Acridone alkaloids from Vepris verdoorniana (Excell & Mendonca) Mziray (Rutaceae)

Atangana AF, Toze FAA, Langat MK, et al. Acridone alkaloids from Vepris verdoorniana (Excell & Mendonca) Mziray (Rutaceae). Phytochemistry Letters. 2017;19:191-195.Two new acridone alkaloids, verdoocridone A (1) and B (4), together with fifteen known compounds were isolated from methanol extracts of the roots and leaves of Vepris verdoorniana. The structures of all compounds were determined by comprehensive spectroscopic analyses (1D and 2D NMR, EI-and ESIMS). The C-13 NMR values of 1,2,3,5-tetramethoxy-N-methylacridone (2) and 5-methoxyaborinine (3) are also reported. The crude extracts and compounds (1-6) were tested for their antimicrobial activity. The test delivered moderate activities for crude extracts and compounds 1, 5 and 6 against the bacterium Staphylococcus aureus and the fungi Mucor meihei and Candida albicans with MIC values between 115 and 180 mu g/mL for extracts and between 21.3 and 29.4 mu M for compounds, compared to gentamycin with 0.2 mu M and nystatin with 5.2 mu M against both fungi. The determination of the radical scanvenging activity using 1,1-dephenyl-2-picrylhydrazyl (DPPH) assay gave moderate antioxidant values for all tested compounds, with IC50 between 0.29 and 0.41 mu M, compared to the standard 3-t-butyl-4hydroxyanisole (BHA) displaying 0.03 mu M. (C) 2017 Phytochemical Society of Europe. Published by Elsevier Ltd. All rights reserved

Chemical Composition and Synergistic Antimicrobial Effects of a Vegetatively Propagated Cameroonian Lemon, Citrus x limon (L.) Osbeck

Nsangou MF, Happi EN, Fannang SV, et al. Chemical Composition and Synergistic Antimicrobial Effects of a Vegetatively Propagated Cameroonian Lemon, Citrus x limon (L.) Osbeck. ACS Food Science & Technology. 2021.This study analyzed the antimicrobial effects of compounds present in the roots and leaves of Citrus x limon (L.) Osbeck to help understand how this plant (1) ecologically modulates microbial defense in the rhizosphere and (2) protects against food-borne bacterial pathogens. Antimicrobial effects of C. limon collected from a farm in Foumban in Cameroon are reported against Salmonella typhi, Salmonella typhimurium, Salmonella enteritidis, Escherichia coli, Shigella flexineri, and Saccharomyces cerevisiae. The study modeled synergistic antifungal effects of an essential oil from the roots of C. limon or E-caryophyllene when combined with the isolated compounds against S. cerevisiae. Twenty-four compounds were identified from the methanol extracts of the roots and leaves: 10 prenylated coumarins (1–10), six methoxylated flavones (11–16), two limonoids (18 and 19), a phenylalanine derivative (20), lupeol, stigmasterol, sitosterol, and sitosterol-3-O-β-d-glucoside. Major compound 16, atalantoflavone, was esterified using lauric acid to yield the undescribed 5,4′-dilaureate atalantoflavone (16a). The essential oil from the roots contained methyl esters of hexadecanoic acid (39%) and 9-octadecenoic acid (9.3%) and sesquiterpenes β-bisabolene (10.1%) and α-santalene (8.0%). The antimicrobial effects of the root extract, leaf extract, compounds 1, 2, 4, 7–9, 11, 12, 14, 16, 16a, and 18 were evaluated against S. typhi, S. typhimurium, S. enteritidis, E. coli, S. flexineri, and S. cerevisiae. Compounds 11, 16, and 18 from the root extract of C. x limon showed significant antimicrobial effects with a minimum inhibitory concentration (MIC) of 62.5 μg/mL against S. flexineri, whereas compounds 5, 7, 11, and 18 showed significant antimicrobial effects with a MIC of 62.5 μg/mL against S. typhi. The essential oil from the roots synergized compounds 11–14 against S. cerevisiae. A synergistic MIC of 7.8 μg/mL was registered by combining 12 and E-caryophyllene

Soyauxinine, a New Indolopyridoquinazoline Alkaloid from the Stem Bark of Araliopsis soyauxii Engl. (Rutaceae)

Noulala CGT, Ouete JLN, Atangana AF, et al. Soyauxinine, a New Indolopyridoquinazoline Alkaloid from the Stem Bark of Araliopsis soyauxii Engl. (Rutaceae). Molecules. 2022;27(3): 1104.The chemical investigation of the total alkaloid extract (TAE) of the stem bark of Araliopsis soyauxii (Rutaceae) afforded an unreported indolopyridoquinazoline (compound 1) along with nine previously known alkaloids 2–10. In addition, six semi-synthetic derivatives 3a–c, 4b, 5a and 6a were prepared by allylation and acetonidation of soyauxinium nitrate (5), edulinine (3), ribalinine (4) and arborinine (6). The structures and spectroscopic data of five of them are reported herein for the first time. The suggested mechanism for the formation of the new N-allylindolopyridoquinazoline 5a is presented. The structures of natural and derived compounds were determined employing extensive NMR and MS techniques. The absolute configuration of stereogenic centers in compounds 2–4 were determined using NOESY technique and confirmed by the single-crystal X-ray diffraction (SC-XRD) technique. The use of SC-XRD further enabled us to carry out a structural revision of soyauxinium chloride recently isolated from the same plant to soyauxinium nitrate (5). The TAE, fractions, compounds 1–7 and 9, and semi-synthetic derivatives 3a–c, 4b, 5a and 6a were evaluated for their cytotoxic activity towards the cervix carcinoma cell line KB-3-1. No significant activity was recorded for most of the compounds except for 9, which showed moderate activity against the tested cancer cell lines

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

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

Long-term neurological symptoms after acute COVID-19 illness requiring hospitalization in adult patients: insights from the ISARIC-COVID-19 follow-up study

in this study we aimed to characterize the type and prevalence of neurological symptoms related to neurological long-COVID-19 from a large international multicenter cohort of adults after discharge from hospital for acute COVID-19