Synthesis and antimycobacterial activity of novel 1,3-dimethylisocyanurate derivatives.

A series of novel 1,3-dimethylisocyanurates has been synthesized as potential inhibitors of ß-ketoacyl synthase in mycobacteria. Most of the 25 compounds described and tested for their activity against M. tuberculosis have a bacteriostatic effect, comparable and even higher that of first-line antituberculosis drugs. These compounds are nontoxic, species-specific, exhibiting no activity against other bacterial species.

Effect of melafen on structure and function of liposome and ehrlich ascitic carcinoma cell membranes.

The effects of melafen (plant growth stimulant) on membrane structure and functions of animal cells were studied. The process of signal transduction from cell surface to intracellular structures and conformation changes in membranes in the presence of this substance were studied by light scatter and differential scanning microcalorimetry. Melafen in a wide range of concentrations (10(-13)-10(-3) M) inhibited Ca(2+) signal system involved in the function of Ca(2+)-dependent K(+) and Cl(-) channels in Ehrlich ascitic carcinoma cells. Being a hydrophilic substance, melafen had little effect on the lipid phase of artificial membranes, but impaired the function state of transformed cell. The importance of studies of transformed cells causes no doubt because of increasing incidence of diseases associated with uncontrolled cell division.

[The impact of melafen on the expression of chloroplastic chaperone protein HSP70B and photosynthetic pigments in cells of Chlamydomonas reinhardtii].

The effects of growth regulator of the new generation-melamine salt of bis(oxymethyl)phosphine acid (melafen)--on culture growth, pigment and protein content, and the induction of protective chloroplastic chaperone HSP70B in Chlamydomonas reinhardtii CW15 cells were studied. Melafen exhibited 10-30% growth inhibition at 10(-9)-10(-2)% concentration. At 10(-9)-10(-4)% of melafen electrophoretic concentration, the pattern of cellular proteins was similar to the control. The alterations in protein content of algae cells were detected only at 10(-2)% concentration. The content of chlorophyll and carotenoids in melafen-treated cells was 17-40% lower than in the control. Melafen at 10(-9)-109-2)% concentration inhibited HSP70B induction by 39-43% compared to untreated cells. The potential mechanism of melafen effect might involve its influence on nuclear gene expression.

[Effect of melafen on expression of Elip1 and Elip2 genes encoding chloroplast light-induced stress proteins in barley].

The effect of melafen, a plant growth regulator of a new generation, on the growth, pigment composition, and expression of nuclear genes Elip1 and Elip2 encoding chloroplast light-stress proteins in barley (Hordeum vulgare L) seedlings was studied. It is shown that the height of seedlings treated with melafen at concentrations of 0.5 x 10(-10) and 0.5 x 10(-8) M increased by approximately 10 and 20%, respectively, as compared to the control. At high concentrations (10(-5) and 10(-3) M), melafen had no effect on the growth of seedlings. The content of chlorophylls and carotenoids in chloroplasts barely differed from the control at all melafen concentrations tested. Reverse transcription-polymerase chain reaction (RT-PCR) showed that melafen did not influence the expression of the nuclear gene encoding the low-molecular-weight plastid stress protein ELIP1. At the same time, the expression of the nuclear gene encoding the high-molecular-weight light-inducible stress protein ELIP2 in the plants treated with melafen at a concentration of 0.5 x 10(-8) M, increased by approximately 70 %. At higher concentrations, melafen suppressed the Elip2 gene expression. Thus, melafen affects the expression of the Elip2 gene, which is involved in the regulation of chlorophyll synthesis and chloroplast biogenesis, which, in turn, may lead to changes in the resistance of plants to light-induced stress.

[The effect of melamine salt of bis(oxymethyl)phosphinic acid (melafen) on the growth processes and cytoplasmic membrane function in potato tuber cells].

The effects of a new synthetic growth regulator, preparation melafen, on the growth processes in potato plant tubers and the H+ -ATPase activity in cell plasmalemma were studied. It was demonstrated that melafen could both stimulate and inhibit the growth of potato tubers depending on its concentration and the physiological state of the tubers. It is likely that one of the manifestations of melafen action is its influence on the division and extension of apical meristem cells. The growth stimulation caused by melafen is connected with modifications of the plasmalemma of potato tuber cells, namely, the activation of H+ -ATPase and increase in the membrane proton permeability.