Estimation of membrane activity of water-soluble polysubstituted fullerene derivatives by luminescence methods

Abstract

Patterns of the interaction between water soluble polysubstituted fullerene derivatives (PFDs) and the lipid bilayer of phosphatidylcholine liposomes were investigated by applying triplet and fluorescent probes. Objective quantitative criteria have been proposed for the evaluation of membranotropic action of chemical substances, notably, fullerene derivatives that quench fluorescent probes with different localizations within the membrane. Thus, the defined criteria are the rate constants for the quenching of the fluorescence of triplet probes and the equilibrium constants for PFD probe complexes, which characterize their stability. The localization of PFDs in the membrane was determined by comparing rate constants for the quenching of eosin phosphorescence and equilibrium constants for PFD-chromophore complexes. In addition, the effi ciency of the interaction of PFDs with various sites of the phospholipid membrane has been seen to depend on the charge of addends that are attached to the polysubstituted derivatives. N Br NH 2 H 2 N Br O COO Br O Br Br − O Br Eosin Y 2,7 Br proflavine Pyrene Fig. 1. Luminescent probes used in the study.

Influence of water-soluble derivatives of [60]fullerene on therapeutically important targets related to neurodegenerative diseases

“…It was shown that WS[60]FDs interact with hydrophilic sites of the phospholipid membranes, and the character of this interaction is dened by the charge state of WS[60]FDs. 30 Known therapeutic targets for the treatment of Alzheimer's disease are the membrane-integrated enzyme monoamine oxidase B (MAO-B), free radical oxidation, and recently, b-amyloidal brils. 31,32 It is known that MAO-B is one of the key enzymes metabolizing dopamine in the brain to a nal product, homovanillic acid.…”

Nanoparticles of N-Vinylpyrrolidone Amphiphilic Copolymers and Pheophorbide a as Promising Photosensitizers for Photodynamic Therapy: Design, Properties and In Vitro Phototoxic Activity

“…Detection of singlet oxygen 1 O 2 formation has been performed by a standard method using 1,3-diphenylisobenzofuran (DPBF) [ 31 ]. To introduce a hydrophobic probe DPBF to an aqueous solution, it was incorporated into the phosphatidylcholine liposomes using a modified method [ 32 , 33 ]. The aqueous solution containing DPBF (0.05 mM of DPBF in liposomes, 0.5·mM of lecithin) and the photosensitizer (5 μM), in a 10 × 10 mm quartz cuvette was irradiated with the setup, as described above.…”

“…Preparation of liposomes solution. Phosphatidylcholine (lecithin) from egg yolk (Sigma) was used to prepare liposomes’ solution according to the method described in [ 32 , 33 ]; lipid concentration in the cuvette was 100 μM.…”

Influence of Nitrosyl Iron Complex with Thiosulfate Ligands on Therapeutically Important Targets Related to Type 2 Diabetes Mellitus

“…The kinetics of eosin Y phosphorescence decay was recorded using Cary Eclipse fluorescence spectrometer (Varian, Palo Alto, CA, USA). Before measurements, oxygen was deleted from the sample by adding 1 μg of glucose oxidase and 1 mg of glucose, as described previously [ 28 ].…”