Characterization of Proanthocyanidin-Rich Dentin Biomodifiers from Plants by Centrifugal Partition Chromatography

Proanthocyanidins (PAs) are one of the large groups of polyphenols, which represent condensed tannins and consist of oligomeric or polymeric flavan-3-ols. While various bioactivities such as anti-oxidant, anti-inflammatory, anti-microbial, and anti-allergic effects have been frequently reported, little is known about their potential as dentin biomodifiers. Cocoa seeds, grape seeds, and cinnamon barks yield PA-rich extracts which unfold this specific activity. This study evaluated these extracts and measured their capacity as natural cross linkers. Forming part of an interdisciplinary project directed toward the development of a clinical preparation with dentin enhancement properties, the polyphenol-rich plant extracts of cocoa seeds, grape seeds, and cinnamon barks were fractionated by centrifugal partition chromatography (CPC) according to the degree of polymerization. The fractions were monitored by thin layer chromatography (TLC), high-performance liquid chromatography (HPLC) with a diol column, and MALDI-TOF. The result showed that CPC fractionation is a suitable analytical tool to evaluate the relationship between dentin cross linking activity and the degree of polymerization of PAs.