Jayanthi Abraham
, Vellore

Agricultural Science, Biology

M.Phil., Ph.D


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    ABSTRACT: Applying the concept of ethnobotany, plant extract was taken into consideration as an alternative to chemicals synthesis of silver nanoparticle. The extracts from the chilli seeds were used to synthesize silver nanoparticles (AgNPs). In this study two species of chilli, Capsicum annuum and Capsicum frutescens, have been used to analyse the characteristics of the bio-active compounds found in their seeds. Analysis of the bioactive compound was performed by using Soxhlet extraction with solvents followed by Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and GC-MS. Furthermore, green synthesis of nanoparticles with chilli extracts was carried out using silver nitrate to detect its antimicrobial activity. The characterizations of both the nanoparticles were carried out using UV-Vis Spectroscopy, Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and energy Dispersive X-Ray Spectroscopy (EDX). Antimicrobial activity against clinical pathogens and the antioxidant assay using DPPH and FRAP assays were performed. The cytotoxicity effects on osteosarcoma cell lines were also evaluated with the synthesized AgNPs.
    No preview · Article · Jan 2016 · Records of Natural Products

  • No preview · Article · Dec 2015 · Journal of Chemical and Pharmaceutical Research
  • Jayanthi Abraham · RITIKA CHAUHAN
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    ABSTRACT: The present work deals with isolation, identification of bioactive metabolite produced by Streptomyces toxytricini JAR4 for various biological activities. The bioactive metabolite (1s,5s)-9-(2,6,6-trimethylbicyclo[3.1.1]heptan-3-yl)-9-borabicyclo[3.3.1]nonane produced by the strain JAR4 was obtained from the optimized culture medium through solvent extraction and molecular weight of the metabolite was characterized through Gaschromatography mass spectrometry. The active constituents obtained after extraction and partial purification from the isolate JAR4 was tested against clinical pathogens and it was found to be efficiently inhibiting Pseudomonas aeruginosa, Salmonella sp., Staphylococcus aureus and Klebsiella pnuemoniae among various gram positive and gram negative pathogens. The in silico studies of the isolated bioactive compound reveal the binding with glutamine 6-phosphate synthase at active binding site when compared with standard antibiotic anticapsin through molecular docking performed by Autodock vina. Actinomycetes are the prolific source of antimicrobial metabolites therefore the present investigation reveals in vitro as well as in silico antimicrobial potential of terrestrial actinomycetes JAR4 against medically important clinical pathogens.
    No preview · Article · Oct 2015 · International Journal of Pharma and Bio Sciences
  • Jayanthi Abraham · Sivagnanam Silambarasan
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    ABSTRACT: The bacterium Serratia marsescens strain JAS16 was isolated from agricultural soil which had prior exposure to monocrotophos for three years. The strain JAS16 tolerated up to 1200 mg L–1 monocrotophos and degraded the insecticide (1000 mg L–1) at a degradation rate constant of 136 d−1 (DT50 = 3.7 d). In soil, the degradation rate constant was 105 d−1 (DT50 = 4.8 d). A schematic pathway is being proposed from the degraded products derived from gas chromatography--mass spectrometry (GC-MS). The phytotoxicity of degradation products to Vigna radiata, Vigna unguiculata, and Macrotyloma uniflorum and the genotoxicity to Allium cepa roots were found to be low. A cost-effective powder-based formulation was achieved with the isolate. The isolate remained viable during the storage and also multiplied with a higher colony forming units (CFU) load g–1 for over a period of seven weeks of storage.
    No preview · Article · Oct 2015 · Toxicological and environmental chemistry
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    Dhaya Rani Varkey · Danie Kingsley · Jayanthi Abraham
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    ABSTRACT: Penicillin binding proteins have been a well established target for antimicrobial therapy. β-lactum antibiotics the widely used inhibitor for PBPs inhibits the transpeptidase activity of PBPs by forming a covalent penicilloyl-enzyme complex which blocks the normal transpeptidation reaction; resulting in bacterial death. Resistant bacteria tend to distort the active site of PBP thereby lowering their acylation efficiency for β-lactams. We have tried to find a solution for this problem with the use of noncovalent inhibitors of PBPs. In order to explore the possibilities of a new drug, 3, 5, 6-trichloro-2-pyridinol (TCP) the hydrolysis product of Chlorpyrifos a broad spectrum moderately toxic organophosphorus insecticide was chosen in this present study. This is the first study which focuses on the use of TCP as a likely drug candidate against commonly encountered pathogens. Four Gram negative bacterial pathogens Escherichia coli (3MZD and 1NZO), Pseudomonas aeruginosa, Shigella dysenteriae and Klebsiella pneumoniae and two Gram positive bacterial pathogens Staphylococcus aureus and Streptococcus pneumoniae were selected for this study and were identified using standard biochemical tests. TCP had a good inhibitory effect against these pathogens, it was found to be most effective against Pseudomonas aeruginosa and Staphylococcus aureus with a zone of inhibition of 22mm and 21mm respectively. TCP was equally effective against Salmonella typhimurium, Shigella dysenteriae, Klebsiella pneumoniae and Escherichia coli-3MZD (20mm each). Insilico analysis was also performed by choosing Penicillin Binding Proteins of the microbes as the target protein sequence. iGEMDOCK is the docking tool used for docking TCP against all of these PBPs. Pseudomonas aeruginosa registered the best docking score of-66.5(which correlates with 22mm zone of inhibition) followed by the others.
    Full-text · Article · Aug 2015 · Research Journal of Pharmaceutical, Biological and Chemical Sciences
  • Pritha Chakraborty · Lavanya P · Jayanthi Abraham

