The defatted marigold residue (1 g) was extracted respectively
with 30 mL of water, EtOH/water (3:7, 5:5, 7:3, v/v)
mixture or pure EtOH in the shaker incubator at 30 °C for
24 h. The solid–liquid mixture was filtered with microporous
membrane by vacuum filter, and each filtered extract was
diluted to a volume of 50 mL with the same extraction solvent,
and then stored in an amber-colored air-tight container
at −20 °C until the analysis.