Design, synthesis, molecular docking, and biological evaluation of coumarin-thymidine analogs as potent anti-TB agents.

With the intent to discover new antituberculosis (TB) compounds, coumarin-thymidine analogs were synthesized using second-order nucleophilic substitution reactions of bromomethyl coumarin with thymidine. The newly synthesized coumarin-thymidine conjugates (1a-l) were characterized using IR, NMR, GC-MS, and CHN elemental analysis. The novel conjugates were found to exhibit potent anti-TB activity against the Mycobacterium tuberculosis H37 Rv strain, with minimum inhibitory concentrations (MIC) of the active compounds ranging between 0.012 and 0.482 µM. Compound 1k was established as the most active candidate with a MIC of 0.012 µM. The toxicity study on HEK cells confirmed the nontoxic nature of compounds 1e, 1h, 1i, 1j, and 1k. Also, the most active compounds (1k, 1j, and 1e) were stable in the pH range from 2.5 to 10, indicating compatibility with the biophysical environment. Based on the pKa studies, compounds 1k, 1j, and 1e are capable of crossing lipid-membrane barriers and acting on target cells. Molecular docking studies on the M. tuberculosis ß-oxidation trifunctional enzyme (PDB ID: 7O4V) were conducted to investigate the mechanisms of anti-TB activity. All compounds showed excellent hydrogen binding interactions and exceptional docking scores against M. tuberculosis, which was in accordance with the results. Compounds 1a-l possessed excellent affinity to proteins, with binding energies ranging from -7.4 to -8.7 kcal/mol.

ON donor tethered copper (II) and vanadium (V) complexes as efficacious anti-TB and anti-fungal agents with spectroscopic approached HSA interactions.

Antimicrobial drug resistance poses a significant threat worldwide, hence triggering an urgent situation for developing feasible drugs. 3D-transition metal coordination complexes being multifaceted, offer tremendous potency as drug candidates. However, there are fewer reports on non-toxic and safe transition metal complexes; therefore, we hereby attempted to develop novel copper and vanadium-based therapeutic agents. We have synthesised six metal complexes viz., [VVO2(Quibal-INH)] (1), [CuII(Quibal-INH)2] (2), [VVO(Quibal-INH) (cat)] (3), [CuII(Quibal-INH) (cat)] (4), [VVO(Quibal-INH) (bha)] (5) and [CuII(Quibal-INH) (bha)] (6). Quibal-INH (L) is an ON bidentate donor ligand synthesized from Schiff base reaction between 4-(2-(7-chloroquinolin-3-yl)vinyl)benzaldehyde (Quibal) and Isoniazid (INH). The synthesized compounds were characterized using analytical techniques involving ATR-IR, UV-Vis, EPR, 1H NMR, 13C NMR, and 51V NMR. Ligand (L) and compound 3 exhibited moderate growth inhibitory activity towards Candida albicans and Cryptococcus neoformans fungal species. Compound 6 has been identified as active against the above fungal species with no toxicity and hemolysis activity on the healthy cells. Compound 5 exhibited significant activity against the Mycobacterium tuberculosis H 37 R v strain. Further, compounds 4, 5 and 6 exhibited excellent free radical scavenging activity. All the developed compounds were found to exhibit stability over a wide range of pH conditions. The complexes were additionally studied for their interaction with human serum albumin (HSA) with the UV-vis spectroscopic technique.

Snake Venom-specific Phospholipase A2: A Diagnostic Marker for the Management of Snakebite Cases.

