Virendra Pratap Singh
Institute of Medical Sciences, Banaras Hindu University
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Publication
Featured researches published by Virendra Pratap Singh.
Journal of Asian Natural Products Research | 2001
R. K. Upadhyay; M. B. Pandey; R. N. Jha; Virendra Pratap Singh; V. B. Pandey
Abstract A new triterpene glycoside, arjunetoside, together with oleanolic and arjunic acids has been isolated from the root bark of Terminalia arjuna. The structure of arjunetoside has been established as 3-O-β-D-glucopyranosyl-2α,3β, 19α-trihydroxyolean-12-en-28-oic acid, 28-O-β-D-glucopyranoside by chemical and spectral data.
Mycobiology | 2005
Sangita Sahni; S. Maurya; U. P. Singh; Ashok K. Singh; Virendra Pratap Singh; V. B. Pandey
Crude extracts and active principles from medicinal plants have shown potential role in controlling plant diseases in glasshouses as well as in fields as one of the safest and eeofriendly methods. The effect of nor-seeurinine (an alkaloid) isolated from Phyllanthus amarus has been seen against spore germination of some fungi (Alternaría brassicae, A soiani, Curvularia pennisetti, Curvularia sp., Erysiphe pisi, Helminthosporium frumentacei) as well as pea powdery mildew (Erysiphe pisi) under glasshouse conditions. The sensitivity of fungi to nor-seeurinine varied considerably. Nor-seeurinine was effective against most of the fungi. H. frumentacei was more sensitive even at the lowest concentration ( 1,000 μg/ml). Likewise conidia of E, pisi were also inhibited in partially or completely appressorium formation. Pre-inoeulation treatment showed greater efficacy than post-inoculation in inhibiting powdery mildew development on pea plants in a glasshouse. Maximum inhibition occurred at 2000 μg/ml.
Pharmaceutical Biology | 2010
Sarita Singh; Tryambak Deo Singh; Virendra Pratap Singh; V. B. Pandey
Four quaternary isoquinoline alkaloids, dehydrocorydalmine, jatrorrhizine, columbamine, and oxyberberine, have been isolated from the whole plant of Argemone mexicana Linn. (Papaveraceae) and their structures established by spectral evidence. This is the first report of these alkaloids (dehydrocorydalmine, jatrorrhizine, columbamine, and oxyberberine) from Argemone mexicana and the Argemone genus.
Journal of Asian Natural Products Research | 2008
Manoj Pandey; Ashok K. Singh; Jagdish P. Singh; Virendra Pratap Singh; V. B. Pandey
Two new cyclopeptide alkaloids, xylopyrine-D and xylopyrine-E, from Zizyphus xylopyra and a new alkaloid, jubanine-E, from Zizyphus jujuba have been isolated and their structures were established by chemical and spectral evidences.
Mycobiology | 2002
Mitul Goel; S. Maurya; V. B. Pandey; Virendra Pratap Singh; Ashok K. Singh; U. P. Singh
Abstract The inhibitory activity of ent-norsecurinine alkaloid was evaluated against spore germination of some plant pathogenic fungi (Curvularia maculans, Curvularia species, C. palliscens, Colletotrichum gloeosporioides, Colletotrichum species, Aiternaria solani, A. brassicae, Fusarium udum, Helminthosporium echinoclova and H. penniseti). It inhibited spore germination of all the test fungi. C. maculans, C. species, and C. palliscens were the most sensitive as complete inhibition of spore germination was observed at 1000 ppm. A solani was not inhibited by this chemical.
Case reports in ophthalmological medicine | 2012
Rajendra P Maurya; Deepak Mishra; Prashant Bhushan; Virendra Pratap Singh
Wohlfahrtia magnifica larvae cause myiasis in mammals, mainly in sheep and rarely in human. In human it may infest the ear, eye, mouth or nose, damaging living tissues. We report a case of ocular myiasis in 1.5 years old child belonging to urban slum after history of minor injury on left upper lid due to fall from bed. The purpose of reporting this case is to highlight the ocular association of W. magnifica.
Natural Product Research | 2007
Ashok K. Singh; Manoj Pandey; Virendra Pratap Singh; V. B. Pandey
Two new 13-membered cyclopeptide alkaloids, xylopyrine-A and xylopyrine-B have been isolated from Zizyphus xylopyra, and their structures established by spectral and chemical evidences.
Natural Product Research | 2008
Manoj Pandey; Ashok K. Singh; Jagdish P. Singh; Virendra Pratap Singh; V. B. Pandey
A new alkaloid, fuyuziphine together with (±)-α-hydrastine has been isolated from the whole plant of Fumaria indica. The structures of these alkaloids have been established by spectral and chemical evidences.
Journal of Asian Natural Products Research | 2008
Manoj Pandey; Jagdish P. Singh; Ashok K. Singh; Virendra Pratap Singh
A new 14-membered ring cyclopeptide alkaloid xylopyrine-F, together with known alkaloids nummularine-P and sativanine-H, has been isolated from the root bark of Zizyphus xylopyra and their structures were established by chemical and spectral evidences.A new 14-membered ring cyclopeptide alkaloid xylopyrine-F, together with known alkaloids nummularine-P and sativanine-H, has been isolated from the root bark of Zizyphus xylopyra and their structures were established by chemical and spectral evidences.
Mycobiology | 2002
M. K. Pandey; R. Pandey; Virendra Pratap Singh; V. B. Pandey; U. P. Singh
Abstract The 4′,7-dimethoxyisoflavone was isolated from the leaves of Albizzia lebbeck for the first time. This flavonoid showed antifungal activity against some plant pathogenic fungi tested in vitro, e.g., Alternaria melongenae, A brassicicola, A brassicae, Curvularia maculans, C. pallescens, C. lunata, Curvularia species, Colletotrichum species, Helminthosporium penniseti and H. speciferum The sensitivity of different fungi to this chemical varied considerably. A brassicae was most sensitive as complete inhibition of germination was observed in all the concentrations (100 to 1000 ppm) of the chemical. Similar effect on H. speciferum and Curvularia species was also recorded at 500 ppm, whereas H. penniseti did not germinate at 250 ppm. A. melongenae and A. brassicicola also did not germinate at 1000 ppm while 750 ppm was inhibitory to C. lunata and C. maculans. Germination in almost all fungi was significantly inhibited at each concentration in comparison to control except Curvularia sp. and H. speciferum. Use of 4′,7-dimethoxyisoflavone to control some plant diseases under field conditions has been suggested.