Genome mining of Mycobacterium tuberculosis: targeting SufD as a novel drug candidate through in silico characterization and inhibitor screening.

Tuberculosis (TB) stands as the second most fatal infectious disease globally, causing 1.3 million deaths in 2022. The resurgence of TB and the alarming rise of antibiotic resistance demand urgent call to develop novel antituberculosis drugs. Despite concerted efforts to control TB, the disease persists and spreads rapidly on a global scale. Targeting stress response pathways in Mycobacterium tuberculosis (Mtb) has become imperative to achieve complete eradication. This study employs subtractive genomics to identify and prioritize potential drug targets among the hypothetical proteins of Mtb, focusing on indispensable pathways. Amongst 177 essential hypothetical proteins, 152 were nonhomologous to human. These proteins participated in 34 pathways, and a 20-fold enrichment of SUF pathway genes led to its selection as a target pathway. Fe-S clusters are fundamental, widely distributed protein cofactors involved in vital cellular processes. The survival of Mtb in a hypoxic environment relies on the iron-sulfur (Fe-S) cluster biogenesis pathway for the repair of damaged Fe-S clusters. It also protects pathogen against drugs, ensuring controlled iron utilization and contributing to drug resistance. In Mtb, six proteins of Fe-S cluster assembly pathway are encoded by the suf operon. The present study was focused on SufD because of its role in iron acquisition and prevention of Fenton reaction. The research further delves into the in silico characterization of SufD, utilizing bioinformatics tools for sequence and structure based analysis. The protein's structural features, including the identification of conserved regions, motifs, and 3D structure prediction enhanced functional annotation. Target based virtual screening of compounds from the ChEMBL database resulted in 12 inhibitors with best binding affinities. Drug likeness and ADMET profiling of potential inhibitors identified promising compounds with favorable drug-like properties. The study also involved cloning in SUMO-pRSF-Duet1 expression vector, overexpression, and purification of recombinant SufD from E. coli BL21 (DE3) cells. Optimization of expression conditions resulted in soluble production, and subsequent purification highlighting the efficacy of the SUMO fusion system for challenging Mtb proteins in E. coli. These findings provide valuable insights into pharmacological targets for future experimental studies, holding promise for the development of targeted therapy against Mtb.

Inhibitory effect of Nifedipine on aldose reductase delays cataract progression.

Aldose reductase (ALR2) is a rate-limiting component of the polyol pathway, which is essential for the NADPH-mediated conversion from glucose to sorbitol. ALR2 dysregulation has been linked to α-crystallin aggregation, increased oxidative stress, and calcium inflow, all of which contribute to a diabetic cataract. Given its crucial role in occular pathologies, ALR2 has emerged as a promising target to treat oxidative stress and hyperglycaemic condition which form the underlying cause of diabetic cataracts. However, several of them had issues with sensitivity and specificity to ALR2, despite being screened as effective ALR2 inhibitors from a wide range of structurally varied molecules. The current study investigates the inhibitory potential of Nifedipine, an analog of the dihydro nicotinamide class of compounds against ALR2 activity. The enzyme inhibition studies were supported by in vitro biomolecular interactions, molecular modeling approaches, and in vivo validation in diabetic rat models. Nifedipine demonstrated appreciable inhibitory potential with the purified recombinant hAR (human aldose reductase; with an IC50 value of 2.5 µM), which was further supported by Nifedipine-hAR binding affinity (Kd = 2.91 ± 1.87 × 10-4 M) by ITC and fluorescence quenching assays. In the in vivo models of STZ-induced diabetic rats, Nifedipine delayed the onset progression of cataracts by preserving the antioxidant enzyme activity (SOD, CAT, and GPX GSH, TBARS, and protein carbonyls) and was shown to retain the α-crystallin chaperone activity by reducing the calcium levels in the diabetic rat lens. In conclusion, our results demonstrate effective inhibition of ALR2 by Nifedipine, resulting in amelioration of diabetic cataract conditions by lowering oxidative and osmotic stress while retaining the chaperone activity of α-crystallins. The present study could be envisaged to improve the eye condition in older adults upon Nifedipine treatment.

