Isolation of Epigallocatechin Gallate from Plant Extracts with Metallic Pivot-Assisted Dummy Imprinting

ABSTRACT

Metallic pivot-assisted dummy imprinting was used to separate epigallocatechin gallate from natural plant extracts. 4-Vinylpyridine was the functional monomer, ethylene glycol dimetacetic acidrylate the cross-linking monomer, and gallic acid the template with a mixture of 1-butyl-3-methylimidazolium tetrafluoroborate, dimethyl-sulfoxide, and dimethylformamide. The introduction of a metallic ion as the pivot improved the affinity and recognition of the template in the preparation of the molecularly imprinted polymer monoliths. The type of metal ion, the amount of template, and the cross-linking degree affected the retention of the template on the resulting product. The imprinted gallic acid polymer provided selective retention for epigallocatechin gallate and was used to purify the analyte from green tea with a mean recovery of 91.9% and a purity of 95.2%. The results demonstrated that gallic acid may be used as a fragmental template to prepare molecularly imprinted polymers for purifying epigallocatechin gallate.

KEYWORDS:

• Dummy-imprinting
• epigallocatechin gallate
• gallic acid
• metallic pivot
• molecularly imprinted polymer
• solid-phase extraction