Chemical characterization and antimicrobial activity of essential oils of salvia L. species

The effect of solvent polarity (methanol and pentane) on the chemical composition of hydrodistilled essential oils (EO’s) ofLippia graveolensH.B.K. (MXO) andOriganum vulgareL. (EUO) was studied by GC-MS. Composition of modified starch microencapsulated EO’s was conducted by headspace-solid-phase microextraction (HS-SPME). The antimicrobial activity of free and microencapsulated EO’s was evaluated. They were tested againstSalmonellasp.,Brochothrix thermosphacta,Pseudomonas fragi, Lactobacillus plantarum, andMicrococcus luteus. Thymol and carvacrol were among the main components of EO’s and their free and microencapsulated inhibitory activity was tested againstM. luteus, showing an additive combined effect. Chemical composition of EO’s varied according to the solvent used for GC analysis and to volatile fraction as evaluated by HS-SPME. Thymol (both solvents) was the main component in essential oil of MXO, while carvacrol was the main component of the volatile fraction. EUO showedα-pinene (methanol) andγ-terpinene (pentane) as major constituents, the latter being the main component of the volatile fraction. EO’s showed good stability after 3 months storage at 4°C, where antimicrobial activity of microencapsulated EO’s remained the same, while free EO’s decreased 41% (MXO) and 67% (EUO) from initial activity. Microencapsulation retains most antimicrobial activity and improves stability of EO’s from oregano.

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Chemical characterization and antimicrobial activity of Campomanesia aurea against three strains of Listeria monocytogenes

Brazilian Journal of Biology ◽

10.1590/1519-6984.219889 ◽

2020 ◽

Author(s):

L. A. Pacheco ◽

E. M. Ethur ◽

T. Sheibel ◽

B. Buhl ◽

A. C. Weber ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Listeria Monocytogenes ◽

Essential Oil ◽

Essential Oils ◽

Chemical Characterization ◽

Culture Collection ◽

American Type Culture Collection ◽

Antibiofilm Activity ◽

Bacteriostatic Effect

Abstract The essential oil (EO) composition of leaves of Campomanesia aurea was analyzed by GC-MS. The plant was collected in April (EOA) and October (EOO) in São Francisco de Assis/RS. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The yields were 4.44% in April, and 6.15%, in October. Thirty-one compounds were identified in EOA, accounting for 96.87% of the total, and twenty-eight compounds were identified in EOO, accounting for 99.46% of the total. For EOA, the major identified monoterpene was p-cymene (8.33%) and the major identified sesquiterpene was α-cadinol (10.72%), while regarding EOO the major identified monoterpene was repeatedly Terpinolene (3.43%), whereas the major identified sesquiterpene was α-cadinol (12.79%). The antibacterial activity of the essential oil was evaluated against the three Listeria monocytogenes from the American Type Culture Collection (strains ATCC 7644, 19114 and 13932). The essential oil showed a MIC of 10 mg/mL against the strains ATCC 7644 and 19114, with bacteriostatic effect of 20 mg/mL and a MIC of 20 mg/mL for ATCC 13932. Regarding the antibiofilm activity, o EOO showed the best results with an inhibition of 90% in the sessile growth with an applied concentration of 4.0 mg/mL.

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