    No preview · Article · Jul 2015 · World Journal of Pharmaceutical Research
  • Jayanthi Abraham · Sivagnanam Silambarasan
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    ABSTRACT: Biodegradation of chlorpyrifos and its major metabolite 3,5,6-trichloro-2-pyridinol (TCP) were studied with a novel bacterial strain JAS2 isolated from paddy rhizosphere soil. The molecular characterization based on 16S rRNA gene sequence homology confirmed its identity as Ochrobactrum sp. JAS2. The JAS2 strain degraded 300 mg l− 1 of chlorpyrifos within 12 h of incubation in the aqueous medium and it produced the TCP metabolite. However, after 72 h of incubation TCP was also completely degraded by the JAS2 strain. A tentative degradation pathway of chlorpyrifos by Ochrobactrum sp. JAS2 has been proposed on basis of GC–MS analysis. The complete degradation of chlorpyrifos occurred within 24 h in the soil spiked with and without addition of nutrients inoculated with Ochrobactrum sp. JAS2. TCP was obtained in both the studies which was degraded completely by 96 h in the soil spiked with nutrients and whereas 120 h in absence of nutrients in the soil. The mpd gene which is responsible for organophosphorus hydrolase production was identified. The isolates Ochrobactrum sp. JAS2 also exhibited a time dependent increase in the amount of tricalcium phosphate solubilization in Pikovskaya's medium. Further screening of the strain JAS2 for auxiliary plant growth promoting activities revealed its remarkable capability of producing the indole acetic acid (IAA), hydrogen cyanide (HCN) and ammonia.
    No preview · Article · Jul 2015 · Pesticide Biochemistry and Physiology
  • Nidhi Singh · Prasenjit Saha · Karthik Rajkumar · Jayanthi Abraham

