Composition and antimicrobial activity of the essential oils of three Satureja species growing in Tanzania

Chemical composition of essential oils in Zataria multiflora Boiss. from different parts of Iran and their radical scavenging and antimicrobial activity

The objective of the study was to characterize the chemical constituents, antioxidant and antibacterial properties of five ecotypes of Zataria multiflora Boiss. essential oil with respect to main phytogeographic grown towns in Iran. Our investigation showed that the plants had essential oil yield ranging from 1.59+/-0.86% to 0.99+/-0.29% v/w. There were qualitative similarities among the oils from different origins, whereas the amounts of some components were varied. From different samples, 34, 34, 32, 29 and 53 various compounds were identified, representing 98.32%, 97.77%, 99.5%, 98.38% and 96.54% of total oils, respectively. The highest oxygenated monoterpens value in this study stood at 72.99%. Moreover, thymol, a phenolic compound of oxygenated monoterpens, was the most abundant component in GC/MS ranging from 27.05% to 64.87%. In the DPPH antioxidant assay, all samples exhibited a remarkable activity with a higher degree of IC(50)=19.7+/-0.7 microg/ml almost similar to BHT (18.1+/-0.4 microg/ml). Escherichia coli O157:H7 was the most resistant and Candida tropicalis was the most vulnerable organisms with MICs of 16 and 0.062 mg/ml, respectively. In conclusion, it seemed that geographical variation might have influenced the oil compounds either quantitatively or qualitatively.

Validation of a high-performance liquid chromatography method for the determination of (-)-alpha-bisabolol from particulate systems

A reversed-phase high performance liquid chromatography method has been developed and validated for determination and quantitation of the natural sesquiterpene (-)-alpha-bisabolol. Furthermore the application of the method was done by characterization of chitosan milispheres and liposomes entrapping Zanthoxylum tingoassuiba essential oil, which contains appreciable amount of (-)-alpha-bisabolol. A reversed-phase C(18) column and gradient elution was used with the mobile phase composed of (A) acetonitrile-water-phosphoric acid (19:80:1) and (B) acetonitrile. The eluent was pumped at a flow rate of 0.8 mL/min with UV detection at 200 nm. In the range 0.02-0.64 mg/mL the assay showed good linearity (R(2 )= 0.9999) and specificity for successful identification and quantitation of (-)-alpha-bisabolol in the essential oil without interfering peaks. The method also showed good reproducibility, demonstrating inter-day and intra-day precision based on relative standard deviation values (up to 3.03%), accuracy (mean recovery of 100.69% +/- 1.05%) and low values of detection and quantitation limits (0.0005 and 0.0016 mg/mL, respectively). The method was also robust for showing a recovery of 98.81% under a change of solvent in standard solutions. The suitability of the method was demonstrated by the successful determination of association efficiency of the (-)-alpha-bisabolol in chitosan milispheres and liposomes.

Composition and Antioxidant Properties of the Essential Oil of the Endemic Cape Verdean Satureja forbesii

The chemical composition of essential oil from the air-dried aerial parts of Satureja forbesii (Benth.) Briq. from Cape Verde was studied by GC and GC/MS. Thirty-nine volatile compounds were identified of which geranial (42.0%) and neral (31.2%) were the major constituents. Using the 2,2-diphenyl-2-picrylhydrazyl free-radical scavenging method and the in vitro assay for prevention of lipid peroxidation by thiobarbituric reactive species, significant activities were evidenced.