Structure elucidation, biological evaluation and molecular docking studies on a new organic salt: 2-Aminobenzimidazolium 5-nitro-2-hydroxybenzoate

An organic salt, 2-aminobenzimidazolium 5-nitro-2-hydroxybenzoate was synthesized and crystals were successfully grown from methanol using slow evaporation solution growth technique and recrystallization was done further to increase the purity of the crystal. The density of the grown crystals was evaluated by flotation method using carbon tetrachloride and xylene as solvents. Single crystal X-ray diffraction showed that the crystal is monoclinic system with P21/n space group and molecular structure was stabilized via three dimensional hydrogen bonding interactions. For the present crystal structure, Hirshfeld surface and fingerprint plots were drawn and analysed for the intermolecular interactions. The title compound AB5N2HB was characterized by 1H and 13C NMR spectroscopy to predict hydrogen and carbon bonded network. FT-IR and Raman spectral studies confirmed the presence of functional groups and their modes of vibrations. In the UV-Vis absorption spectrum the band at 313 nm confirmed that the proton was transferred from cation to anion. Simultaneous thermogravimetric and differential thermal analyses revealed the thermal stability and decomposition point of compound and it was stable up to 289 °C. The synthesized compound exhibited significant anti-bacterial and anti-fungal activity against different pathogens. Among them it showed good antibacterial and anti-fungal activity against Escherichia Coli and Candida albicans when compared to standard drug Penicilin G and Ketaconazole respectively. A molecular docking interaction of compound was also studied.