    No preview · Article · Jun 2015 · International Journal of Nanoscience
  • Ritika Chauhan · Hezel Lizia D'Souza · RS Shabnam · Jayanthi Abraham
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    ABSTRACT: Adenanthera pavonina is an important traditional plant with various medicinal properties which cures major human ailments. The present study was carried out to explore the antimicrobial as well as anticancer effect of seed and leaves extract of red wood plant. The seed and leaves methanolic extract exhibited efficacious antimicrobial and anticancer activity against various pathogens whereas acetone seed extract did not show any biological activity. The methanol extract has anticancer effect being effective against bone cancer cell line when compared with acetone extract. A. pavonia is known to produce anti-inflammatory drugs whereas this traditional plant is used for anticancer drugs as well which will be greater benefit to mankind.
    No preview · Article · Feb 2015 · Research Journal of Pharmacy and Technology
  • Ritika Chauhan · Jayanthi Abraham
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    ABSTRACT: Actinomycetes are versatile and prolific source of microbial natural products with great advantage in medicine and agriculture. Recently there is growing interest in exploring biological active compounds from rare actinomycetes. Usually rare actinomycetes are regarded as strains of actinomycetes whose isolation frequency by conventional methods is much lower than that of Streptomycetes strains. Amycolatopsis orientalis JAR10 rare genera of actinomycetes which have been isolated, characterized and antimicrobial activity against various pathogens have been determined in the present work. The morphological, cultural, genotypical and physiological characteristics of strain JAR10 has been examined by International Streptomyces Project. The bioactive metabolites produced by strain JAR10 were extracted by solvent extraction method and the crude extract obtained was further analyzed against various pathogens. The minimum inhibitory concentration of crude extract obtained from Amycolatopsis orientalis JAR10 was analyzed by broth dilution method and was found to inhibit Staphylococcus aureus at 60 µg/ml indicating the presence of biological active compounds.
    No preview · Article · Feb 2015 · International Journal of Pharmaceutical Sciences and Research
  • Jayanthi Abraham · Sivagnanam Silambarasan
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    ABSTRACT: Endosulfan and their metabolites can be detected in soils with a history of endosulfan application. Microbial degradation offers an effective approach to remove toxicants, and in this study, Enterobacter asburiae JAS5 and Enterobacter cloacae JAS7 were isolated through enrichment technique. The biodegradation of endosulfan and its metabolites rate constant (k) and DT50 were determined through first-order kinetic models. E. asburiae JAS5 degraded the endosulfan, and its metabolites in liquid medium was characterized by the k which was 0.382 day−1 (α-endosulfan), 0.284 day−1 (β-endosulfan) and 0.228 day−1 (endosulfan sulphate), and DT50 was 1.8 day (α-endosulfan), 2.4 days (β-endosulfan) and 3.0 days (endosulfan sulphate). The α-endosulfan, β-endosulfan and endosulfan sulphate metabolites were present in the liquid medium that was degraded by E. cloacae JAS7 which was characterized by the k of 0.391, 0.297 day−1 and 0.273 day−1, and DT50 was 1.7, 2.3 and 2.5 days, respectively. The infrared spectrum of endosulfan degraded sample in the aqueous medium by E. asburiae JAS5 and E. cloacae JAS7 showed a band at 1402 cm−1 which is the characteristics of COOH group. E. asburiae JAS5 and E. cloacae JAS7 strains also showed the ability of plant growth promoting traits such as indole-3-acetic acid (IAA) production, organic acids production and solubilization of various inorganic phosphates. E. asburiae JAS5 solubilized 324 ± 2 μg ml−1 of tricalcium phosphate, 296 ± 6 μg ml−1 of dicalcium phosphate and 248 ± 5 μg ml−1 of zinc phosphate, whereas E. cloacae JAS7 solubilized 338 ± 5, 306 ± 4 and 268 ± 3 μg ml−1 of tricalcium phosphate, dicalcium phosphate and zinc phosphate, respectively. The IAA production by JAS5 and JAS7 strains were estimated to be 38.6 ± 0.3 and 46.6 ± 0.5 μg ml−1, respectively. These bacterial strains form a potential candidate for bioremediation of pesticide-contaminated agricultural fields. In addition, it has been demonstrated that the development of powder formulation has several advantages including high cell count, longer shelf life, greater protection against environmental stresses and increased field efficacy.
    No preview · Article · Feb 2015 · Applied biochemistry and biotechnology
  • Nidhi Singh · Aniket Chaudhary · Jayanthi Abraham
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    ABSTRACT: Methicillin resistant Staphylococcus aureus (MRSA) is a very common nosocomial pathogen and in this study the occurrence of MRSA infections and their susceptibility pattern were tested. A total of 50 MRSA strains were collected from pus samples. All isolates were found to be sensitive to vancomycin and imipenem. Further minimum inhibitory concentration (MIC) of vancomycin was performed by agar dilution method, 24 % of the strains were inhibited at a concentration of 4 µg/ml and other 10 % at 8 µg/ml. It was observed that none of the isolates could tolerate 16 µg/ml and E-test also showed that 64 % of them were sensitive and 36 % were intermediately resistant. All the strains were tested for slime production by Congo red agar method and biofilm formation by microtitre plate method. Out of the total strains tested 58 % exhibited positive result for slime production and 70 % were biofilm positive. All the MRSA strains were tested for MIC with two types of honey which gave MIC of 30 %. Sarvodaya honey and Tulsi honey were chosen for the study. Further silver nanoparticles were synthesized using honey and the antimicrobial activities against the pathogens were checked. The study showed that honey has antibacterial activity against test organisms and may form an alternative therapy against certain bacteria.
    No preview · Article · Jan 2015
  • Ritika Chauhan · Nidhi Singh · Jayanthi Abraham

