## 3 Results and Discussion
### Multivariate Analysis
Eight biological assays i.e., metal chelating, anti-amylase anti-glucosidase and all the antioxidant assays had a variable importance in projection (VIP) score above 1; this suggested that the results of that assays varied considerably from an organ to another. The present study revealed that the distribution of phytoconstituents as well as the derived biological activities of _C. officinalis_ differ significantly between the different parts. This observation is in line with that of [41] who indicated that the synthesis and accumulation of the molecules varied to one organs to another of the same plant, as a consequence of their differential gene expression which by extension impacts the pharmaceutical activities of the plant extracts. Much further according to these authors reported that the amount and composition of bioactive compounds differ at the sub-cellular level as well as within plant tissues. On the other hand, [PERSON], et al. [42] mentioned that the differential distribution of phenolic compounds in the different part of plants is due to their endogeneous biosynthesis and within their transport to one organ to another as well. When compared the biological activities of the different organs, the flower extracts showed the higher total antioxidant content and free radical scavenging (ABTS and DPPH), power reducing (FRAP and CUPRAC) and anti-amylase activities compared to the extracts of the other organs (Figure 4). Nevertheless, overall weak BChE, tyrosinase, metal chelating activity (MCA) and glucosidase activities were detected for flowers extracts. Higher metal chelating activity were obtained with the leaves extracts whereas their anti-tyrosine and anti-glucosidase activities were close to those of the roots' extracts. Despite our findings that the biological activities of _C. officinalis_ were predominantly influenced by the type of organs, it is worth noting that within organs there is a remarkable extraction process effect on the biological activities. Numerous publications reported the variation of the nature and yield of biocompatibility as well as the bioactivities of the extracts obtained using different extraction techniques [43; 44; 45; 46]. It is well known that biologically active molecules occur in low concentration in plant materials. Thus, extraction is a crucial in the discovery of biologically-active molecules from herbal materials. Figure 2: Hierarchical cluster analysis on the biological activities of _Calendula officinalis_ samples. (**A**): Estimation of the optimal number of clusters. (**B**): Cluster plot. (**C**): Assessment of the goodness of the cluster analysis using the average distance between the clusters. Figure 3: (**A**) Samples plot of supervised partial least squares discriminant analysis. (**B**) Area under the curve average and receiver operating characteristic curve using one-vs-all comparisons reflecting the robustness of the supervised model. (**C,D**) Discriminant biological activities evaluation by VIP approach for the first two function of the discriminant model. Figure 4: Comparison of antioxidant properties and enzyme inhibitory capacities of the different organs of C. _officialis._**(a)** ARTS radical scavenging, **(b)** DPPH radical scavenging, **(c)** CUPRAC assay, **(d)** FRAP assay, **(e)** Metal chelating (MCA) assay, **(f)** Phosphomolybdenum (PBD) assay, **(g)** AChE inhibition, **(h)** BChE inhibition, **(i)** Tyrosine inhibition, **(j)** Amylase inhibition, **(k)** Glucosidase inhibition.