## 4 Discussion
### Correlation of Phenolic Acids with TPC, Antioxidant and AChE Inhibitory Activities  
The lack of significant correlations between the quantified phenolic compounds and the measured activities (DPPH, ABTS, FRAP, and anti-AChE) or TPC suggests that the biological activities and overall phenolic content are not solely attributable to the individual compounds analyzed. This is further supported by the HPTLC-DPPH fingerprint, which reveals the presence of more intense antioxidant zones beyond those corresponding to the reference compounds quantified in this study. These findings indicate that other phenolic compounds, not quantified here, or synergistic interactions among various bioactive constituents likely play a pivotal role in determining the observed activities and TPC. The structural diversity and specific properties of the quantified phenolics may not fully align with the mechanisms assessed in the antioxidant and anticholinesterase assays, further explaining the lack of correlation. This underscores the complexity of natural extracts, where the overall activity often arises from the collective influence and synergistic interactions of multiple compounds, rather than the isolated effects of individual phenolics. The HPTLC-DPPH results highlight the importance of considering the entire phenolic profile and unquantified compounds when evaluating the bioactive potential of plant-based samples [52; 53; 55]. The PCA biplot provides valuable insights into the relationships between phenolic compounds, antioxidant (DPPH, ABTS, FRAP) and anti-AChE activities, and TPC. By illustrating how these variables group and align across two principal components, the PCA plot complements the Pearson's correlation analysis and highlights patterns of association that may not be immediately evident from numerical correlations alone (Figure 6). The PCA analysis revealed that the first principal component (PC1) explained 50.94% of the total variance, while the second principal component (PC2) accounted for 30.98%. Together, these two components explained 81.92% of the variability in the dataset, providing a robust summary of the relationships among the analyzed variables. The remaining variance was distributed among subsequent components, which were not considered for further analysis due to their lower explanatory power (Figure 6). In the PCA plot, gallic acid, caffeic acid, and protocatechic acid are positioned positively along the first principal component (PC1), which is closely aligned with AChE inhibitory, FRAP, and TPC assays. This grouping suggests that these compounds contribute to the activities associated with this axis. However, when examining the Pearson's correlation for gallic acid and TPC, the value is weakly negative (\(r=-0.154\), \(p=0.67\)), indicating that gallic acid's contribution to TPC is either negligible or slightly antagonistic. This apparent contradiction can be explained by the overall complexity of interactions among the phenolic compounds and other bioactive constituents, as the PCA represents collective variance rather than individual direct correlations. PCA also shows that DPPH and ABTS activities, which are represented as IC\({}_{50}\) values, are located on the negative side of PC1, opposite to TPC, FRAP, and AChE inhibitory activities. This positioning reflects the inverse relationships between DPPH and ABTS with TPC, as confirmed by the strong negative Pearson's correlations (DPPH, \(r=-0.787\), \(p=0.007\); ABTS, \(r=-0.732\), \(p=0.016\)). These findings underscore the fact that higher TPC, which correlates positively with FRAP and anti-AChE activity, is associated with lower IC\({}_{50}\) values for DPPH and ABTS, indicating stronger radical scavenging activity. Chlorogenic acid and \(p\)-coumaric acid, on the other hand, are positioned negatively along PC1 and show limited alignment with TPC, FRAP, and AChE inhibitory assays. This  
Figure 6: PCA highlights the relationships between phenolic acid content, TPC, and antioxidant (DPPH, ABTS, FRAP) and AChE inhibitory activities.