Benzoporphyrin

Haimovici, R, Kramer, M, Miller, JW, Hasan, T, Flotte, TJ, Schomacker, KT, and Gragoudas, ES, 1997. Localization of lipoprotein-delivered benzoporphyrin derivative in the rabbit eye. Curr Eye Res 16, 83-90. 

The forms of phototherapy in common use include (i) the phototherapy of jaundice (neonatal hyperbilirubinemia) in the newborn, and especially in the prematurely born 5 (ii) the treatment of psoriasis using light in the UV-A range (320 100 nm) and an administered photosensitizer, such as 8-methoxypsoralen 6 (iii) the treatment of the wet form of age-related macular degeneration with a photosensitizer such as a benzoporphyrin derivative (VISUDYNE ), and a laser light source 7 and (iv) the treatment of certain cancers with a photosensitizer such as a porphyrin derivative, and red light.8... 

Benzoporphyrin derivative, monoacid, ring A adduct BPD, VERTEPORFIN, VISUDYNE... 

Other photosensitisers in clinical or pre-clinical trials include zinc phthalocya-nine, aluminium sulphonated phthalocyanines, benzoporphyrins, benzochlorins and purpurin-lS-iV-alkylamides, all of which absorb strongly in the 675-700 nm region. An alternative approach to the photosensitisation in PDT involves the use of 5-aminolaevulinic acid (ALA). This compound itself is not a sensitiser but in human cells it is the key metabolic precursor in the biosynthesis of protoporphyrin IX, which can act as a photosensitiser. Normally the biosynthetic process would continue beyond protoporphyrin IX to the iron containing haem. However, by adding extra ALA and iron chelators, the ferrochelatase action is inhibited and the normal feedback mechanism by-passed resulting in a build up of protoporphyrin IX in the cell. The mechanism is illustrated in Figure 4.24. ... 

Chowdhary, R. K., Shariff, I., and Dolphin, D. (2003). Drug release characteristics of lipid based benzoporphyrin derivative.J. Pharm. Pharm. Sci., 6, 13-19. 

Fig. 2 Examples of photosensitizers presently approved for clinical applications or in clinical studies. mTHPC, tetra (meso-hydroxy) phenyl chlorin BPD-MA, benzoporphyrin derivative Photofrin is a mixture of several compounds where dimers or trimers of the indicated structure are assumed to be of major importance PpIX, protoporphyrin IX - accumulating upon treatment with 5-aminolevulinic acid or its ester derivatives, NPe6, HPPH, Hexyl pyropheophorbide TPPS2a, disulfonated (adjacent) tetraphenylporphin AlPcS2a, disulfonated (adjacent) aluminum phthalocyanine. Areas with ionic side groups are indicated in shadow...

Ir(III) porphyrins and benzoporphyrins in a recent article, reporting that these compounds have lifetimes on the order of tens of microseconds and luminescence quantum yields of 14—30% [204]. The large discrepancy between Ir(III) porphyrin and corrole photophysics warrants further investigation. 

A benzoporphyrin derivative mono ester (Figure 16) obtained by Diels-Alder addition of dimethylacetylenedicarboxylate to protoporphyrin dimethyl ester followed by rearrangement and partial hydrolysis has been studied by Richter et al. [53]. This material has a relatively strong absorption near 690 nm but appears to be rapidly cleared and/or metabolized in vivo, which may make proper dosimetry difficult as described above. 

Figure 16. Structure of a benzoporphyrin derivative-mono acid form.

Richter AM, Waterfield E, Jain AK, Sternberg ED, Dolphin D, Levy JG. In vitro evaluation of phototoxic properties of four structurally related benzoporphyrin derivatives. Photochem Photobiol 1990 52 495-500. 

Richter AM, Cerruti-Sola S, Sternberg ED, Dolphin D, Levy JG. Biodistribution of tritiated benzoporphyrin derivative (3H-BPD-MA), a new potent photosensitizer, in normal and tumor-bearing mice. J Photochem Photobiol B 1990 5 231-244. 

Richter AM, Waterfield E, Jain AK, et al. Photosensitising potency of structural analogues of benzoporphyrin derivative (BPD) in a mouse tumour model. Br J Cancer 1991 63 87-93. 

Richter AM, Yip S, Waterfield E, Logan PM, Slonecker CE, Levy JG. Mouse skin photosensitization with benzoporphyrin derivatives and Photofrin macroscopic and microscopic evaluation. Photochem Photobiol 1991 53 281-286. 

Schmidt-Erfurth U, Bauman W, Gragoudas E, et al. Photodynamic therapy of experimental choroidal melanoma using lipoprotein-delivered benzoporphyrin. Ophthalmology 1994 101 89-99. 

Moulton RS, Walsh AW, Miller JW. Response of retinal and choroidal vessels to photodynamic therapy using benzoporphyrin derivative monoacid. Invest Ophthalmol Vis Sci 1993 34 S1169. 

Kramer M, Miller JW, Michaud N, et al. Liposomal benzoporphyrin derivative verte-porfin photodynamic therapy. Selective treatment of choroidal neovascularization in monkeys. Ophthalmology 1996 103 427-438. 

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