Fluorescence Determination of Artemisinin Using Hemoglobin as Catalyst and Pyronine B as Substrate

【Abstract】 Fluorescence decrease ratio was applied to determine of artemisinin （qinghaosu, QHS） based on the catalytic effect of hemoglobin （Hb） using tetraethyldiaminoxanthenyl chloride （Pryonine B, PB） as monitor in this work. Experimental results show that the catalytic characteristics of Hb for QHS, being expressed as Michaelis-Menten parameters, K_m, V max , and K cat are 2.8×10 -5 mol·L -1 , 4.2×10 -6 mol·L -1 5s -1 and 280 s -1 , respectively. Like hemin, enzymatic bioactivities of Hb is inhibited by both deactivated agents and high temperature whereas enhanced by ethanol. With the catalytic action of Hb, quantitative method of QHS can be established based on the fluorescence decrease of PB and linear relationship between the fluorescence decrease ratio F₀/F and the concentration of QHS is in the range of （0.0-1.1）×10 -6 mol·L -1 with detection limit （3σ） being 7.2×10 -9 mol·L -1 . The concentration of QHS in the media of plasma or urine was detected using this method.更多还原