Fast isolation method for the natural scaffold ursolic acid from <i>Diospyros melanoxylon </i>

摘要

The present invention relates to a process for the fast isolation of ursolic acid, a highly potent natural scaffold, from the leaves of Diospyros melanoxylon. The present invention also provides an improved and fast isolation process of the title compound, which is a pentacyclic triterpenic acid highly useful for the synthesis of a wide range of novel and potent bio-active molecules.

主权项

1. A process for fast isolation of ursolic acid from Diospyros melanoxylon, comprising:
(i) soxhlet extraction of powdered coppiced leaves of Diospyros melanoxylon with a polar organic solvent for a period in a range of 12 to 36 hrs at a temperature in a range of 64-78° C. so as to obtain a reaction mixture; (ii) concentrating the reaction mixture as obtained in step (i) under reduced pressure to obtain a crude extract; (iii) absorbing the crude extract as obtained in step (ii) on a silica gel followed by a flash chromatographic separation of the crude extract using a CombiFlash chromatographic system to obtain a crude ursolic acid; (iv) decolorising the crude ursolic acid as obtained in step (iii) with charcoal in acetone solution followed by recrystallisation from an organic solvent to obtain a pure colorless ursolic acid.