Background: Snakebites are a common cause of morbidity and mortality, especially in tropical countries. Snakebites in any community are managed based on the clinical features and intravenous administration of antisnake venom (ASV). The administration of ASV is either deficient or given in excess based on clinical decisions and whole blood clotting test results. The present study is designed to analyze the level of snake venom component in the blood of snakebite in association with the clinical features. Patients and methods: Blood samples were collected from the patients admitted to Karnataka Institute of Medical (KIMS) hospital with a history of snakebite considering the inclusion criteria. Serum was collected from the blood of snakebite patients before and after ASV and used to assess the level of venom-specific phospholipase A2 (PLA2) enzyme using the enzyme-linked immunosorbent assay (ELISA) method. Results: Quantitative ELISA results revealed that the snake venom-specific PLA2 in the victim's blood was in the range of 0.3-1.27 mg/mL before the administration of ASV. However, the concentration of PLA2 after 24 hours of ASV administration was decreased in most of the patients. Further, it was observed that envenomation complications were directly proportional to the amount of snake venom-specific PLA2 found in the blood of the snakebite patient. Conclusion: The study concludes that snake venom-specific PLA2 in the blood of snakebite patients could be used as a reliable venom marker, which helps in determination of appropriate ASV dosage in snakebite patients. How to cite this article: Kaulgud RS, Hasan T, Vanti GL, Veeresh S, Uppar AP, Kurjogi MM. Snake Venom-specific Phospholipase A2: A Diagnostic Marker for the Management of Snakebite Cases. Indian J Crit Care Med 2022;26(12):1259-1266.

Prevalence of hypertension and its associated risk factors in Dharwad population: A cross-sectional study.

The study aims to determine the prevalence of hypertension and associated risk factors. The study includes 9754 participants, out of which 6403 were found to be associated with hypertension. Among 6403 participants 27.75% were newly diagnosed with hypertension during examination. The present study showed, age as one of the significant risk factors for prevalence of hypertension. Further observations revealed that, the prevalence of hypertension was higher in alcohol-intake, tobacco-smoking/chewing participants and sedentary life style is also one of significant risk factor for hypertension. Overall increased rate of hypertension pose a biggest challenge for health sector in Dharwad district.

Synthesis and antibacterial activity of solanum torvum mediated silver nanoparticle against Xxanthomonas axonopodis pv.punicae and Ralstonia solanacearum.

To meet the food demand of growing population, agricultural productivity needs to be increased by employing safe strategies without harming ecosystem. Silver nanoparticle (AgNP) using a green approach has become a promising substitute to the synthetic pesticides to overcome pest menace. In this study, AgNPs were synthesized from Solanum torvum fruit extract and their bactericidal property against phyto bacteria was shown. UV-vis spectroscopic observation revealed a surface resonance peak of 440 nm corresponding to the formation of AgNPs. Microscopic and particle-size analyses showed a nearly spherical size, with an average diameter of 27 nm. Surface charge and polydispersity index of the synthesized AgNPs were -11.8 mV and 0.29, respectively. Powder X-ray diffraction, energy-dispersive X-ray and Infrared spectroscopy techniques were used to explore phase formation, composition and possible biological molecules involved in AgNP formation. AgNPs exhibited minimum inhibitory concentrations of 6.25 µg mL-1 and 12.5 µg mL-1 against bacterial plant pathogens Xanthomonas axonopodis pv. punicae and Ralstonia solanacearum. In-vitro disk-diffusion assay showed inhibition zones of 11.4 ± 1 mm for R. solanacearum and 18.1 ± 1 mm for X. axonopodis pv. punicae treated with 50 µg mL-1 AgNPs. The AgNPs generated intracellular reactive oxygen species in the pathogens. DNA damage and DNA replication inhibition studies showed genotoxicity of AgNPs to the bacterial cells. A plant toxicity study demonstrated a nontoxic effect of the synthesized NPs. Overall; the results show that AgNPs can be used as an economically feasible, ecologically safe and effective approach to overcome bacterial diseases.

Synthesis and application of chitosan-copper nanoparticles on damping off causing plant pathogenic fungi.

Damping-off disease in seeds and young seedlings in agricultural crops is a major fungal disease that limits the agriculture production. Frequent use of synthetic fungicides against damping-off diseases is known to hamper the environmental balance. Thus, an alternative approach needs to be explored for the management of such economically important fungal diseases. In the present study, simple, economically feasible chitosan-coupled copper nanoparticles (Ch-CuNPs) were synthesized and demonstrated antifungal activity against damping-off disease causing phytopathogens, Rhizoctonia solani and Pythium aphanidermatum. Physico-chemical studies confirmed the size, shape, surface charge, element confirmation and mono-dispersed nature of Ch-CuNPs. In vitro efficacy studies revealed up to 98% mycelial growth inhibition at 0.1% Ch-CuNPs. An extracellular conductivity study of the mycelium showed cellular content leakage within 12 h of treatment. Further, plant toxicity study against chili, cowpea and tomato plants; showed that ≤0.2% NPs were safe under greenhouse conditions. NPs also exhibited growth-promoting activity with chili seeds, by overcoming the limited germination rate of susceptible seeds. Overall, the present study emphasizes the benefits of synthesized Ch-CuNPs on agricultural crops as fungicide and growth-promoter, as well as a safe alternative to pesticides in order to avoid hazardous effect on the environment.

