In vitro antimicrobial activity and phytochemical screening of leaf and stem extracts of Michelia champaca Linn.

Michelia champaca leaf and stem extracts have been evaluated for phytochemical constituents, in vitro antimicrobial efficacy and TLC bioautography assay. Qualitative phytochemical analysis of various solvents and water extracts demonstrated the presence of tannins, glycosides, steroids, flavonoids, anthraquinones, coumarins and lactones, phlobatanins, and reducing sugars. Polysaccharides was not observed in both the extracts and saponins was absent in all the leaf extracts tested. The in vitro antimicrobial activity of various solvents and water extracts was further assessed against nine bacteria and two fungi respectively. Hexane and chloroform extracts were found to be more potent being capable of exerting significant inhibitory activities against majority of the isolates such as Pseudomonas sp., Salmonella sp., Staphylococcus aureus 1 and 2 and Aspergillus niger. The highest in vitro inhibitory activity was observed for S. aureus 1 with wide zone of inhibition diameter (31 mm) followed by Aspergillus niger (29 mm). Thin layer bioautography assay of hexane leaf extract demonstrated a single large welldefined growth inhibition zone against S. aureus 1 observed at Rf value of 0.67. [ABSTRACT FROM AUTHOR]