Browsing by Author "M.B. Pandey"

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A new chalcone glycoside from Rhamnus nipalensis
(2008) M.B. Pandey; A.K. Singh; U. Singh; S. Singh; V.B. Pandey
A new chalcone glycoside, chalcone-2′,4-dihydroxy-4′-O-β-D-glucoside has been isolated from Rhamnus nipalensis together with sitosterol, lupeol, di-O-methyldaidzein, kaempferol-4′-methylether, quercetin, physcion, sitosterol glucoside, emodin and their structures established by spectroscopic data. Isolation of these compounds are the first report from this plant.
A new indole alkaloid from Alstonia scholaris
(2009) Luna Jain; M.B. Pandey; Sarita Singh; A.K. Singh; V.B. Pandey
A new indole alkaloid, N-formylscholarine, together with picrinine, strictamine and nareline has been isolated from the fruit pods of Alstonia scholaris, and their structures were established by various spectral data. This is the first report of these alkaloids in A. scholaris fruit pods. © 2009 Taylor & Francis.
A new isoflavone glycoside from Heliotropium indicum
(Indian Chemical Society, 2007) M.B. Pandey; A.K. Singh; D.P. Pandey; V.B. Pandey
A new isoflavone glycoside helioside, together with 7-hydroxyflavanone and naringenin-5-methylether has been isolated from the whole plant of Heliotropium indicum. The structure of helioside has been established as genistein-7-O- {α-L-rhamnosyl-(1→2)-[β-D-glucosyl-(1→ 3)]-β-D- glucoside) by chemical and spectral data.
Alkaloids of Alstonia scholaris
(Indian Chemical Society, 2009) Luna Jain; Sarita Singh; M.B. Pandey; V.B. Pandey
Picrinine, strictamine and nareline has been isolated from the fruit pods of Alstonia scholaris and their structure established by various spectral data. This is the first report of these alkaloids in A. scholaris fruit pods.
Antifungal activity of the alkaloids from Eschscholtzia californica
(2009) S. Singh; L. Jain; M.B. Pandey; U.P. Singh; V.B. Pandey
The isoquinoline alkaloids hunnemanine and norsanguinarine have been isolated from methanolic extract of the whole plant of Eschscholtzia californica. These two alkaloids were checked for their antifungal activity against phytopathogenic fungi Alternaria melongenae, A. brassicola, A. brassicae, Curvularia lunata, C. maculans, Helminthosporium pennisetti, H. oryzae, H. turcicum, Fusarium undum and F. lini. Hunnemanine exhibited 100 % inhibition of spore germination of A. brassicae, H. pennisetti and F. lini at 1000 ppm whereas norsanguinarine exhibited 100 % inhibition of A. brassicicola and C. maculans at this concentration. © 2009 Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic.
Antifungal flavonoids of Melochia corchorifolia
(Indian Chemical Society, 2010) R.C. Tripathi; M.B. Pandey; Sarita Singh; V.B. Pandey
5,7-Dihydroxyflavone, apigenin, kaempferol and quercetin has been isolated from aerial parts of Melochia corchorifolia and their structures established by spectral evidences. These flavonoids exhibited significant antifungal activity. This is the first report of these flavonoids in M. corchorifolia and their antifungal activity.
Constituents of Rhamnus nipalensis
(Indian Chemical Society, 2006) M.B. Pandey; J.P. Singh; U. Singh; V.B. Pandey
Three flavonoids, 4,7-dimethoxyisoflavone, quercetin and kacmpferol-4′-methyl ether have been isolated from the whole plant of Rhamnus nipalensis and their structures established by spectral evidences. This is the first report of these flavonoids in R. nipalensis.
Constituents of Zizyphus jujuba
(Indian Chemical Society, 2008) M.B. Pandey; J.P. Singh; Sarita Singh; A.K. Singh
Three flavonoids, kaempferol-7-methylether, kaempferol and myrecetin together with a cyclopeptide alkaloid, nummularine-K have been isolated from the barks of Zizyphus jujuba and their structures established by spectral evidences. This is the first report of occurrence of these compounds in Z. jujuba.
Constituents of Zizyphus species: A review
(2006) M.B. Pandey; Nisha Rai; A.K. Singh
Most of the Zizyphus species available in India finds use system of medicine for the treatment of scabies, throat troubles, skin diseases, abdominal pain, diarrhoea, dysentery, healing of wounds, colds, coughs, bilious affection and also as an important source of the fruit. In view of this, a review on chemical constituents has been presented upto the year 2003 which may be of great help to the workers in this area.
Cyclopeptide alkaloids from Zizyphus jujuba
(2001) M. Tripathi; M.B. Pandey; R.N. Jha; V.B. Pandey; P.N. Tripathi; J.P. Singh
A new cyclopeptide alkaloid, jubanine-C (1), together with known alkaloids scutianine-C (4) and zizyphine-A (5), have been isolated from the stem bark of Zizyphus jujuba and identified by spectral analysis. Copyright © 2001 Elsevier Science B.V.
