A COMPARATIVE STUDY ON THE AGGREGATE STATES AND THE QUANTUM YIELDS OF SINGLET OXYGEN GENERATED FROM PHOTOSENSITIZATION IN NEUTRAL AQUEOUS SOLUTION FOR SEVERAL HEMATOPORPHYRIN DERIVATIVES
几种血卟啉衍生物在中性水溶液中的聚集状态和光敏产生单线态氧量子产额的比较

The aggregate states of five hematoporphyrin derivatives, includinS three Chinese-made hematoporphyrin derivatives (BHpd, YHpd and DHE), hematoporphyrin dihydrochloride (HpdHC) and protoporphyrin disodium salt (PppSS), were studied in neutral aqueous solution by analysing the absorption spectrum changes caused by dilution of the sample solutions. The results show that the binding manners of YHpd and DHE in aggregate states may be different from that of BHpd and HpdHC. The former two compounds were tightly bound, whereas the two latter ones were more loosely bound.The relative quantum yields of singlet oxygen of five porphyrins in neutral solution irradiated by 626nm light were determined by using the method of try-ptophan photodegradation. The 1O2 quantum yield of BHpd is 1.6 and 3.6 times of that of YHpd and DHE, respectively. No significant amount of 1O2 was apparently observed in the case of HpdHC and PpdSS, but light irradiation resulted in more destruction for them.The invastigation suggests that the difference on the aggregate manners of BHpd, YHpd and DHE leads to the different properties of the photodynamic action.