No abstract

In this study, a series of new organic compounds with piperazine as a fundamental skeleton was synthesized and evaluated for their tyrosinase inhibitory potentials by in vitro and in silico studies. The in vitro studies have shown that compounds 10a and 10b bearing 1,2,4, triazole nucleus could be considered potent tyrosinase inhibitors with IC 50 values of 31.2 ± 0.7 and 30.7 ± 0.2 µM, respectively. 10b (K i = 9.54 µM, mixed type inhibition) with the lowest IC 50 value among derivatives was selected to determine kinetic constants and inhibition types. Furthermore, molecular docking analysis was performed for all compounds and it was observed that 4b, 5a, 4c, and 10b showed promising inhibitory effect on tyrosinase activity. Based on docking results, ADME predictions and in vitro studies, 10b might be considered suitable oral drug candidates for further studies.

In this study, we have synthesized a series of 3-(pyridin-2-yl)-2-(pyridin-2-ylimino)thiazolidin-4-ol derivatives regioselectively from 2-iminothiazolidin-4-ones using LiAlH 4 at room temperature. Due to the presence of the restricted rotation around the N3-C aryl single bond, the formation of M/P isomers was observed. The OH group of the hemiaminal was found to orient itself on the same side with pyridyl nitrogen during this restricted rotation to form an intramolecular hydrogen bond, which was demonstrated by the computational DFT study. This orientation presumably inhibited the occurrence of dehydration and stabilized the molecule.2-iminothiazolidin-4-ol, axially chiral hemiaminal, intramolecular hydrogen bonding, pyridine compounds, stable hemiaminal