    No preview · Article · Jan 2015 · Research Journal of Pharmacy and Technology
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    ABSTRACT: The present investigation reveals the green synthesis of silver nanoparticles using Solanum nigrum and Cardiospermum halicacabum. The silver nanoparticles were synthesized and characterized by UV-Vis spectrophotometer (UV-Vis), Fourier transfer infrared spectrophotometer (FT-IR), X-ray diffraction (XRD), atomic force mass spectroscopy (AFM) and particle shape of the synthesized nanoparticles were determined by scanning electron microscopy (SEM). Furthermore, synthesized nanoparticles were evaluated for antimicrobial effect against various pathogens and cytotoxic effect on human osteosarcoma (MG-63) cell line. The plant mediated silver nanoparticles exhibited good antimicrobial activity against clinical pathogens and cytotoxic effect against bone cancer cells. Plant mediated silver nanoparticles possess therapeutic properties which may be useful in pharmaceutical applications.
    No preview · Article · Jan 2015 · World Journal of Pharmaceutical Research
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    ABSTRACT: Pistia stratiotes belongs to family Araceae. Pistia stratiotes leaves are traditionally used against ringworm infection of scalp, boils and syphilitic eruptions. Traditionally, oil extracts of Pistia stratiotes are used for treatment of tuberculosis, asthma and dysentery. As the effect of Pistia stratiotes extracts on the area of cytotoxicity is unexplored, the present work was aimed at evaluating the effect of extracts on cancer cell line and also on clinical pathogens. Phytochemical study was done with methanol extract of Pistia stratiotes leaves. Analytical study (GC-MS and TLC) was done with methanol, chloroform and hexane extracts of Pistia stratiotes leaves. Antimicrobial activity by well diffusion method and antioxidant activity by DPPH assay were also done. Antimicrobial study was done against eight clinical pathogens namely, Proteus mirabilis, Enterococcus sp., Salmonella sp., Shigella sp., Staphylococcus aureus, Serretia sp., Klebsiella sp., Pseudomonas aeuroginosa. As bone cancer is an aggressive form of cancer MG63 cell line of osteocarcoma was choosen for the study.
    Full-text · Article · Dec 2014 · International Journal of Drug Development & Research
  • Sivagnanam Silambarasan · Jayanthi Abraham

