Synthesis of Novel Stilbene–Coumarin Derivatives and Antifungal Screening of Monotes kerstingii-Specialized Metabolites Against Fusarium oxysporum

Abstract

Fusarium is one of the most toxigenic phytopathogens causing diseases and reduced agricultural productivity worldwide. Current chemical fungicides exhibit toxicity against non-target organisms, triggering negative environmental impact, and are a danger to consumers. In order to explore the chemical diversity of plants for potential antifungal applications, crude extract and fractions from Monotes kerstingii were screened for their activity against two multi-resistant Fusarium oxysporum strains: Fo32931 and Fo4287. Antifungal activity was evaluated by the determination of minimum inhibitory concentration (MIC) by broth dilution of fermentative yeasts using kinetic OD600 nm reading by a spectrophotometer. The n-butanol fraction showed the best activity against Fo4287. We screened eleven previously reported natural compounds isolated from different fractions, and a stilbene–coumarin 5-[(1E)-2-(4-hydroxyphenyl)ethenyl]-4,7-dimethoxy-3-methyl-2H-1-benzopyran-2-one (1) was the most active compound against both strains. Compound 1 was employed as a nucleophile with a selection of electrophilic derivatizing agents to synthesize five novel stilbene–coumarin analogues. These semisynthetic derivatives showed moderate activity against Fo32931 with only prenylated derivative exhibiting activity comparable to the natural stilbene–coumarin (1), demonstrating the key role of the phenolic group.

Synthesis of Altissimacoumarin D and Other Prenylated Coumarins and Their Ability to Reverse the Multidrug Resistance Phenotype in Candida albicans

“…Nonetheless, they are not the most studied group of compounds found in A. altissima and require further investigation [9]. Coumarins, and especially prenylated coumarins, have already been studied and have antibacterial [10,11], antifungal [12], antileishmanial [13], anticancer [14], anti-inflammatory and antiviral [15] activities.…”

Predictive Quantitative Structure–Activity Relationship Modeling of the Antifungal and Antibiotic Properties of Triazolothiadiazine Compounds

“…In addition, phenolic compounds, including components of essential oils, exhibit a variety of antimicrobial properties [ 11 , 12 ]. Furthermore, it has been demonstrated that the efficacy of antimicrobial compounds could be enhanced through synthetic modification [ 13 ]. To this end, we report a convenient method to develop QSAR models based on topological descriptors and density functional theory derived molecular orbital properties that is capable of predicting antifungal and antibiotic activity against Aspergillus species, Penicillium species, Gram-positive Staphylococcus aureus and Bacillus subtilis , and Gram-negative Escherichia coli and Pseudomonas aeruginosa [ 10 ].…”

Synthesis and antimicrobial activity of 3-(2-N-(aryl,acyl)amino-5-methyl-1,3-thiazol-4-yl)-2H-chromen-2-ones

“…Coumarin (2H-chromen-2-one) is the part of many compounds with antimicrobial and antifungal activity [1][2][3][4]. The recent studies show that 2H-chromen-2ones can reduce the bacterial biofilm formation for some strains of bacteria as the result making them less antibiotic resistant [5][6][7][8].…”