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V. Chandra , S. N. Srivastava

Abstract

In recent years Catharanthus roseus Don (Vinca rosea L.) has gained considerable importance due to discovery of anticancerous activity of its alkaloids. The plant grows throughout India up to 1,300 meters and has run wild in coastal areas. It is grown as an ornamental shurb in gardens and around temples in India. Though it is comronly found in India yet no efforts have been made to carry out its phytochemical studies. Since 1965 studies on cultivation of plant have been started at the institute. The studies show that on average, the ischolar_mains contain 0.13% total alkaloids and smaller ischolar_main laterals contain 0.08%.

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P. C. Sharma , S. N. Srivastava , L. D. Kaipoor

Abstract

The present note deals with the identity of 'Mirchakand' or 'Keerkand' of Madhya Pradesh, its morphological features and also the bitter principle present in it.

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V. K. Sharma ¹, S. N. Srivastava ¹

Affiliations
1 Department of Chemistry, Agra College, Agra, IN

Abstract

The effect of varying concentrations of various biopolymers and proteins was studied on the choline chloride stabilized xylene in water emulsion. The system was flocculated by Ribonucleic acid, Deoxyribonucleic acid, Bovine serum albumin and Egg albumin and the flocculation occurred in the system was studied haemocytometrically by counting the number of flocculated and unflocculated droplets from the microphotographs of the emulsions. Zeta potential in presence of these biopolymers and proteins was measured using microelectrophoretic technique with the help of Hukel and Overbeek's equations. The operating van der Waal's forces of attraction and coulombic force of repulsion were calculated, and summing up these two, the interaction energies were evaluated. The stability of the emulsions was discussed in the light of the modern theory of colloidal stability.

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M. M. Srivastava ¹, S. N. Srivastava ¹

Affiliations
1 Department of Chemistry, D.E.I., Dayalbagh, Agra, IN

Abstract

A study on the effect of increasing concentrations of ionic and non-ionic surfactants on the polarographic behaviour of acetophenone and p-bromoacetophenone with special reference to the kinetics of the electrode reactions in Britton Robinson buffer (BR) of pH 7 has been carried out at 25-0.1°C. The reduction of the depolarizers in different steps has been found to be diffusion-controlled and irreversible. The kinetic parameters (αn_a and k^o_f,h) have been calculated by Konteckey's method.

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S. P. Jain ¹, S. N. Srivastava ¹

Affiliations
1 Chemical Laboratories, Agra College, Agra, IN

Abstract

The emulsifying behaviour of finely divided solid stabilizers has been studied in detail under different physico-chemical conditions. The solid emulgents used include freshly precipitated Fe(OH)₃ and Cr(OH)₃ and their colloidal sols specially the partially flocculated ones. The promotion of the emulsion stability has been ascertained both kinetically and in terms of interaction energies between the emulsion drop lets. The hydroxide stabilized emulsions are found to be most stable (insensitive to the addition of electrolytes and heat). Partially flocculated sols promote reasonably stable emulsions, but the sols as such act as weak emulgents. Relatively high stability of the emulsions is mainly due to (i) their large size which leads to only secondary minimum flocculation and (ii) solidous nature of compact consistency of the emulgent film which prevents the drainage of the oil underneath.

Keywords

Emulsions, Emulgents, Stabilization, Adsorption.

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