Comparative assessment of the spectral characteristics and biological activity of acetone extracts of medical rubbers and their effect on the morphology of test culture colonies

Acetone extracts of various brands of natural and synthetic cis-1,4-isoprene rubbers were obtained by extraction using the Soxlet apparatus. Using a modified method for evaluating the biological activity of compounds, the effect of the prepared extracts of various concentrations in the range from 1 to 50 mg/ml on the size of the growth inhibition zone of test culture colonies was analyzed. Bacterial colonies were used to determine the antimicrobial properties of rubber extracts, and fungicidal activity was determined using mold fungi and yeast. It was shown by the method of IR- spectroscopy with DTIR that the extracts of the studied rubbers have different compositions and contain different amounts of stearic, oleic and linoleic acids, proteins and enzymes. The mathematical processing of the results, the calculation of the biological and fungicidal activity of the extracts were carried out using the PASS-online software package. A comparative assessment of the antimicrobial properties of synthetic and natural rubber extracts showed that extracts of synthetic isoprene rubber of the SKI-5 PM brand (PM - food medical) have the greatest inhibitory effect against yeast Saccharomyces boulardii CNCM I-745. It was also found that these extracts have a maximum growth suppression rate (1.2 $\pm$ 0.1 mm/day) of widespread Aspergillus niger mold fungi compared with extracts of natural rubbers. Thus, it is shown that for the production of medical and food industry products, imported natural rubbers can be replaced to a large extent by domestic synthetic analogues.