Process for isolation, purification, and recrystallization of lutein from saponified marigold oleoresin and uses thereof

Abstract

A method of isolating, purifying and recrystallizing substantially pure lutein, preferably from saponified marigold oleoresin in its pure free form, apart from chemical impurities and other carotenoids. Lutein may be used as an analytical standard or in cancer prevention trials and as a safe and effective color additive for human food.

Description

[0001]NOTICE More than one reissue application has been filed for the reissue of U.S. Pat. No. 5,382,714. The reissue applications are the present reissue application and reissue patent application Ser. No. 11 / 150,599, both of which are reissues of U.S. Pat. No. 5,382,714.BACKGROUND OF THE INVENTION[0002]Lutein is a naturally occurring carotenoid that has no vitamin A activity. There are three asymmetric centers in lutein at C-3, C-3′, and C-6′ positions. The absolute configuration of lutein in foods (fruits and vegetables) and human serum / plasma is known to be 3R,3′R,6′R. This configurational isomer of lutein which is the most abundant form of lutein is also known as lutein A. However in human serum / plasma a small amount of another configurational isomer of lutein, namely (3R,3′S,6′R)-lutein also known as 3′-epilutein or lutein B has been shown to be present. The chemical structures of lutein and 3′-epilutein are shown below. Other known configurational isomers of lutein have only ...

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Problems solved by technology

The non-allylic hydroxyl group at the C-3 position of the β-end group can also activate the C-4 carbon allylic to the double bond making this carbon highly susceptible to direct oxidation.

To date, pure lutein suitable for human use has not been commercially available for use as a chemopreventive agent in clinical trials.

However, the isolation and purification of free form, pure lutein in large quantities from green vegetables is not economical.

Many expensive and time-consuming purification steps are required to remove and purify lutein from the large quantities of chlorophylls, β-carotene, and carotenoids epoxides that are also present in green vegetables.

However, these yellow / orange fruits and vegetables also contain high concentrations of a number of other carotenoids which make the isolation and purification of lutein costly and time-consuming.

However, the resulting lutein is still contaminated with a number of chemical impurities.

To date, no method has been described to isolate and purify the free form of lutein from these chemical impurities.

However, the extract is not acceptable as a direct color additive for human foods because of the presence of impurities.

While chemical processes for synthesis of lutein from commercially available starting materials are known, such processes are extremely time-consuming, involve multiple steps, and to date have simply not provided an economical process for production of lutein.

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