Photosensitizer hematoporphyrin

Ethinyloestradiol (133), irradiated at 450 nm in a mixture of aqueous buffer (pH 7.4) and methanol 7 3 in the presence of oxygen and the photosensitizer hematoporphyrin, gave the peroxide (134), identified by its ready reduction with potassium iodide to the corresponding alcohol [95]. Oestrone (135) reacted similarly [96]. 

Photo-induced Diels Alder reaction occurs either by direct photo activation of a diene or dienophile or by irradiation of a photosensitizer (Rose Bengal, Methylene Blue, hematoporphyrin, tetraphenylporphyrin) that interacts with diene or dienophile. These processes produce an electronically excited reagent (energy transfer) or a radical cation (electron transfer) or a radical (hydrogen abstraction) that is subsequently trapped by the other reagent. 

Various dyes can be used as photosensitizers, including methylene blue, riboflavine, and hematoporphyrin derivative. The selection of the photosensitizer should be in favor of a compound that exclusively leads to Reaction (b), so that a clear interpretation of the results is possible. 

Kessel D, Thompson P, Musselman B, Chang CK (1987a) Chemistry of hematoporphyrin-derived photosensitizers. Photochem Photobiol 46 563-568. 

Grossweiner LI, Patel AS, Grossweiner JB (1982) Type I and type II mechanisms in the photosensitizing lyses of phosphatidylcholine liposomes by hematoporphyrin. Photochem Photobiol. 36 159-167. 

Chemistry and Structure of the Principal Tumor-Localizing Porphyrin Photosensitizer in Hematoporphyrin Derivative... 

It was precisely this lack of activity towards non-polar substrates that provided an important motivation for the antibacterial and cell localization studies [94]. The cadmium texaphyrin 116 was investigated with regard to photo-activity against a strain of an antibiotic-resistant bacteria (S. aureus). The texaphyrin complex 116 proved to be an effective photosensitizer for the photoinactivation of S. aureus cells, being comparable but somewhat less active than hematoporphyrin at any given concentration tested. 

The final in vitro photodynamic studies involved the use of human cancer cells. Here, K562 leukemic cells of myelocutic origin were used. The texaphyrin complex 116 was very effective in the photo-eradication of K562 leukemic cells, being considerably more effective than hematoporphyrin under similar conditions. This suggests that the texaphyrin expanded porphyrins, as a class of photosensitizers, could have further application in the photo-kilUng of these and other cancer cells... 

Selective photosensitized oxidation of some amino acids present in proteins can be also utilized for specific labeling with a chosen sensitizer (methylene blue and hematoporphyrin for methionine, crystal violet or cresol red for cysteine, proflavine for tryptophan, etc.). This topic is described by Scoffone et al. 

Hematoporphyrins as photosensitizers for photodynamic diagnostics and therapy of tumors 90WCH149. 

Singlet oxygen generation is used in photodynamic tumor therapy—for instance, with porphyrins as photosensitizers. (Cf. Dougherty, 1992.) The disadvantage of natural porphyrins such as hematoporphyrin is that they are of low chemical stability and have an absorption spectrum similar to that of... 

Figure 7. Incident light dose at the surface versus depth of photodynamically induced tumor necrosis in vivo as a function of injected dose of Photofrin (hematoporphyrin oligomers). The value of a (total attenuation coefficient) was taken as 0.33 a typical value for tumors and other tissues with low levels of absorbing chromophores. Each curve represents a different injected dose of photosensitizer (Photofrin) in mg per kg of body weight as indicated on this graph.

Roberts, J.E., Roy, D., and Dillon, J. (1985) The photosensitized oxidation of the calf lens main intrinsic protein (MP26) with hematoporphyrin, Curr. Eye Res., 4, 181-185. 

Hematoporphyrin (HP) is widely used as photosensitizer in photodynamic therapy because of its photosensitivity. It has been successfully used in the therapy for different forms of leukemia.4 In this paper we describe the interactions between amino acids and Zn(II)-HP, Cu(II)-HP, Co(II)-HP, and Ni(II)-HP by fluorescence and absorption spectra in aqueous solution. The binding constants were calculated and the mechanism of recognition discussed. 

J. Moan, T. Christensen, J. Sommer (1982). The main photosensitizing components of hematoporphyrin derivative. Cancer Lett., 15, 161-166. 

J. Moan, S. Sandberg, T. Christensen, S. Elander (1983). Hematoporphyrin derivative chemical composition, photochemical and photosensitizing properties. In D. Kessel, T.J. Dougherty (Eds), Porphyrin photosensitization (Vol. 1, pp. 165-179). Plenum Publishing Co. 

J. Moan, C. Rimington, A. Western (1988). Hematoporphyrin ethers Vol. Ill Cellular uptake and photosensitizing properties. Ini J. Biochem., 20, 1401-1404. 

J. Moan, S. Sommer (1985). Oxygen dependence of the photosensitizing effect of hematoporphyrin derivative in NHIK 3025 cells. Cancer Res., 45, 1608-1610. 

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