Three new prenylated furoquinoline alkaloids named lecomtequinoline A (1), B (2), and C (3), together with the known compounds anhydroevoxine (4), evoxine (5), dictamnine (6), N-methylflindersine (7), evoxanthine (8), hesperidin, lupeol, β-sitosterol, stigmasterol, β-sitosterol-3-O-β-d-glucopyranoside, stearic acid, and myristyl alcohol, were isolated by bioassay-guided fractionation of the methanolic extracts of leaves and stem of Vepris lecomteana. The structures of compounds were determined by spectroscopic methods (NMR, MS, UV, and IR) and by comparison with previously reported data. Crude extracts of leaves and stem displayed high antimicrobial activity, with Minimum Inhibitory Concentration (MIC) (values of 10.1–16.5 and 10.2–20.5 µg/mL, respectively, against Escherichia coli, Bacillus subtilis, Pseudomonas agarici, Micrococcus luteus, and Staphylococcus warneri, while compounds 1–6 showed values ranging from 11.1 to 18.7 µg/mL or were inactive, suggesting synergistic effect. The extracts may find application in crude drug preparations in Western Africa where Vepris lecomteana is endemic, subject to negative toxicity results in vivo.

The phytochemical investigations of the methanol extract of Zanthoxylum gilletii bark led to the isolation of thirteen compounds identified as two alkaloids including one acridone 5-hydroxynoracronycine (1) and one benzo [c] phenanthridine decarine (2), three lignans trans- and cis-fagaramide (3 and 4) and sesamin (5), two coumarins scoparone (6) and scopoletin (7), three pentacyclic triterpenoids fridelin (8), lupeol (9) and erythrodiol-3-O-palmitate (10), one phenolic compound vanillic acid (11) as well as two common steroids stigmasterol (12), and its derivative stigmasterol-3-O-β-D-glucopyranoside (13). The structures of all the isolated compounds were elucidated by means of their spectroscopic and spectrometric data (1D, 2D-NMR, MS) as well as the comparison of these data with those reported in the literature. Except for compounds 9 and 1113, all the other isolated compounds are reported for the first time from Z. gilletii but have been already obtained from other Zanthoxylum species and in the Rutaceae family. Compounds 1, 35, and 9 were tested in vitro for their antiplasmodial potencies against Plasmodium falciparum 3D7, and the results revealed that all the tested compounds displayed an inhibition between 51.89 and 54.69 while only the mixture of 3+4 gave an IC₅₀ lower than 10 000nM (IC₅₀=1333nM). Furthermore, all the compounds have been evaluated in silico for their ability to inhibit the Plasmodium falciparum dihydroorotate dehydrogenase 5TBO. Sesamin (5) showed the greatest affinity to the antiplasmodium receptor than artemether® and chloroquine®. Further recorded data from their ADMET study, as well as their chemotaxonomy, are also discussed herein. The present study provides further information to enrich the chemistry of Z. gilletii and its qualification as an important source for good candidates in new antiplasmodial drug development.

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.