Novel pyrazoline amidoxime and their 1,2,4-oxadiazole analogues: Synthesis and pharmacological screening

A novel series of pyrazoline amidoxime (2a–d) and pyrazoly-1,2,4-oxadiazole (3a–p) and (4) of pharmacological significance have been synthesised. Structures of newly synthesised compounds were characterized by spectral studies. New compounds were screened for their in vitro antioxidant, antimicrobial and antiinflammatory activities. Among the synthesized compounds, compound 2a, 3l and 3o were found to be active antimicrobial agents in addition to having potent antioxidant activity, while the compound 3f showed promising antiinflammatory activity in comparison with standard drug.     

Role of Pseudomonas fluorescens and INA against Black Rot of Cabbage

Cabbage (Brassica oleracea var. capitata) is an important vegetable crop among crucifers. It is affected by a bacterial disease known as black rot. Black rot is caused by Xanthomonas campestris pv. campestris a disease of worldwide importance. The present study highlights the effect of biotic inducer—Pseudomonas fluorescens—and an abiotic inducer—2,6‐dichloro‐isonicotinic acid—in combating black rot, followed by their effect on the seed treatment and disease incidence, role of antioxidant enzymes followed by validation of the defence‐related genes by quantitative real‐time PCR. The resistant (Pusa mukta) and the highly susceptible (NBH boss) cabbage cultivars were analysed for defence‐related enzymes such as peroxidase and superoxide dismutase. An increase in total peroxidase and superoxide dismutase activity was observed upon inoculation with X. campestris pv. campestris. The activity was greater in resistant cultivar when compared to susceptible ones. Both enzyme activity assays and qPCR analyses for the expression of the defence genes in susceptible and resistant cultivars demonstrated that the peroxidase gene was up‐regulated in resistant cultivar compared to susceptible cultivar. The present study proved that P. fluorescens‐induced resistance against X. campestris pv. campestris in cabbage seedlings is more efficient as compared to the use of INA—abiotic inducer.     

Synthesis and pharmacological studies of new pyrazole analogues of podophyllotoxin

The pyrazole analogues of podophyllotoxin were synthesized by the chalcone route. This route attracts the attention because of its simple operating conditions and easy availability of the chemicals. Initially, benzylideneacetophenones (chalcones) were prepared in high yields by Claisen-Schmidt reaction of acetophenones with 4-(methylthio)benzaldehyde. The cyclopropyl ketones were prepared in good yields by the reaction of chalcones with trimethylsulfoxonium iodide. Tetralones were prepared in good yields by the Friedel-Craft’s intramolecular cyclization reaction of cyclopropyle ketones in the presence of anhyd. stannic chloride and acetic anhydride. The tetralones on formylation to give substituted hydroxylmethylene tetralones. Condensation of substituted hydroxylmethylene tetralones with hydrazine hydrate afforded target compounds. The structures of the synthesized compounds were confirmed by IR, ¹H NMR and Mass spectral technique. The title compounds were screened for their antimitotic and antimicrobial activities. Among the synthesized compounds cyclopropyl ketones and pyrazole analogues of podophyllotoxin, compound 7-(methylthio)-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole is more active than 5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole, 7-methyl-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole, 7-methoxy-5-(4-(methylthio)phenyl)-4,5-dihydro-² H-benzo[g]indazole and the key intermediate tetralones in 100, 200 and 400 ppm at 12, 18 and 24 h and also showed very good activity against screened bacteria and fungi compared to their standard.     

Molecular detection of plant pathogenic bacteria using polymerase chain reaction single-strand conformation polymorphism

The application of polymerase chain reaction (PCR) technology to molecular diagnostics holds great promise for the early identification of agriculturally important plant pathogens. Ralstonia solanacearum, Xanthomoans axonopodis pv. vesicatoria, and Xanthomonas oryzae pv. oryzae are phytopathogenic bacteria, which can infect vegetables, cause severe yield loss. PCR-single-strand conformation polymorphism (PCR-SSCP) is a simple and powerful technique for identifying sequence changes in amplified DNA. The technique of PCR-SSCP is being exploited so far, only to detect and diagnose human bacterial pathogens in addition to plant pathogenic fungi. Selective media and serology are the commonly used methods for the detection of plant pathogens in infected plant materials. In this study, we developed PCR-SSCP technique to identify phytopathogenic bacteria. The PCR product was denatured and separated on a non-denaturing polyacrylamide gel. SSCP banding patterns were detected by silver staining of nucleic acids. We tested over 56 isolates of R. solanacearum, 44 isolates of X. axonopodis pv. vesicatoria, and 20 isolates of X. oryzae pv. oryzae. With the use of universal primer 16S rRNA, we could discriminate such species at the genus and species levels. Species-specific patterns were obtained for bacteria R. solanacearum, X. axonopodis pv. vesicatoria, and X. oryzae pv. oryzae. The potential use of PCR-SSCP technique for the detection and diagnosis of phytobacterial pathogens is discussed in the present paper.     

