UPLC-PDA-TOFMS based chemical profiling approach to rapidly evaluate chemical consistency between traditional and dispensing granule decoctions of traditional medicine combinatorial formulae.

In the present study, an ultra performance liquid chromatography coupled with photo-diode array detector and time-of-flight mass spectrometry (UPLC-PDA-TOFMS) based chemical profiling approach to rapidly evaluate chemical consistency between traditional and dispensing granule decoctions of traditional medicine combinatorial formulae was proposed and validated using San-Huang-Xie-Xin-Tang (SHXXT) as a model combinatorial formula. Two different kinds of decoctions, namely traditional decoction: water extract of mixed three constituent herbs of SHXXT, and dispensing granules decoction: mixed water extract of each individual herbs of SHXXT, were prepared. Batches of these two kinds of decoction samples were subjected to UPLC-PDA-TOFMS analysis, the datasets of t(R)-m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis (OPLS-DA) to holistically compare the difference between these two kinds of decoction samples. Once a clear classification trend was found in score plot, further statistics was performed to generate S-plot, in which the variables (t(R)-m/z pair) contributing most to the difference were clearly depicted as points at the two ends of "S", and the components that correlate to these ions were regarded as the most changed components during decocting of combinatorial formula. The identities of the changed components can be identified by comparing the mass/UV spectra and retention times with those of reference compounds and/or tentatively assigned by matching empirical molecular formulae with those of the known compounds published in the literatures. Using the proposed approach, global chemical difference was found between traditional and dispensing granule decoctions, and berberine, palmatine, epiberberine, baicalin, wonogoside, 2-O-golloyl-1-O-cinnamoylglucose and emodin were identified as the most changed components during decocting SHXXT. It is suggested that this newly established approach could be used practically for the evaluation of chemical consistency between traditional and dispensing granule decoctions of traditional medicine combinatorial formulae.