Antifungal Polyacetylenic Deoxyglycosides Isolated from Endophytic Fungus sp. VDL4 Associated with .

One novel C polyacetylene rhamnoside, 4,6,8-decatriyne-1--α-L-rhamnopyranoside, named xylariside A (), together with two novel C polyacetylene quinovopyranosides, 4,6,8-decatriyne-1--α-D-quinovopyranoside, xylariside B (), and 8-decaene-4,6-diyne-1--α-D-quinovopyranoside, xylariside C (), were obtained from the solid fermentation of sp. VDL4, an endophytic fungus isolated from wight (Ericaceae). Their chemical structures were elucidated through a combination of spectroscopic techniques. The antifungal activities of these compounds were evaluated in vitro against four phytopathogenic fungi (, , , and ). Compound demonstrated significant antifungal activities, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 7.81 μg/mL. Compound 's effectiveness levels were similar to those of the reference drugs thiabendazole and carbendazim (each MIC = 0.98-15.62 μg/mL). Xylariside B () was further evaluated against in vivo. It exhibited remarkable efficacy in both the prevention and treatment of tomato and strawberry gray mold. Molecular docking studies confirmed the antifungal mechanism of compound by revealing its binding interactions with key enzyme targets in , thereby supporting the observed in vitro and in vivo results. Additionally, compound showed effective inhibition of α-glucosidase, with IC values of 5.27 ± 0.0125 μg/mL.