Detection and determination of stability of the antibiotic residues in cow's milk.

In the present study, antibiotic residues were detected in milk samples collected from the dairy herds located in Karnataka, India, by microbiological assay. Subsequently, the detected antibiotics were identified as azithromycin and tetracycline, by high-performance liquid chromatography, further both the antibiotics detected in the cow milk samples were found to be at high concentration (9708.7 and 5460 µg kg-1, respectively). We then investigated the effects of temperature and pH on the stabilities of azithromycin and tetracycline to determine the degradation rate constant k using first-order kinetic equation. Results indicated that significant reduction in stability and antibacterial activity of azithromycin solution when subjected to 70 and 100°C for 24 h. While stability of tetracycline was significantly reduced when subjected to 70 and 100°C for 24 h. However no significant reduction in antibacterial activity of tetracycline was observed at respective temperatures when compared with that of control. In addition, the stabilities of azithromycin and tetracycline were found to be decreased in acidic pH 4-5. The results of the present study revealed the high risk of contamination of milk sample with veterinary antibiotics and also demonstrated the effect of temperature and pH on stability of antibiotics. Therefore the study suggest that the qualitative and quantitative screening of milk for the presence of antibiotics need to be strictly performed to ensure safe drinking milk for consumers.

Physiological adaptation and spectral annotation of Arsenic and Cadmium heavy metal-resistant and susceptible strain Pseudomonas taiwanensis.

In the present study, the 16S-rRNA sequencing of heavy metal-resistant and susceptible bacterial strains isolated from the industrial and agriculture soil showed resemblance with Pseudomonas taiwanensis. Based on the growth rate, two bacterial strains SJPS_KUD54 and KUD-MBBT4 exhibited 10 ppm tolerance to Arsenic and Cadmium. These two heavy metals caused, a significant increase in stress enzymes like superoxide dismutase, catalase and glutathione S-transferase activities in SJPS_KUD54 when compared to KUD-MBBT4. Following heavy metal treatment, the atomic-force-microscopy observations showed no change in the cell-wall of SJPS_KUD54, whereas the cell-wall of KUD-MBBT4 got ruptured. Moreover, the protein-profile of SJPS_KUD54 treated with heavy metals exhibited varied patterns in comparison with untreated control. In addition, the accumulation of hydroxyl, thiol and amides were found in the SJPS_KUD54 relative to its control. Furthermore, the resistant SJPS_KUD54 strain showed a remarkable bioaccumulation properties to both Arsenic and Cadmium. Thus, it is inferred that the growth rate, stress enzymes and functional-groups play a significant role in the physiological-adaption of SJPS_KUD54 during stress conditions, which is positively involved in the prevention or repair mechanism for reducing the risks caused by heavy metal stress.

Genome-wide Characterization and Expression Analysis of Sugar Transporter Family Genes in Woodland Strawberry.

