Rauwolfia tetraphylla mediated synthesis of herbal nano powders by ball milling and GC-MS analysis, evaluation of their antimicrobial activity

Synthesis, characterization and evaluation of biological applications of nanoparticles is of immense importance in recent years in the field of Nanotechnology. Due to increasing demand of nanoparticle synthesis from medicinal plants now a days, in the present study, it is aimed to produce bio compatible, non-toxic, homogenous nanopowders by Ball milling, one of the top-down approaches from root, stem and leaf of Rauwolfia tetraphylla, an important medicinal plant of Apocynaceae. Rauwolfia tetraphylla L., an endangered species, is rich in various phytochemicals and often used as a substitute of Rauwolfia serpentina and therefore aimed to produce nanopowders from different parts of this plant. These biosynthesized nanopowders were characterized by UV-Visible Spectroscopy, Scanning Electron Microscopy, X-Ray Diffraction and Fourier Transform Infrared Spectroscopy. Further bioactive components of root, stem and leaf nanopowders were analysed by Gas Chromatography-Mass Spectrometry(GC-MS), and different compounds were identified by comparison of GC-MS spectrum with library searches. Methanolic root, stem and leaf nanopowders were evaluated for antibacterial and antifungal activity. Antibacterial activity was assessed against human pathogenic bacteria Klebsiella pneumoniae, Salmonella typhi, Vibrio cholerae, Corynebacterium diphtheriae, Vibrio parahemolyticus. Human pathogenic fungi Aspergillus fumigatus, Candida albicans, Mucor hiemalis were selected for evaluating antifungal activity. The present study confirms the good antibacterial and antifungal activity of Rauwolfia tetraphylla synthesized nanopowders. As GC-MS analysis revealed different phytoconstituents, other pharmacological activities need to be evaluated.