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V. V. Milevskaya, T. S. Butylskaya, Z. A. Temerdashev, M. A. Statkus, N. V. Kiseleva
Kinetics
of different extraction techniques of
biologically active substances from medicinal plant raw materials
Abstract
The paper deals with the problems and peculiarities of obtaining the
kinetic characteristics of extraction of biologically active substances (BAS)
from plant samples of different nature. We have studied the establishment of
the kinetic characteristics of BAS extraction under various extraction
conditions on the example of St. John’s wort and sage samples. The lowest value
of an average rate of extraction of BAS from the studied materials was observed
for static extraction with an aqueous alcohol extractant under heating. The
methods of the static extraction under heating (with similar conditions to
pharmacopoeia), with ultrasonication, as well as using double extraction by
ultrasonication, differ little from each other in terms of kinetic efficiency.
The highest values of the rate constants is characterized by a method of
dynamic extraction of BAS at elevated temperature and pressure, which leads to
an acceleration of diffusion of BAS into the extractant medium. It is noted
that for certain bioactive substances (for example, hyperforin, carnosic acid et al.),
there is a simultaneous extraction and chemical transfirmations, as evidenced
by a decrease in their concentrations in the extractant over the extraction
time.
Key words: extraction, kinetics, biologically active substances, Hypericum perforatum,
Salvia officinalis.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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