Chemical Composition and Biological Activities of Oregano Essential Oil and Its Fractions Obtained by Vacuum Distillation

Abstract

Oregano (Poliomintha longiflora) essential oil (Ooil) is a product of high commercial value and many applications, including chemotherapy. Aiming to achieve the best use of this resource, the present study focuses on the characterization of separated fractions of Ooil by fractional vacuum distillation at low pressure. Four fractions (F1–F4) and undistilled oil (Unoil) were separated from Ooil and analyzed for their chemical composition and biological activities, such as antioxidant and antimicrobial activities. Gas chromatography–mass spectrometry shows differences in the composition among the fractions and Ooil. The amount of monoterpenes oxygenated (MO), sesquiterpenes hydrocarbon (SeH) and monoterpenes hydrocarbon (MH) varied between the fractions in ranges of 1.51–68.08, 3.31–25.12 and 1.91–97.75%, respectively. The major concentrations of MO and SeH were observed in F4 and Unoil. On the other hand, the highest concentrations of MH were found in F1 and F2, while the lowest were in F4 and Unoil. These results were correlated with the biological activity. Free-radical scavenging activity varied among fractions, with F4 and Unoil showing the highest activity. The antimicrobial test showed that F4 and Unoil had the highest activity in almost all cases. The correlation between the variables studied in the different fractions allows the definition of the particular properties for each one of them.

In Vitro Evaluation of the Antifungal Activity of Ghassoul-Based Formulations with Oregano and Thyme Essential Oils against Penicillium sp.

“…On the other hand, the EO of oregano is composed mainly of carvacrol (59.82%), c-terpinene (10.85%), and α-pinene (9.89%), which account for about three-quarters of the total chemical composition accompanied by other constituents with relatively low contents. Similar results were found by Rostro-Alanis et al for oregano EO whose majority compound is carvacrol with a higher concentration of 60.03% [33]. ere is a slight difference in the chemical composition of the main components of the two EOs with those of literature studies, and this may be due to abiotic factors such as the specific climate of the origin regions of the samples.…”

Bioactive Natural Compounds and Antioxidant Activity of Essential Oils from Spice Plants: New Findings and Potential Applications

“…Additionally, different studies have demonstrated the antimicrobial activities of oregano EOs against bacterial strains with medical relevance [ 136 , 137 , 138 ]. Despite the antioxidant activities, recent studies have demonstrated their antidiabetic, anti-inflammatory, and cytotoxic activities against cancer cell lines [ 47 , 131 , 139 , 140 ].…”

“…Regarding the antimicrobial activities, the EO of different oregano species has shown inhibitory activities against bacterial and fungal strains, which indicates their potential application in the food industry as a preservative [ 149 , 150 ]. The antimicrobial activity has been pointed out due to the synergic effect of constituents of oregano EO and fractions, especially when carvacrol and thymol are present [ 140 ].…”

Underutilized Mexican Plants: Screening of Antioxidant and Antiproliferative Properties of Mexican Cactus Fruit Juices

“…One mL of this mother solution was added to a new 25 mL volumetric flask and filled to the mark with methanol, creating a diluted solution. The solutions were placed in 4.0 mL cuvettes (75 µL of clarified juices dilutions and 3 mL DPPH solution), and left to react for 16 min before being read by the spectrophotometer (Model DR 500, Hach Lange GmbH, Düsseldorf, Germany) at 515 nm [ 37 ]. All measurements were made in triplicates with a calibration curve of Trolox at varying concentrations from 5 to 200 ppm.…”