A Peroxidase-linked Spectrophotometric Assay for the Detection of Monoamine Oxidase Inhibitors.
To develop a new more accurate spectrophotometric method for detecting monoamine oxidase inhibitors from plant extracts, a series of amine substrates were selected and their ability to be oxidized by monoamine oxidase was evaluated by the HPLC method and a new substrate was used to develop a peroxidase-linked spectrophotometric assay. 4-(Trifluoromethyl) benzylamine (11) was proved to be an excellent substrate for peroxidase-linked spectrophotometric assay. Therefore, a new peroxidase-linked spectrophotometric assay was set up. The principle of the method is that the MAO converts 11 into aldehyde, ammonia and hydrogen peroxide. In the presence of peroxidase, the hydrogen peroxide will oxidize 4-aminoantipyrine into oxidised 4-aminoantipyrine which can condense with vanillic acid to give a red quinoneimine dye. The production of the quinoneimine dye was detected at 490 nm by a microplate reader. The ⊿OD value between the blank group and blank negative control group in this new method is twice as much as that in Holt's method, which enables the procedure to be more accurate and avoids the produce of false positive results. The new method will be helpful for researchers to screening monoamine oxidase inhibitors from deep-color plant extracts.
School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
Kangkang
K
Zhi
School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
Zhongduo
Z
Yang
School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
Jie
J
Sheng
School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China.
Zongmei
Z
Shu
Key Lab of New Animal Drug Project, Gansu Province; Key Lab of Veterinary Pharmaceutical Development, Ministry of Agriculture; Lanzhou Institute of Husbandry and Pharmaceutical Sciences of CAAS, Lanzhou 730050, PR China.
Yin
Y
Shi
Amine substrate; HPLC; Monoamine oxidase inhibitors; Spectrophotometric Assay