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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 IC 50 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.

A rotameric tryptamide alkaloid (1a-1b) was isolated from the methanolic extract of the roots of Vepris lecomteana together with the known compounds anhydroevoxine (2), lecomtequinoline C (3), evoxine (4), N-methylflindersine (5), evoxanthine (6), hesperidin, lupeol, β-sitosterol and stigmasterol. The previously not reported 7-(3-anilino-2-hydroxyprenyloxy)-8-methoxydictamine (2a) was obtained by opening the epoxide of anhydroevoxine (2). The structures of above compounds were determined by comprehensive spectroscopic analyses of 1D and 2D NMR, EI-/ESI-MS, X-ray crystallography and comparison with the reported data. At room temperature, 1 H and 13 C NMR spectra show two rotamers (1a and 1b) with integrated intensities of 2/3, whereas at around 60 °C, only the 1b conformer was observed. Furthermore, the crystal structure of 1 was determined by the direct method of single crystal X-ray diffraction. The suggested biosynthesis for the formation of the new rotameric tryptamide alkaloid 1 is presented. Some of the isolated compounds (1, 2 and 2a) were tested in vitro against bacteria, resulting in weak for (1 and 2) to moderate activity for (2a) against Micrococcus luteus and Escherichia coli with MIC values of 15.3 and 15.3 μg/mL, respectively., (Copyright © 2019. Published by Elsevier B.V.)