Twenty-one samples of Sideritis species (S. scardica, S. raeseri, S. taurica, S. syriaca and S. perfoliata) from various locations on the Balkan Peninsula were evaluated for their chemical constituents. Chemical analyses were focused on secondary metabolites, particularly phenolic compounds, which have several roles in the plant physiological processes and have demonstrated significant health beneficial effects. The occurrence of hydroxycinnamic acids, phenylethanoid glycosides and flavonoids has been investigated in taxonomically related taxa of the genus Sideritis. A systematic method for phenolic compounds identification was developed using tandem mass spectrometry coupled to high performance liquid chromatography with diode array detection. Scanning for precursor ions of commonly found phenolics in Sideritis species using LC/MS n with an ion trap instrument permitted the specific determination of hydroxycinnamic acid derivatives, and phenylethanoid and flavonoid glycosides. Further characterization of each phenolic compound was performed using MS/MS production analysis and commonneutral-loss analysis. This on-line technique allowed identification of three hydroxycinnamic acid derivatives, eight phenylethanoid glycosides, and twenty-four flavonoid glycosides. All thе taxa analysed produced very similar phenolic patterns characterized by the presence of 5-caffeoylquinic acid, lavandulifolioside, verbascoside, hypolaetin 7-O-[6′′′-O-acetyl]-allosyl(1→2)glucoside, apigenin 7-(4"-p-coumaroylglucoside), 4'-O-methylisoscutellarein 7-O-[6′′′-O-acetyl]-allosyl(1→2)glucoside, and minor amounts of isoverbascoside, apigenin 7-O-allosyl(1→2)glucoside, isoscutellarein 7-Oallosyl-(1→2)-[6′′-O-acetyl]-glucoside, hypolaetin 7-O-allosyl-(1→2)-[6′′-O-acetyl]-glucoside and 4'-O-methylhypolaetin 7-O-[6′′′-Oacetyl]-allosyl-(1→2)-[6′′-O-acetyl]-glucoside. These results show that the investigated species are systematically very closely related. Phenylethanoid glycosides and flavonoid acetylglycosides are dominant and constitute 90% of the total phenolic compounds compared with hydroxycinnamic acid and flavonoid 7-O-glycosides.

No abstract

Flavonoids and other phenolic compounds in young needles of four pine species, Pinus peuce, P. nigra, P. mugo and P. sylvestris from the Macedonian flora were investigated. The amount of total phenols and total flavonoids were determined using Folin-Ciocalteau and aluminum chloride assay, respectively. The obtained results revealed that the total phenolic content (TPC) and total flavonoids content (TFC) varied among different pine species ranging from 9.8 to 14.0 mg GAE/g and from 3.3 to 7.2 mg CE/g of dried plant material, respectively. Qualitative analysis of flavonoids and other phenolic components was made by a LC-DAD/ESI-MSn optimized chromatographic method. A total of 17 phenolic components were identified and classified as: acids (2), procyanidins (2) and flavonoid glycosides (13). The most prevalent components were flavonoid glycosides, especially flavonols and methylated flavonols (9). Additionally, 3 components were found as acylated flavonol glycosides with ferulic and p-coumaric acid. The last one was found not only in esterified form but also in the free form. Only one flavone-apigenin glycoside was detected. Procyanidins were identified as catechin derivatives, both dimers and trimers.

Background:There are no information of the yield, chemical composition and antimicrobial activity of essential oils of berries (EOB) or leaves (EOL) of Juniperus excelsa Bieb. (Cupressaceae) growing wild in R. Macedonia.Materials and Methods:Plant material was collected from two localities during two seasons. Essential oil composition was analyzed by gas chromatography/flame ionization detector/mass spectrometry (GC/FID/MS) and antimicrobial screening was made by disc diffusion and broth dilution method.Results and Discussion:EOB yield ranged from 1.6-9.4 ml/kg and from 8.9-13.9 ml/kg for EOL. Two chemotypes of essential oil were differentiated, α-pinene-type (with 70.81% α-pinene in EOB and 33.83% in EOL), also containing limonene, β-pinene and β-myrcene while the sabinene-type (with 58.85-62.58% sabinene in EOB and 28.52-29.49% in EOL), was rich in α-pinene, β-myrcene, limonene, cis-thujone, terpinolene and α-thujene. The most sensitive bacteria to the antimicrobial activity of EOB was Haemophilus influenzae (MIC = 31 μl/ml). EOL have showed high activity towards: Staphylococcus aureus, Streptococcus pyogenes and Haemophilus influenzae (MIC = 125 μl/ml). The pinene-type of essential oil showed moderate activity against Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Corynebacterium spp. and Campylobacter jejuni (MIC >50%). The sabinene-type of the oil showed moderate activity to Streptococcus pyogenes, Haemopilus influenzae, Campylobacter jejuni and Escherichia coli (MIC >50%). No activity was observed toward Candida albicans.Conclusion:The analysis of EOB and EOL revealed two chemotypes (α-pinene and sabinene type) clearly depended on the geographical origin of the Macedonian Juniperus excelsa which also affected the antimicrobial activity of these oils.

No abstract