Determination of the Volatile Fraction of Polygonum bistorta L. at Different Growing Stages and Evaluation of Its Antimicrobial Activity against Two Major Honeybee (Apis mellifera) Pathogens

Abstract

The composition of the volatile fraction of Polygonum bistorta L. (also known as bistort or snakeroot) was investigated. Fresh aerial parts of this plant species were collected in the Western Italian Alps during the summer at three different phenological stages, namely vegetative, flowering, and fruiting, and steam-distilled in a Clevenger-type apparatus. The oils accounted for 0.004 to 0.010% of the fresh plant material, and their compositions were determined by GC/FID and GC/MS. The composition of the oils during the vegetative period varied both in quantity and quality; several classes of compounds were found with a predominance of alcohols in the vegetative phase, terpenes and linear-chained saturated hydrocarbons in the flowering phase, while saturated aliphatic acids and their methyl esters were predominant in fruiting phase. The most abundant compounds were 3-methylbut-3-en-1-ol in the vegetative phase, linalool in the flowering phase, and dodecanoic acid and its methyl ester in the fruiting phase. The obtained essential oils were then tested against two major bee pathogens, i.e., Paenibacillus larvae and Melissococcus plutonius, and against a reference bacterial species, Bacillus subtilis. Data were compared to those obtained with reference standards used against those pathogens such as the essential oils obtained from leaves and bark of Cinnamomum zeylanicum (cinnamon), and the antibiotic oxytetracyclin.

Synthesis and Biological Evaluation of Novel Gallic Acid Analogues as Potential Antimicrobial and Antioxidant Agents

“…Agar Well-diffusion Protocol [23] Autoclaved MHA plates were seeded onto the surface with 24 hour old broth culture of different bacteria. Samples were dissolved thoroughly in DMSO and different concentrations were prepared by serial dilution method.…”

Anti-Virulence Potential and In Vivo Toxicity of Persicaria maculosa and Bistorta officinalis Extracts

“…According to the extensive literature, different species of the Polygonoideae subfamily are used in traditional medicine for the treatment of various health problems, but data confirming their potential to fight bacterial infections are both scarce and incomplete [11]. Although the antibacterial activities of different PEM and BIO extracts were assessed in a few recent studies, the extracts were typically tested in disk or well diffusion assays, often in concentrations too high (up to 30 mg/mL) to be relevant [12][13][14][15]. Therefore, we re-evaluated the activity of PEM and BIO extracts against several important human pathogens in a more quantitative way and demonstrated that the BIO extract has moderate antibacterial activity against Staphylococcus aureus with the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of 156 µg/mL and 312 µg/mL, respectively, but weak bactericidal activity against Pseudomonas aeruginosa PAO1 with MIC of 1 mg/mL.…”

Chemical Composition, Antimicrobial Activity, and Mode of Action of Essential Oils against Paenibacillus larvae, Etiological Agent of American Foulbrood on Apis mellifera

“…Probably, because EOs affect different targets, no cases of bacterial resistance or adaptation have been detected in contrast to the use of antibiotics . Several EOs proved to be effective for controlling A. mellifera diseases such as AFB . EOs of the Argentinian native aromatic plants Acantholippia seriphioides , Artemisia absinthium , Artemisia annua , Aloysia polystachya , Heterothalamus alienus , Lepechinia floribunda , Satureja odora, and Wedelia glauca , presented antimicrobial activity against P .…”