Abundant Extractable Metabolites from Temperate Tree Barks: The Specific Antimicrobial Activity of Prunus Avium Extracts

Abstract

Tree barks are mainly considered as wood wastes from forestry activities, but represent valuable resources as they may contain antimicrobial compounds. Here, we aimed to evaluate the possible antimicrobial activities of bark extracts and to characterize the chemical composition of the most active extract. Ten methanol bark extracts were tested in vitro against 17 bacterial strains and 5 yeast strains, through minimum inhibitory concentration (MIC) and minimum bactericidal (or fungicidal) concentration (MBC/MFC) assays. The extract from Prunus avium (E2-4) displayed the largest bactericidal activity against Gram-positive bacteria, with a lethal effect on 6 out of 8 strains. Antibiofilm assays of E2-4 were performed by crystal violet staining and enumeration of adhered bacteria. Assays demonstrated a biofilm inhibitory effect of E2-4 against Staphylococcus aureus CIP 53.154 at concentrations equal to or higher than 250 µg/mL. Chemical profiling of E2-4 by 13 C nuclear magnetic resonance (NMR) revealed the presence of dihydrowogonin as a major constituent of the extract. E2-4 was fractionated by centrifugal partition chromatography and the three fractions containing dihydrowogonin were tested for their antibacterial and antibiofilm activities, revealing similar activities to those of E2-4. Dihydrowogonin was positively assessed as an interesting antimicrobial compound, which could be valued from wastes of Prunus avium barks.

In vitro antioxidant and antibacterial activities with polyphenolic profiling of wild cherry, the European larch and sweet chestnut tree bark

“…For example, the larch bark extracts were reported to give MIC values of 1.2 mg/mL and 1.75 mg/mL against S. aureus [48,49]. In contrast, it showed no antibacterial activity against Gram-negative strains [43,48]. Similar results for MIC have also been found for wild cherry bark, as in this study.…”

“…This trend has also been observed in previous studies. For example, the larch bark extracts were reported to give MIC values of 1.2 mg/mL and 1.75 mg/mL against S. aureus [48,49]. In contrast, it showed no antibacterial activity against Gram-negative strains [43,48].…”

“…Similar results for MIC have also been found for wild cherry bark, as in this study. According to Abedini et al (2020), the wild cherry bark extract was the most effective against Grampositive and Gram-negative bacterial strains at MIC values of 0.125 mg/mL and 0.250 mg/mL, respectively [48]. Arora and Mahajan (2018) investigated the antimicrobial activity of a wild Himalayan cherry bark extract against several bacterial strains and observed MIC values of 1.0 mg/mL against E. coli and 5.0 mg/mL against S. aureus [50].…”

Evaluation of biological activities of two essential oils as a safe environmental bioinsecticides: case of Eucalyptus globulus and Rosmarinus officinalis

“…The MIC values corresponded to the first well of each row where no visible microbial growth was detected. The MBC was determined from the first three wells of each row that showed no microbial growth after plate incubation (Man, Santacroce, Iacob, Mare & Man, 2019;Abedini et al, 2020). For that, 10 μL from the corresponding wells were seeded on Mac-Conkey agar plates.…”

Dereplication of Natural Extracts Diluted in Propylene Glycol, 1,3-Propanediol and Glycerin. Comparison of Leontopodium alpinum Cass. (Edelweiss) Extracts as a Case Study

“…This article presents an original and efficient workflow for the rapid identification of the main compounds in natural extracts diluted in propylene glycol and propanediol, which complements the recently published work with a glycerinated extract [7]. The original identification procedure, published in 2014 [8], has already been used to characterize hundreds of dry extracts [9][10][11][12][13] both for academic or industrial purposes. It starts with a fractionation step of the starting extract by centrifugal partition chromatography (CPC) followed by the 13 C nuclear magnetic resonance (NMR) analysis of each chemically simplified CPC fraction.…”