Molecular docking-based screening of methicillin-resistant Staphylococcus aureus FEM proteins with FDA-approved drugs.

Antibiotic resistance stands as one of the most significant public health challenges in recent decades. FEM proteins are responsible for the synthesis of pentaglycine cross-bridge, a primary constituent of bacterial peptidoglycan polymer crosslinking during cell wall biosynthesis. Since they are necessary for bacterial survival and antibiotic resistance, they were considered as significant antibacterial targets. We report herein, the virtual screening and selection of FDA-approved drugs and their potent similar molecules as FEM protein inhibitors and analyzed for inhibiting affinity and their ADMET pharmacokinetic properties. This data provide a foundation for the development and optimization of structurally innovative antimicrobial drugs.

Cloning, Purification, and Biophysical Characterization of FemB Protein from Methicillin-Resistant Staphylococcus aureus and Inhibitors Screening.

Methicillin-resistant Staphylococcus aureus has emerged as a leading cause of nosocomial, community acquired infections worldwide. Earlier investigations revealed that mecA-encoded FEM proteins play a role in antimicrobial resistance by developing unique peptidoglycan cross-linking which helps in the formation of protective cell membrane. In view to this, present study focused on expression, purification FEM proteins, and FemB biophysical characterization with the aid of in silico and in vitro approaches. Furthermore, we carried out biological screening assays and identified the novel potent 1,2,3-triazole conjugated 1,3,4-oxadiazole hybrid molecule which could inhibit the MRSA than the proven oxacillin.

The protein conformational basis of isoflavone biosynthesis.

Isoflavonoids play important roles in plant defense and also exhibit a range of mammalian health-promoting activities. Their biosynthesis is initiated by two enzymes with unusual catalytic activities; 2-hydroxyisoflavanone synthase (2-HIS), a membrane-bound cytochrome P450 catalyzing a coupled aryl-ring migration and hydroxylation, and 2-hydroxyisoflavanone dehydratase (2-HID), a member of a large carboxylesterase family that paradoxically catalyzes dehydration of 2-hydroxyisoflavanones to isoflavone. Here we report the crystal structures of 2-HIS from Medicago truncatula and 2-HID from Pueraria lobata. The 2-HIS structure reveals a unique cytochrome P450 conformation and heme and substrate binding mode that facilitate the coupled aryl-ring migration and hydroxylation reactions. The 2-HID structure reveals the active site architecture and putative catalytic residues for the dual dehydratase and carboxylesterase activities. Mutagenesis studies revealed key residues involved in substrate binding and specificity. Understanding the structural basis of isoflavone biosynthesis will facilitate the engineering of new bioactive isoflavonoids.

Characterization of 'QTL-hotspot' introgression lines reveals physiological mechanisms and candidate genes associated with drought adaptation in chickpea.

'QTL-hotspot' is a genomic region on linkage group 04 (CaLG04) in chickpea (Cicer arietinum) that harbours major-effect quantitative trait loci (QTLs) for multiple drought-adaptive traits, and it therefore represents a promising target for improving drought adaptation. To investigate the mechanisms underpinning the positive effects of 'QTL-hotspot' on seed yield under drought, we introgressed this region from the ICC 4958 genotype into five elite chickpea cultivars. The resulting introgression lines (ILs) and their parents were evaluated in multi-location field trials and semi-controlled conditions. The results showed that the 'QTL-hotspot' region improved seed yield under rainfed conditions by increasing seed weight, reducing the time to flowering, regulating traits related to canopy growth and early vigour, and enhancing transpiration efficiency. Whole-genome sequencing data analysis of the ILs and parents revealed four genes underlying the 'QTL-hotspot' region associated with drought adaptation. We validated diagnostic KASP markers closely linked to these genes using the ILs and their parents for future deployment in chickpea breeding programs. The CaTIFY4b-H2 haplotype of a potential candidate gene CaTIFY4b was identified as the superior haplotype for 100-seed weight. The candidate genes and superior haplotypes identified in this study have the potential to serve as direct targets for genetic manipulation and selection for chickpea improvement.

