Cytochrome c electrochemical detection utilizing molecularly imprinted poly(3, 4-ethylenedioxythiophene) on a disposable screen printed carbon electrode.

Cytochrome c (cyt c) has been found to play a function in apoptosis in cell-free models. This work presents the creation of molecularly imprinted conducting poly(3, 4-ethylenedioxythiopene) (MIPEDOT) on the surface of a screen printed carbon electrode (SPCE) for cyt c. Cyt c was imprinted by electropolymerization due to the presence of an EDOT monomer hydrophobic functional group on SPCE, using CV to obtain highly selective materials with excellent molecular recognition ability. MIPEDOT was characterized by CV, EIS, and DPV using ferricyanide/ferrocyanide as a redox probe. Further, the characterization of the sensor was accomplished using SEM for surface morphological confirmation. Using CV, the peak current measured at the potential of +1 to -1 V (vs. Ag/AgCl) is linear in the cyt c concentration range from 1 to 1200 pM, showing a remarkably low detection limit of 0.5 pM (sensitivity:0.080 µA pM). Moreover, the applicability of the approach was successfully confirmed with the detection of cyt c in biological samples (human plasma). Similarly, our research has proven a low-cost, simple, and efficient sensing platform for cyt c detection, rendering it a viable tool for the future improvement of reliable and exact non-encroaching cell death detection.

Biological evaluation and molecular docking studies of new curcuminoid derivatives: Synthesis and characterization.

In the present study, three series of dimethylamino curcuminoids viz. 4-phenylaminomethyl curcumin (3a-d), arylidene curcumin (3e) and pyrazole curcumin (3f-i) derivatives have been synthesized and studied for their in vitro anti-inflammatory, antioxidant and antibacterial activities. Synthesized dimethylamino curcuminoid derivatives namely 3d, 3e, 3h and 3i have shown potent anti-inflammatory properties than parent curcumin. Molecular docking interactions of dimethylamino curcuminoids derivatives against cyclooxygenase enzymes (COX-1 and COX-2) were studied.

Enhanced production of phenazine-like metabolite produced by Streptomyces aurantiogriseus VSMGT1014 against rice pathogen, Rhizoctonia solani.

The efficacy of a rhizobacterium Streptomyces aurantiogriseus VSMGT1014 for the production of bioactive metabolites with antifungal properties was evaluated under in vitro conditions. The production of bioactive metabolites by S. aurantiogriseus VSMGT1014 in International Streptomyces Project-2 (ISP-2) broth, supplemented with glucose and ammonium acetate was found to be the most suitable carbon and nitrogen sources for the maximum production of bioactive metabolites against rice pathogen, Rhizoctonia solani. The zone of inhibition range from 23.5 to 28.5 mm and 10.3 to 18.3 mm for glucose and ammonium acetate supplemented media, respectively. The culture filtrate of S. aurantiogriseus VSMGT1014 at pH 7.5, 37 °C at 120 rpm in 6 days of incubation showed the maximum production of bioactive metabolites with antagonistic potential. The crude metabolite was characterized by different spectral studies such as Ultraviolet spectrum, infrared-spectrum and based on the different analytical techniques, including thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with the retention time 29.4 and the bioactive metabolite was identified as phenazine, which was confirmed by pure phenazine compound as positive control.

An eco-friendly and water mediated product selective synthesis of 2-aminopyrimidines and their in vitro anti-bacterial evaluation.

A greener water mediated protocol for the efficient synthesis of a library of 2-amino-6-styryl pyrimidines (4) and their dihydro analogues (3) has been reported. Most of the saturated compounds (3) rather than their unsaturated analogues (4) showed better anti-bacterial (in vitro) activity against three human pathogens viz. Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli. In particular, three of them (3 b, 3 i &3 k) exhibited high inhibition against the growth of all the three pathogens comparable with that of the reference drug, tetracycline.

Antagonistic potential of native strain Streptomyces aurantiogriseus VSMGT1014 against sheath blight of rice disease.

