The identification and quantification of the phenolic contents of methanolic extracts of three Salvia L. species namely S. brachyantha (Bordz.) Pobed, S. aethiopis L., and S. microstegia Boiss. and Bal. were evaluated using reverse phase high performance liquid chromatography, UV adsorption, and mass spectrometry (RP-HPLC/MS). In order to determine the antioxidant capacity of these species, cupric ions (Cu²⁺) reducing assay (CUPRAC) and ferric ions (Fe³⁺) reducing assay (FRAP) were performed to screen the reducing capacity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed for evaluation of the radical scavenging activity for both solvents. In further investigation, the antimicrobial activities of Salvia species were tested using the disc diffusion method against three Gram-positive and four Gram-negative microbial species, as well as three fungi species. The results showed that there is a total of 18 detectable phenols, the most abundant of which was kaempferol in S. microstegia and rosmarinic acids in S. brachyantha and S aethiopis. The other major phenols were found to be apigenin, luteolin, p-coumaric acid, and chlorogenic acid. All species tested showed moderate and lower antioxidant activity than standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and ascorbic acid. The ethanolic extracts of Salvia species revealed a wide range of antimicrobial activity. S. brachyantha and S. microstegia showed the highest antimicrobial activities against B. subtilis, whereas S. aethiopis was more effective on Y. lipolytica. None of the extracts showed anti-fungal activity against S. cerevisiae. Thus these species could be valuable due to their bioactive compounds.

Continuing our work on the sources of natural bioactive compounds, we evaluated the antimicrobial and antioxidant activities of Nepeta trachonitica as well as its major phenolic content using the high-performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) technique. For antioxidant activity, ferric reducing antioxidant power (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) methods were performed to measure the reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed to evaluate the radical scavenging activity of the sample. For antimicrobial activity, three Gram-positive and four Gram-negative microbial species as well as three fungi species were tested. N. trachonitica appeared to have reasonable antioxidant activity and decent antimicrobial activity as indicated by the inhibition of the organisms’ growth. The most susceptible species were Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 11229 among the organisms tested. Ethanol extract of the plant has the highest effect on Saccharomyces cerevisiae but no effect on Yarrowia lipolytica. The HPLC-MS/MS analysis showed that at least 11 major phenolic compounds of N. trachonitica exist, the major ones being rosmarinic acid, chlorogenic acid and quinic acid. The obtained results suggest that N. trachonitica could be a promising source for food and nutraceutical industries because of its antimicrobial and antioxidant properties and phenolic compounds.

In this study the chemical composition of four Salvia L. species (S. trichoclada Bentham., S. virgata Jacq., S. ceratophylla L., S. multicaulis Vahl.) from Turkey, were analyzed by GC-MS (Gas chromatography-Mass spectrometry) system. Forty, forty one, forty three and thirty nine compounds were identified representing 91.9 %, 90.4 %, 89.7 %, 88.4 % of the S. trichoclada, S. virgata, S. ceratophylla and S. multicaulis oils, respectively. Caryophyllene oxide (25.1 %), spathulenol (15.4 %) and β-pinene (12.3 %) were identified to be the main constituents of S. trichoclada. 1,8-Cineole (20.3 %), α-copaene (18.6 %) and germacrene D (17.6 %) were determined the major compounds of S. virgata. Germacrene D (23.6 %), α-copaene (19.4 %) and 1,8-cineole (7.8 %) were found to be the main constituents of S. ceratophylla. Caryophyllene oxide (22.5 %), spathulenol (12.7 %) and β-pinene (7.5 %) were detected to be the main constituents of S. multicaulis. The results were discussed in view of chemotaxonomy and natural products.

In this study two endemic Centaurea L. species from Turkey (C. kurdica Reichardt and C. saligna (K.Koch) Wagenitz) which were collected in the similar habitat, have been investigated. The hydro distilled essential oil of aerial parts of C. kurdica and C. saligna were analysed by GC and GC-MS. As a result thirty five and thirty seven components were identified representing 89.0 % and 89.6 % of the oil, respectively. Germacrene D (28.3 %), caryophyllene oxide (10.5 %) and β-caryophyllene (9.5 %) were detected main compounds of C. kurdica, however caryophyllene oxide (25.2 %), β-eudesmol (11.5 %) and germacrene D (10.2 %) were detected major constituents of C. saligna. Studied species manufactured many similar constituents in their essential oils that could be verified by the same ecological conditions of their habitat, but also differences were detected that could approve their taxonomic separation. The results have given some clues on the chemotaxonomy of these taxa.