To obtain the subject new compound, having actions on the induction of apoptosis in cells, suppressing action on cell proliferation, inhibiting actions, etc., on the infiltration into basement membranes and useful as an antitumor agent and an inhibitor of the basement membrane infiltration.

This compound is a jolkinolide D represented by the formula and capable of providing an active ingredient of an apoptosis inducer, an antitumor agent, an inhibitor of the basement membrane infiltration. The jolkinolide D represented by the formula can be obtained by separation and purification from Euphorbia jolkini Boiss. which is a plant of the family Euphorbiaceae. The daily dose of the active ingredient is usually about 1 μg to 500 mg and is preferably administered in one to divided several portions. Thereby, the compound can be used as a therapeutic agent for, e.g. malignant tumor, autoimmune diseases and inflammations.