o-Vanillin, a promising antifungal agent, inhibits Aspergillus flavus by disrupting the integrity of cell walls and cell membranes

Paeonol Disrupts the Integrity of Aspergillus flavus Cell Walls via Releasing Surface Proteins, Inhibiting the Biosynthesis of β-1,3-Glucan and Promoting the Degradation of Chitin, and an Identification of Cell Surface Proteins

“…Plasmolysis can also be visualized in the paeonol treated mycelia. A similar mode of action was reported previously in o -vanillin treated mycelia, of which the chitin content was not changed remarkably [ 9 ].…”

“…The absorption band at 2360 cm −1 (3) was associated with stretching vibration of triple bond and cumulative double bond such as (-N=C=O, -N=C=O, etc.) [ 9 ]. The band at 1653 cm −1 (4) corresponds to the amide I band and amide II band, which are the characteristic infrared spectra of proteins [ 29 ].…”

“…TEM characterization was performed according to Li et al [ 9 ] with slight modifications. One hundred microliters of A. flavus spore suspension (5 × 10 5 /mL) were added into 20 mL SDB and cultured for 24 h. Then, paeonol dissolved in ethanol was added to the SDB to reach the final concentrations of 0 and MIC (0.625 mg/mL, previously tested in our lab [ 17 ]).…”

“…As a unique and dynamic structure, fungal cell wall has been extensively studied and considered as an attractive antimicrobial target [ 6 , 7 , 8 ]. Although there has been no report on the detailed components of A. flavus cell walls, in our previous study, they are assumed to be organized into two layers [ 9 ], similar to Aspergillus fumigatus ( A. fumigatus ). The outer amorphous layer contains N -glycosylated proteins and the fibrous inner layer contains mainly glucans and chitin [ 10 , 11 ].…”

“…Besides the commercial antifungal agents on the market, several plant-derived natural compounds have been reported to be capable of destroying cell walls to different extents, such as cinnamaldehyde [ 15 ], 2-hydroxy-4-methoxybenzaldehyde (HMB) [ 16 ], and o -vanillin [ 9 ]. In our previous study, we have screened a new natural antifungal compound-paeonol, which exerts a strong inhibitory effect against A. flavus via destroying cell surface and reducing the content of β-1,3-glucan and chitin [ 17 ].…”