    No preview · Article · Sep 2014 · ChemInform
  • Jayanthi Abraham · Sivagnanam Silambarasan
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    ABSTRACT: Microbial degradation offers an effective approach to remove toxicants and in this study, a microbial consortium consisting bacterial strains and fungal strains were originally obtained from endosulfan contaminated agricultural soils. Identification of the bacterial isolates by 16S rRNA sequences revealed the isolates to be Halophilic bacterium JAS4, Klebsiella pneumoniae JAS8, Enterobacter asburiae JAS5, Enterobacter cloacae JAS7, whereas the fungal isolates were identified by 18S rRNA sequences and the isolates were Botryosphaeria laricina JAS6, Aspergillus tamarii JAS9 and Lasiodiplodia sp. JAS12. The biodegradation of endosulfan was monitored by using HPLC and FTIR analysis. The bacterial and fungal consortium could degrade 1000 mg l-1 of endosulfan efficiently in aqueous medium and in soil. The infrared spectrum of endosulfan degraded samples in the aqueous medium by bacterial and fungal consortium showed bands at 1400 and 950 cm-1 which are the characteristics of COOH group and acid dimer band respectively. In the present investigation, low cost solid materials such as sawdust, soil, fly Page 2 of 15ash, molasses and nutrients were used for the formulation of microbial consortium and to achieve greater multiplication and survival of the microbial strains.
    No preview · Article · Sep 2014 · Pesticide Biochemistry and Physiology
  • Jayanthi Abraham · Sivagnanam Silambarasan · Peter Logeswari
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    ABSTRACT: Several researchers have focussed on degradation of pesticides by microorganisms, which is the most viable option in remediation of agricultural soil. However, very few have illustrated the degradation of mixed pesticides. Hence, in the present investigation biodegradation of a mixture of both organophosphorus and organochlorine pesticide directed by microbial consortium was carried out in a fermentor–bioreactor system. The pesticides chosen were chlorpyrifos, monocrotophos (organophosphorus) and endosulfan (organochlorine). In order to accomplish an effective degradation, the microorganisms were isolated from agricultural fields which were previously exposed to the pesticides mentioned above. The bacteria were isolated by minimal meda with the individual pesticide as the only carbon source. The individual strains were identified by morphological, biochemical and 16S rRNA characterization. The bacterial consortium comprised of 10 organisms which were as follows: Alcaligenes sp. JAS1, Ochrobactrum sp. JAS2, Sphingobacterium sp. JAS3 which were screened and selected from chlorpyrifos contaminated soil, Enterobacter ludwigii JAS17, Pseudomonas moraviensis JAS18 and Serratia marcescens JAS16 which were isolated from monocrotophos spiked soil and Klebsiella pneumoniae JAS8, Enterobacter cloacae JAS7, Halophilic bacteria JAS4, Enterobacter asburiae strain JAS5 were obtained from endosulfan persistent soil sample. The fermentor–bioreactor system containing 2 L of sterile minimal medium supplemented with 300 mg l−1 of chlorpyrifos, 1000 mg l−1 of monocrotophos, 1000 mg l−1 of endosulfan as the only source of carbon and inoculated with 20 ml of bacterial consortium (approximately 3 × 106 cells ml−1). The HPLC and GC–MS studies were performed to record the degradation of mixed pesticides.
    No preview · Article · Sep 2014 · Journal of the Taiwan Institute of Chemical Engineers
  • Jayanthi Abraham · Sivagnanam Silambarasan
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    ABSTRACT: The present investigation was carried out with the concept of bioremediation in isolating microbes with the unique capability of utilizing endosulfan for their growth thereby enhancing degradation of the persistant organochlorine pesticide. The fungal and bacterial strain was isolated from rhizosphere soil. Molecular characterization based on 18S rRNA and 16S rRNA gene sequence analysis of JAS12 and JAS8 strains isolated from endosulfan treated soil confirmed its identity as Lasiodiplodia sp. JAS12 and Klebsiella pneumoniae JAS8, respectively. The infrared spectrum of endosulfan degraded sample in the aqueous medium by JAS12 and JAS8 showed bands at 1400 and 1402 cm−1 respectively which are the characteristics of COOH group. Furthermore, K. pnuemoniae JAS8 strain confirmed plant growth promoting traits which exhibited production of indole-3-acetic acid (IAA), organic acids and solubilization of various sources of inorganic phosphates. The modern agro-techniques necessitate the development of a new formulation where powder inoculants can play a significant role. In the present investigation, low cost solid materials such as sawdust, soil, fly ash, molasses and nutrients were used to achieve greater multiplication and survival of the microbial strains.
    No preview · Article · Sep 2014 · Ecological Engineering
  • Jayanthi Abraham · Ritika Chauhan
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    ABSTRACT: Amycolatopsis decaplanina JAR8 is rare actinomycetes which was isolated from agricultural field of Punjab, India. The 16S rRNA gene sequencing of strain JAR8 showed 98% similarity with Amycolatopsis decaplanina. The morphological, cultural and physiological characteristics were determined by International Streptomyces project by using various mediums. The bioactive metabolites produced by the strain were obtained from the optimized culture medium through solvent extraction method. The ethyl acetate extract obtained after extraction was characterized using UV, FTIR and GC-MS spectroscopic analysis. The minimum inhibitory concentration of active metabolite was found to be 60 µg/ml against Staphylococcus aureus. The present study deals with the exploration of rare actinomycetes which also produces various biological active compounds against infectious diseases.
    No preview · Article · Aug 2014 · International Journal of Pharmaceutical Sciences Review and Research

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