In higher plants, sugars are nutrients and important signal molecules. Sugar transporters (STs) facilitate sugar transport across membranes and are associated with loading and unloading of the conducting complex. Strawberry ( Duchesne ex Rozier) is one of the most economically important and widely cultivated fruit crop and a model plant among fleshy fruits worldwide. In this study, 66 woodland strawberry ( L.) ST (FvST) genes were identified and further classified into eight distinct subfamilies in the woodland strawberry genome based on the phylogenetic analysis. In the promoter sequences of FvST gene families, a search for -regulatory elements suggested that some of them might probably be regulated by plant hormones (e.g., salicylic acid, abscisic acid, and auxin), abiotic (e.g., drought, excessive cold, and light), and biotic stress factors. Exon-intron analysis showed that each subfamily manifested closely associated gene architectural features based on similar number or length of exons. Moreover, to comprehend the potential evolution mechanism of FvST gene family, the analysis of genome duplication events was performed. The segmental and tandem duplication analysis elucidated that some of ST genes arose through whole-genome duplication (WGD) or segmental duplication, accompanied by tandem duplications. The expression analysis of 24 FvST genes in vegetative and during fruit development has shown that the expression of several ST genes was tissue and developmental stage specific. Generally, our findings are important in understanding of the allocation of photo assimilates from source to sink cell and provide insights into the genomic organization and expression profiling of FvST gene families in woodland strawberry.

Synthesis and evaluation of novel coumarin-oxime ethers as potential anti-tubercular agents: Their DNA cleavage ability and BSA interaction study.

As a contribution to the development of novel coumarin-oxime ether conjugates with therapeutically interesting properties, a series of coumarin-oxime ether (1a-1j) was synthesised using SN2 reaction of bromomethyl coumarins with butane-2,3-dione monoxime. Invitro anti-tuberculosis activityagainstMTBH37Rv strain was established for the coumarin-oxime ether (1a-1j). Most of the compounds exhibited significant activity with minimum inhibitory concentration (MIC)in the range of 0.04-3.12 µg mL-1. Compound (1h) was identified as a hit candidate exhibiting MIC of 0.04 µg mL-1, closer to the MIC value of Isoniazid (0.02 µg mL-1), a commercially available drug for the treatment of tuberculosis. Compound 1h also displayed a low level of toxicity in Vero cells along with a good safety profile in vitro. Compounds that showed potent anti-tubercular activity were also found to cleave DNA more efficiently and thereby exhibit nuclease activity. The most active compound (1h) was further studied to deduce the mode of interaction with model serum protein, bovine serum albumin (BSA).

Synthesis of coumarin-theophylline hybrids as a new class of anti-tubercular and anti-microbial agents.

A series of novel coumarin-theophylline hybrids were synthesized and examined for their anti-tubercular activity in vitro against Mycobacterium tuberculosis H37Rv, anti-microbial activity in vitro against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacterias (Escherichia coli, Salmonella typhi) as well as fungi (Candida albicans). The compound (3a) has shown excellent anti-tubercular activity with MIC of 0.12 µg/mL. Electron donating compounds (3a, 3f) have displayed significant anti-microbial activity. The compounds have also been precisely elucidated using single crystal X-ray diffraction techniques. Molecular docking study has been performed against 4DQU enzyme of Mycobacterium tuberculosis showed good binding interactions and is in agreement with the in vitro results.

Computational Modeling of the Staphylococcal Enterotoxins and Their Interaction with Natural Antitoxin Compounds

Staphylococcus aureus is an opportunistic bacterium that produces various types of toxins, resulting in serious food poisoning. Staphylococcal enterotoxins (SEs) are heat-stable and resistant to hydrolysis by digestive enzymes, representing a potential hazard for consumers worldwide. In the present study, we used amino-acid sequences encoding SEA and SEB-like to identify their respective template structure and build the three-dimensional (3-D) models using homology modeling method. Two natural compounds, Betulin and 28-Norolean-12-en-3-one, were selected for docking study on the basis of the criteria that they satisfied the Lipinski's Rule-of-Five. A total of 14 and 13 amino-acid residues were present in the best binding site predicted in the SEA and SEB-like, respectively, using the Computer Atlas of Surface Topology of Proteins (CASTp). Among these residues, the docking study with natural compounds Betulin and 28-Norolean-12-en-3-one revealed that GLN43 and GLY227 in the binding site of the SEA, each formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one; while GLY227 residue established a hydrogen bond with Betulin. In the case of SEB-like, the docking study demonstrated that ASN87 and TYR88 residues in its binding site formed hydrogen bonds with Betulin; whereas HIS59 in the binding site formed a hydrogen-bond interaction with 28-Norolean-12-en-3-one. Our results demonstrate that the toxic effects of these two SEs can be effectively treated with antitoxins like Betulin and 28-Norolean-12-en-3-one, which could provide an effective drug therapy for this pathogen.

