Fig. 4.

Multivariate analysis of metabolomic data. (A) PCA scores plot, PC2 (t[2]) versus PC1 (t[1]) from the unsupervised PCA showing the maximum variation in the metabolomic data based on all detected metabolites. The plot shows a clear separation between the two sample classes, Ga citrate (red) and Na citrate (blue). Each symbol represents one sample described by all detected metabolites. (B) Cross-validated OPLS-DA scores plot, orthogonal component 1 (to[1]) versus predictive component 1(tcv[1]) from the supervised OPLS-DA showing the separation between the two sample classes. The separation was statistically significant (P = 1.5503e-017) as determined by analysis of variance of the cross-validated model.