Measuring Brain Uptake and Incorporation into Brain Phosphatidylinositol of Plasma myo-[2H6]Inositol in Unanesthetized Rats: An Approach to Estimate In vivo Brain Phosphatidylinositol Turnover

The in vivo rate of turnover of phosphatidylinositol (PtdIns) in brain is not known. In brain, certain receptor-mediated signal transduction involves metabolism of PtdIns and a method to measure its turnover in awake animals is useful in studying the effect of lithium and other therapeutic agents. In a method described here, rats were infused subcutaneously with myo-[²H₆]inositol (Ins*) using an osmotic pump and, at 1 and 8 weeks, concentrations of free myo-inositol (Ins) and Ins* in plasma and brain were measured by GC-MS (chemical ionization). Also, PtdIns and PtdIns* together in brain were isolated, and Ins and Ins* from their headgroups were released enzymatically and specific activity of incorporated inositol was measured. The specific activity of inositol reached a steady state in plasma within 1 week of infusion, but not in brain even at 8 weeks. However, in brain, the specific activity of phosphatidylinositol was same as that of inositol at both time-points, suggestive of fast turnover of PtdIns. The animal experiment and the analytical methodology described here should be useful for measuring the rate of turnover of brain PtdIns in pathological and drug treatment conditions.     

Bacterial wilt of tomato in Karnataka and its management by <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis>

Field surveys undertaken in major tomato growing districts of the Karnataka state, located in southern part of India, revealed a high incidence of bacterial wilt caused by Ralstonia solanacearum and it is one of the most destructive bacterial diseases of economically important crops. Across all the tomato cultivars under evaluation, the disease incidence in plants ranged from 9% to 39% whereas the incidence in seeds ranged from 4% to 18%. The effects of tomato seed treatments with Pseudomonas fluorescens in the control of bacterial wilt under greenhouse conditions revealed that the treatments protected plants against soil-borne infections of the bacterial wilt organism. Seed treatment with antagonistic P. fluorescens strain significantly improved the quality of seed germination and seedling vigour. The disease incidence was significantly reduced in plants raised from P. fluorescens treated seeds followed by challenge inoculation with R. solanacearum. Periodic field surveys for the incidence of bacterial wilt of tomato could be recommended to monitor the populations of the bacterial wilt pathogen. Workable measures are presented that could lead to the reduction of the prevalence of this serious disease in affected fields of the small farm-holders.     

Detection of hepatopancreatic parvovirus (HPV) in wild shrimp from India by nested polymerase chain reaction (PCR)

The prevalence of hepatopancreatic parvovirus (HPV) in wild penaeid shrimp samples from India was studied by nested polymerase chain reaction (PCR) using primers designed in our laboratory. The virus could be detected in 9 out of 119 samples by non-nested PCR. However, by nested PCR 69 out of 119 samples were positive. The PCR results were confirmed by hybridization with digoxigenin-labelled DNA probe. Shrimp species positive by non-nested PCR included Penaeus monodon, Penaeus indicus and Penaeus semisulcatus and by nested PCR Parapenaeopsis stylifera, Penaeus japonicus, Metapenaeus monoceros, M. affinis, M. elegans, M. dobsoni, M. ensis and Solenocera choprai. This is the first report on the prevalence of HPV in captured wild shrimp from India.     

Molecular docking of 1H-pyrazole derivatives to receptor tyrosine kinase and protein kinase for screening potential inhibitors

Tyrosine kinase receptor and protein kinases drawn much attention for the scientific fraternity in drug discovery due to its important role in different cancer, cardiovascular diseases and other hyper-proliferative disorders. Docking studies of pyrazole derivatives with tyrosine kinase and different serine/threonine protein kinases were employed by using flexible ligand docking approach of AutoDock 4.2. Among the molecules tested for docking study, 2-(4-chlorophenyl)-5-(3-(4-chlorophenyl)-5-methyl-1- phenyl-1H-pyrazol-4-yl)-1,3,4-thiadiazole (1b), 2-(4-methoxyphenyl)-5-(3-(4-methoxyphenyl)-5-methyl-1-phenyl-1H-pyrazol-4-yl)- 1,3,4-thiadiazole (1d) and 2-(4-chlorophenyl)-5-(3-(4-chlorophenyl)-5-methyl-1-phenyl-1H-pyrazol-4-yl)-1,3,4-thiadiazole (2b) revealed minimum binding energy of -10.09, -8.57 and -10.35 kJ/mol with VEGFR-2 (2QU5), Aurora A (2W1G) and CDK2 (2VTO) protein targets, respectively. These proteins are representatives of plausible models of interactions with different anticancer agents. All the ligands were docked deeply within the binding pocket region of all the three proteins, showing reasonable hydrogen bonds. The docking study results showed that these pyrazole derivatives are potential inhibitor of all the three protein targets; and also all these docked compounds have good inhibition constant, vdW + Hbond + desolv energy with best RMSD value.