Patent ID: 8362238

Claim:
A process of purifying tacrolimus, comprising: (a) collecting mycelia cake in conducting diatomite coating filtration of a tacrolimus-containing oily compound; (b) extracting the collected mycelia cake with a first organic solvent to obtain a mycelia cake extract, (c) concentrating the mycelia cake extract under reduced pressure to obtain a concentrate; (d) diluting the concentrate in a second organic solvent to obtain a dilute solution; (e) a chromatography step comprising removing at least one of a coloring matter and lipid by passing the dilute solution through an active aluminum oxide column or a silica gel column to obtain an eluate, wherein the dilute solution has not undergone any prior chromatography step; (f) concentrating the eluate under reduced pressure to obtain a concentrated eluate; (g) crystallizing the concentrated eluate to obtain a crude tacrolimus.