A total of 132 actinomycetes was isolated from different rice rhizosphere soils of Tamil Nadu, India, among which 57 showed antagonistic activity towards Rhizoctonia solani, which is sheath blight (ShB) pathogen of rice and other fungal pathogens such as Macrophomina phaseolina, Fusarium oxysporum, Fusarium udum and Alternaria alternata with a variable zone of inhibition. Potential actinomycete strain VSMGT1014 was identified as Streptomyces aurantiogriseus VSMGT1014 based on the morphological, physiological, biochemical and 16S rRNA sequence analysis. The strain VSMGT1014 produced lytic enzymes, secondary metabolites, siderophore, volatile substance and indole acetic acid. Crude metabolites of VSMGT1014 showed activity against R. solani at 5 µg ml(-1); however, the prominent inhibition zone was observed from 40 to 100 µg ml(-1). Reduced lesion heights observed in culture, cells-free filtrate, crude metabolites and carbendazim on challenge with pathogen in the detached leaf assay. The high content screening test clearly indicated denucleation of R. solani at 5 µg ml(-1) treatment of crude metabolite and carbendazim respectively. The results conclude that strain VSMGT1014 was found to be a potential candidate for the control of ShB of rice as a bio fungicide.

Characterization and Assessment of 2, 4-Diacetylphloroglucinol (DAPG)-Producing Pseudomonas fluorescens VSMKU3054 for the Management of Tomato Bacterial Wilt Caused by Ralstonia solanacearum.

Microbial bio-products are becoming an appealing and viable alternative to chemical pesticides for effective management of crop diseases. These bio-products are known to have potential to minimize agrochemical applications without losing crop yield and also restore soil fertility and productivity. In this study, the inhibitory efficacy of 2,4-diacetylphloroglucinol (DAPG) produced by Pseudomonas fluorescens VSMKU3054 against Ralstonia solanacearum was assessed. Biochemical and functional characterization study revealed that P. fluorescens produced hydrogen cyanide (HCN), siderophore, indole acetic acid (IAA) and hydrolytic enzymes such as amylase, protease, cellulase and chitinase, and had the ability to solubilize phosphate. The presence of the key antimicrobial encoding gene in the biosynthesis of 2,4-diacetylphloroglucinol (DAPG) was identified by PCR. The maximum growth and antimicrobial activity of P. fluorescens was observed in king's B medium at pH 7, 37 °C and 36 h of growth. Glucose and tryptone were found to be the most suitable carbon and nitrogen sources, respectively. DAPG was separated by silica column chromatography and identified by various methods such as UV-Vis, FT-IR, GC-MS and NMR spectroscopy. When R. solanacearum cells were exposed to DAPG at 90 µg/mL, the cell viability was decreased, reactive oxygen species (ROS) were increased and chromosomal DNA was damaged. Application of P. fluorescens and DAPG significantly reduced the bacterial wilt incidence. In addition, P. fluorescens was also found effective in promoting the growth of tomato seedlings. It is concluded that the indigenous isolate P. fluorescens VSMKU3054 could be used as a suitable biocontrol agent against bacterial wilt disease of tomato.

Partial purification and characterization of 2, 4-diacetylphloroglucinol producing Pseudomonas fluorescens VSMKU3054 against bacterial wilt disease of tomato.

