Synthesis of structural analogues of hexadecylphosphocholine and their antineoplastic, antimicrobial and amoebicidal activity.

Twelve derivatives of hexadecylphosphocholine (miltefosine) were synthesized to determine how the position and length of the alkyl chain within the molecule influence their biological activities. The prepared alkylphosphocholines have the same molecular formula as miltefosine. Activity of the compounds was studied against a spectrum of tumour cells, two species of protozoans, bacteria and yeast.

[Flavonoids - main constituents of the leaves of Philadelphus tenuifolius Rupr. et Maxim].

The paper deals with the isolation and identification of the constituents of the leaves of Philadelphus tenuifolius Rupr. et Maxim. A methanolic extract was used to isolate quercetin-3-O-glucoside (isoquercitrin), and a butanolic extract to isolate kaempferol-3-O-glucoside-7-O-rhamnoside.

Phase behavior of the DOPE + DOPC + alkanol system.

Small- and wide-angle X-ray diffraction was used to study the effect of 1-alkanols, as simple models of general anesthetics, (abbreviation CnOH, n = 8-18 is the even number of carbons in the aliphatic chain) on the lamellar to hexagonal Lα→ H(II) phase transition in the dioleoylphosphatidylethanolamine-dioleoylphosphatidylcholine = 3 : 1 mol/mol (DOPE + DOPC) system. All studied CnOHs were found to decrease the phase transition temperature of the DOPE + DOPC system in a CnOH chain length and concentration dependent manner and thus promote the formation of the HII phase. Anesthetically active C8OH and C10OH were found to decrease the lattice parameter d of the Lα phase, however longer non-anesthetic CnOHs increased the parameter d; this effect being more pronounced with increasing CnOH concentration.

Molecular and component volumes of N,N-dimethyl-N-alkylamine N-oxides in DOPC bilayers.

The volumetric properties of fluid bilayers formed of dioleoylphosphatidylcholine (DOPC) with incorporated N,N-dimethyl-N-alkylamine N-oxides (CnNO, n=6, 10-18 is the even number of carbons in alkyl chain) were studied by vibrating tube densitometry in the temperature interval from 20°C to 50°C. It was found that the DOPC and CnNO mixed ideally in the investigated composition range and hence the molecular volumes of DOPC (VDOPC) and incorporated CnNO (VCnNO) were constant and additive within error limits. From the temperature dependencies of the molecular volumes of DOPC and CnNO their coefficients of isobaric thermal expansivities in the investigated temperature interval were obtained.

Study of interaction of long-chain n-alcohols with fluid DOPC bilayers by a lateral pressure sensitive fluorescence probe.

The excimer 1,2-dipyrenedecanoyl-sn-glycero-3-phosphatidylcholine (dipy10PC) fluorescence probe was used to determine effects of aliphatic alcohols (CnH2n+1OH, n = 12-18 is the even number of carbons in alkyl chain) on fluid dioleoylphosphatidylcholine (DOPC) +dioleoylphosphatidylserine (DOPS) bilayers in multilamellar vesicles at molar ratio DOPC/DOPS = 24.7. The excimer to monomer fluorescence intensity ratio increases with the increase of CnH2n+1OH/DOPC molar ratio and decreases with the CnH2n+1OH alkyl chain length n at a constant CnH2n+1OH/DOPC = 0.