Browsing by Author "R.N. Jha"

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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 Berberine and (±)-Bicuculline Isolated from Corydalis chaerophylla on Spore Germination of Some Fungi
(Czech Academy of Sciences, 2002) S. Ameer Basha; R.K. Mishra; R.N. Jha; V.B. Pandey; U.P. Singh
Berberine and (±)-bicuculline were isolated from roots and leaves, respectively, of Corydalis chaerophylla. Both were effective in vitro against spore germination of some plant pathogenic fungi (Alternaria brassicicola, A. brassicae, A. cheiranthi, A. melongenae, A. solani, Colletotrichum musae, C. falcatum, Curvularia penniseti, C. lunata, C. maculans, C. pallescens, Curvularia sp., Erysiphe pisi, E. cichoracearum, Erysiphe sp., Fusarium udum, Helminthosporium spiciferum, H. penniseti, H. frumentacei, Heterosporium sp., Oidium erysiphoides and Ustilago cynodontis). Berberine and (±)-bicuculline significantly inhibited spore germination of all the fungi at concentrations of 100-1000 ppm. Berberine was effective against all the fungi at all concentrations; most of the fungi did not germinate at 1000 ppm. H. penniseti conidia did not germinate at any concentration of (±)-bicuculline. U. cynodontis was the least sensitive fungus at lower concentrations but 800 ppm dose was highly effective.
Efficacy of alkaloid (-)-corypalmine against spore germination of some fungi
(Czech Academy of Sciences, 2002) S. Maurya; J.S. Srivastava; R.N. Jha; V.B. Pandey; U.P. Singh
Inhibition activity of the alkaloid (-)-corypalmine on spore germination of plant pathogenic and saprophytic fungi (Alternaria solani, A brassicicola, A. brassicae, A. melongenae, Curvularia pallescens, C. lunata, C. maculans, Curvularia sp., Colletotrichum sp., Helminthosporium speciferum, H. frumentacei, H. pennisetti, Heterosporium sp., Penicillum sp., Ustilago cynodontis) was determined. Spore germination of all the tested fungi was inhibited, Heterosporium sp. and Ustilago cynodontis being the most sensitive (complete inhibition of spore germination was observed at the very low concentration of 200 ppm). Curvularia palliscens, C. maculans and Curvularia sp. were less sensitive; complete inhibition of spore germination occurred at 400 ppm.
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.
New alkaloids from Corydalis species
(2009) R.N. Jha; M.B. Pandey; A.K. Singh; S. Singh; V.P. Singh
A new alkaloid, chaerophylline (1), together with known alkaloids (-)-corypalmine, berberine chloride, (-)-isocorypalmine, (-)-corydalmine and (+)-bicuculline have been isolated from the crude base fraction of Corydalis chaerophylla. The crude base fractions of Corydalis longipes gave a new alkaloid, longicine (4), together with known alkaloids (±)-α-hydrastine, (±)-β-hydrastine, N-methylhydrasteine hydroxylactam, 1-methoxyberberine chloride and berberinium hydroxide. These alkaloids are reported for the first time from the above species and their structures were established by chemical and spectroscopic evidence.
Phenolic constituents of Eclipta alba
(Indian Drug Manufacturers' Association, 2000) R.K. Upadhyay; M.B. Pandey; R.N. Jha; V.B. Pandey
The flavonoids, apigenin, luteolin, wedelolactone, apigenin-7-0-glucoside and luteolin-7-0-glucoside has been isolated from the whole plant of E. alba and identified by spectral data. This is the first report of the presence of luteolin and apigenin-7-0-glucoside in E. alba.
Triterpene glycoside from terminalia arjuna
(Harwood Academic Publishers GmbH, 2001) R.K. Upadhyay; M.B. Pandey; R.N. Jha; V.P. Singh; V.B. Pandey
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-βD-glucopyranoside by chemical and spectral data.
Two Plant Alkaloids Isolated from Corydalis longipes as Potential Antifungal Agents
(Czech Academy of Sciences, 2003) N.V. Singh; S. Azmi; S. Maurya; U.P. Singh; R.N. Jha; V.B. Pandey
The alkaloids N-methylhydrasteine hydroxylactam and 1-methoxyberberine chloride were isolated from Corydalis longipes. Both alkaloids showed high efficacy individually (in concentration of 50-150 ppm) and also in a 1 : 1 mixture against spore germination of some fungi, viz. Alternaria alternata, A. brassicae, Curvularia maculans, Curvularia sp., Colletotrichum gloeosporioides, Colletotrichum sp., Helminthosporium speciferum, H. pennisetti, Helminthosporium sp. and Ustilago cynodontis. The antifungal effect of single compounds was dose-dependent. If the mutual ratio of the two components in the mixture was changed from 1 : 1 to a major content of any of the two compounds, the inhibitory effect on spore germination decreased.