Although Undaria pinnatifida sporophyll is rich in beneficial components such as polysaccharides, proteins, and phytochemicals, its inaccessible structure limits its usability. To overcome this limitation, we ultrasonically extracted U. pinnatifida sporophyll extract (UPE) under optimized conditions (20 kHz, 1,080 W, 30°C) for 8 h and used gradient ethanol precipitation to isolate the UPE fractions (UEF). The yield, compositio...