The chemistry and biological activities of Citrus clementina Hort. Ex Tanaka (Rutaceae), a vegetatively propagated species

Abstract

We report the chemistry and biological activities of a Cameroonian Citrus clementina Hort. Ex Tanaka, a vegetatively propagated species. The compounds isolated from this plant were determined to be the known 5-hydroxy-6,7,8,3’,4’-pentamethoxyflavone (1), tangerine (3), nobilletin (4), 5,7,8,4’-tetramethoxyflavone (5), citracridone I (6), 5-hydroxynoracronycine (7), citracridone III (8), xanthyletin (10), suberosin (9), E-suberenol (11), E-methoxysuberenol (13), 6-formylumbelliferone (12), aurantiamide acetate (2), limonin (14), stigmasterol, β-sitosterol and β-sitosterol-3-O-β-D-glucoside. The structures of the compounds were established on the basis of their NMR spectroscopic data and comparison with published data. Methanol leaf extract and compounds 1, 2, 4, 6, 7 and 10 were evaluated for their anti-inflammatory, antioxidant, urease and anti-diabetic effects. Compound 10 showed antioxidant activity, anti-inflammatory effect, urease activity and anti-diabetic activity with IC₅₀ values of 47.3 µM, 33.5 µM, 25.2 µM and 33.9 µM respectively, values that were comparable to the respective positive standards.

Graphical Abstract

Keywords:

• Citrus clementina
• acridone
• anti-inflammatory
• antioxidant activity
• anti-diabetic activity
• urease inhibition
• xanthyletin

Acknowledgements

The authors thank Dr Martin Cheek of the Royal Botanic Gardens Kew for the discussion on the taxonomy of the plant.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors thank the TWAS-ICCBS 2016 program Fellowship for the opportunity to carry out above research. Samuel Magloire Bissim is grateful for his stay at the ICCBS Centre in 2017.