## 3 Results and Discussion
### Structure-Activity Relationships
The labeling of analyzed variables was as follows: A (vector related to the \(m/z_{\text{measured}}\) variable), B (log \(\varepsilon_{2}\)(Ch–T)), C (log \(k_{\text{w}}\)), \(I_{\text{GPI}}\) (connected with the \(I_{\text{GPI}}\) variable), \(I_{\text{MPI}}\) (\(I_{\text{MPI}}\)), \(I_{\text{CADT}}\) (\(I_{\text{CADT}}\)), \(I_{\text{B}}\) (\(I_{\text{B}}\)), \(I_{\text{P}}\) (\(I_{\text{P}}\)), \(I_{\text{T}}\) (\(I_{\text{JT}}\)), \(I_{\text{QP}}\) (\(I_{\text{QP}}\)), and 1 (vector constructed on the log (1/MIC (M)) values. These MIC parameters resulted from the in vitro screening of **6a–g** against \(Mtb\) H\({}_{\text{M}}\)\({}_{\text{M}}\)\({}_{\text{B}}\)), 2 (\(MK\) DSM), 3 (\(MS\)), 4 (\(MM\)), and 5 (vector constructed on the log (1/IC\({}_{50}\) (M)) values. These IC\({}_{50}\) values resulted from the in vitro screening of **6a–g** against the HepG2 cell line). The color-coded vectors were also labeled according to their position in a circle of correlation (Figure 6b). The proper indication of variables with letters A-C or digits 1-5 is provided in the Supplementary Materials. The cycle was characterized with a radius = 1 (absolute value). The visualization based on such relationships provided the sharpest angles between some pairs of vectors, i.e., A and 5, C and 3, 1 and 5, 3 and 4, \(I_{\text{QTP}}\) and \(I_{\text{GTI}}\) as well as \(I_{\text{B}}\) and \(I_{\text{CADT}}\). Pearson's correlation coefficient (\(r\)) values indicated relatively satisfactory correlation between \(m/z_{\text{measured}}\) (vector 1) of the compounds **6a-g** and their log \(k_{\text{w}}\) (C; \(r\) = 0.8450), log \(\varepsilon_{2\text{ (Ch-T)}}\) (B; \(r\) = 0.7959), in vitro activity against \(MS\) (3; \(r\) = 0.9431), \(Mtb\) H\({}_{37}\)R\({}_{\text{a}}\) (1; \(r\) = 0.9240) as well as \(MM\) (4; \(r\) = 0.8141). The moderate correlation was observed between \(m/z_{\text{measured}}\) and toxicity in the HepG2 cell line (5; \(r\) = 0.6681). Absorption intensity increased slightly for the compounds containing bulky substituents with strong EW properties (**6e** and **6f**) and molecules with a bulky diphenylmethyl moiety (**6g**). This behavior was connected with increased efficiency, especially against \(Mtb\) H\({}_{37}\)R\({}_{\text{a}}\) (1; \(r\) = 0.7909) and \(MS\) (3; \(r\) = 0.7798). The correlation between log \(\varepsilon_{2\text{ (Ch-T)}}\) (B) and log \(k_{\text{w}}\) was weaker (C; \(r\) = 0.5896). The increased log \(\varepsilon_{2\text{ (Ch-T)}}\) parameters of analyzed salts increased the probability for their bases to cause tachycardia (\(r\) = 0.7182). The prolongation of a QT interval was less probable (\(r\) = 0.5260). The activity of **6a-g** against all in vitro tested mycobacteria was quite strongly associated with their lipohydphilic properties. In more detail, the increase in lipophilicity provided higher efficiency against \(MM\) (\(r\) = 0.9128), \(MS\) (\(r\) = 0.8650), and \(MK\)\(DSM\) (\(r\) = 0.8411) as well as \(Mtb\) H\({}_{37}\)R\({}_{\text{a}}\) (\(r\) = 0.8199). It should be stated that both highly lipophilic adamantyl and phenyl moieties in a structure of \"similar\" compounds did not guarantee particularly high in vitro antimycobacterial activity. The molecule **MOG-1** (Figure 7) was more than two-fold less efficient against \(Mtb\) H\({}_{37}\)R\({}_{\text{v}}\) compared to its regioisomer [90]. The good news was that a higher log \(k_{\text{w}}\) of **6a-g** might be connected with a notably lower probability of palpitation issues, which could eventually be caused by their bases (**5a-g**; \(r\) = -0.8623). In addition, the salts would cause neither significant tachycardia (\(r\) = 0.6040) nor prolongation of a QT interval of the heart (\(r\) = 0.4478). The increase in lipophilicity of the tested compounds provided a stronger potential to reduce the in vitro viability of the HepG2 cell population to 50% of its maximum viability (\(r\) = 0.8320).