Thirteen compounds (<b>1</b>‒<b>13</b>) were isolated and identified during phytochemical analysis of the leaves and stem bark of <i>Guibourtia ehie</i> (A. Chev) J. Leonard. Spectroscopic and spectrometric methods and the comparison of their results with those given in the literature were used to ascertain their structures. Furthermore, the acetylation of 3,3′-di-<i>O</i>-methylellagic acid 4′-<i>O</i>-β-D-xylopyranoside (<b>2</b>) afforded a new derivative 3,3′-di-<i>O</i>-methylellagic acid 4′-<i>O</i>-β-D-(4,2′′,4′′-triacetyl)-xylopyranoside (<b>2a</b>). Extracts, fractions, and isolated compounds were assessed for their antioxidant, urease, and α-glucosidase inhibitory activities. Compound <b>1</b> demonstrated potent antioxidant activity in the DPPH with an IC₅₀ value of 36.4 ± 0.2 µM, while rhaponticin (<b>3</b>), 2,6-dimethoxybenzoquinone (<b>4</b>), and taraxerol (<b>6</b>) exhibited a strong α-glucosidase inhibitory activity with the IC₅₀ values of 35.5 ± 0.1, 25.5 ± 0.2 and 43.4 ± 0.3 µM, respectively. The present study enriches the chemistry of <i>Guiboutia ehie</i> and provides further evidence on its bioactive constituents, which might help in the development of hypoglycaemic drugs.

The stem bark of Citrus × paradisi Macfad. (Rutaceae) gave (23S)‐isolimonexic acid (1), limonin (2), citracridone II (3), citpressine II (4), citpressine I (5), grandisine (6), 2‐hydroxynoracronycine (7), citracridone I (8), 5‐methoxyseselin (9), umbelliferone (10), scopoletin (11), naringenin (12), apigenin (13), friedelin (14), agrostophyllinone (15) and stigmasterol‐3‐O‐β‐D‐glucopyranoside (16). The structures of the compounds were determined using NMR and MS spectroscopic data, and by comparison with published data. The relative configuration of 1 was proposed as (23S)‐isolimonexic acid using NOE studies. Hydrogenation reaction of compound 3 led to the new derivative 3’,4’‐dihydrocitracridone II (3a). Cytotoxicity activities against the human adenocarcinoma alveolar basal epithelial cell lines A549 and the Caucasian prostate adenocarcinoma cell lines PC3, using the MTT assays showed that the methanol crude extract was significant with IC50 values of 30.1 and 31.7 μg/mL, respectively, with the positive control, doxorubicin giving an IC50 of 0.9 μM. In addition, compounds 3, 7 and 8 gave moderate cytotoxic activities with IC50 values of 33.1, 31.2 and 32.5 μM for A549 cells and 35.7, 33.8 and 34.9 μM for PC3 cells, respectively. The hydrogenated 3a was less active than 3, suggesting that the presence of the double bond in pyrans is important for structure‐activity relationship.