Design, synthesis, and evaluation of new α-aminonitrile-based benzimidazole biomolecules as potent antimicrobial and antitubercular agents.

The study explores the one-pot synthesis of novel α-aminonitriles by reacting 4-[(1H-benzimidazol-2-yl)methoxy]benzaldehyde, substituted anilines and sodium cyanide using a catalytic amount of copper dipyridine dichloride (CuPy2 Cl2 ) and employing the Strecker reaction under mild conditions. All the synthesized compounds were screened for antimicrobial and antitubercular activity. The promising lead compounds 4d and 4e were identified, with MIC values ranging between 3.9 and 7.8 µg/mL against different bacterial strains. Compounds 4c-e and 4g also showed good antifungal activities against the tested fungal strain. Among those tested, compound 4e exhibited excellent antitubercular activity (MIC 0.05 µg/mL) with a low level of cytotoxicity, suggesting that compound 4e is a promising lead for subsequent investigations in search for new antitubercular agents.

Grapevine immune signaling network in response to drought stress as revealed by transcriptomic analysis.

Drought is a ubiquitous abiotic factor that severely impedes growth and development of horticulture crops. The challenge postured by global climate change is the evolution of drought-tolerant cultivars that could cope with concurrent stress. Hence, in this study, biochemical, physiological and transcriptome analysis were investigated in drought-treated grapevine leaves. The results revealed that photosynthetic activity and reducing sugars were significantly diminished which were positively correlated with low stomatal conductance and CO2 exchange in drought-stressed leaves. Further, the activities of superoxide dismutase, peroxidase, and catalase were significantly actuated in the drought-responsive grapevine leaves. Similarly, the levels of abscisic acid and jasmonic acid were also significantly increased in the drought-stressed leaves. In transcriptome analysis, 12,451 differentially-expressed genes (DEGs) were annotated, out of which 8021 DEGs were up-regulated and 4430 DEGs were down-regulated in response to drought stress. In addition, the genes encoding pathogen-associated molecular pattern (PAMP) triggered immunity (PTI), including calcium signals, protein phosphatase 2C, calcineurin B-like proteins, MAPKs, and phosphorylation (FLS2 and MEKK1) cascades were up-regulated in response to drought stress. Several genes related to plant-pathogen interaction pathway (RPM1, PBS1, RPS5, RIN4, MIN7, PR1, and WRKYs) were also found up-regulated in response to drought stress. Overall the results of present study showed the dynamic interaction of DEG in grapevine physiology which provides the premise for selection of defense-related genes against drought stress for subsequent grapevine breeding programs.

Insights into grapevine defense response against drought as revealed by biochemical, physiological and RNA-Seq analysis.

Grapevine is an important and extensively grown fruit crop, which is severely hampered by drought worldwide. So, comprehending the impact of drought on grapevine genetic resources is necessary. In the present study, RNA-sequencing was executed using cDNA libraries constructed from both drought-stress and control plants. Results generated 12,451 differentially expressed genes (DEGs), out of which 8,021 genes were up-regulated, and 4,430 were down-regulated. Further physiological and biochemical investigations were also performed to validate the biological processes associated with the development of grapevine in response to drought stress. Results also revealed that decline in the rate of stomatal conductance, in turn, decrease the photosynthetic activity and CO2 assimilation in the grapevine leaves. Reactive oxygen species, including stress enzymes and their related proteins, and secondary metabolites were also activated in the present study. Likewise, various hormones also induced in response to drought stress. Overall, the present study concludes that these DEGs play both positive and negative roles in drought tolerance by regulating various biological pathways of grapevine. Nevertheless, our findings have provided valuable gene information for future studies of abiotic stress in grapevine and various other fruit crops.

Isolation and evaluation of proteolytic actinomycete isolates as novel inducers of pearl millet downy mildew disease protection.