We find out the antimicrobial potential of partially purified 2,4-diacetylphloroglucinol (DAPG) against Ralstonia solanacearum and fungal plant pathogens isolated from tomato rhizobacterium Pseudomonas fluorescens VSMKU3054. The present study is mainly focused on the control of wilt disease of tomato by our isolate VSMKU3054 and DAPG. The cell free culture filtrate of P. fluorescens VSMKU3054 was significantly arrested the growth of R. solanacearum and fungal pathogens such as Rhizoctonia solani, Sclerotium rolfsii, Macrophomina phaseolina and Fusarium oxysporum compared to control. The existence of DAPG from the crude metabolites of P. fluorescens VSMKU3054 was confirmed on TLC with Rf value 0.34, which is coincide with that of authentic phloroglucinol. The partially purified DAPG exhibited much higher activity against R. solanacearum at 30 µg/ml than the fungal plant pathogens compared to control. The antimicrobial partially purified compound was identified as DAPG by UV, FT-IR and GC-MS analysis. The percentage of live cells of R. solanacearum when supplemented with DAPG at 30 µg/ml, significantly controlled the living nature of R. solanacearum up to 68% compared to tetracycline and universal control observed under high content screening analysis. The selected isolate P. fluorescens VSMKU3054 and DAPG significantly controlled wilt disease of tomato up to 59.5% and 42.12% on 3rd and 7th days compared to positive and negative control by detached leaf assay. Further, in silico analysis revealed that high interaction of DAPG encoding protease with lectin which is associated with R. solanacearum. Based on our findings, we confirmed that P. fluorescens VSMKU3054 and DAPG could be used a potential bio inoculants for the management of bacterial wilt disease of tomato.

Synthesis of some novel imidazole-based dicationic carbazolophanes as potential antibacterials.

Synthesis of fluorescent imidazole-based dicationic carbazolophanes incorporating various spacer units is described. Interestingly, the cyclophanes 2a and 5a incorporating a pyridine moiety exhibited superior antibacterial activity against most of the pathogenic bacteria in the tested concentrations as compared to the other cyclophanes as well as the test control, benzalkonium chloride (BAC), cetylpyridinium chloride (CPC) and tetracycline.

Molecular Cloning and Docking of speB Gene Encoding Cysteine Protease With Antibiotic Interaction in Streptococcus pyogenes NBMKU12 From the Clinical Isolates.

Streptococcus pyogenes causes a variety of diseases ranging from mild diseases to severe invasive infections which result in significant morbidity and mortality. This study focuses on the antibiotic resistance of S. pyogenes and their interaction with cysteine protease. Around 36 beta-hemolytic isolates were collected from the clinical lab, of which seven isolates (19.4%) were identified as Streptococcus pyogenes. One of the seven isolates was collected from a urinary tract infection, which was identified by antibody agglutination and MALTI-TOF-MS, and it is designated as S. pyogenes NBMKU12. Around 8.3 to 66.6 % of the isolates were found to be resistant to one or more antimicrobial agents, especially, penicillin-G resistance was exhibited by 29.1% of the isolates. In the NBMKU12 isolate, the beta lactem (TEM) gene was detected among the 13 antibiotic genes for which it was tested. Furthermore, when analysis for presence of 13 virulence genes were carried out in NBMKU12 isolate, only speJ and speB were detected. The speB (streptococcal pyrogenic exotoxin B) encoding cysteine protease gene was cloned. This was followed by performing DNA sequencing to understand the putative cysteine protease interaction with antibiotics, inhibitors, and substrate. The speB gene consists of 1197 nucleotides and encodes a protein with multiple domains, including a signal peptide (aa 1-22), an inhibitor region (aa 27-156), and a catalytic cysteine domain (aa 160-367). The signal peptide cleavage site is predicted between Ala22 and Asn23. The putative 398 amino acid residues were found to have a theoretical pI of 8.76 and a molecular mass of 43,204.36 Da. The tested culture supernatants of NBMKU12 isolate exhibited the proteolytic activity against casein, papaya and pineapple used as substrates. The proteolytic activity suggests the expression of speB gene. Molecular docking analysis of cysteine protease showed that erythromycin (bond length 2.41 Å), followed by chloramphenicol (2.51 Å), exhibited a strong interaction; while penicillin-G (3.24 Å) exhibited a weak interaction, and this factor could be considered as a cause for penicillin-G resistance. The present study contributes to a better understanding of speB gene encoding cysteine protease, antibiotic resistance, and their interaction in the isolate, S. pyogenes NBMKU12. The antibiotics and cysteine protease interaction study confirms the resistance or sensitivity of S. pyogenes. Hence, it could be hypothesized that the isolate NBMKU12 is resistant to most of the tested antibiotics, and this resistance might be a cause for mutation.

