Abstract
Psidium guajava leaves are rich source of nutrients, antioxidants, phytoconstituents and biological active compounds. The
study was designed to elucidate secondary metabolites like alkaloids, saponins, flavonoids, tannins and glycosides in extracts
of guava leaves through Gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography
(HPLC) by qualitative as well as quantitative procedures. These metabolites were further tested for their antimicrobial potential
against two-gram positive (Bacillus subtilis and Staphylococcus aureus) and two-gram negative (Escherichia coli and
Pasteurella multocida) bacteria and three pathogenic fungal strains (Asprrgillus niger, Fusarium solani and Aspergillus flavus).
GC-MS analysis revealed the presence of major constituents like Ca- Carrophyllene (22.70%), α cubebene (11.2%) and alphaHumulene (5.91%). The ethyl-acetate, methanol, n-hexane and chloroform extracts were tested for antibacterial and antifungal
activities against above mentioned microbes. Among all the tested solvent extracts, Chloroform and ethyl acetate extracts of
P. guajava demonstrated more sensitivity towards the growth of B. subtilis and P. multocida with MIC of 230±3.02, 316.±6.2
and 237±5.09 and 288±1.55 μg/ml, respectively. Methanolic extracts showed higher MIC against S. aureus (233±5.51 μg/ml)
and E. coli (192±2.05 μg/ml), respectively. The findings of this current study would provide the way to use guava as a potential
therapeutic agent to combat antimicrobial and antifungal resistance.
