New prenylated flavonoid and neuroprotective compounds from Tephrosia purpurea subsp. dunensis

Abstract

Continuation of the phytochemical investigation of the aerial parts of Tephrosia purpurea subsp. dunensis resulted in the isolation and structural elucidation of a new prenylated flavonoid demeapollinin (1), glabratephrinol (2) and a mixture (3) of tephroapollin G (3a) and epi-tephroapollin G (3b). The neuroprotective activity of compounds (1–3) besides the previously isolated compounds; dunensin (4), pseudosemiglabrin (6), glabratephrin (7), apollinin (5), kampferol 3, 7-O-α-L-dirhamnoside (8) and quercetin 3, 7-O-α-L-dirhamnoside (9) was examined. Molecular docking, acetylcholine esterase inhibitory assay and protection against both H₂O₂ and induced neurotoxicity were used to evaluate their neuroprotective effect. Compound 2 showed the highest acetylcholine esterase inhibitory activity (IC₅₀ 4.31 ± 0.75 µM) compared to galantamine (IC₅₀ 1.64 ± 0.32 µM), compounds 4 and 3 exhibited potent protective effect against induced neurotoxicity (IC₅₀ 7.70 ± 5.23 and 10.91 ± 6.27 µM, respectively) compared to standard epigallocatechin gallate (IC₅₀ 18.36 ± 6.22 µM).

Graphical Abstract

Keywords:

• Tephrosia purpurea
• prenylated flavonoids
• neuroprotective
• molecular docking

Supplementary material

Supplementary material relating to this article is available online including figures (S1–S24), tables (S1–S5) and experimental part Data S1.

Disclosure statement

No potential conflict of interest was reported by the authors.