The chemical composition and antifungal activity of cork from Quercus variabilis

In this study we separated the chemical components of cork from Quercus variabilis by various solvent extraction and alcoholysis methods. We identified the content and chemical composition of suberin and dichloromethane extract with gas chromatography-mass spectrometry (GC-MS) and analyzed the antifungal effects of different cork extracts against wood-decaying fungi. The results showed that the main structural component of cork, suberin, averaging 36.34% of the total dry weight, exhibited a pronounced inhibitory effect on wood-decaying fungi, compared to the dichloromethane extract. By the end of the entire culture period, the colony diameter of white rot fungi was 5 mm in the 40 mg/mL suberin treatment group, 19 mm for brown rot fungi, both significantly smaller than the control group (90 mm). Hydroxy fatty acids, free fatty acids, and α,ω-diacids may be the key components contributing to the antifungal activity of suberin. The inhibitory mechanism of suberin components on wood-decaying fungi may involve suppressing the respiratory metabolism of the fungi and increasing the permeability of their cell membranes, thereby limiting their normal life activities.