High-throughput screening for amyloid- binding natural small-molecules based on the combinational use of biolayer interferometry and UHPLC-DAD-Q/TOF-MS/MS.

Discovery of drugs rapidly and effectively is an important aspect for Alzheimer's disease (AD). In this study, a novel high-throughput screening (HTS) method aims at screening the small-molecules with amyloid- (A) binding affinity from natural medicines, based on the combinational use of biolayer interferometry (BLI) and ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time-of-flight tandem mass spectrometry (UHPLC-DAD-Q/TOF-MS/MS) has been firstly developed. Briefly, the components in natural medicines disassociated from biotinylated A were collected to analyze their potential A binding affinity by UHPLC-DAD-Q/TOF-MS/MS. Here, baicalein was confirmed to exhibit the highest binding affinity with A in . Moreover, polyporenic acid C (PPAC), dehydrotumulosic acid (DTA), and tumulosic acid (TA) in Kai-Xin-San (KXS) were also identified as potent A inhibitors. Further bioactivity validations indicated that these compounds could inhibit A fibrillation, improve the viability in A-induced PC-12 cells, and decrease the A content and improve the behavioral ability in . The molecular docking results confirmed that PPAC, DTA, and TA possessed good binding properties with A. Collectively, the present study has provided a novel and effective HTS method for the identification of natural inhibitors on A fibrillation, which may accelerate the process on anti-AD drugs discovery and development.