Genetic variation in CaTIFY4b contributes to drought adaptation in chickpea.

Chickpea production is vulnerable to drought stress. Identifying the genetic components underlying drought adaptation is crucial for enhancing chickpea productivity. Here, we present the fine mapping and characterization of 'QTL-hotspot', a genomic region controlling chickpea growth with positive consequences on crop production under drought. We report that a non-synonymous substitution in the transcription factor CaTIFY4b regulates seed weight and organ size in chickpea. Ectopic expression of CaTIFY4b in Medicago truncatula enhances root growth under water deficit. Our results suggest that allelic variation in 'QTL-hotspot' improves pre-anthesis water use, transpiration efficiency, root architecture and canopy development, enabling high-yield performance under terminal drought conditions. Gene expression analysis indicated that CaTIFY4b may regulate organ size under water deficit by modulating the expression of GRF-INTERACTING FACTOR1 (GIF1), a transcriptional co-activator of Growth-Regulating Factors. Taken together, our study offers new insights into the role of CaTIFY4b and on diverse physiological and molecular mechanisms underpinning chickpea growth and production under specific drought scenarios.

Morpho-Physiological and Proteomic Response of Bt-Cotton and Non-Bt Cotton to Drought Stress.

Drought stress impacts cotton plant growth and productivity across countries. Plants can initiate morphological, cellular, and proteomic changes to adapt to unfavorable conditions. However, our knowledge of how cotton plants respond to drought stress at the proteome level is limited. Herein, we elucidated the molecular coordination underlining the drought tolerance of two inbred cotton varieties, Bacillus thuringiensis-cotton [Bt-cotton + Cry1 Ac gene and Cry 2 Ab gene; NCS BG II BT (BTCS/BTDS)] and Hybrid cotton variety [Non-Bt-cotton; (HCS/HDS)]. Our morphological observations and biochemical experiments showed a different tolerance level between two inbred lines to drought stress. Our proteomic analysis using 2D-DIGE revealed that the changes among them were not obviously in respect to their controls apart from under drought stress, illustrating the differential expression of 509 and 337 proteins in BTDS and HDS compared to their controls. Among these, we identified eight sets of differentially expressed proteins (DEPs) and characterized them using MALDI-TOF/TOF mass spectrometry. Furthermore, the quantitative real-time PCR analysis was carried out with the identified drought-related proteins and confirmed differential expressions. In silico analysis of DEPs using Cytoscape network finds ATPB, NAT9, ERD, LEA, and EMB2001 to be functionally correlative to various drought-responsive genes LEA, AP2/ERF, WRKY, and NAC. These proteins play a vital role in transcriptomic regulation under stress conditions. The higher drought response in Bt cotton (BTCS/BTDS) attributed to the overexpression of photosynthetic proteins enhanced lipid metabolism, increased cellular detoxification and activation chaperones, and reduced synthesis of unwanted proteins. Thus, the Bt variety had enhanced photosynthesis, elevated water retention potential, balanced leaf stomata ultrastructure, and substantially increased antioxidant activity than the Non-Bt cotton. Our results may aid breeders and provide further insights into developing new drought-tolerant and high-yielding cotton hybrid varieties.

Design and synthesis, biological evaluation of bis-(1,2,3- and 1,2,4)-triazole derivatives as potential antimicrobial and antifungal agents.

