Abstract:

The medicinal value and economical benefit of Lonicerae Japonicae Flos are affected directly by the processing methods. The present work investigates the metabolites from six types of Lonicerae Japonicae Flos sample processed by different drying methods， which is accomplished by a methodology introducing an automatic chemometric ultrahigh performance liquid chromatography-high resolution mass spectrometry （UHPLC-HRMS） data analysis methodology in combination with untargeted metabolomics. Samples of six processing methods are collected， i.e.， sun drying， shade drying， oven drying， hot chamber drying， hot pump drying and vacuum freeze drying. The samples are ultrasonically extracted by methanol-water （volume ratio 8∶2） for 30 min and centrifuged twice. The supernatant is separated on a Waters Acquity UPLC HSS T3 （2.1×100 mm， 1.8 μm） column， and gradiently eluted with acetonitrile-water （both with 0.1%（volume fraction） formic acid） solution. The HRMS acquisition mode is FULL MS/DD-MS² （TOP4） in a positive ionization mode. The raw UHPLC-HRMS files are used for data analysis and 16 metabolites are identified in AntDAS. Finally， hierarchical clustering analysis and principal component analysis are used for discriminating samples from various processing methods. High quality samples with good appearance characteristics can be obtained by vacuum freeze drying， hot chamber drying and heat pump drying. Moreover， the antioxidant components are well preserved under vacuum freeze drying.

Key words: Lonicerae Japonicae Flos, Ultrahigh performance liquid chromatography-high resolution mass spectrometry, Chemometrics, Automatic data analysis strategy, Processing methods