This study investigates the functional and biological activities of a polysaccharide-polyphenolic complex derived from the edible mushroom Agrocybe aegerita. Polyphenols were extracted using a modified solvent evaporation technique, and polysaccharides (AMP) were extracted using enzyme-assisted methods, yielding 8.02 %. The presence of fructose, mannose, glucose, galactose, sucrose, and maltose in varying amounts was confirmed. Different mushroom extracts concentrations (0.025-1.00 %) were tested for interaction with AMP. Samples with 0.2 % and 0.5 % extracts showed significantly higher binding efficiency with polysaccharides. AMP exhibited a particle size of 319 nm, while mushroom polysaccharide-polyphenolic compound complex (AMPP) revealed 136 nm with an irregular shape and smooth surface. Both AMP and AMPP showed three stages of decomposition, with distinct weight loss. Anti-quorum sensing tests against P. aeruginosa PAO1 showed that AMPP significantly decreased pyocyanin, pyoverdine, and swarming activity and exhibited higher biofilm inhibition. These findings suggest that the AMPP has substantial potential for developing sustainable health products, owing to its enhanced bioactivity.