Antimicrobial activity of the diarylheptanoids from the black and green alder

Abstract

Antimicrobial activity of fourteen diarylheptanoids isolated from the bark of black and green alder against twelve bacterial species (five Gram-positive and seven Gram-negative) and eight fungal strains has been reported. The most sensitive bacterial species were Klebsiella pneumoniae and Pseudomonas aeruginosa (Gramnegative), and Streptosporangium longisporum and Bacillus subtilis (Gram-positive). Among fungal strains the most sensitive to the diarylheptanoids were Fusarium equiseti, F. tricinctum, Candida albicans, and Saccharomyces cerevisiae. Oregonin (8), platyphyllenone (13), hirsutenone (14), (5S)-5-hydroxy-1,7-bis(4-hydroxyphenyl)heptan-3-one-5-O-b-D-apiofuranosyl(1 ? 6)-b-D-glucopyranoside (2), and platyphylloside (1) were the most active diarylheptanoids against both bacteria and fungi, especially against fungi. Eleven of fourteen investigated diarylheptanoids exhibited stronger antifungal activity than standards nystatin and fluconazole against C. albicans and eight against S. cerevisiae. Structure/activity analysis revealed the importance of the enone moiety in the structure of diarylheptanoids for the antifungal activity. Significant antifungal activity and high content of oregonin (8) and hirsutenone (14) in the black alder bark chloroform/ methanol (1:1) extract recommend the use of these compounds as easily accessible potential antifungal remedies.

Composition, Antioxidant Potential, and Antimicrobial Activity of Helichrysum plicatum DC. Various Extracts

“…Ten µL of bacterial or yeast suspension or suspension of spores were added to each well to give a final concentration of 10 6 CFU/mL for bacteria and 10 5 CFU/mL for yeasts and fungi. In order to compare the activity of an extract with already existing, commercially available antimicrobial agents, broad-spectrum compounds commonly used in such assays served as positive controls [130]. Chloramphenicol served as the positive control for bacteria, while nystatin served as the positive control for yeasts and fungi.…”

Diarylheptanoids from Alnus viridis ssp. viridis and Alnus glutinosa: Modulation of Quorum Sensing Activity in Pseudomonas aeruginosa

“…They were the most common diarylheptanoids in these extracts. Poor to moderate antibacterial activity previously observed with these compounds [19] led us to examine their activity on bacterial communication within this study. Bacterial cell-to-cell signaling, so-called quorum sensing (QS), is involved in the regulation of virulence expression and biofilm development, traits that are crucial for pathogenicity and the interaction with colonization of eukaryotic hosts [20,21].…”

Bactericidal and cytotoxic activity of a diarylheptanoid (etlingerin) isolated from a ginger ( Etlingera pubescens ) endemic to Borneo

“…; Novaković et al . ). Some reported bioactivities of these compounds include antioxidant, anti‐inflammatory, antiviral and anticancer (Choi et al .…”

“…5 for its chemical structure) is classified as a diarylheptanoid, which is a small group of phytochemicals that consist of two aromatic rings joined by a heptane chain. Most of the diarylheptanoids compounds can be found in the Zingiber, Curcuma, Alpinia, Betula, Alnus and Etlingera genera (Chan et al 2013;Novakovi c et al 2015). Some reported bioactivities of these compounds include antioxidant, anti-inflammatory, antiviral and anticancer (Choi et al 2008;Tung et al 2010a,b;Lai et al 2012).…”