New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
J Clin Biochem Nutr. 2011 Sep;49(2):87-95. doi: 10.3164/jcbn.10-125. Epub 2011 Jul 14.
The aim of the present study is to compare different analytical methods for singlet oxygen and to discuss an appropriate way to evaluate the yield of singlet oxygen photogenerated from photosensitizers. Singlet oxygen photogenerated from rose bengal was evaluated by electron spin resonance analysis using sterically hindered amines, spectrophotometric analysis of 1,3-diphenylisobenzofuran oxidation, and analysis of fluorescent probe (Singlet Oxygen Sensor Green®). All of the analytical methods could evaluate the relative yield of singlet oxygen. The sensitivity of the analytical methods was 1,3-diphenylisobenzofuran < electron spin resonance < Singlet Oxygen Sensor Green®. However, Singlet Oxygen Sensor Green® could be used only when the concentration of rose bengal was very low (<1 µM). In addition, since the absorption spectra of 1,3-diphenylisobenzofuran is considerably changed by irradiation of 405 nm laser, photosensitizers which are excited by light with a wavelength of around 400 nm such as hematoporphyrin cannot be used in the 1,3-diphenylisobenzofuran oxidation method. On the other hand, electron spin resonance analysis using a sterically hindered amine, especially 2,2,6,6-tetramethyl-4-piperidinol and 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide, had proper sensitivity and wide detectable range for the yield of photogenerated singlet oxygen. Therefore, in photodynamic therapy, it is suggested that the relative yield of singlet oxygen generated by various photosensitizers can be evaluated properly by electron spin resonance analysis.
本研究旨在比较不同的单线态氧分析方法，并探讨评估光敏剂产生的单线态氧产率的合适方法。通过使用空间位阻胺的电子自旋共振分析、1,3-二苯基异苯并呋喃氧化的分光光度分析和荧光探针（单线态氧传感器绿®）分析来评估吖啶酮产生的单线态氧。所有分析方法均可评估单线态氧的相对产率。分析方法的灵敏度为 1,3-二苯基异苯并呋喃 < 电子自旋共振 < 单线态氧传感器绿®。然而，只有当吖啶酮的浓度非常低（<1 μM）时，才能使用单线态氧传感器绿®。此外，由于 1,3-二苯基异苯并呋喃的吸收光谱在 405nm 激光照射下会发生很大变化，因此不能将波长在 400nm 左右的光激发的光敏剂（如血卟啉）用于 1,3-二苯基异苯并呋喃氧化法。另一方面，使用空间位阻胺（特别是 2,2,6,6-四甲基-4-哌啶醇和 2,2,5,5-四甲基-3-吡咯啉-3-羧酰胺）的电子自旋共振分析具有适当的灵敏度和较宽的检测范围，适用于评估光生成单线态氧的产率。因此，在光动力疗法中，建议通过电子自旋共振分析适当评估各种光敏剂产生的单线态氧的相对产率。