A new series of bis-1,2,3- and 1,2,4-triazoles (10a-m) were designed and efficiently synthesized using methyl salicylate as potential antimicrobial agents. All compounds were characterized by their proton & 13C NMR, IR, Mass spectral data, and elemental analysis. The final compounds 10a-m were in vitro screened for antimicrobial and antifungal activity against gram negative Pseudomonas aeruginosa, Escherichia coli, gram positive Bacillus subtilis, Staphylococcus aureus strains and Aspergillus niger & Saccharomyces cerevisiae. Majority of the synthesized compounds exhibited potent antimicrobial activity (MIC 3.9 µg/mL) and promising antifungal activity with the zone of inhibition (ZOI) 1.5-8.2 mm. Compounds like 10d and 10f exhibited best antimicrobial activity against S. aureus. The molecular docking analysis revealed that all the synthesized derivatives shown better binding affinities. Among all, compound 10f exhibited best scores. Hence, there was an assumption that introduction of para-chloro and bromo-phenyl aromatic groups on triazole moiety could result excellent antimicrobial activity. This substantial growth inhibitory activity of bis-1,2,3- and 1,2,4-triazole derivatives suggested these compounds could assist a new way in the development of lead molecules against microbial infection and antimicrobial resistance investigations.

Synthesis and cytotoxicity of novel 14α-O-(1,4-disubstituted-1,2,3-triazolyl) ester derivatives of andrographolide.

A series of novel 14α-O-(1,4-disubstituted-1,2,3-triazolyl) ester derivatives of andrographolide (5a-n) were synthesized from andrographolide (1). For this endeavour, selective esterification at C-14 hydroxyl group of andrographolide (1) with propiolic acid via protection, deprotection strategy followed by 1,4-regioselective [1,3]dipolar cycloaddition of alkyne, azide using Cu(I) catalyzed Click chemistry. All the synthesized derivatives were screened for their cytotoxicity on HCT-15, HeLa and K562 cell lines. Compounds 5c and 5j showed highest activity against HCT-15 and K562 cell lines whereas compound 5a displayed activity in all the three cell lines. Loss of cell viability was not observed with the non-transformed cell line MRC-5 with compounds 5j, 5k, 5h and 2 indicating cytotoxic activity of these compounds towards cancer cell lines. Further, molecular docking analysis and SAR studies of highly active compounds 5c and 5j revealed enhanced binding affinity to the target NF-κB protein.

Designing of Nucleocapsid Protein Based Novel Multi-epitope Vaccine Against SARS-COV-2 Using Immunoinformatics Approach.

The COVID-19 disease is caused by SARS-CoV-2 and spreading rapidly worldwide with extremely high infection rate. Since effective and specific vaccine is not available to combat the deadly COVID-19, the objective of our study was to design a multi-epitope vaccine using immunoinformatics approach with translational implications. Nucleocapsid (N) protein of SARS-CoV-2 is stable, conserved and highly immunogenic along with being less prone to mutations during infection, which makes it a suitable candidate for designing vaccine. In our study, B- and T-cells epitopes were identified from N protein and screened based on crucial parameters to design the multi-epitope vaccine construct. Additionally, human beta-defensin-2 was incorporated into the vaccine construct as an adjuvant along with suitable linkers followed by its further evaluation based on crucial parameters including allergenicity, antigenicity, stability etc. Combined major histocompatibility complexes (MHC-I and MHC-II) binding epitopes presented broader population coverage of the vaccine throughout the world. The three-dimensional structure of vaccine candidate implied strong interaction with toll-like receptor 3 (TLR3) using molecular docking. The vaccine-TLR3 complex was observed to be highly stable during simulation and electrostatic free energy was foremost contributor for stabilization of the structure. Subsequently, in silico cloning of vaccine candidate was carried out to generate the construct into pET-28a(+) expression vector succeeded by its virtual confirmation. Altogether, our results advocate that the designed vaccine candidate could be an effective and promising weapon to fight with COVID-19 infection worldwide.

Development of a dense genetic map and QTL analysis for pod borer Helicoverpa armigera (Hübner) resistance component traits in chickpea (Cicer arietinum L.).

