Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance
AbstractDisruption of fungal cell wall should be an effective intervention strategy. However, the cell wall-disrupting echinocandin drugs, such as caspofungin (CAS), cannot exterminate filamentous fungal pathogens during treatment. For potency improvement of cell wall-disrupting agents (CAS, octyl gallate (OG)), antifungal efficacy of thirty-three cinnamic acid derivatives was investigated against Saccharomyces cerevisiae slt2Δ, bck1Δ, mutants of the mitogen-activated protein kinase (MAPK), and MAPK kinase kinase, respectively, in cell wall integrity system, and glr1Δ, mutant of CAS-responsive glutathione reductase. Cell wall mutants were highly susceptible to four cinnamic acids (4-chloro-α-methyl-, 4-methoxy-, 4-methyl-, 3-methylcinnamic acids), where 4-chloro-α-methyl- and 4-methylcinnamic acids possessed the highest activity. Structure-activity relationship revealed that 4-methylcinnamic acid, the deoxygenated structure of 4-methoxycinnamic acid, overcame tolerance of glr1Δ to 4-methoxycinnamic acid, indicating the significance of para substitution of methyl moiety for effective fungal control. The potential of compounds as chemosensitizers (intervention catalysts) to cell wall disruptants (viz., 4-chloro-α-methyl- or 4-methylcinnamic acids + CAS or OG) was assessed according to Clinical Laboratory Standards Institute M38-A. Synergistic chemosensitization greatly lowers minimum inhibitory concentrations of the co-administered drug/agents. 4-Chloro-α-methylcinnamic acid further overcame fludioxonil tolerance of Aspergillus fumigatus antioxidant MAPK mutants (sakAΔ, mpkCΔ). Collectively, 4-chloro-α-methyl- and 4-methylcinnamic acids possess chemosensitizing capability to augment antifungal efficacy of conventional drug/agents, thus could be developed as target-based (i.e., cell wall disruption) intervention catalysts. View Full-Text
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Kim, J.H.; Chan, K.L.; Cheng, L.W. Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance. Molecules 2017, 22, 1783.
Kim JH, Chan KL, Cheng LW. Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance. Molecules. 2017; 22(10):1783.Chicago/Turabian Style
Kim, Jong H.; Chan, Kathleen L.; Cheng, Luisa W. 2017. "Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance." Molecules 22, no. 10: 1783.
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