GC/MS analysis and antimicrobial activity of essential oils of Telekia speciosa (Schreb.) Baumg

Abstract

Telekia speciosa (Schreb.) Baumg., Asteraceae, is widespread in Eastern and Central Europe and the Balkan Peninsula. Previous phytochemical investigations have revealed T. speciosa as a rich source of sesquiterpene lactone -isoalantolactone, especially in its underground parts. The aim of the present study was to analyze the essential oils from aerial and underground parts of T. speciosa and investigate their antimicrobial activity. Chemical composition of essential oils was determined by GC-FID/MS method leading to the identification of 67 compounds in total, with 15.77 % oxygenated monoterpenes, 7.77 % sesquiterpene hydrocarbons, 49.14 % oxygenated sesquiterpenes, and 12.37 % other compounds from aerial parts, and 3.80 % oxygenated monoterpenes, 3.13 % sesquiterpene hydrocarbons, 90.33 % oxygenated sesquiterpenes from underground parts essential oil. The main components from aerial parts were (E)-nerolidol (11.54 %) and caryophyllene oxide (10.54 %), while isoalantolactone was the predominant component from essential oil underground parts (83.41 %). The minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration of the essential oils were evaluated against six strains of bacteria and two strains of fungus using in vitro microdilution method. Both oils presented antimicrobial properties against pathogens Staphylococcus aureus, Bacilus cereus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Inhibition of growth of tested microorganisms by T. speciosa underground parts essential oil was achieved with MICs ranging from 1.0 to 11.0 mg mL -1 , while MICs of aerial parts essential oil varied from 4.0 to 30.0 mg mL -1 . The obtained results contribute to the knowledge of antimicrobial properties of T. speciosa, which support traditional uses underground parts of the plant.

Bioprospecting of the Telekia speciosa: Uncovering the Composition and Biological Properties of Its Essential Oils

“…Previous analysis of Telekia speciosa flower EO, distilled from plants grown in Poland, revealed the presence of isoalantolactone (23.0%) and 10-isobutyryloxy-8,9-epoxythymol isobutyrate (20.5%) as dominant constituents [10]. These two compounds were present in much lower amounts in a recently studied T. speciosa EO [11], probably due to the fact that the EO was obtained from aerial parts, in which flowers represented only a minor part. In total, EOs from aerial and unground parts of T. speciosa from Bosnia and Herzegovina contained 67 compounds.…”

“…This article is a continuation of the research on "Polish" T. speciosa oils, which, despite being an invasive plant in Poland, have benefits for honey bees. The knowledge based on the composition and biological properties of EOs from Bosnia and Herzegovina was expanded in 2021 [11]. It is worth mentioning that regardless of the region of origin of the T. speciosa leaf EO, dominant volatiles are oxygenated derivatives of sesquiterpene, e.g., (E)-nerolidol (10%) and (E,E)-farnesol (6.7%).…”

“…Several studies linked the chemicals present in EOs to the biological properties of the oils. EOs from T. speciosa demonstrated antibacterial activities against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans strains [11]. Terpenoids based on thymol skeleton, as well as isoalantolactone, might be, at least in part, responsible for this activity [5,11,13,14].…”

“…In total, EOs from aerial and unground parts of T. speciosa from Bosnia and Herzegovina contained 67 compounds. The major volatiles identified in green parts were (E)-nerolidol (11.5%) and caryophyllene oxide (10.5%), while isoalantolactone predominated in roots (83.4%) [11]. EO from the aerial parts of T. speciosa collected in Serbia contained (E,Z)-farnesol (12.0%), (E)-nerolidol (10.2%), and β-caryophyllene (5.4%) as major constituents [5].…”

“…EOs from T. speciosa demonstrated antibacterial activities against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans strains [11]. Terpenoids based on thymol skeleton, as well as isoalantolactone, might be, at least in part, responsible for this activity [5,11,13,14]. Isoalantolactone, a compound found in EOs, has been connected to a number of biological activities, including anti-inflammatory and anti-cancer effects.…”