As is known [1,2] dimephosphon is successfully used for the treatment of various disorders, which suggests that this compound influences the key points common in the main metabolic processes. This conclusion stimulates investigations aimed at elucidation of the universal mechanism of drug action at the molecular level.Based on an analysis of data on the effect of dimephosphon on the aggregation of thrombocytes and the functional-metabolic activity of leukocytes, it was suggested [3] that such a universal mechanism can be related to the drug effect on the relative content of calcium ions in the intra-and extracellular medium. In recent years, experiments using direct measurement of the Ca 2+ ion dynamics in the intracell medium showed that DMP increases the level of calcium ions in the cell by stimulating their release from intracellular depots [4]. In this context, we have studied the possibility that dimephosphon participates in the molecular biological processes via interaction with calcium ions and their environment.
EXPERIMENTAL PARTWe have measured and analyzed the Fourier-transform IR spectra (FTIR) of the parent substance of dimephosphonand calcium chloride with the general formula CaCl 2 × nH 2 O (usually occurring in the form of the hexahydrate CaCl 2 × 6H 2 O [5]). We have also studied the mixture of both components in various forms: (i) calcium chloride powder impregnated with liquid DMP (a jelly-like sample), (ii) an emulsion in Vaseline oil, (iii) a mixture palletized with KBr, (iv) a powdered mixture pressed between polyethylene plates, and joint solutions (v) in water, and (vi) in physiological solution (0.9 % aqueous NaCl solution).The experiments were performed with the parent substance of DMP synthesized as described in [6] and commercial calcium chloride (granulated, analytical grade) corresponding to all requirements of the corresponding pharmacopoeial article (FS 42-2993-99). The jelly mixture was prepared by adding liquid DMP to calcium chloride powder until complete impregnation (the supernatant phase was decanted and studied separately). The concentration of DMP solutions in water and physiological solution was 10 -15 wt%. In order to eliminate the influence of hydrolysis (appearing with time in the IR spectra), all measurements were performed with freshly prepared samples.The IR spectra were measured in the frequency range from 4000 to 400 cm -1 using an IFS-113v Fourier-transform spectrophotometer (Bruker, Germany). The FTIR spectra were obtained at a resolution of 4 cm -1 ; the data were accumulated and averaged over 128 scans. The samples of solutions were measured using cells with KRS-5 windows. The thicknesses of sample layers were empirically selected (typically, within 5 -15 mm) so as to obtain the optimum pattern. Changes in the IR spectra were revealed and interpreted using the differential spectroscopy technique.
RESULTS AND DISCUSSIONA detailed interpretation of the vibrational spectrum of dimephosphon molecules was performed in the previous investigations of their conformat...
