A Comparative Study of Macrocyclic Mn(II) Nanocomplex Synthesized Using Sonication-Assisted and Conventional Methods for Biomedical Applications

Abstract

Macrocyclic ligand, (7,18-diamino-7,8,17,18-tetrahydrodibenzo[b,j][1,4,9,12]tetraazacyclohexadecine- 6,9,16,19(5H,10H,15H,20H)-tetraone) and its Mn(II) complex was synthesized via sonochemical and conventional methods in nano dimension of 42.29 and 85.63 nm, respectively. The quantitative and qualitative analyses have been done using Fourier Transform Infrared (FTIR), ultraviolet-visible (UV-Vis), mass, electron spin resonance (ESR) spectroscopies and elemental (CHN) analyses. Powder X-ray diffraction (PXRD) and field emission scanning electron microscopy (FE-SEM) have been used for the crystallographic and morphological analyses of the synthesized nano complex, respectively. Based on these studies, octahedral geometry and hexagonal unit cell structure have been proposed for the synthesized Mn(II) nanocomplex. The nano complexes of transition metal can be introduced as the effective nano metal based antimicrobial drugs as they do not require encapsulating or solubilizing chemicals and further offer less side effects and low toxicity as well as improved antimicrobial efficiency. So, it is the need of the hour to work upon such nano based transition metal drugs. The purity, yield and crystallinity of nano complex synthesized by the sonochemical method were found to be far better than those synthesized by the conventional method. The nanocomplex synthesized using two different protocols were screened for in vitro against pathogenic bacteria and fungal species by a two-fold serial dilution method and antioxidant studies were as done using the DPPH scavenging method indicating the better and enhanced performance of the nanocomplex obtained using sonication-assisted method. The sonochemical method enhances the properties of the complex by effectively regulating and reducing the size of the nanocomplex and hindering their agglomeration and has better biomedical applications in comparison to conventional methods.