- K Kikugawa: Tokyo College of Pharmacy, 1432-1 Horinouchi, 192-O3, Hachioji, Tokyo, Japan.
- S Watanabe: Kanagawa Prefectural Public Health Laboratories, 52-1 Nakao-cho, Asahi-ku, 241, Yokohama, Japan.
Reaction of 13-monohydroperoxy linoleic acid and methylamine in the presence of ferric ions produced at least four fluorescent substances. They were separated by high performance liquid chromatography with a reverse phase column, and major fluorescent substances 1 and 3 were isolated. Fluorescent substances 1 and 3 showed the same fluorescence spectra with excitation maxima at 360 nm and emission maxima at 430 nm, and the same ultraviolet spectra with absorption maxima at 275 and 360 nm. Fluorescence of 1 and 3 was lost in alkaline media owing to the instability of the fluorophores. The fluorophores of 1 and 3 were destroyed on treatment with borohydride. The fluorescence characteristics of 1 and 3 were similar to those of the age-related fluorescent substances produced in tissues. They were different from those of the fluorescent substances derived from malonaldehyde and resembled those of the fluorescent substances derived from monofunctional aldehydes.