LC-Triple Quadrupole MS Enables Sample Classification in Viscum combreticola: Detecting Subtle Photochemical Isomerization in Hydroxycinnamic Acid Derivatives.

High-resolution MS techniques such as time-of-flight (TOF)-MS are preferred for putative metabolite identification due to their unprecedented high resolution and accuracy in metabolomics studies. However, exploring cost-effective alternative instruments for routine analyses would be advantageous, particularly in laboratories where access to high-resolution mass spectrometry (MS) is limited. This study investigated the ability of the LC-QQQ-MS instrument operating in Q3 scan mode in replicating results obtained from the qTOF-MS. Methanolic extracts of non-treated and UV-treated samples of Viscum combreticola were used as model samples for the analysis. Multivariate statistical models including principal component analysis (PCA), hierarchical clustering analysis and volcano plots were employed to highlight metabolite differences between UV-treated and non-treated plant extracts. The findings of this study demonstrated that the LC-QQQ-MS is effective in distinguishing between the two contrasting extracts of V. combreticola. Several cis isomers of hydroxycinnamic acid containing molecules such as 3-feruloylquinic acid, 4,5-dicaffeoylquinic acid and 4-p-coumaroyl-5-caffeoylquinic acids that underwent geometrical isomerization following UV exposure were identified as differentiating molecules (biomarkers), consistent with previous findings using high-resolution qTOF-MS instruments. This study positions QQQ-MS as a valuable tool for authenticating samples containing known metabolites, particularly when the identification of unknowns is not the primary objective and high-resolution MS instruments are not accessible.