Abstract: The disclosure discloses a fatty acid synthase inhibitor and application thereof and belongs to the technical field of medical biology. The fatty acid synthase inhibitor of the disclosure can significantly inhibit the activity of fatty acid synthase without affecting normal expression, and adjust the ratio of fatty acids in cells. The fatty acid synthase inhibitor of the disclosure has a good tumor proliferation inhibitory effect, can arrest the growth cycle of tumor cells in the interphase, prevent tumor cell division, inhibit tumor cell proliferation, promote tumor cell apoptosis and exert a tumor treatment effect, can be used to treat tumors and metabolism related diseases, and has an important clinical application prospect.

Abstract: The present disclosure provides a preparation method of tofacitinib citrate, which comprises the following steps: passing an intermediate TOF-2 into hydrogen at a normal pressure in the presence of a catalyst to obtain an intermediate TOF-3; in the presence of a solvent and a base, under a reduced pressure of ?490 mmHg to ?760 mmHg, and at a temperature of 10° C. to 25° C., reacting TOF-3 with ethyl cyanoacetate to generate an intermediate TOF-4; heating and dissolving TOF-4 and citric acid in a solvent, and performing separation by cooling to obtain tofacitinib citrate. The present disclosure obtains tofacitinib citrate with high yield, high purity and low impurities by changing a gas flow rate and a reaction temperature and pressure of a hydrogenation reaction. Therefore, the preparation method is suitable for industrial production.