Objective:in this work we have investigated the photodynamic efficiency of octaethylporphyrin (OEP) and vanadyl octaethylporphyrin (VOOEP). Methods: this study was per formed by the evaluation of photophysical parameters of these porphyrins, the photooxidation rate constants (kf) of the biomolecules (tryptophan -Trp and bovine serum albumin - BSA) and the er ythrocytes photodestruction percentage. Results:photophysical parameters value such as singlet oxygen quantum yield (Φ∆) and triplet state lifetime (τT) indicated that OEP (Φ∆ = 0.64 ±0.02, tT = 0.91 ± 0.02 ms) is more efficient than VOOEP (Φ∆ = 0.26 ±0.02, tT = 0.22 ± 0.03 ms). The values of kf/10-4s-1 for Trp and BSA photoxidation demonstrated that OEP (Trp = 2.80 ± 0.05 and BSA= 2.50 ± 0.1) is more ef ficient than VOOEP (Trp = 0.81 ± 0.08 and BSA = 0.62 ± 0.04).
The photodestruction percentage of erythrocytes revealed that the photodynamic activity of OEP is more pronounced than photoactivity of VOOEP. These results indicated that differences observed in the photodynamic activity between the porphyrins could be associated with differences in their molecular structures. Conclusion: photophysical parameters, photooxidation of biomolecules, and photodestruction of erythrocytes clearly indicate that the vanadyl group (V=O) interferes in the photoactivity of OEP, causing a considerable reduction in its efficiency. Evaluation of photodynamic activity of octaethylporphyrin and vanadyl octaethylporphyrin.
Ribeiro, J.N., da Silva, A.R., Pelegrino, A.C., Tedesco, A.C. and Jorge, R.A., 2005. Evaluation of photodynamic activity of octaethylporphyrin and vanadyl octaethylporphyrin. Applied Cancer Research, 25(3), pp.142-150.
Categories: Medical & Pharmaceutical