Extraction Condition Optimization, Quantitative Analysis, and Anti-AD Bioactivity Evaluation of Acorn Polyphenols from Quercus variabilis, Quercus aliena, and Quercus dentata

In the present study, <i>Quercus variabilis (Q. variabilis), Quercus aliena (Q. aliena),</i> and <i>Quercus dentata (Q. dentata)</i> acorn kernels were taken as the research objects, and the free polyphenols and bound polyphenols in acorn kernels were extracted using improved ultrasound-assisted ethanolic and alkaline extraction methods, after which the contents of gallic acid, quercetin, azelaic acid, ellagic acid, and ferulic acid were quantified by LC-MC/MS. The results demonstrated that <i>Q. variabilis</i> and <i>Q. aliena</i> acorns were suitable as raw materials to extract ellagic acid, the contents of ferulic acid and bound gallic acid in them were different, and <i>Q. aliena</i> acorns were more suitable for the research of gallic acid, but not for azelaic acid. Results on APP/PS1 transgenic mice verified that five polyphenols significantly suppressed the progression of AD. This study provides a theoretical basis for the drug development of acorn polyphenols.