ANTIBACTERIAL ACTIVITY OF FIVE TERPENOID COMPOUNDS: CARVACROL, LIMONENE, LINALOOL, α-TERPINENE AND THYMOL

Abstract

The objective of the research was to evaluate the antibacterial activity of five terpenoid compounds: carvacrol, limonene, linalool, α-terpinene and thymol in Gram negative bacteria (Escherichia coli, Salmonella spp and Pseudomona spp) and Gram positive (Staphylococcus aureus and Streptococcus spp). The antibacterial activity was determined by the disk diffusion method on Mueller-Hinton agar; as controls were used alcohol 70% and two antibiotics (ceftibuten and cephalexin) were used for Gram negative and positive bacteria respectively. Were made five concentrations of 0.75, 0.45, 0.15, 0.075 and 0.05 mg mL-1 for the terpenoids compounds and antibiotics. The largest inhibition zone were presented with carvacrol (5.5 mm), linalool (6 mm) and thymol (5.5 mm) in the bacteria Salmonella spp, S. aureus and E. coli respectively. The bacteria most sensitive to the terpenoids were E. coli, Salmonella spp and S. aureus while the most resistant bacteria were Pseudomona spp and Streptococcus spp. It is concluded that there is no difference in antibacterial activity among the five terpenoids compounds when exposed to Gram negative and positive bacteria, except when evaluated with S. aureus bacteria where carvacrol, limonene and linalool have an antibacterial effect similar to that of cephalexin antibiotic.