Authors:M. R Chakraborty, S. Dutta, S. Ojha and N. C. Chatterjee
Biological control of die-back of bottle brush (Callistemon citrinus) caused by Botryodiplodia theobrome was made with the application of antagonistic agents like Trichoderma viride, T. lignorum, T. harzianum, Aspergillus niger and Penicillium citrinum. The effect of volatile and non-volatile antibiotics of Trichoderma origin on growth inhibition of the die-back pathogen was studied. T. harzianum showed maximum growth inhibition (75.33%) of the pathogen through mycoparasitism and the non-volatiles produced by the same agent exhibited its excellent antagonism to the growth of the pathogen (91.11%) under in vitro condition and that the effect was also proved to be durable.
Authors:M. Chakraborty, I. Ghosh, S. Ojha, S. Dutta and N. Chatterjee
Influence of an endomycorrhizal species
on the growth of two vegetable plants, namely,
and for reduction of the incidence of fusarial wilt disease under field condition was studied. VAM treated plants showed more vigor in terms of productivity parameters viz., plant height, number of branching twigs and fruit production. VAM and pathogen treated plants also showed positive effect of VAM-symbiont over control indicating reduction of pathogenic stress of the plant and give resistance. Leaf phosphate, chlorophyll content and percentage of mycorrhization were recorded highest when plants were singly inoculated with
. Synergistic effect of VAM and pathogen to increase on productivity vis-à-vis resistance was also studied in respect of polyphenol oxidase. The experimental findings indicated the potential use of
for improving the growth and imparting resistance of brinjal and tomato.
Authors:S. Dutta, A. Kundu, M. R. Chakraborty, S. Ojha, J. Chakrabarti and N. C. Chatterjee
Siderophores are low molecular weight
(<1000 D) iron chelating compounds produced by microorganisms. Production of
siderophore is a device of antagonism as by virtue of the capacity of
siderophore production, a microorganism competes for Fe (III) with the others.
Production of siderophores by 9 different soil fungi and wood-decay fungi was
studied following CAS - assay and CAS - agar plate assay. Optimization for the production of
siderophores was done by varying the levels of pH and Fe (III) concentrations
in the low nutrient medium. All the test fungi could produce siderophores,
though the degree of production recorded to be very low both in Botryodiplodia
theobromae and in Fusarium spp. On the other hand, all the species of
Trichoderma showed their excellency in siderophore production. The optimum pH
for production of siderophores remained at neutral pH level though the range
varied from pH 6.0-8.0. The optimum range of the
concentration of Fe (III) required for siderophore production was recorded to
be 1.5-21.0 µM. However, the stress condition of
iron might be a decisive factor for siderophore production.
Authors:Pankaj Kumar, J. Pattanaik, S. Ojha, S. Gargari, R. Joshi, G. Roonwal, S. Balakrishnan, S. Chopra and D. Kanjilal
An accelerator mass spectrometry (AMS) facility for measurements of 10Be has been developed by upgrading the 15UD Pelletron accelerator at Inter-University Accelerator Centre (IUAC), New Delhi.
Details of the up gradation of the facilities and the measurement procedure are described briefly. Chemical processing for
the separation of 10Be from manganese nodules and results of recent experiments on 10Be are presented.
Authors:P. R. Desai, P. J. Mehta, S. K. Ojha and A. B. Chokshi
A novel, simple, robust, and rapid reversed-phased high-performance liquid chromatographic method has been developed for the separation and quantitative determination of the related substances of ezetimibe and simvastatin in combined dosage forms. Successful separation of the drug from the process-related impurities and degradation products formed under stress conditions was achieved on Inertsil ODS-3V (150 × 4.6 mm, 5.0 μm) column. The gradient liquid chromatography (LC) method employs solution A and solution B as mobile phase. The solution A contains 0.1% orthophosphoric acid solution in water, and solution B contains 0.1% orthophosphoric acid solution in acetonitrile. Flow rate was monitored at 2.0 mL/min, and the ultraviolet (UV) detection, at 238 nm. In forced degradation studies, the effect of acid, base, oxidation, UV light, and temperature was investigated, showing that good resolution between the peaks corresponds to process-related impurities and degradation products from both analyte. The performance of the method was validated according to the present International Conference on Harmonization (ICH) guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness, and robustness. To the best of our knowledge, a rapid LC method, which separates all the impurities of ezetimibe and simvastatin in combined dosage forms, disclosed in this investigation was not published elsewhere.
Authors:S.M. Nurulain, S. Ojha, S. Dhanasekaran, K. Kuča, N. Nalin, C. Sharma, A. Adem and H. Kalász
Distribution of K027, a hydrophilic, positively charged compound is monitored in the body of pregnant mice using high-performance liquid chromatography (HPLC). Intraperitoneal injection was done on the 18th day of pregnancy; the plasma and brains of the mother mice, placentae and the fetuses’ brains were dissected following 5, 15, 30, 60, and 120 min of treatment. Significant incorporation of K027 was found in the placentae and in fetuses’ brains relative to its levels in the mothers’ plasma and brains. This incorporation warns of a possible adjustment of dose of pyridinium aldoxime antidotes in case of pregnancy. Further studies with different gestational periods and animal models are warranted.