Nanocerium oxide increases the survival of adult rod and cone photoreceptor in culture by abrogating hydrogen peroxide-induced oxidative stress.

In vitro cell culture system for adult rod and cone photoreceptor (PR) is an effective and economical model for screening drug candidates against all kinds of age related retinal blindness. Interestingly, adult PR cells have a limited survival in the culture system, thus preventing full exploitation of this in vitro approach for drug screening applications. The limited survival of the adult PR cells in culture is due to their inherently high oxidative stress and photic injury. Mixed valence-state ceria nanoparticles have the ability to scavenge free radicals and reduce oxidative stress. Here, ceria nanoparticles of 5-10 nm dimensions have been synthesized, possessing dual oxidation state (+3 and +4) as evident from x-ray photoelectron spectroscopy and exhibiting real time reduction of hydrogen peroxide (H2O2) as quantified by absorbance spectroscopy and cyclic voltammogram analysis. Using flow cytometry and cell culture assay, it has been shown that, upon one time addition of 10 nM of nanoceria in the PR culture of the 18 months old adult common carp (Cyprinus carpio) at the time of plating the cells, the oxidative stress caused due to hydrogen peroxide assault could be abrogated. A further single application of nanoceria significantly increases the survival of these fragile cells in the culture, thus paving way for developing a more robust photoreceptor culture model to study the aging photoreceptor cells in a defined condition.

Novel Bioactive Wild Medicinal Mushroom--Xylaria sp. R006 (Ascomycetes) against Multidrug Resistant Human Bacterial Pathogens and Human Cancer Cell Lines.

In the present study, the fruiting body extracts of Xylaria sp. strain R006 were obtained from hexane, ethyl acetate and methanol. Among them, the ethyl acetate extract exhibited significant antimicrobial activities against bacterial and fungal pathogens. Based on the effective antimicrobial activity, the crude ethyl acetate extract was fractionized by two-step siliga gel column chromatography. All the fractions were tested for antibacterial activity against drug resistant Staphylococcus aureus strains (1-10) and Pseudomonas aeruginosa strains (1-8). The fraction E showed a maximum inhibition zone of 27.9 mm against drug resistant S. aureus strain 3 and 29.4 mm against drug resistant P. aeruginosa strain 4. Minimal inhibitory concentration of fraction E showed potential result against all the drug resistant strains however, the lowest concentration of 75 µg/mL-1 was observed against S. aureus strains 1 and 6 and P. aeruginosa strain 3. Further, 60 µg/mL of fraction E had significant cytotoxic activity of 54.9, 55.1 and 54.9% against MDA-MB-231 (breast carcinoma cells), A-549 (lung carcinoma cells) and MCF-7 (breast carcinoma cells) human cancer cell lines, respectively. The spectral data revealed that the fraction E has chromophoric groups in it and had the C = O stretching, C-C = C asymmetric stretch, N-H stretch and C-O stretch as functional groups. The results indicate that the metabolites of fruiting bodies of Xylaria sp. R006 are the potential natural source for the development of new anticancer agents.

Novel bioactive metabolites producing endophytic fungus Colletotrichum gloeosporioides against multidrug-resistant Staphylococcus aureus.

The emergence of antibiotic-resistant bacteria such as Staphylococcus aureus calls for inventive research and development strategies. Inhibition of this bacterial pathogenesis may be a promising therapeutic approach. The screening of antimicrobial compounds from endophytes is a promising way to meet the increasing threat of drug-resistant strains of human and plant pathogens. In the present study, a novel endophytic fungus, Colletotrichum gloeosporioides, was isolated from the medicinal plant Vitex negundo L. Extracts of C. gloeosporioides were obtained using hexane, ethyl acetate and methanol solvents. The fungal extracts exhibited an effective antimicrobial activity against bacterial and fungal strains. The extracts were also analysed for antibacterial activity against methicillin-, penicillin- and vancomycin-resistant S. aureus strains (1-10). The methanol extract showed an effective antibacterial activity against S. aureus strain 9, with a minimal inhibitory concentration of 31.25 µg mL(-1) . The synergistic action of endophytic fungal extract with antibiotics such as methicillin, penicillin and vancomycin was observed against S. aureus strain 6. The fractional inhibitory concentration index of methanol extract with methicillin, penicillin and vancomycin was 1.0, 0.5 and 0.375, respectively. These results clearly indicate that the metabolite of endophytic fungus C. gloeosporioides is a potential source of new antibiotics.

