C4 significantly inhibited the migration and adhesion of colon cancer cells. C4 significantly increased the intracellular reactive oxygen species (ROS) and induced apoptotic cell death. Cell cycle analysis revealed that C4 interfered in the cell cycle distribution and arrested the cells at the G2/M phase of the cell cycle. Consistent with these results C4 also down-regulated the Bcl-XL and Bcl-2 and up-regulated the caspase-3 expression. These findings introduced C4 as the potential anticancer agent against colon cancer.

Production and Characterization of Cross-Linked Aggregates of Geobacillus thermoleovorans CCR11 Thermoalkaliphilic Recombinant Lipase.

Immobilization of enzymes has many advantages for their application in biotechnological processes. In particular, the cross-linked enzyme aggregates (CLEAs) allow the production of solid biocatalysts with a high enzymatic loading and the advantage of obtaining derivatives with high stability at low cost. The purpose of this study was to produce cross-linked enzymatic aggregates (CLEAs) of LipMatCCR11, a 43 kDa recombinant solvent-tolerant thermoalkaliphilic lipase from Geobacillus thermoleovorans CCR11. LipMatCCR11-CLEAs were prepared using (NH4)2SO4 (40% w/v) as precipitant agent and glutaraldehyde (40 mM) as cross-linker, at pH 9, 20 °C. A U10(56) uniform design was used to optimize CLEA production, varying protein concentration, ammonium sulfate %, pH, glutaraldehyde concentration, temperature, and incubation time. The synthesized CLEAs were also analyzed using scanning electron microscopy (SEM) that showed individual particles of <1 µm grouped to form a superstructure. The cross-linked aggregates showed a maximum mass activity of 7750 U/g at 40 °C and pH 8 and retained more than 20% activity at 100 °C. Greater thermostability, resistance to alkaline conditions and the presence of organic solvents, and better durability during storage were observed for LipMatCCR11-CLEAs in comparison with the soluble enzyme. LipMatCCR11-CLEAs presented good reusability by conserving 40% of their initial activity after 9 cycles of reuse.

Inter-kingdom prediction certainty evaluation of protein subcellular localization tools: microbial pathogenesis approach for deciphering host microbe interaction.

Microbial pathogenesis involves several aspects of host-pathogen interactions, including microbial proteins targeting host subcellular compartments and subsequent effects on host physiology. Such studies are supported by experimental data, but recent detection of bacterial proteins localization through computational eukaryotic subcellular protein targeting prediction tools has also come into practice. We evaluated inter-kingdom prediction certainty of these tools. The bacterial proteins experimentally known to target host subcellular compartments were predicted with eukaryotic subcellular targeting prediction tools, and prediction certainty was assessed. The results indicate that these tools alone are not sufficient for inter-kingdom protein targeting prediction. The correct prediction of pathogen's protein subcellular targeting depends on several factors, including presence of localization signal, transmembrane domain and molecular weight, etc., in addition to approach for subcellular targeting prediction. The detection of protein targeting in endomembrane system is comparatively difficult, as the proteins in this location are channelized to different compartments. In addition, the high specificity of training data set also creates low inter-kingdom prediction accuracy. Current data can help to suggest strategy for correct prediction of bacterial protein's subcellular localization in host cell.

Interaction of an abiraterone with calf thymus DNA: Investigation with spectroscopic technique and modelling studies.

Binding of toxic ligands to DNA could result in undesirable biological processes, such as carcinogenesis or mutagenesis. Binding mode of Abiraterone (ABR), a steroid drug and calf thymus DNA (ctDNA) was investigated in this study using fluorescence and ultraviolet-visible spectroscopy. The probable prediction of binding and the type of interaction forces involved in the arrangement between ABR and ctDNA were explored through spectroscopic and molecular docking studies. The results indicated that ABR binds to the ctDNA in the minor groove. The binding constants were in the range of 1.35 × 106-0.36 × 106 L mol-1 at the studied temperatures. Fluorescence and spectrophotometric data suggested static quenching between ctDNA and ABR. The endothermic values of thermodynamic parameters ΔH°=-82.84 kJ mol-1; ΔS°=-161 J mol-1K-1 suggested that hydrogen bonding is the main force involved in binding of ABR with ctDNA. In experimental studies, the free binding energy at 298 K was -34.9 kJ mol-1 with the relative binding energy ≈ -29.65 kJ mol-1 of docked structure. The Ksv obtained for ABR-KI was similar to that for ABR- ctDNA -KI demonstrating no protection by ctDNA against quenching effect of KI. Thus, suggesting involvement of groove binding between ABR and ctDNA. No change in the fluorescence intensity of ABR-ctDNA was observed in presence of NaCl. Thus, ruling out the involvement of electrostatic interaction. These studies could serve as new insights in understanding the mechanisms of toxicity, resistance and side effects of ABR.

Novel sulindac derivatives: synthesis, characterisation, evaluation of antioxidant, analgesic, anti-inflammatory, ulcerogenic and COX-2 inhibition activity.

A new series of N'-(substituted phenyl)-2-(1-(4-(methylsulfinyl) benzylidene)-5-fluoro-2-methyl-1H-inden-3-yl) acetohydrazide derivatives (1 - 25) were prepared in good yields in an efficient manner. All the compounds were fully characterised by the elemental analysis and spectral data. Synthesised compounds were evaluated for antioxidant activity by DPPH method. Compounds 7 (R = 3-methoxyphenyl), 3 (R = 4-dimethylaminophenyl) and 23 (R = 2,4,5-trimethoxy phenyl) substitutions were found to be having highly potent antioxidant activity. Compound 3, with para dimethylaminophenyl substitution was found to be having highest antioxidant activity. It was further evaluated in vivo for various analgesic, anti-inflammatory, ulcerogenic and COX-2 inhibitory activity in different animal models. Lead compound 3 was found to be significant anti-inflammatory and analgesic agent. It was also evaluated for ulcerogenic activity and demonstrated significant ulcerogenic reduction activity in ethanol and indomethacin model. The LD50 of compound 3 was found to be 131 mg/kg. The animals treated with compound 3 prior to cisplatin treatment resulted in a significant reduction in COX-2 protein expression when compared to cisplatin-treated group. Sulindac derivative with para dimethylaminophenyl substitution was found to be the most potent antioxidant, anti-inflammatory and analgesic agent as well as with significant gastric sparing activity as compared to standard drug sulindac. Compound 3 significantly downregulated liver tissue COX-2 gene expression.

Synthesis of Novel Sulfamethaoxazole 4-Thiazolidinone Hybrids and Their Biological Evaluation.

A search for potent antitubercular agents prompted us to design and synthesize sulfamethaoxazole incorporated 4-thiazolidinone hybrids (7a-l) by using a cyclocondensation reaction between 4-amino-N-(5-methylisoxazol-3-yl)benzenesulfonamide (4), aryl aldehyde (5a-l), and mercapto acetic acid (6) resulting in good to excellent yields. All the newly synthesized 4-thiazolidinone derivatives were screened for their in vitro antitubercular activity against M. Bovis BCG and M. tuberculosis H37Ra (MTB) strains. The compounds 7d, 7g, 7i, 7k, and 7l revealed promising antimycobacterial activity against M. Bovis and MTB strains with IC90 values in the range of 0.058-0.22 and 0.43-5.31 µg/mL, respectively. The most active compounds were also evaluated for their cytotoxicity against MCF-7, HCT 116, and A549 cell lines and were found to be non-cytotoxic. Moreover, the synthesized compounds were also analyzed for ADME (absorption, distribution, metabolism, and excretion) properties and showed potential as good oral drug candidates.