Spectroscopic detection of photoproducts in lecithin model system after 8-methoxypsoralen plus UV-A treatment

Waszkowska, E.; Zarebska, Z; Poznański, Jarosław; Zhukov, Igor

doi:10.1016/s1011-1344(00)00037-3

Cited by 5 publications

(2 citation statements)

References 24 publications

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“…It is also clear that reactions other than DNA cross-linking are important in both the beneficial and deleterious effects of PUVA therapy. Photoaddition to membrane components, singlet oxygen-mediated chemistry, and reaction with amino acids and proteins have all been postulated, on the basis of a variety of studies both in model systems and in a cellular environment (7)(8)(9)(10)(11)(12)(13)(14)(15).…”

Section: Introductionmentioning

confidence: 99%

Psoralen and Coumarin Photochemistry in HSA Complexes and DMPC Vesicles†

Chen

Rinco

Popov

et al. 2006

Photochem Photobiol

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The photochemistry and photophysics of several psoralens and coumarins have been examined in human serum albumin (HSA) complexes and dimyristoylphosphatidylcholine (DMPC) vesicles. Fluorescence spectroscopy indicates that there are multiple binding sites with polarities that are intermediate between those of acetonitrile and water for the substrates complexed to HSA. In the case of the 6,7-dimethoxycoumarin-HSA complex, laser flash photolysis experiments provide evidence for the formation of radical cation in addition to triplet. Radical cations are not detected for other coumarin-HSA complexes, either due to a lower yield of formation or to rapid reaction of an initial radical cation with adjacent amino acids. Fluorescence spectra for coumarins indicate that they are primarily solubilized in the polar headgroup region in DMPC vesicles. Consistent with this, radical cations generated by photoionization are detected in transient experiments. For dimethoxycoumarins the radical cation is long-lived, indicating rapid exit from the vesicle and decay in the aqueous phase. However, 4,5',8-trimethylpsoralen and 7-ethoxy-4-hexadecylcoumarin radical cations are much shorter-lived, presumably due to rapid decay by electron recombination in the vesicle. The results for both HSA complexes and vesicles indicate that radical ions may play a role in psoralen and coumarin photochemistry in a cellular environment.

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Section: Introductionmentioning

confidence: 99%

Psoralen and Coumarin Photochemistry in HSA Complexes and DMPC Vesicles†

Chen

Rinco

Popov

et al. 2006

Photochem Photobiol

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“…35 A scheme outlining lecithin photolysis in the presence of 8-MOP has been proposed and stresses the complexity of the possible reactions involved. 36 Studies with other photosensitizers have also shown a higher binding rate to lipids than DNA, although to different extent. 34,[37][38][39] The delivery of photodynamic drugs to their cellular targets can be a problem because of low cellular uptake, due to hydrophilic/hydrophobic imbalance.…”

Section: Introductionmentioning

confidence: 99%

Properties and behaviour of tetracyclic allopsoralen derivatives inside a DPPC lipid bilayer model

Santos

Saenz‐Méndez²,

Eriksson

et al. 2011

Phys. Chem. Chem. Phys.

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Allopsoralens are angular psoralen derivatives presenting advantages over the parent compound because of monofunctional DNA-photobinding and consequent lower toxicity. Allopsoralen molecules with three different substituents and different protonation states were studied using the molecular dynamics technique. The location of these molecules when inside the lipid bilayer is of major importance because their photochemical properties can change with the environment. Also, the ability of psoralens to form photoadducts with unsaturated phospholipids depends on the preference of the molecules to locate themselves closer to the bilayer middle were the double bond functionality can be found. Herein we show that the allopsoralens tend to accumulate inside the lipid bilayer closer to the water interface when protonated or closer to the interface middle otherwise. Allopsoralens containing one amine terminated carbon chain tend to have different rotational and orientational behaviour and an orientation preference close to the ones shown by the lipids. The size and chemical nature of the substituent also affect the molecular mobility and capacity to interact with water molecules and the nitrogen or phosphorus atoms of the lipids.

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