The essential oils of the aerial parts of Jasonia candicans and J. montana were analyzed by gas chromatography-mass spectrometry (GC/MS) technique. Of twenty-one components identified in the volatile oil of J. candicans, intermediol was the main constituent. Fifty-eight components were characterized in the essential oil of J. montana. Camphor, borneol, bornyl acetate, chrysanthemol, intermediol, and 1,8-cineole were the major constituents in this oil. The two oils showed antibacterial activity against Bacillus subtilis. They also showed a marked antifungal activity against Trichophyton mentagrophytes, Cryptococcus neoformans, and Candida albicans.

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The genus Centaurea is recognized in folk medicine for anti-inflammatory, anti-itch, antitussive, purgative, astringent, and tonic activities. To study the chemical determinant for antimicrobial activity essential oils (EOs), five Centaurea species were analyzed including: C. scoparia, C. calcitrapa, C. glomerata, C. lipii and C. alexandrina. Conventional hydro-distillation (HD) and microwave-assisted extraction (MAE), as new green technologies, were compared for the extraction of essential oils. GC/MS analysis identified 120 EOs including mostly terpenoid except from C. lipii and C. alexandrina in which nonterpenoids were the major constituents. Major terpenoids included spathulenol, caryophyllene oxide and alloaromadendrene oxide-2. To probe antibacterial activity, potential EO inhibitors of a bacterial type II DNA topoisomerase, DNA gyrase B were screened via an in silico molecular docking approach. Spathulenol and alloaromadendrene oxide-2 possessed the best binding affinity in the ATP- binding pocket of Gyrase B enzyme. Principal component analysis and agglomerative hierarchical clustering were used for sample classification and revealed that sesquiterpenes contributed the most for accessions classification. In vitro antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger for all EOs were also evaluated. EOs from C. lipii, C. glomerata and C. calcitrapa exhibited significant MIC against S. aureus with an MIC value of 31.25 µg/mL.

The chemical composition of the fatty acids in twenty four different samples of cannabis seeds was determined by gas liquid chromatography with flame ionization detector and coupled with a mass spectrometer. The identification of twenty fatty acids was based on comparison with authentic samples. In addition six other components were detected in some samples and shown to be oxygenated acids. The data showed that the seeds could be divided broadly into two groups, one with saturated and unsaturated fatty acids averaging 9.5±1.7% and 89.4±1.9% respectively, and the other with averages of 60.1±4.1% and 21.9±6.1% of the respective fatty acids. Examination of the effect of seed maturity on the fatty acid composition showed that the more mature the seeds are, the higher is the percentage of unsaturated fatty acids and the lower the percentage of saturated ones. Detection of oxygenated low molecular weight acids in the second group could be attributed to ageing. Comparison of the fatty acid composition of seeds of drug and fibre types showed no significant difference among mature seeds. In addition, there was no correlation between the fatty acid composition of the seeds and their geographical origin.

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