The invention discloses a
deep eutectic solvent (DESs) for extracting procyanidine of gingko leaves, a preparation method of the
deep eutectic solvent and an extraction method. The
deep eutectic solvent is prepared from
choline chloride and
malonic acid in a
molar ratio of 1 to (1-2.5). The prepared deep eutectic
solvent is an environment-friendly
solvent, is safe and free of
pollution, can be repeatedly utilized and is easily biodegraded; furthermore, the preparation process is simple and low in cost, and the deep eutectic
solvent has the properties of low
steam pressure, incombustibility, excellent solubleness and electrical
conductivity and stable
electrochemical window and the like; and meanwhile, the prepared deep eutectic solvent is low in
viscosity and good in fluidity, and a
hydrogen bond is stable. According to the method for extracting the procyanidine of the gingko leaves by virtue of the deep eutectic solvent, the extraction time is shortened, the operation is safe, and noharm is caused to the environment and a
human body. The preparation method of the deep eutectic solvent is simple and convenient, wide in
raw material source, low in cost and high in biodegradability.