Generic DART-MS platform for monitoring the on-demand continuous-flow production of pharmaceuticals: Advancing the quantitative protocol for caffeates in microfluidic biocatalysis.
Today, continuous processing is regarded as an effective on-demand production technique of pharmaceuticals. Homemade microreactors packed with immobilized lipase under continuous-flow conditions were first applied to tailor the production of high-value caffeic acid phenethyl ester (CAPE) from methyl caffeate (MC) and 2-phenylethanol (PE) in cyclohexane via transesterification; however, this method is challenging due to the lack of a rapid platform for monitoring caffeates in microfluidic biocatalysis. The reactants were directly analyzed using Direct Analysis in Real Time Mass Spectrometry (DART-MS), and the corresponding ionization parameters were investigated. Special ions produced from MC (parent ion m/z 192.87 and product ion m/z 133.44) and CAPE (parent ion m/z 282.93 and product ion m/z 178.87) were determined using DART-MS2in the negative ion mode. The peak areas of the select reaction monitoring (SRM) signals were calculated to develop the standard curves for quantitative analyses of the concentration. Reasonable linear regression equations of MC and CAPE were obtained in the range of 3.125-50.000mg/L, with linear coefficients (R2) of 0.9515 and 0.9973, limits of detection (LOD) of 0.005 and 0.003mg/L, limits of quantification (LOQ) of 0.02 and 0.01mg/L, and recovery ranges of 92.50-97.11% and 90.11-97.60%, respectively. The results using DART-MS2were in good agreement with those using conventional High-Performance Liquid Chromatography with a UV detector (HPLC-UV) and were successfully applied to monitor the kinetics constants and mass transfer coefficients in a continuous-flow packed bed microreactor. Thus, the DART-MS2method is an efficient tool for analyzing caffeates in microfluidic biocatalysis with limited sample preparation and short operating time.
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China.
Yan
Y
Xu
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China.
Dong-Yang
DY
Zhang
School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China.
Xiang-Yun
XY
Meng
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China.
Xi
X
Liu
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China.
Sheng
S
Sheng
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China.
Guo-Hua
GH
Wu
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China. Electronic address: wangjun@just.edu.cn.
Jun
J
Wang
School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, PR China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, PR China. Electronic address: fuword@163.com.
Fu-An
FA
Wu
D055162:Biocatalysis; D002109:Caffeic Acids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods; D044085:Microfluidics / Q000379:methods; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000737:chemistry
D002109:Caffeic Acids; D007477:Ions; D004364:Pharmaceutical Preparations; C042405:methyl caffeate; C055494:caffeic acid phenethyl ester; D010626:Phenylethyl Alcohol; C040048:caffeic acid
Caffeates; Caffeic acid phenethyl ester; Continuous-flow synthesis; Direct analysis in real time mass spectrometry; Methyl caffeate; Microfluidic biocatalysis