Two new flavone glycosides from the leaves of Ochna afzelii Oliv. (Ochnaceae)

• Published in: Natural product research 2024, Vol.38 (3), p.447-457
• Main Authors: Kakabi, Morel Hervé D., Simo Mpetga, James D., Tamokou, Jean-De-Dieu, Matsuete, Germaine Takongmo, Nago, Romeo Désiré T., Bitchagno, Gabin Thierry M., Lenta, Bruno N., Sewald, Norbert, Tene, Mathieu, Ngouela, Augustin Silvère
• Format: Article
• Language: English
• Subjects: Antibacterial activity; antioxidant capacity; Antioxidants; Bacteria; C-galactopyranosylflavonoids; Flavone glycosides; Flavones; Glycosides; Gram-negative bacteria; Gram-positive bacteria; Mannitol; medicinal plant; Ochna; Ochna afzelii; Spectrometry
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2022.2126840

Two new glycosylflavones, 6′′-O-acetyl-8-C-β-D-galactopyranosylchrysoeriol (1) and 8-C-β-D-galactopyranosylchrysoeriol (2) were isolated from the methanol extract of the leaves of Ochna afzelii Oliv., along with four known compounds namely 8-C-β-D-galactopyranosylapigenin (3), ochnaflavone (4), sitosterol-3-O-β-D-glucopyranoside (5) and D-mannitol (6). Isolation was performed chromatographically and the structures of the purified compounds were elucidated by analyzing their spectroscopic and mass spectrometric data. The antibacterial activity of extract, fractions, and compounds 1 − 4 was evaluated using broth microdilution method against Gram-positive and Gram-negative bacteria while the antioxidant capacity was performed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) methods. The new flavones (1 and 2) displayed moderate antibacterial activities (MIC = 32 − 64 µg/mL) and weak antioxidant properties.