The hemolytic activity of epoxydammarane triterpenoids.

The hemolytic activity of the epoxydammarane triterpenoids isolated from the Far-East species of the genus Betula and their semi-synthetic derivatives was investigated. Comparative studies of epoxydammarane triterpenoid activities at pH 5.5 and 5.0 and at 37 and 42 degrees C showed that 3-oxo, 3,11-dioxo, 3- and 11-acetoxy, as well as 3,11-diacetoxy derivatives had hemolytic potencies lower than the corresponding polyols; triterpenoids with a 3alpha-OH group were stronger than their analogues with a 3beta-OH group; epoxydammaranetriols were somewhat more potent than epoxydammaranediols. Triterpenoids esterified with malonic acid at C-3 possessed the strongest hemolytic activity among the tested compounds.

[A comparative study of the hemolytic activity of triterpene polyols of the dammarane series]. / Sravnitel'noe izuchenie gemoliticheskoi aktivnosti triterpenovykh poliolov dammaranovogo riada.

We studied membranotropic effect of dammarane-type triterpenes (isolated from birch leaves) with a variable side chain structure, as well as the number and configuration of OH groups as a function of temperature and pH. Polyols with an acyclic side chain and four OH groups proved to have a higher hemolytic activity as compared to polyols with three or five hydroxyl groups. The triterpenes, with tetrahydrofurane cycle as the side chain, exert a hemolytic effect at a more acidic pH (5.0) and higher temperature (45 degrees C), as compared to the polyols with acyclic side chain. Irrespective of the side chain structure, the compounds with a 24(S) configuration lysed the erythrocytes at lower rate, as compared to the compounds with a 24(R) configuration.

The membranotropic activity of cyclic acyldepsipeptides from bacterium Bacillus pumilus, associated with the marine sponge Ircinia sp.

The isolate of Bacillus pumilus associated with the marine sponge Ircinia sp. produced the surfactin-like lipopeptides, cyclic acyldepsipeptides. The hemolytic activity of individual cyclic acyldepsipeptides, bacircines (BI) 2, 3, 4, 5 and 5A having different acyl side chain structures (anteiso-C13, iso-C14, normal-C14, anteiso-C15, and iso-C15, respectively) was studied. The hemolytic power of bacircines depended on both the structure of the side chain (n->iso->anteiso-) and pH values (5.6 and 6.5 > 7.4). Hemolytic potency as a function of BI 5 concentration was given for pH 6.5; 7.4; 8.0; 9.0. pH dependent hemolysis induced by BI 5 was shown to be reversible. The membrane damaging potential of bacircine 5 (5 microM) at pH 6.5 was characterized by a higher rate of hemolysis and by a shorter time between the introduction of BI 5 solution into the RBC samples and the onset of hemolysis. Under this condition, BI 5 decreased abnormally the microviscosity of erythrocyte ghosts bilayer. The damaging potency of BI 5 decreased with an increase pH from 6.5 to 7.4 or its decrease from 6.5 to 4.9. It was shown that fatty acid bacircine fragment penetrated into the lipid bilayer to a depth of minimum 7 carbon atoms. Constants of dissociation of the Asp (pK 4.75) and Glu (pK 6.65) residues of bacircine in the lipid bilayer were obtained. These results showed that at pH 6.5 BI 5 possessed membranotropic activity in the monoionic form.

[Comparative study of anti-tumor activity of the monoglucosides protopanaxadiol and betulafolientriol]. / Sravnitel'noe izuchenie protivoopukholevoi aktivnosti monogliukozidov protopanaksadiola i betulafolientriola.

Antitumor and cytotoxic activity of monoglucosides such as 3-0-panaxadiol (1), 12-0-panaxadiol (2) and 20-0-panaxadiol (3) and 3-0-betulafolientriol (4), 12-0-betulafolientriol (5) and 20-0-betulafolientriol (6) was studied. It was found that in concentrations of 10 to 50 micrograms/ml the above monosides induced marked impairment of the selective permeability of the tumor cells and the inhibition of the labeled precursor inclusion into the macromolecule biosynthesis. Administration of the monosides in a single dose of 100 mg/kg 24 hours after the inoculation of the Ehrlich tumor cells resulted in prolongation of the mean life-span of the mice by 144 per cent (1), 153 per cent (2), 144 per cent (3), 125 per cent (4), 133 per cent (5) and 178 per cent (6). A significant reduction of the tumor mass was observed at the early stages of the tumor development and later the tumor progress intensively resumed. The tests for the effect of the monoside-activated macrophages on the growth of the tumor cells showed that production of the growth factors by the macrophages was stable and had a negative action on the efficacy of the chemotherapy with the monoglucosides.

[Effect of glycosides of betulafolientriol and its 3-epimer on the growth of tumor cells in vitro]. / Vliianie glikozidov betulafolientriolai ego 3-épimera na rost opukholevykh kletok in vitro.

The effect of triterpene glycosides synthesized on the basis of betulafolientriol, ginsenoside Rb1 from gingseng, betulafolientriol and its 3-epimer on the growth of the Ehrlich tumor cell cultures was studied. It was shown that, in relation to the quantitative composition and sites of carbohydrate residue linkage to aglycone as well as configuration of the alpha- or beta-hydroxyl group at C-3, the activity of the triterpenoids of the dammaranic series changed within wide ranges. 3- and 12-0-beta-D-glycosides of 3-epibetulafolientriol proved to be the most active.

[Antimicrobial activity of polyhydroxynaphthoquinones from sea urchins]. / Antimikrobnaia aktivnost' poligidroksinaftokhinonov iz morskikh ezei.

Antimicrobial activity of polyhydroxynaphthoquinones from sea urchins was studied. 6-Ethyl-2,3,5,7,8-pentahydroxy-1,4-naphthoquinone (equinochrome A) containing the beta-ethyl functional group was found to be the most active substance. Methylation of beta-hydroxyls markedly increased the inhibitory effect of the derivatives as compared to that of the initial quinones.

[Spectrophotometric determination of the stichoposide A from the holothurian Stichopus japonicus S]. / Spektrofotometricheskoe opredelenie stikhopozida A iz goloturii Stichopus japonicus S.

The absorption spectrum of stichoposid A with sulfuric acid, vanillin and alkaline was studied for the purpose of possibly using the reactions with these substances for quantitative determination of stichoposid A in biological materials. The reaction with 1 N NaOH was shown to be the most useful since it is highly specific with respect to the glycoside aglycone and makes it possible to investigate stichoposid A interaction with the cells of the yeast microflora.