New Monoterpenoid Indole Alkaloids from Tabernaemontana crassa Inhibit β-Amyloid42 Production and Phospho-Tau (Thr217).

ABSTRACT: Eleven monoterpenoid indole alkaloids, including three new ones, tabercrassines A-C (1-3), were isolated from the seeds of Tabernaemontana crassa. Tabercrassine A (1) is an ibogan-ibogan-type bisindole alkaloid which is formed by the polymerization of two classic ibogan-type monomers through a C3 unit aliphatic chain. Their structures were established by extensive analysis of HRESIMS, NMR, and ECD spectra. Cellular assays showed that alkaloids 1-3 all reduce Aβ42 production and inhibit phospho-tau (Thr217), a new biomarker of Alzheimer's disease [AD] associated with BACE1-, NCSTN-, GSK3β-, and CDK5-mediated pathways, suggesting these alkaloids' potential against AD.

SUBMITTER: Li S 

PROVIDER: S-EPMC9862887 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature