摘要
Enzyme-catalytic fluorescence determination of artemisinin (qinghaosu, QHS) was developed using pyronine B (PB) as substrate of horseradish peroxidase (HRP). The interaction between HRP and QHS was an enzyme-substrate model. The catalytic characteristic of HRP in the oxidation reaction, in which the fluorescence of PB was decreased in the presence of QHS, was studied. The steady-state catalytic rate depended upon enzyme and substrate concentrations, and the Michaelis-Menten parameters Km, Vmax and Kcat were 8.4×10?5 mol · L?1, 7.4×10?6 mol · L?1 s?1 and 50.23 s?1. The catalytic activity of enzyme was inhibited in the presence of deactivated agents and at high temperature, respectively. Under optimum conditions, linear relationship between fluo-rescence intensity change (F0?F) of pyronine B and concen-tration of QHS was in the range of 1.41×10?7―1.27×10?6 mol · L?1. The detection limit (3σ) was determined to be 2.7×10?8 mol · L?1. The proposed method was applied to the concentration determination of QHS in the media of plasma or urine samples.
Enzyme-catalytic fluorescence determination of artemisinin （qinghaosu, QHS） was developed using pyronine B （PB） as substrate of horseradish peroxidase （HRP）. The interaction between HRP and QHS was an enzyme-substrate model. The catalytic characteristic of HRP in the oxidation reaction, in which the fluorescence of PB was decreased in the presence of QHS, was studied. The steady-state catalytic rate depended upon enzyme and substrate concentrations, and the Michaelis-Menten parameters Km, Vmax and Kcat were 8.4×10^-5mol·L^-1, 7.4×10^-6mol·L^-1s^-1 and 50.23s^-1. The catalytic activity of enzyme was inhibited in the presence of deactivated agents and at high temperature, respectively. Under optimum conditions, linear relationship between fluorescence intensity change （F0-F） of pyronine B and concen- tration of QHS was in the range of 1.41×10^-7-1.27×10^-6mol·L^-1. The detection limit （3σ） was determined to be 2.7×10^-8mol·L^-1. The proposed method was applied to the concentration determination of QHS in the media of plasma or urine samples.
基金
This work Was supported by the National Natural Science Foundation of China(Grant No.20075012)
the Scientific Research Foundation of Hunan Educational Committee(Grant No.02C313).
关键词
光谱荧光计
派若宁B
山葵
过氧化酶
荧光亮度
artemisinin （qinghaosu）, pyronine B, horseradish peroxidase, fluorescence intensity change.