Genetic enhancement for resistance against the pod borer, Helicoverpa armigera is crucial for enhancing production and productivity of chickpea. Here we provide some novel insights into the genetic architecture of natural variation in H. armigera resistance in chickpea, an important legume, which plays a major role in food and nutritional security. An interspecific recombinant inbred line (RIL) population developed from a cross between H. armigera susceptible accession ICC 4958 (Cicer arietinum) and resistant accession PI 489777 (Cicer reticulatum) was evaluated for H. armigera resistance component traits using detached leaf assay and under field conditions. A high-throughput AxiomCicerSNP array was utilized to construct a dense linkage map comprising of 3,873 loci and spanning a distance of 949.27 cM. Comprehensive analyses of extensive genotyping and phenotyping data identified nine main-effect QTLs and 955 epistatic QTLs explaining up to 42.49% and 38.05% phenotypic variance, respectively, for H. armigera resistance component traits. The main-effect QTLs identified in this RIL population were linked with previously described genes, known to modulate resistance against lepidopteran insects in crop plants. One QTL cluster harbouring main-effect QTLs for three H. armigera resistance component traits and explaining up to 42.49% of the phenotypic variance, was identified on CaLG03. This genomic region, after validation, may be useful to improve H. armigera resistance component traits in elite chickpea cultivars.

Genetic Dissection and Identification of Candidate Genes for Salinity Tolerance Using Axiom®CicerSNP Array in Chickpea.

Globally, chickpea production is severely affected by salinity stress. Understanding the genetic basis for salinity tolerance is important to develop salinity tolerant chickpeas. A recombinant inbred line (RIL) population developed using parental lines ICCV 10 (salt-tolerant) and DCP 92-3 (salt-sensitive) was screened under field conditions to collect information on agronomy, yield components, and stress tolerance indices. Genotyping data generated using Axiom®CicerSNP array was used to construct a linkage map comprising 1856 SNP markers spanning a distance of 1106.3 cM across eight chickpea chromosomes. Extensive analysis of the phenotyping and genotyping data identified 28 quantitative trait loci (QTLs) explaining up to 28.40% of the phenotypic variance in the population. We identified QTL clusters on CaLG03 and CaLG06, each harboring major QTLs for yield and yield component traits under salinity stress. The main-effect QTLs identified in these two clusters were associated with key genes such as calcium-dependent protein kinases, histidine kinases, cation proton antiporter, and WRKY and MYB transcription factors, which are known to impart salinity stress tolerance in crop plants. Molecular markers/genes associated with these major QTLs, after validation, will be useful to undertake marker-assisted breeding for developing better varieties with salinity tolerance.

Synthesis, cytotoxicity, and molecular docking of substituted 3-(2-methylbenzofuran-3-yl)-5-(phenoxymethyl)-1,2,4-oxadiazoles.

A series of new benzofuran/oxadiazole hybrids (8a-n) was synthesized from 2H-chromene-3-carbonitriles (3a-c) through the multistep synthetic methodology, and these hybrids are known to exhibit anticancer activities. All the compounds were evaluated for their in vitro cytotoxicity against the HCT116 and MIA PaCa2 cell lines. Compounds 6a (IC50 : 9.71 ± 1.9 µM), 6b (IC50 : 7.48 ± 0.6 µM), and 6c (IC50 : 3.27 ± 1.1 µM) displayed a significant cytotoxic activity, whereas compounds 8d and 8e exhibited good activity against both cell lines. The depletion of glycogen synthase kinase-3ß (GSK3ß) induces apoptosis through the inhibition of basal NF-κB activity in HCT116 colon cancer cells and MIA PaCa2 pancreatic cancer cells. Molecular docking of compounds 6a, 6b, 6c, 8d, and 8e with GSK3ß demonstrated the best binding affinity, correlating with the biological activity assay. Furthermore, the structure-activity relationship of these novel compounds reveals promising features for their use in anticancer therapy.

Elucidating the preference of dimeric over monomeric form for thermal stability of Thermus thermophilus isopropylmalate dehydrogenase: A molecular dynamics perspective.