Synthesis of novel carbazole based macrocyclic amides as potential antimicrobial agents.

A series of carbazole based macrocyclic diamides with thia and oxy linkages have been synthesized and the inhibitory activity of the cyclophane amides against human pathogenic bacteria and plant pathogenic fungi are documented. (S)-1,10-Bi-2-naphthol [(S)-BINOL] based chiral carbazolophane amide emerged as the most interesting compound in this series exhibiting excellent antibacterial and antifungal activities.

Antibacterial activity of essential oil components and their potential use in seed disinfection.

Among the main (> or = 0.7%) components of some essential oils, considerable antibacterial activity was shown by terpenoid and phenylpropanoid derivatives containing phenol and alcohol functionalities. A reduced or no activity was shown by those derivatives containing ketones, aldehydes, ethers, and ester functionalities as well as the remaining terpenoids. Eugenol emulsion treatments (1-8 mg/mL) of bean seeds bearing about 2.6 x 10(6) cfu/seed of strain ICMP239 of Xanthomonas campestris pv. phaseoli var. fuscans determined a highly significant reduction of the bacteria on seeds. In particular, eugenol at 4 mg/mL disinfect seeds bearing about 7.0 x 10(2) cfu/seed and lower densities. However, after 72 h, incubation treatments with 2, 4, and 8 mg/mL of eugenol caused germination reduction of 3%, 7%, and 16%, respectively, which was significantly different from the controls. No effect on germination was observed with 1 mg/mL eugenol emulsion treatment. These data indicate eugenol as potentially useful for bean seed disinfection from X. campestris pv. phaseoli var. fuscans. Further studies on the effects on seed vitality and on formulation of essential oils are needed.

Synthesis, characterization and electrochemistry of 4'-functionalized 2,2':6',2''-terpyridine ruthenium(II) complexes and their biological activity.

The synthesis and characterization of Ru(II) terpyridine complexes derived from 4'-functionalized 2,2':6',2''-terpyridine ligands by a multi step procedure have been described. The complexes are redox-active, showing both metal-centred (oxidation) and ligand-centred (reduction) processes. The antibacterial and antifungal activity of the synthesized ruthenium(II) complexes [Ru(attpy)2](PF6)2 (attpy = 4'-(4-acryloyloxymethylphenyl)-2,2':6',2''-terpyridine); [Ru(mttpy)2](PF6)2 (mttpy = 4'-(4-methacryloyloxymethylphenyl)-2,2':6',2''- terpyridine); [Ru(mttpy)(MeOPhttpy)](PF6)2 (MeOPhttpy = 4'-(4-methoxyphenyl)-2,2':6',2''-terpyridine); and [Ru(mttpy)(ttpy)](PF6)2 (ttpy = 4'-(4-methylphenyl)-2,2':6',2''-terpyridine) were tested against four human pathogens (Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa and Escherichia coli) and five plant pathogens (Curvularia lunata, Fusarium oxysporum, Fusarium udum, Macrophomina phaseolina and Rhizoctonia solani) by the well diffusion method and MIC values of the complexes are reported. A biological study of the complexes indicated that the complexes [Ru(mttpy)2](PF6)2 and [Ru(mttpy)(MeOPhttpy)](PF6)2 exhibit very good activity against most of the test pathogens and their activity is better than those of some of the commercially available antibiotics like tetracycline and the fungicide carbendazim.