Potapenko A Ia, Bezdetnaia L N, Wunderlich Z, Sukhorukov V L, Pliquett F
Biofizika. 1986 Jul-Aug;31(4):549-54.
Psoralens are capable of photosensitizing oxidation of unsaturated fatty acids due to the two-stage mechanism. During the first (light) stage psoralen solution in ethanol undergoes photooxidation under UV-irradiation (366 nm). At the second (dark) stage the addition of photooxidized psoralen (POP) to the aqueous solution of liposomes is followed by lipid oxidation. Antioxidants inhibited the UV-stage, but did not influence the dark one. Neither spectrophotometry, nor spectrofluorometry could detect photoproducts of psoralen involved in the two-stage oxidation of lipids. However, mixing of ethanol solution of POP with water resulted in the flash of chemiluminescence. The inhibition constants by antioxidants of photoproducts formation which are active in the two-stage oxidation of lipids were estimated by chemiluminescence. Stern--Volmer's constants for antioxidants: 2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine (DHP), 6-hydroxy-2,2,5,7,8-pentamethylchroman (chromanol--C1), water soluble sodium phenozan and butilated hydroxytoluen (ionol) appeared to be (7.4 +/- 2.2) X 10(3) M-1, (4.4 +/- 1.0) X 10(3) M-1, (3.3 +/- 0.7) X 10(3) M-1, (4.5 +/- 2.5) X 10(2) M-1, respectively. The biological importance of these two-stage oxidation photosensitized by furocoumarins is discussed.
补骨脂素能够通过两阶段机制使不饱和脂肪酸发生光氧化。在第一阶段（光照阶段），乙醇中的补骨脂素溶液在紫外线照射（366nm）下发生光氧化。在第二阶段（黑暗阶段），将光氧化的补骨脂素（POP）添加到脂质体水溶液中后会发生脂质氧化。抗氧化剂抑制紫外线阶段，但不影响黑暗阶段。分光光度法和荧光分光光度法均无法检测到参与脂质两阶段氧化的补骨脂素光产物。然而，将POP的乙醇溶液与水混合会导致化学发光闪烁。通过化学发光估算了在脂质两阶段氧化中具有活性的光产物形成的抗氧化剂抑制常数。抗氧化剂2,6 - 二甲基 - 3,5 - 二乙酰基 - 1,4 - 二氢吡啶（DHP）、6 - 羟基 - 2,2,5,7,8 - 五甲基色满（色满醇 - C1）、水溶性苯并吩嗪钠和丁基化羟基甲苯（离子醇）的斯特恩 - 沃尔默常数分别为(7.4 ± 2.2)×10³ M⁻¹、(4.4 ± 1.0)×10³ M⁻¹、(3.3 ± 0.7)×10³ M⁻¹、(4.5 ± 2.5)×10² M⁻¹。讨论了呋喃香豆素光敏化的这一两阶段氧化的生物学重要性。
