title: Inquiry of photosensitization mechanism of yangzhou hematoporphyrin derivative (YHPD).
abstract: By the use of the advanced ESR technique and through comparing with BHPD, the characteristic of YHPD photosensitization is discussed in this paper in the respect of the primary process of photosensitization. The experiment results showed: (i) not only 1O2, but also free radicals (O2-. .OH and YHPD-.) can be formed by the aid of YHPD; and (ii) as to the ability of producing 1O2, YHPD less than BHPD, while for generating O2-. and .OH, YHPD greater than BHPD. Two points are indicated: first, the photosensitized damage of YHPD is interrelated to not only 1O2, but also free radicals (O2-. .OH and YHPD-.); second, although the photosensitized damage of YHPD is stronger than that of BHPD, yet the photosensitized damage is negatively correlated to the yield of 1O2 but positively correlated to those of O2-. and OH. Based on these two points, it is suggested that activated oxygen free radicals (O2-. and .OH) instead of 1O2 play the main role as instantaneously activated material in the photosensitized damage of YHPD.
authors.affiliation: Institute of Biophysics, Academia Sinica, Beijing, PRC.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Zhang
authors.forename: N B
authors.initials: NB
authors.lastname: Tao
authors.forename: R G
authors.initials: RG
authors.lastname: He
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000032:analysis; D017324:Hematoporphyrin Derivative; D006415:Hematoporphyrins / Q000737:chemistry*; D006878:Hydroxides / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D011838:Radiation-Sensitizing Agents / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D006415:Hematoporphyrins; D006878:Hydroxides; D011838:Radiation-Sensitizing Agents; D017324:Hematoporphyrin Derivative; D010100:Oxygen