Enhanced antimicrobial activity and physicochemical properties of an organic nonlinear optical crystal: L-tryptophan l-tryptophanium bromide (LTTB) for biomedical applications

Abstract

A good quality biologically active single crystal of l -tryptophan l -tryptophanium bromide (LTTB) with molecular formula C 22 H 27 BrN 4 O 5 was successfully synthesized and grown from aqueous solution using slow evaporation solution growth technique. The synthesized crystal was subjected to various characterization techniques. Single crystal XRD study revealed that the grown crystal corresponds to monoclinic system of space group P2 1 and its crystallinity was tested by powder XRD analysis. The elemental composition of LTTB was confirmed by EDS analysis. The optical characteristics of the synthesized crystal were assessed by UV–Vis-NIR and Photoluminescence analyses. Moreover, the frequency dependent optical constants were computed and discussed in detail. The mechanical strength and the mechanical factors of the synthesized crystal were calculated based on Vickers microhardness test. The thermal stability and its characteristics were computed by TG-DTA-DSC analysis. Dielectric studies of LTTB were observed at various frequencies and temperature. The nonlinear optical performance of the synthesized crystal was examined by Kurtz-Perry technique. The antimicrobial capacity of the synthesized crystal was tested in-vitro against various bacterial and fungal species by Kirby-Bauer agar disk diffusion technique. The susceptibility test showed that the compound has the greatest activity against Aspergillus Niger and Staphylococcus aureus. Finally, all of these studies suggested that LTTB might be useful in biomedical and nonlinear optics applications.