Study of the relationship between geometric isomerism and biologically active properties of compounds

The results of the research in the field of studying the relationship of the geometric structure of organic compounds with their biological activity are presented. It has been shown that the stereospecific structure of organic and inorganic molecules can have a direct effect on the biologically active properties of substances. Among the known types of stereoisomerism (geometric and optical), this work summarizes the effect of various types of geometric isomerism on the bioactivity of compounds. In addition, the results of the authors’ own research are presented. In particular, the results of studying the antimicrobial and antifungal activity of hydroxyalkyl monoesters of norbornedicarboxylic acid depending on their stereoisomeric forms in relation to various pathogenic microorganisms are shown. The studies were carried out by the serial dilution method. As nutrient media, we used MPA pH 7,2–7,4 for bacteria and Sabouraud’s medium for fungi. The incubation time in a thermostat for bacteria was 18–24 hours at 37ºC, for fungi 1–10 days at 28ºC. It has been noted that the endo-isomers of the synthesized compounds have a higher antimicrobial and antifungal activity against grampositive (Staphylococcus aureus), gramnegative (Escherichia coli, Pseudomonas aeruginosa) bacteria, as well as yeast-like fungi of the genus Candida. Based on the obtained test reports, the synthesized compounds have been recommended for use as local antiseptic preparations.

ANTIOXIDANT ACTIVITY OF TRITERPENE GLYCOSIDE (CORTUSOSIDE A) FROM CORTUSA MATTHIOLI L. PLANT

The antioxidant activity of triterpene glycoside, first isolated from the aboveground part of the plant Cortusa matthioli L. and identified as β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranoside-(1→3)-13β,28-epoxyolean-30-al-3β,16α-diol (cortusoside A), is studied. Tests for the ability of cortusoside A to bind 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals did not reveal any activity of this compound. However, in experiments to study the ability to chelate Fe2+ ions, its sufficiently high iron chelating activity was found, which was only 2.24 times lower compared to the powerful Fe2+ chelator dipyridyl. The EC50 values for cortusoside A and dipyridyl were 0.417±0.057 and 0.186±0.018 mM, respectively. Literature analysis has shown that the structural analogue of cortusoside A, saxifragifolin B, has a much weaker iron chelating ability (13,4 times) compared to the standard Fe2+ EDTA-Na2 ion chelator, as well as a weak ability to bind free radicals of DPPH compared to the reference antioxidants – catechin and ascorbic acid (50 and 32 times, respectively). Despite the structural identity of the molecules cortusoside A and saxifragifolin B, low radiculopathy activity cortusosoide A may be due to differences in the structure of these substances (optical or geometric isomerism), as well as different methods were used in its definition.

Influence of geometric isomerism on the binding of platinum anticancer agents with phospholipids

A holistic approach to the molecular mechanism of platinum anti-cancer agents extends DNA interactions to membrane phospholipids relevant to cellular accumulation and delivery.