An oligomer usually refers to a macromolecular complex formed by non-covalent interactions of monomers. Several thermophilic proteins are oligomers. The significance of oligomerization of individual proteins for stability at higher temperature is of prime importance for understanding evolution and increasing industrial productivity. The functional form of Thermus thermophilius isopropylmalate dehydrogenase (IPMDH), a widely studied protein to understand the factors affecting the thermal stability of a protein is a dimer, a simplest oligomer. To decipher the relationship between the effects of oligomerization on thermal stability of a protein, we have applied all-atom molecular mechanics approach by analyzing how temperature effects dynamics of a subunit in the presence and absence of another subunit in dimeric (SS) and monomeric forms (SA), respectively, before its denaturation begins. Comparing the difference in overall dynamic structural aspects at two different temperatures, 300 K and 337 K. Analysis of root mean square deviation (RMSD), root mean square fluctuations (RMSF) and Cα-Cα distance with an increase in temperature from 300 K to 337 K for a total of 0.2 µs reveals higher thermal stability of the dimer as compared to monomer. In contrast to dimeric form, the monomer is relatively stable at 300 K but cannot withstand the structural stability at 337 K leading to loosening of intramolecular interactions with maximum fluctuation at B23-B24 within a subunit. Energetic and structural properties indicate that B24-B24' is the major contributor to maintaining subunit-subunit interaction at 337 K. Correlation between the favorable interaction energy (IE) with the minimal perturbance in Cα atoms of domain 2 in a subunit in the presence of another subunit enhances the rigidity of the domain with subunit-subunit interaction. Overall, the study indicates that the dimeric over monomeric form enhances the protein's thermal stability and not all major subunit interacting regions contribute equally in maintaining the former.

Molecular docking analysis of an isoflavone derivative with the protein phosphatase 1 from Leishmania donovani.

Leishmaniasis is one of the most neglected diseases with high morbidity and mortality rate. Severe side effects with existing drug and lack of proper vaccine encouraged us to design alternative models to combat the disease. We showed that PP1 of Leishmania donovani mediates immunomodulation in host macrophages needed for parasite survival. Therefore, it is of interest to report the molecular docking analysis of 512 isoflavone derivatives with the phosphatase 1 protein from Leishmania donovani to highlight compound 362 (5-hydroxy-5-{9-[2-methoxy-2-(2-methylfuran-3-yl) ethyl]-1H, 3H, 4H, 10bH-pyrano[4,3-c]chromen-3-yl}pentanoic acid) having good binding features and acceptable ADMET properties for further consideration.

Association of CDKN2BAS gene polymorphism with periodontitis and Coronary Artery Disease from South Indian population.

BACKGROUND: Periodontal disease (PD), a chronic inflammatory disorder mediated by progressive destruction of the oral cavity is one of the key factors for many systemic disorders including Coronary Artery Disease (CAD). The upregulation of CDKN2BAS, a long noncoding RNA gene expression in gingival epithelial cells and gingival fibroblasts of periodontitis shows a strong correlation between the severity of atherosclerosis and PD. Considering the crucial role of CDKN2BAS gene polymorphisms (rs496892 G > A and rs7865618 A > G) and its expression the present study sought to identify the possible association with the disease predisposition in South Indian population. METHODS: For the present case-control study a total of 200 subjects that include 100 PD-CAD patients and 100 controls were recruited with prior consent. Genomic DNA and RNA were extracted and utilized for genotyping via ARMS-PCR and PCR-RFLP, and expression using RT-PCR respectively. RESULTS: The results showed a significant association of both the polymorphisms with that of the disease predisposition. The wild type genotypes (GG: OR-0.37; p-0.001; & AA: OR-0.29; p-0.005) conferred protection against the disease, whereas, the heterozygotes (GA: OR-2.45; p-0.004 & AG: OR-3.41; p-0.0001) conferred risk towards the disease, suggesting the involvement of the variant allele in disease causation. These results were further confirmed by haplotype analysis among A-G block (two variant alleles at both loci) with 2.5 fold risk (OR = 2.49, 95% CI = 1.16-5.36, p = 0.02) and G-G block (single risk allele at rs7865618 locus) with 3-fold risk (OR-3.0; p-0.01) towards the disease, suggesting the dominant involvement of rs7865618 in the disease causation. Though the expression of the CDKN2BAS gene is more in patients than controls, the variant genotypes among patients were evaluated to be down-regulated than the other genotypes. CONCLUSION: The present study concludes that the two selected polymorphisms have significant involvement individually and in interaction with each other in the disease predisposition. The expression studies also suggest that the selected polymorphisms in the 9p21.3 locus affect the CDKN2BAS gene expression. However, the results obtained in the present study should be confirmed with large samples in other ethnic cohorts.

