
Chemical and Pharmaceutical Bulletin p. 2107 - 2109 (1997)
Update date:2022-08-28
Topics:
Ishimitsu, Susumu
Mishima, Ikuko
Tsuji, Sumiko
Shibata, Tadashi
Photo-illumination of riboflavin sodium phosphate (Rp) with phenylalanine produced significant levels of o-tyrosine, m-tyrosine and p- tyrosine as hydroxylated products. The hydroxylation of Rp was pH-dependent, and the maximum rate was around pH 4.5. Replacement of air with nitrogen prevented the formation of tyrosine isomers while the addition of superoxide dismutase or catalase to this system prevented hydroxylation. The tyrosine formation by the system was significantly prevented by hydroxyl radical (HO·) scavengers such as potassium iodide, potassium bromide, thiourea and sodium formate. No free iron and cupric ions were detected in the reaction mixture by inductively-coupled plasma atomic emission spectrometry. The above results suggest that the formation of HO· may occur in the photochemical reaction system in the presence of Rp under aerobic conditions, and that a superoxide radical and hydrogen peroxide may be involved in HO· formation.
View More
Contact:886 2 2541 0022
Address:8 Fl., No. 11, Sec. 1, Chung Shan North Rd., Taipei, Taiwan R.O.C.
Contact:+1-284-4950244
Address:Box 3069, Road Town, Tortola, British Virgin Islands
Contact:+86-21-61318535
Address:Building 29,No.2139 Xizha Road, Fengxian District, Shanghai
Anhui Redstar Pharmaceutical Corp., Ltd
Contact:+86-563-5120837
Address:Jingxian Industrial Development Zone, Anhui , China
Contact:13813902930 025-52714267
Address:20 Fengji Road, Yuhua Economic Development Zone, Nanjing, Jiangsu, P. R. China
Doi:10.1002/chem.201701771
(2017)Doi:10.1002/cjoc.201900494
(2020)Doi:10.1039/C39770000478
(1977)Doi:10.1021/acs.orglett.6b03030
(2016)Doi:10.1016/S0040-4039(98)01656-6
(1998)Doi:10.1021/ja00063a075
(1993)