Process for removing pesticides from ginkgo biloba extracts, and extracts obtainable by said process

Abstract

Process for removing pesticides from Ginkgo biloba extracts, which involves submitting an extract obtained by conventional methods to the following steps:a. Liquid-liquid extraction of the extract to obtain a medium polarity fraction containing ginkgo terpenes and pesticides not removable with hexane, and a high polarity fraction containing ginkgo flavone glycosides;b. crystallisation from the medium polarity fraction obtained at step a) to give an intermediate with a ginkgolide content of not less than 50%;c. crystallisation from the residual solution obtained at step b) to give an intermediate with a bilobalide content of not less than 50%;d. mixing of the high polarity fraction obtained at step a) with the ginkgo terpene intermediate and the bilobalide intermediate obtained at steps b) and c).

Description

[0001]This U.S. non-provisional application is a continuation of U.S. application Ser. No. 13 / 258,715 filed on Nov. 18, 2011, which is a national stage of PCT / EP2010 / 002046 filed on Mar. 31, 2010 which claims priority to and the benefit of Italian Application No. MI2009A000548 filed on Apr. 6, 2009, the content of which are all incorporated herein by reference in their entireties.[0002]The present invention relates to a process for removing pesticides from Ginkgo biloba extracts, and the extracts obtainable by said process.PRIOR ART[0003]Ginkgo biloba leaf extracts have long been used in Chinese traditional medicine and in numerous Western countries due to the multiple pharmacological properties attributed to the components of said extracts (vasodilating, immuno stimulating, antioxidant and antiaggregant properties).[0004]Processes for the preparation of Ginkgo biloba leaf extracts are disclosed in U.S. Pat. No. 5,700,468, EP 360 556, EP 431 535 and JP 09110713. Pesticides such as o...

AI Technical Summary

Benefits of technology

The patent describes a process for extracting ginkgo terpenes from the leaves of the ginkgo tree. The process involves first creating a terpene-rich fraction, followed by a step to crystallize the terpenes using water and alcohol mixtures. This process eliminates certain pesticides that were not removed by the ginkgols. The technical effect of this process is the extraction of high-quality ginkgo terpenes with minimal contamination.

Problems solved by technology

Although many health and agricultural authorities have banned or restricted the use of such pesticides, it is not always easy to establish the origin of plant material, and even in countries where the use of pesticides is regulated, it is impossible to rule out unlawful or improper use of substances with pesticidal action, whose presence in the pharmaceutical or nutritional grade extract is wholly undesirable.

A particularly insidious problem is possible cross-contamination from pesticides originating from nearby crops.

In this case, however, the undesirable components are naturally present in the plant.

The process described is highly complex, comprising eleven steps, long preparation times and the use of expensive reagents such as polyamides, or toxic reagents such as lead salts.