The flavonoid compounds concentration in the methanolic extracts from the mushrooms was evaluated by the colorimetric assay previously described (Balbaa, Zaki, & Elshamy, 1974) with some modifications. Catechin was employed to calculate the standard curve of the described method (0.03–1.00 mM; r2 > 0.999). Estimation of the flavonoids was six times repeated (n = 6). The results were expressed as mg of catechin equivalents per gram of dried mushroom.