Further in vitro Evaluation of Antimicrobial Activity of the Marine Sesquiterpene Hydroquinone Avarol

Abstract

This work extends in vitro screening of antimicrobial activity of the sesquiterpene hydroquinone avarol, a main secondary metabolite of the Mediterranean sponge species Dysidea avara. The antimicrobial activity was in part evaluated by microdilution method against selected bacterial and fungal strains. Additionally, the screening included evaluation of anti-quorum sensing (anti-QS) effects. At a different extent avarol was proven to be active against all the microorganisms tested (MIC 0.002-0.008 mg/mL and MBC 0.004-0.016 mg/mL; MIC 0.004-0.015 mg/mL and MFC 0.008-0.030 mg/mL; respectively). This marine natural product also showed moderate anti-QS effects, reducing Pseudomonas aeruginosa PAO1 biofilm formation (75%), its twitching and protrusions motilities as well as pyocianin production (39%). According to the best of our knowledge, this is the first report both on avarol anti Gram-negative bacterial activity and anti-QS effects.

Design, synthesis, molecular docking, anti‐quorum sensing, and anti‐biofilm activity of pyochelin‐zingerone conjugate

“…These kinds of biofilm can show increased permeability and penetration of pyochelin-zingerone conjugate 4 through the extracellular polymeric substances. Active components from different sources such as Avarol, a marine sesquiterpene hydroquinone (Pejin et al, 2014), a phytol, acyclic monounsaturated diterpene from biosphere (Pejin et al, 2015) and phytochemicals from herbal extracts are known to inhibit P. aeruginosa biofilm formation (Vattem et al, 2007). In line with this, potent anti-biofilm inhibitory effect has been shown by ginger (Kim & Park, 2013), cranberry (Harjai et al, 2014), and garlic extract (Vadekeetil et al, 2014; Figure 6).…”

Comparative Analysis of Virulence Factors of Homozygous and Heterozygous Strains of Candida albicans Vaginal Isolates

“…On the other hand, topical imidazoles (i.e., econazole, clotrimazole, miconazole, and ketoconazole) are used and have noticeable effect [25]. Combination therapy of this conventional azole therapy and this supplementary agent may have a synergistic International Journal of Microbiology effect in treatment of vaginal candidiasis and could reduce symptoms [26]. Despite the statistical analysis results on exoenzyme activity, which showed no correlation between the two strains, we believe that in the case of increasing the number of samples, the statistical data could be statistically significant.…”

“…On the other hand, topical imidazoles (i.e., econazole, clotrimazole, miconazole, and ketoconazole) are used and have noticeable effect [ 25 ]. Combination therapy of this conventional azole therapy and this supplementary agent may have a synergistic effect in treatment of vaginal candidiasis and could reduce symptoms [ 26 ].…”

Synthesis, Antifungal Activity and 3D‐QSAR Study of Novel (E)‐Longifolene‐Derived Tetralone Oxime Ethers

“…However, there are some problems of toxicity [1] and drug resistance [2] for various commercial fungicides used currently. Therefore, the development of novel effective antimicrobial compounds [3][4] including antifungals is particularly important.…”