Flavonoids and saponins from two Bulgarian Astragalus species and their neuroprotective activity. (August 2018)

• Record Type: Journal Article
• Authors: Shkondrov, Aleksandar; Krasteva, Ilina; Bucar, Franz; Kunert, Olaf; Kondeva-Burdina, Magdalena; Ionkova, Iliana
• Is Part Of: Phytochemistry letters. Volume 26(2018)
• Page Start: 44
• Page End: 49
• Publication Date: 2018-08
• Subjects: hMAO B human recombinant monoamine oxidase type B enzyme -- HRESIMS high resolution electro spray ionization mass spectrometry -- NMR nuclear magnetic resonance spectroscopy -- MTT 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide -- DTNB 5, 5′-dithio-bis-(2-nitrobenzoic acid) -- GSH reduced glutathione; Astragalus glycyphylloides -- Astragalus spruneri -- Saponins -- Flavonoids -- Protective activity -- Synaptosomes; Botanical chemistry -- Periodicals; Chimie végétale -- Périodiques; 572.205
• DOI: 10.1016/j.phytol.2018.05.015
• Languages: English
• ISSNs: 1874-3900

Abstract

Graphical abstract: Highlights: Novel compounds were isolated and identified from A. glycyphylloides . Rare flavonoids from A. spruneri were reported. 1D and 2D NMR techniques, HRESIMS and chemical methods were used. Neuroprotective and antioxidant activity in in vitro models were proved. Abstract: Two novel compounds from A. glycyphylloides DC (1–2) and three rare flavonoids from A. spruneri Boiss. (3–5), alongside their neuroprotective activity and possible effects as human monoamine oxidase type B inhibitors were reported. The structural elucidation of the compounds was achieved by chemical, HRESIMS and NMR analyses. Their effects were investigated in vitro on isolated rat brain synaptosomes in 6-hydroxydopamine-induced toxicity. In addition, their effect on human monoamine oxidase type B was explored, using Selegiline as a reference. 3- O -β-d -glucopyranosyl-28- O -[β-d -xylopyranosyl-(1 → 2)-β-d -glucopyranosyl] oleanolic acid (1 ) and kaempferol-3- O -β-d -glucopyranosyl-(1 → 4)- O -α-l -rhamnopyranosyl-(1 → 6)- O -[β-d -glucopyranosyl-(1 → 2)]-β-d -galactopyranoside (2 ) were isolated for the first time, alongside three known flavonoids, baimaside (3 ), isobioquercetin (4 ) and quercetin-3- O -α-l -rhamnopyranosyl-(1 → 2)-[6- O -(3-hydroxy-3-methylglutaryl)-β-d -galactopyranoside (5 ). On 6-hydroxydopamine in vitro model in synaptosomes, compounds 1-3 had neuroprotective activity similar to that of Silybin A + B. All compounds exhibited weak activity on the monoamine oxidase type B enzyme.