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Xanthohumol, a major prenylated chalcone found in hop resin, has recently attracted scientific interest due to its health-promoting properties. In the present work, we investigated the mechanism of xanthohumol cyclization to isoxanthohumol in an aqueous solution with a high pH by means of UV–Vis spectroscopy and liquid chromatography. The results were modeled by DFT methods with the SMD solvation model. The results of theoretical calculations were consistent with experimental data. The proposed mechanism comprises two stages, where the first step involves cyclization of xanthohumol ions and the second step involves the addition of H + ion from a water molecule to an isoxanthohumol ion. The second step is responsible for the stabilization of isoxanthohumol. Based on these results some practical information can be drawn, which may be important from the point of view of the problem xanthohumol stability in commercial dietary supplements.

The paper shows that new N'-substituted 2,4-dihydroxybenzocarbothiohydrazides are able to inhibit the in vitro proliferation of human tumor cell lines. The compounds were prepared by the reaction of sulfinylbis[(2,4-dihydroxyphenyl)methanethione] (STB) or its analogs with the hydrazines. The panel of N'-substitution included aryl, pyridinyl and pyrimidinyl rings. The highest antiproliferative activity for N'-(4-(4-chlorophenyl)-6-(trifluoromethyl)pyrimidin-2-yl)-5-ethyl-2,4-dihydroxybenzothiohydrazide (5b) was found. The antiproliferative potency of some compounds was similar to that of cisplatin. Analogs with the Et substituent on benzenediol moiety displayed higher potency than with the unsubstituted one. The influence of N'-substitution on antiproliferative activity of compounds was discussed.

A new crystallization method of N-iodoacetylamphotericin B derivative is reported. The crystallization process in the presence of different quantities of amphotericin B additives was extensively studied and its mechanism was proposed. It also resulted in good quality single crystals suitable for X-ray structure determination (100 K). The structural information obtained allowed for periodic and dimer single point computational studies at the B3LYP/6-31G** level of theory. These confirmed the proposed controlled crystallization mechanism and the stabilization of crystals formed by the iodoacetyl derivative and parent amphotericin B. The calculation results indicate the strength of different intermolecular interactions and reveal the great contribution of the solvent molecules to the crystal lattice formation, with the total energy gain of about 335 kJ·mol–1, which almost doubles the cohesive energy value. Hirshfeld surface analysis shows the more efficient crystal packing of N-iodoacetylamphotericin versus ...