PHYSICOCHEMICAL PROPERTIES OF SOME BIOLOGICALLY ACTIVE SUBSTANCES OBTAINED FROM VEGETABLE RAW MATERIAL THROUGH CO_2-EXTRACTION

摘要

Extraction with the gases, which are in the supercritical state, has been successfully used lately as an ecology-friendly technique for producing valuable biologically active substances (BAS) [1-4]. This technique has all grounds to be called a "green chemistry" method [5]. Reliable data on physical-chemical properties of the BAS, obtained using the technique of supercritical fluid extraction with carbon dioxide, are required for BAS standartization [6]. Thus, using the technique of differential thermal analysis (DTA) within the range of 80-550K, we investigated phase and physical transitions (melting, crystallization, evaporation, vitrification) in the samples of the CO_2-extracts of pine shoots, weeping birch (Betuia pendula) bark, holy thistle (Silybum) seed blending, and corcule of wheat and sea-buckthorn berries. The investigation was aimed at considering a possibility to use the temperatures of the aforementioned transitions as the reference ones when compiling different lots of the obtained products. In addition, qualitative and quantitative compositions of the CO_2-extracts were studied using chromatographic and spectral methods. Radiation protecting, anti-atherogenic and anti-oxidative properties of CO_2-pine extracts were investigated as well. Betulin (C_30H_50O_2), it being a natural BAS which represents itself pentacyclic triterpenoid alcohol of lupane structure, was extracted from the CO_2- weeping birch bark extract and purified up to the concentration of the ground substance of 99.5mas.%. It exerts antiseptic, antiviral, choleretic and gastro-hepatoprotective action. The elemental analysis of betulin revealed the following concentrations, mas.%: C - 81.67, H - 11.45,O - 6.88 (theory- 81.39; 11.38; 7.23, respectively). Its solubility at 296.35K in chloroform (1.678g of C_30H_50O_2 per 100g of solvent), thermodynamic characteristics and phase transition temperatures were determined.