Chemical traits and antimicrobial activity of endemic Teucrium arduini L. from Mt Biokovo (Croatia)

Abstract

Chemical composition of the essential oil (analysed by GC-FID and GC-MS), the content of macroelements and trace elements (analysed by ICP-AES), and antimicrobial activities were investigated in Teucrium arduini L. from Mt Biokovo (Croatia). Additionally, a study on the types and distribution of glandular trichomes which produce essential oils was investigated. The oil was characterized by a high concentration of sesquiterpene hydrocarbons (68.5%) of which β-caryophyllene (32.9%) and germacrene D (16.4%) being the major compounds. Among the macroelements, the content of calcium was the highest (9772 mg/kg), while the content of sodium was the smallest (117.74 mg/kg). Among the micronutrients, the most represented element was iron (72.07 mg/kg). The content of each investigated toxic metal (As, Hg, Pb, Cd and Cr) was below permissible levels. The essential oils showed antimicrobial activity against bacterial species tested, with MIC values ranging from 6.25 mg/mL to 37.50 mg/mL. Fungal species were susceptible with MIC values from 7.81 mg/mL and 25.00 mg/mL.

The composition and antibacterial activity of essential oils in three Ocimum species growing in Romania

“…These types are usually found in species of the Lamiaceae family [12,17,18] and in Ocimum genus [19]. The peltate hairs (PH) ( Figure 1A on the mature leaves.…”

Endemic Veronica saturejoides Vis. ssp. saturejoides–Chemical Composition and Antioxidant Activity of Free Volatile Compounds

“…For SEM investigation, stem, leaf, and calyx samples were transferred from 70% ethanol to 70% acetone and then further dehydrated (70%, 90% and 100% acetone) and subjected to critical point drying using CO 2 as drying medium (CPD030; Bal-tec, Balzers, Liechtenstein). The samples were then sputtered with gold (Sputter Coater, AGAR) and examined under an XL30 ESEM (FEI) SEM with an acceleration voltage of 20 kV in high vacuum mode [46]. Common terminology [47] was used to describe the trichomes.…”

Morphological, genetic and phytochemical variation of the endemic Teucrium arduini L. (Lamiaceae)

“…Previous analysis of the essential oils of Teucrium species (Teucrium polium L., Teucrium flavum L., Teucrium montanum L., and Teucrium chamaedrys L.), and T. arduini from other localities on Mt Biokovo (Croatia) indicated that the sesquiterpene hydrocarbons, i.e. bcaryophyllene and germacrene D, are the dominant group Kremer et al, 2012aKremer et al, , 2013. Additionally, b-caryophyllene was identified as a major compound in the oil of Teucrium orientale L. var.…”

“…These habitats primarily belong to plant associations within the Dinaric endemic vegetation order Moltkietalia petraeae Lakušić 1968. Chemical investigations of T. arduini revealed the presence of volatile oils , tannins (Jurišić Grubešić et al, 2012;Kremer et al, 2012b), flavonoids (Harborne et al, 1986;Valant-Vetschera et al, 2003), phenolic acids (Šamec et al, 2010), phytosterols and bitter principles (Jurišić Grubešić et al, 2012), and macroelements and micronutrients (Kremer et al, 2012a T. arduini is used in folk medicine in Bosnia and Herzegovina in the form of an infusion for stomach ailments (Redžić , 2007). Antimicrobial investigations of the species have shown a broad spectrum of antimicrobial activity (Šamec et al, 2010;Vuković et al, 2010;Kremer et al, 2012a). T. arduini is also a source of polyphenols and other antioxidants with radical-scavenging and chelating properties (Šamec et al, 2010;Kremer et al, 2013).…”