Geeta Joshi nee Pant

Plant growth inhibitors (Proanthocyanidins) from Prunus armeniaca

Abstract A field survey in Prunus armeniaca growing areas of Garhwal Himalaya was conducted with reference to the germination and growth of some companion crops at various sites of different soil fertility. Retardation in germination, growth and yield were noted in nearby Triticum aestivum plants, particularly on those sites where the percentage of soil organic matter was low. It was also observed that the magnitude of interference gradually decreased as the distance from the tree increased. Aqueous and organic solvent extracts of the aerial parts of Prunus armeniaca were made and their residues were tested, after proper dilution, for their phytotoxic effect on germination and growth of the test crop. Residues of light petroleum and ethyl acetate extracts showed maximum inhibition in growth and germination of the test species. The isolated compounds were identified with the help of spectroscopic techniques and bioassays. β -Sito-sterol, 2,6-dihydroxy-4-methoxyacetophenone and kaempferol were isolated from a petroleum extract whereas aromadendrin, quercetin, β -sitosterol- β - d -glucoside, pleoside and tannins (four proanthocyanidins – A-type) were characterized from an ethyl acetate extract. Of these, proanthocyanidins showed maximum inhibition, whereas quercetin, aromadendrin, kaempferol and genin of pleoside inhibited to a lesser extent.

Synthesis, characterization and fluorescence studies of 3,5-diaryl substituted 2-pyrazolines.

A series of 2-pyrazolines have been synthesized from α, β unsaturated ketones and hydrazine hydrate with acetic/formic acid in ethanol/DMSO. The structures of 2-pyrazolines have been established by spectroscopic techniques i.e. UV, IR, (1)H NMR, (13)C NMR and micro element analysis. Fluorescence spectra were recorded in the solution at fixed concentration and same excitation wavelength at 290 nm. The absorption band positions of all the compounds broadly lie between 280 and 336 nm and fluorescence band positions in the range between 300 and 370 nm, the near ultraviolet region.

Spirostanol glycoside from fruits of Asparagus officinalis

Abstract A spirostanol glycoside was isolated, together with some known compounds, from the methanolic extract of the fruits of Asparagus officinalis and characterized by chemical and spectral methods including 13 C NMR-DEPT and 2D-hetcor NMR spectra. The spirostanol glycoside caused 100% immobilization of human spermatozoa at 1.5% level.

Proanthocyanidins from Prunus armeniaca roots

Abstract Three isomeric A-type proanthocyanidins have been isolated from the root of Prunus armeniaca . They were identified as ent -epiafzelechin-(4α→8; 2α→O→7)-epiafzelechin (mahuannin A), ent -epiafzelechin-(4α→8; 2α→O→7)-(+)-afzelechin and ent -epiafzelechin-(4α→8; 2α→O→7)-(−)-afzelechin, by means of spectral studies.

A betulinic acid glycoside from Schefflera venulosa

Abstract A new betulinic acid glycoside, lup-20(29)-en-28-oic-3-O-β- d -glucopyranosyl (2→1)-O-β- d -glucopyranoside has been characterized from the leaves of Schefflera venulosa.

Synthesis and Characterization of a Novel 2-Pyrazoline

Abstract: Reaction of dibenzalacetone with hydrazine hydrate and formic acid yielded a novel 2-pyrazoline 1 , characterized by ESI-MS, FT-IR, UV, 1 HNMR and 13 CNMR data and microanalysis. Keywords: dibenzalacetone; hydrazine hydrate; pyrazoline; 5-phenyl-3-[( E )-2-phenyl-vinyl]-4,5-dihydro-1 H -pyrazole-1-carbaldehyde; fluorescence Introduction Substituted pyrazolines are useful in pharmaceutical and agrochemical research. Pyrazoline derivatives with a phenyl group at the 5-position possess good film-forming properties, exhibit excellent characteristics of blue photoluminescence and electroluminescence [1]. Pyrazolines are also used as optical brighteners and whiteners. Pyrazolines display various biological activities such as antimicrobial [2], antifungal [3], antidepressant [4], immunosuppressive [5], anticonvulsant [6], anti-tumor [7], antiamoebic [8], antibacterial [9] and antiinflammatory [10] activities. Syntheses of pyrazolines by reaction of α,β-unsaturated carbonyl compounds with diazoalkanes [11] or with hydrazine hydrate [12,13] were reported in literature. N-Substituted thiocarbamoyl-3,5-diphenyl-2-pyrazoline derivatives having NS donor, their palladium II complexes [14] and hydroxyl phenyl pyrazolines have also been synthesized [15]. The reaction of

High-performance liquid chromatography analysis of plant saponins: An update 2005-2010

Saponins are widely distributed in plant kingdom. In view of their wide range of biological activities and occurrence as complex mixtures, saponins have been purified and separated by high-performance liquid chromatography using reverse-phase columns at lower wavelength. Mostly, saponins are not detected by ultraviolet detector due to lack of chromophores. Electrospray ionization mass spectrometry, diode array detector , evaporative light scattering detection, and charged aerosols have been used for overcoming the detection problem of saponins.

Quantification of Mineral Elements of Rheum emodi Wallr. (Polygonaceae)

Present investigation was carried out to estimate mineral elements in Rheum emodi Wallr. by atomic absorption spectroscopy. The samples of R. emodi Wallr., both wild and cultivate populations, were collected from different localities at different altitudes of Uttarakhand, India. The concentration of micro- and macroelements was different in roots and leaves. The concentration of mineral elements was found in both the leaves and roots in the order of K > Ca > Fe > Mn > Na > Zn > Co > Li > Cu.

A persicogenin 3′-glucoside from the stem bark of Prunus amygdalus

Abstract A new flavanone glycoside, persicogenin 3′-glucoside (5,3′-dihydroxy-7,4′-dimethyoxyflavanone 3′-glucoside) has been characterized from the stem bark of Prunus amygdalus .

A methyl ester of melilotoside from the sapwood of Prunus cornuta

A new methyl ester of melilotoside, methyl-o-coumarate-β-d-glucoside, has been characterized from the sapwood of Prunus cornuta.