Phytosterols: Wide-Spectrum Antibacterial Agents

The petroleum ether extract from the leaves of Annona squamosa, Adenocalymna alliceum, and Amaranthus tricolor yielded n-alkanes, n-alkanols, 16-hentriacontanone, and sterols. These were purified, characterized, and evaluated for their antibacterial activity against Staphylococcus aureus, Staphylococcus albus, and Streptocorus viridans (all gram-positive bacteria) and Escherichia coli, Pseudomonas pvocyanea, and Klebsiella (all gram-negative bacteria). Based on their net zone of inhibition against these microorganisms, among the compounds isolated from these plants, 16-hentriacontanone and sterols exhibited stronger antibacterial properties than the n-alkanes, which gave a moderate response.