[The structure of sulfated cauloside C].

The structure of the sulfated analogue of cauloside C, a biologically active triterpenoid glycoside, was elucidated to be 3-O-[beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl]-he deragenin 23,4',4",6"-tetrasulfate pentasodium salt by the comparison of its 13C NMR spectrum with that of cauloside C potassium salt.

The effect of pH on biological activity of plant cytotoxin cauloside C.

The effect of plant carboxyl-containing glycoside cauloside C upon eucaryotic cells has been studied. The glycoside interacts with cells as a pH-dependent cytotoxin and increases K+ leakage and Ca2+ uptake with strong action in acidic media Cell viability after glycoside action at acidic pH may be recovered by the shift of medium pH from 5.6 to 7.

[The mechanism of the interaction of the pH-dependent cytostatic cauloside C with the membranes of tumor cells and liposomes].

The effect of the medium pH on accumulation of [3H]-cauloside C by tumor cells, its intracellular localization, and interaction of the glicoside with membranes of tumor cells and liposomes has been studied. The shift towards weakly acids pH leads to the increase in the amount of cauloside C accumulated by tumor cells and changes the pattern of interaction of cauloside C with the membranes.

[Effect of triterpene glycosides on the stability of bilayer lipid membranes, containing different sterols].

Low concentrations of triterpene glycosides: holothurin A, stichoposide A and cauloside C sharply change the stability of bilayer lipid-sterine membranes. The glycosides activity decreases in the line: holothurin A, stichoposide A, cauloside C. The effective doses of glycosides are to a great extent determined by structural peculiarities of sterines which compose the films.