Synthesis and biological evaluation of 1H-pyrrolo[2,3-d]pyrimidine-1,2,3-triazole derivatives as novel anti-tubercular agents.

A series of novel 1H-pyrrolo[2,3-d]pyrimidine-1,2,3-triazole derivatives have been synthesized in good to excellent yields. Through the copper-catalyzed azide-alkyne cycloaddition via reaction of 7-(prop-2-ynyl)-7H-pyrrolo[2,3-d]pyrimidine and aryl, heteroaryl and alkyl azides in the presence of CuSO4·5H2O and sodium ascorbate. These compounds were evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain. Most of these pyrrolopyrimidine-triazole hybrids exhibited good anti tubercular activity. The antimycobacterial assay results showed that the minimum inhibitory concentration of compounds 4q and 4r were 0.78 µg/mL. The molecular docking results also had shown highest Moldock score for same compounds. These novel compounds exhibited good inhibition activities and further structure-activity studies of the derivatives had shown promising features to use in antitubercular therapy.

Design and synthesis of chiral 2H-chromene-N-imidazolo-amino acid conjugates as aldose reductase inhibitors.

Aldose reductase (ALR2) inhibitors provide a viable mode to fight against diabetic complications. ALR2 exhibit plasticity in the active site vicinities and possible shifts in the nearby two supporting alpha helices. Therefore, a novel series of amino acid conjugates of chromene-3-imidazoles (13-15) were designed and synthesized based on natural isoflavonoids. The compounds were identified on the basis of spectral (1H NMR, 13C NMR and MS) data and tested in vitro for ALR2 inhibitory activity with an IC50 value ranges from 0.031 ± 0.082 µM to 4.29 ± 0.55 µM. Our in silico and biochemical studies confirmed that 15e has the best inhibition activity among the synthesized compounds with a high selective index against the Aldehyde reductase (ALR1). Supplementation of 15e to STZ induced rats decreased the blood glucose levels and delayed the progression of cataract in a dose-dependent manner. The present study thus provides novel series of compounds with a promising inhibitor to prevent or delay the cataract progression.

Association of Beta 2 adrenergic receptor (Thr164Ile) polymorphism with Salbutamol refractoriness in severe asthmatics from Indian population.

BACKGROUND: Thr164Ile polymorphism in the ADRB2 gene encoding ß2 adrenergic receptor (ß2AR) has its functional consequence in declining ligand-receptor interactions and depressed coupling of ß2AR to adenylcyclase. In the present study, we sought to evaluate the possible association of Thr164Ile polymorphism with asthma susceptibility, pharmacogenetic response to Salbutamol and varying degrees of severity. METHODS: Three hundred and ninety eight clinically diagnosed patients and four hundred and fifty six healthy controls were enrolled in the study. Patients were classified into severity classes according to the Global Initiative for Asthma (GINA) guidelines. To assess bronchodilator response, spirometry was performed before and 15min after Salbutamol (200µg) delivery. Responders to Salbutamol were categorized if percentage reversibility was greater than or equal to 12% in them, while those showing reversibility <12% were classified as non-responders. Further, responding phenotypes were stratified into severity groups. Genotyping was carried out by ARMS-PCR technique. Statistical methods were applied to test the significance of the results. RESULTS: In the present study, polymorphism was not associated with disease susceptibility however; there was significant association with non-responding asthmatics. In case of severity subsets, the polymorphism was not associated with milder subtypes; although, notable association was observed with moderate and severe asthma subtypes. In addition, the polymorphism was significantly associated with non-responding patients with severe asthma. CONCLUSIONS: In south Indian population, the ADRB2 Thr164Ile polymorphism may not form susceptible variant to develop asthma, however, it can form a predictive maker for bronchodilator (Salbutamol) response in severe asthmatics.