PURPOSE: To obtain the titled mixture useful various kinds of drugs, having anticomplementary actions, industrially advantageously, by extracting fatty soybeans with a lower alcohol solution with a low concentration, diluting the extracted solution with water to a specific concentration, acidifying it.

CONSTITUTION: Fatty soybeans are extracted with 50W80wt% lower alcohol solution (e.g., preferably aqueous solution of 1W4C alcohol). The prepared extracted solution is diluted with water to prepare ≤40wt% alcohol solution, and acidified with an acid such as hydrochloric acid, sulfuric acid, etc. (preferably ≤5pH), to give the desired mixture shown by the formula I (R is formula II W formula IV).