Fluorescence Determination of Artemisinin Using Tyrosinase as Catalyst and Pyronine B as Monitor

✍ Scribed by Chen Li-Hua; Yin Hong; Yang Zhao-Xia; Zhang Ke-Mei; Liu Liu-Zhan; Shen Han-Xi

• Book ID: 102096114
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 68 KB
• Volume: 23
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.200591047

✦ Synopsis

Abstract

Fluorescence decrease ratio (F~0~/F) was applied to determination of artemisinin (qinghaosu, QHS) based on the catalytic effect of tyrosinase using tetraethyldiaminoxanthenyl chloride (pyronine B, PB) as monitor. A catalyst used commonly in the decomposition of QHS, tyrosinase, exhibited higher binding activity than hemin, which was expressed as Michaelis‐Menten parameters, k~m~, v~max~, and k~cat~ respectively. Interaction of QHS with tyrosinase was inhibited in the presence of deactivating agents at high temperature whereas enhanced by ethanol. Under optimal conditions, a concentration of 1.4×10^‐7^‐8.4×10^‐7^ mol·L^‐1^of QHS could be determined on the basis of fluorescence decrease ratio of PB, with a detection limit 3σ of 2.6×10^‐9^ mol·L^‐1^. The proposed method was applied to detection of the concentration of QHS in the media of plasma and urine.