Eclalbatin, a triterpene saponin from Eclipta alba
(Harwood Academic Publishers GmbH, 2001) R.K. Upadhyay; M.B. Pandey; R.N. Jha; V.B. Pandey
From the whole plant of Eclipta alba, a new triterpene saponin, named eclalbatin, together with α-amyrin, ursolic acid and oleanolic acid were isolated. The structure of eclalbatin has been established as 3-O-β-D-glucopyranosyl-3-β-hydroxy-olean-12-en-28-oic acid, 28-O-β-D-arabinopyranoside (1) on the basis of chemical and spectral data.
Effect of biotic and abiotic factors on pupation height in four species of Drosophila.
(1993) M.B. Pandey; B.N. Singh
Effect of different biotic and abiotic factors such as sex, density, larval development time, moisture, temperature and light on pupation height were tested in Drosophila ananassae, D. bipectinata, D. malerkotliana and D. biarmipes which are commonly distributed in India. In the four species there are no sex differences in pupation height. Density of larvae and moisture content of food medium strongly influence pupation height. Larval development time, light and temperature also affect pupation height but there are intra- and interspecific variations in response to these factors for pupation site preference. Thus pupation site preference in these Indian species of Drosophila is influenced by various biotic and abiotic factors. The comparison of the present results with those found in other species clearly indicates that different species may vary in their response to different factors.
Effect of mutation on mating propensity in Drosophila biarmipes.
(1993) B.N. Singh; M.B. Pandey
By using multiple-choice technique, mating success between purple eye colour mutant and wild type D. biarmipes was studied in an Elens-Wattiaux mating chamber. Red eyed (wild type) males were more successful in mating than mutant males. However, mutant females were more receptive than wild females. The results suggest that purple eye colour mutation affects mating propensity in D. biarmipes.
Flavonoids from Echinops echinatus
(2006) S. Singh; R.K. Upadhyay; M.B. Pandey; J.P. Singh; V.B. Pandey
A new isoflavone glycoside, echinoside (7), together with 7-hydroxyisoflavone, kaempferol-4′-methylether, kaempferol-7-methylether, myrecetin-3-O-α-l-rhamnoside, kaempferol and kaempferol-3-O-α-l- rhamnoside, has been isolated from the whole plant of Echinops echinatus . The structure of echinoside has been established by chemical and spectral data. This is the first report of the occurrence of these flavonoids in E. echinatus. © 2006 Taylor & Francis.
Flavonoids of Echinops echinatus
(Indian Chemical Society, 2006) S. Singh; M.B. Pandey; J.P. Singh; V.B. Pandey
Six flavonoids, 7-hydroxyisoflavone, kaempferol-4′-methylether, kaempferol-7-methylether, kaempferol, kaempferol-3-O-α-L-rhamnoside and myrecetin-3-O-α-L-rhamnoside has been isolated from the whole plant of Echinops echinatus.
Flavonoids of Zizyphus rugosa
(Indian Chemical Society, 2009) A. Singh; M.B. Pandey; Sarita Singh; A.K. Singh; J.P. Singh
Three flavonolds - kaempferol-4′-methylether, luteolin and luteolin-7-O-glucoside have been isolated from the barks of Zizyphus rugosa and their structures were established by spectral evidences. This is the first report of these flavonoids from Z. rugosa.
Flavonoids of Zizyphus species
(Indian Chemical Society, 2007) A.K. Singh; M.B. Pandey; V.P. Singh; V.B. Pandey
7-Methoxyflavone and quercetin from Zizyphus mauritiana and kaempferol-4′-methylether and kaempferol from Zizyphus xylopyra has been isolated from their root barks and their structures established by spectral evidences. This is the first report of these flavonoids from these plants.
Fuyuziphine, a new alkaloid from Fumaria indica
(2008) M.B. Pandey; A.K. Singh; J.P. Singh; V.P. 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.
Geographic distribution of I-R and P-M systems of hybrid dysgenesis in Indian populations of Drosophila melanogaster.
(1993) B.N. Singh; M.B. Pandey
[No abstract available]
Individual and combined effect of (±)-α-hydrastine and (±)-β-hydrastine on spore germination of some fungi
(Czech Academy of Sciences, 2003) M. Goel; U.P. Singh; R.N. Jha; V.B. Pandey; M.B. Pandey
(±)-α-Hydrastine and (±)-β-hydrastine were isolated from Corydalis longipes; both exhibited considerable efficacy against spore germination of some saprophytic and phytopathogenic fungi. While (±)-α-hydrastine was effective against most of the fungi, Helminthosporium echinoclova was least affected even at the highest dose (150 ppm). (±)-β-Hydrastine was equally effective against several fungi. Mixture of both compounds was more effective than each one individually. Helminthosporium species were again the most resistant toward the mixture. The effect of both alkaloids independently on germination and development of E. pisi conidia on excised pea leaves was also shown. After pre-inoculation with (±)-α-hydrastine, the effect was more pronounced than the addition post-inoculation; maximum inhibition occurred at 200 ppm. (±)-β -Hydrastine also reduced germination of conidia but was less effective than (±)-α-hydrastine. The number of primary and secondary branches of conidia and number of appressoria were not affected significantly by either compound.