Photochemical Reactions of Hypocrellin A with Dibenzylamine and N-methylbenzylamine

In order to discuss the free radicals formation mechanism of Hypocrellin A（HA）with amino derivatives，the electron-spin resonance（ ESR） spectroscopy was adopted to study the photochemistry on HA with dibenzyl amine（DBA）and N-methyl benzyl amine（NMBA），respectively. When HA with DBA or NMBA in chloroform solution was illuminated with visible light，singlet oxygen，semiquinone radical and oxynitride radical were formed depending on the condition of the solvent system containing the amino-substituted and solved oxygen. The signal intensity of oxynitride radical decreased with increasing the illumination time，and the signal intensity of semiquinone radical increased with increasing the illumination time. The oxynitride radical content was in inverse ratio with the semiquinone radical generated by being irradiated. In the aerobic system of chloroform solution containing DBA/HA，smiquinone radical was the main radical irradiated. The results indicated that HA induced amino derivatives into HA semiquinone radical.