TABLE 1.

Compounds used in this work.

Compounds	Bioavailability radar	Predicted LD50 [mg/kg] (predicted toxicity class)
11, LogP 2.56		70 (3) for neutral form
		3500 (5) for zwitterion
15, LogP 1.06		3 (1) for neutral form
		1,600 (4) for zwitterion

Bioavailability radar was used to determine the drug-likeness of the tested compounds. The prediction LD50 method is based on the analysis of the two-dimensional similarity to compounds with known LD50 values and the identification of fragments overrepresented in toxic compounds. LD50 values are given in [mg/kg]. Class I: fatal if swallowed (LD50 ≤ 5), Class II: fatal if swallowed (5 < LD50 ≤ 50), Class III: toxic if swallowed (50 < LD50 ≤ 300), Class IV: harmful if swallowed (300 < LD50 ≤ 2000), Class V: may be harmful if swallowed (2000 < LD50 ≤ 5,000), Class VI: nontoxic (LD50 > 5,000).- lipophilicity (LIPO) is within the range -0.7 < XlogP3 < +5.0; molecular weight (SIZE) is 150 g/mol < MW < 500 g/mol; polarity (POLAR) is 20 Å² < TPSA <130 Å²; insolubility (INSOLU) is 0 < logS <6; insaturation (INSATU) is 0.25 < fraction Csp3 < 1; and flexibility (FLEX) is 0 < Num rotatable bonds <9). For drug-like properties, compounds were found to have a good bioavailability score (0.55) (Lipinski et al., 2012)^, which is consistent with Lipiński’s rule of five. This compound meets the rules of Lipinski, Ghose, Veber and Muegge (Ghose et al., 1999; Muegge et al., 2001; Veber et al., 2002; Lipinski et al., 2012). Shown in the BOILED-Egg diagram, the test samples do not pass the blood–brain barrier but are absorbed in the gastrointestinal tract. The compounds are not available through the skin, as indicated by a negative logKp value (-7.84 cm/s). The ProTox II, webserver classified the toxicity classes of the ligands.