Native endophytic actinomycetes isolated from pearl millet roots were examined for their efficacy to protect pearl millet against downy mildew. Nineteen of 39 isolates were found to be proteolytic, of which 7 strains could directly suppress the sporangium formation of Sclerospora graminicola, the pearl millet downy mildew pathogen. Thus, mycelial suspensions containing either spores or cell-free extract of these 7 isolates were used for seed-coating and -soaking treatments to test for their induction of downy mildew resistance. Results indicated that seed-coating overall provided better protection to downy mildew than seed-soaking. In both treatments, the tested isolates demonstrated differential abilities in downy mildew disease protection, with Streptomyces griseus SJ_UOM-07-09 and Streptosporangium roseum SJ_UOM-18-09 showing the highest protection rates. Additionally, the levels of disease protection conferred by the actinomycetes were just slightly lower than that of the systemic fungicide Apron, suggesting their effectiveness. Further studies revealed that the more rapid root colonization by SJ_UOM-18-09 resulted in faster and higher induced resistance in comparison with SJ_UOM-07-09 under greenhouse conditions, indicating that SJ_UOM-18-09 was superior than SJ_UOM-07-09 in inducing resistance. Results from this study provide comprehensive information on biocontrol functions of SJ_UOM- 18-09 with great potential to control downy mildew disease in pearl millet.

Epidemiology of Bovine Mastitis in Cows of Dharwad District.

Bovine mastitis is very common in cows of both developed and developing countries. The prevalence of clinical and subclinical mastitis (SCM) varies from region to region. Hence, the present study was carried out to determine the prevalence of mastitis using three diagnostic tests by considering different risk factors like age, lactation, breed, season, quarters, and herd. The results showed that surf field mastitis test (SFMT) is the most sensitive test for diagnosis of bovine mastitis, the older age and cows with later part of lactation period were more prone to bovine mastitis, and exotic breeds like Holstein freshen (HF) were more susceptible to bovine mastitis. The highest incidence of mastitis was recorded in monsoon season. The prevalence of subclinical and clinical mastitis was more in single and two quarters, respectively, and the rate of bovine mastitis was more in unorganized herds. The study concluded that SCM is directly associated with age, lactation period, and environmental factors of the cow and clinical mastitis is more associated with breed of the cow and environmental conditions.

In silico characterization of putative drug targets in Staphylococcus saprophyticus, causing bovine mastitis.

The bovine mastitis caused by coagulase negative staphylococci (CNS) has increased in many herds of urban and rural areas of India. Emergence of multi drug resistant bacteria has further made its management more complex and serious. Therefore, innovation of novel specific drug for the treatment of disease caused by particular organism remained to be a challenge. Hence, in the present study a bacterium was isolated from milk of the cow with bovine mastitis and was identified as S. saprophyticus, 44 pathways of S. saprophyticus retrieved (KEGG) from web server were found to be non homologous to the host Bos taurus, out of which 39 pathways were found to be in cytoplasm, 2 in cell wall and 3 in the cell membrane. The knowledge of the present study could make the drug discovery easier which have high affinity to the target site of the causative organism.

Identification and analysis of putative promoter motifs in bovine herpes virus.

The purpose of this study is to identify and analyse the putative promoter motifs in the bovine herpes virus which causes several diseases in cattle worldwide including bovine mastitis with large economic impact on dairy industry. Bovine mastitis caused due to virus is often neglected as bacterial infections are held mainly responsible for the disease. Therefore, in this in silico investigation with all the existing experimental data a total of 147 promoter were identified along with their sequences from three genome viz bovine herpes virus 1 (BHV), bovine herpes virus 4 and bovine herpes virus 5, out of which 39 promoters were from bovine herpes virus 4 (BHV 4), 95 from BHV1 and 13 from BHV5 and it was observed that BHV1 and BHV5 have a close evolutionary history. However, they belong to the same subfamily and size of the genome and GC% of BHV1 and BHV5 was almost equal and very high compare to that of BHV4. This analysis may help in designing the live attenuated vaccine against BHV causing bovine mastitis that reduces the incidence of bovine mastitis. Identification of promoters may also help in designing of expression vectors which help in better understanding of the regulation of gene expression. In the era of large genomics and proteomics prediction of promoters in the whole genome is crucial for the advancement of drug discovery and gene therapy.