A β-Secretase (BACE1)-inhibiting C-Methylrotenoid Induced by Yeast Elicitation in Abronia nana Suspension Cultures

Suspension cultures of Abronia nana were established to produce C-methylisoflavones. Treatment of the A. nana cultures with yeast elicitor induced boeravinone E (1), with maximum induction at 24 h after elicitor treatment. Of the biotic and abiotic elicitors tested, yeast extract gave the strongest induction of 1. The IC50 value of 1 against beta-secretase (beta-amyloid cleaving enzyme-1) was 5.57 mu M. Other proteases such as trypsin, chymotrypsin, and elastase were not inhibited by concentrations up to 1.0 mM, indicating that inhibition of beta-secretase was specific. 1 was noncompetitive in Dixon plot, and Ki value was 3.79 mu M.