Sepn. of polyphenols from vegetable extracts - by conversion to their betainates and fractional precipitation

摘要

Polyphenols such as monomers and oligomers of catechins, leucocyanadins, or their derivatives are sepd. from polyphenol-rich vegetable extracts by treatment with betaine base in an alcoholic medium and fractional pptn. of the polyphenol betainates. Cpds. are anti-oxidants for foods, they improve permeability of capillary vessels, are anti-inflammatories, and leucoanthocyanidols and their oligomers and polymers are useful in preventing tumours. Process is simpler and cheaper to carry out than known methods of separation. Typically a stoichiometric amount of betaine is added, and the polyphenols are precipitated by addition of a 3-5C aliphatic alcohol. In an example maritime pine bark extract (30g) was treated with 15g betaine base and polyphenols pptd. by gradual addition of isopropanol, n-butanol, and ethyl acetate.