Anti-Alzheimer Activity and UHPLC-MS Based Molecular Networking of Pseudobombax ellipticum Cultivars Coupled to Multivariate Data Analysis and In Silico Molecular Docking.

Abstract

Pseudobombax ellipticum (Kunth) Dugand and the cultivar alba Hort. are members of family Bombacaceae.Their chemical composition is still under investigation. The current study aimed to investigate their chemical compositions, exploring the variations between organs and or cultivars and in vitro screening of the anti-Alzheimer activity of their ethanolic extracts against butyryl and acetyl cholinesterases enzymes. Primary phytochemical screening revealed the presence of secondary metabolites of mainly flavonoids, tannins, and terpenoids classes. Total phenolics and flavonoids were quantified in both cultivars; leaves, bark, and flowers as mg gallic acid equivalent /gm extract and mg rutin equivalent/gm extract, respectively. Metabolic profiling of leaves, bark and flowers of both cultivars via UHPLC-HRMS in negative and positive modes resulted in the identification of 89 compounds of different classes, including simple phenols, flavonoids, fatty amides and alcohols, triterpenes, fatty acids, esters, and triacylglycerols. All of the identified compounds are reported for the first time in Pseudobombax ellipticum. Feature-based Molecular Networking (FBMN) demonstrated the different phytochemical classes and highlighted the major compounds in each class. Principal component analysis (PCA), hierarchical clustering analysis (HCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) explored the variance between organs and or cultivars and detected the abundant and unique compounds in each organ. Acetyl and butyryl cholinesterases inhibitory activities of both cultivars; leaves, bark, and flowers were screened at 10 and 100 µg/mL using donepezil as a positive control. All extracts showed more than 50% acetyl cholinesterase inhibitory activity at 100µg/mL and did not inhibit butyryl cholinesterase up to 100µg/mL. Furthermore, selected identified compounds were subjected to a molecular docking study that showed the highly binding affinity of most of the examined compounds towards the acetyl cholinesterase target. These results revealed the chemical richness of Pseudobombax ellipticum cultivars and their probability of managing several health problems.