69-89-6Relevant articles and documents
Label-Free Surface Enhanced Raman Scattering Approach for High-Throughput Screening of Biocatalysts
Westley, Chloe,Xu, Yun,Carnell, Andrew J.,Turner, Nicholas J.,Goodacre, Royston
, p. 5898 - 5903 (2016)
Biocatalyst discovery and directed evolution are central to many pharmaceutical research programs, yet the lack of robust high-throughput screening methods for large libraries of enzyme variants generated (typically 106-108) has hampered progress and slowed enzyme optimization. We have developed a label-free generally applicable approach based on Raman spectroscopy which results in significant reductions in acquisition times (>30-fold). Surface enhanced Raman scattering (SERS) is employed to monitor the enzyme-catalyzed conversion by xanthine oxidase of hypoxanthine to xanthine to uric acid. This approach measures the substrates and products directly and does not require chromogenic substrates or lengthy chromatography, was successfully benchmarked against HPLC, and shows high levels of accuracy and reproducibility. Furthermore, we demonstrate that this SERS approach has utility in monitoring enzyme inhibition illustrating additional medical significance to this high-throughput screening method.
-
Herak,Gordy
, p. 1287 (1965)
-
The Influencing of Preanodized Inlaying Ultrathin Carbon Paste Electrode on the Oxidation for the Xanthine and Hypoxanthine by the Hydrogen Bond
Qiao, Yue-Chun,Li, Jing,Li, Yao,Li, Quan-Min
, p. 1011 - 1019 (2015)
In this paper, a pre-anodized inlaying ultrathin carbon paste electrode (PAIUCPE) with 316L as a matrix was constructed by a simple and fast electrochemical pretreatment. Using xanthine (Xa) and hypoxanthine (HXa) as the target compounds, the pH effects compositions of buffer solution, the accumulation times, hydrogen bond catalysis, degree of auxiliary electrode reaction on the size of peak currents (Ip) of Xa and HXa was discussed in detail. Also, it was proposed that Xa and HXa were respectively absorbed at the surface of PAIUCPE through hydrogen bonding. The influencing mechanisms of the PAIUCEP on electrochemical oxidation of Xa and HXa were explained in detail. Moreover, the linear relationships for the Xa and HXa were obtained in the range of 6×10-8-3×10-5 mol/L and 2×10-7-7×10-5 mol/L, respectively. The detection limits for the Xa and HXa were 1.2×10-8 mol/L and 5.7×10-8 mol/L, respectively. Moreover, this proposed method could be applied to determine the Xa and HXa in human urine simultaneously with satisfactory results.
Inhibition of xanthine oxidase by theaflavin: Possible mechanism for anti-hyperuricaemia effect in mice
Chen, Jianmin,Jin, Nan,Li, Qinglian,Ran, Mengnan,Ruan, Zhipeng,Ye, Yaling
, p. 11 - 18 (2020/07/03)
Xanthine oxidase (XO) catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Excessive production of uric acid leads to hyperuricaemia. Due to the serious side effects of allopurinol, it is an urgent need to explore new XO inhibitors. Herein, the effects of theaflavin (TF1) on XO and anti-hyperuricaemia effect in hyperuricemic mice were investigated. Kinetic analysis indicate that TF1 is a reversible competitive inhibitor and has a significant inhibitory effect on XO with an IC50 value of 63.17 ± 0.13 μmol/L. Analysis of fluorescence spectra suggests that TF1 causes the obvious fluorescence quenching of XO, which is mainly driven by hydrophobic interactions and hydrogen bonds. Docking studies demonstrate that TF1 interacts with dozens of amino acid residues surrounded in the active cavity of XO, including Glu-879, Pro-1012, Thr-1010, Val-1011, Lys-771, Glu-802, Pro-1076, Leu-873, Leu-1014, Asn-768, Leu-648 and Phe-649. The inhibitory mechanism may be the insertion of TF1 into the active site of XO, which hinders the substrate xanthine to enter into the site. Furthermore, the results from animal experiments demonstrate that TF1 is effective in reducing serum uric acid in mice. These findings suggest that TF1 may be a potential drug candidate for the treatment of hyperuricaemia.
One-Step Synthesis of 2-Fluoroadenine Using Hydrogen Fluoride Pyridine in a Continuous Flow Operation
Salehi Marzijarani, Nastaran,Snead, David R.,McMullen, Jonathan P.,Lévesque, Fran?ois,Weisel, Mark,Varsolona, Richard J.,Lam, Yu-Hong,Liu, Zhijian,Naber, John R.
supporting information, p. 1522 - 1528 (2019/07/10)
We report the development of a one-pot synthesis of 2-fluoroadenine from an inexpensive 2,6-diaminopurine starting material using diazonium chemistry in a continuous fashion. Given the sensitivity of this transformation to temperature, we conducted critical experiments to study the exothermicity of the reaction and the heat removal, which were critical for the development of the process. Our goal was to improve the yield and purity of this pharmaceutical intermediate (2-fluoroadenine) and develop a more robust process.
