Cytotoxic stilbenes and canthinone alkaloids from Brucea antidysenterica (Simaroubaceae)

Phytochemical study of the root and bark of Brucea antidysenterica J. F. Mill. (Simaroubaceae) afforded three new compounds including a stilbene glycoside bruceanoside A (1), and two canthinone alkaloids bruceacanthinones A (3) and B (4), as well as ten known secondary metabolites, rhaponticin (2), 1,11-dimethoxycanthin-6-one (5), canthin-6-one (6), 1-methoxycanthin-6-one (7), 2-methoxycanthin-6-one (8), 2-hydroxy-1,11-dimethoxycanthin-6-one (9), β-carboline-1-propionic acid (10), cleomiscosin C (11), cleomiscosin A (12) and hydnocarpin (13). The structures of all the compounds were determined using spectrometric and spectroscopic methods including 1D and 2D NMR, and HRSEIMS. The identity of the known compounds was further confirmed by comparison of their data with those reported in the literature. The root and bark methanolic extracts, the dichloromethane and ethyl acetate soluble fractions, as well as the isolated compounds (3–13), were assessed for their cytotoxicity against the cancer cell lines A-549, MCF-7 and PC-3. The results suggested that compounds in the extracts might possess a synergic action in their cytotoxicity

Bioactive beta-indoloquinazoline Alkaloids from Oricia renieri

Wansi J, Happi EN, Bavoua JLD, Devkota KP, Sewald N. Bioactive beta-indoloquinazoline Alkaloids from Oricia renieri. Planta Medica. 2012;78(01):71-75.Three new beta-indoloquinazoline alkaloids, orirenierine A (1), B (2) and C (4), together with eleven known compounds were isolated from the methanol extract of the stems of Oricia renieri. The structures of all compounds were determined by comprehensive analyses of their spectroscopic data and comparison with literature information. The alkaloids 9-11 were isolated for the first time from this genus. All compounds were tested for their activity against bacteria, fungi, and plant pathogen oomycetes using the paper disk agar diffusion assay. The agar diffusion test gave only low antimicrobial activities, corresponding to MICs > 1 mg/mL. However, compounds 1-4 and 11 exhibited a strong suppressive effect on phagocytosis response upon activation with serum opsonized zymosan in the range of IC(50) = 2.6-6.5 mu M, while low cytotoxic activity against the human Caucasian prostate adenocarcinoma cell line PC-3 was observed with IC(50) values ranging from 22.9 to 39.4 mu M

Bioactive Phenylethanoids and Coumarines from Basalmocitrus cameroonensis

Wansi J, Bavoua JLD, Happi EN, et al. Bioactive Phenylethanoids and Coumarines from Basalmocitrus cameroonensis. Zeitschrift für Naturforschung B. 2009;64(4):452-458.Two new phenylethanoids, basalethanoid A (1) and B (2), and one new ceramide, basalamide A (3), together with eleven known compounds (4-14) were isolated from the MeOH extract of the stem barks of Basalmocitrus cameroonensis. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, chemical reactions, and comparison with previously known analogs. Compounds 1, 2, 5, and 7-10 demonstrated a strong inhibition on reactive Oxygen species (ROS) production in the oxidative burst activity of whole blood on activation with serum opsonized zymosan in the range of IC50 = 0.06-12.30 mu g mL(-1)

Antibacterial constituents from the roots, stem bark and leaves of Manilkara obovata (Sabine & G. Don) J. H. Hemsl. (Sapotaceae)

Akosung E, Djouaka Bavoua JL, Tabekoueng GB, et al. Antibacterial constituents from the roots, stem bark and leaves of Manilkara obovata (Sabine &amp; G. Don) J. H. Hemsl. (Sapotaceae). Phytochemistry Letters. 2021;44:55-61.The investigation of the methanolic extracts of the roots, stem bark and leaves of Manilkara obovata (Sabine & G. Don) J. H. Hemsl. (Sapotaceae), synonym Manilkara argentea Pierre ex Dubard, has led to the isolation and characterization of a new 4-phenylcoumarin derivative, in form of a racemic mixture of obovacoumaric acid (1a) and the previously reported callophyllic acid (1b) as well as a new taraxerane type triterpene named obovatol (2), alongside twenty-five known compounds. In addition, ethylcanophyllate (3a), obtained by esterification of canophyllic acid (3) is reported here for the first time. The structures of compounds were determined by comprehensive spectroscopic analyses of their 1D and 2D NMR, EI/ESI-MS and single crystal X-ray diffraction (SC-XRD) analysis for 1a and 1b, accompanied by comparison with reported records. In addition, the antibacterial activity of crude extracts, fractions and some of the isolated compounds including the hemi-synthesized ethylcanophyllate (3a) was determined against Salmonella typhi, Staphylococcus aureus ATCC4330, Enterobacter cloacae, Pseudomonas aeruginosa HM801, Streptococcus pneumoniae ATCC491619 and Escherichia coli ATCC25322 applying the broth microdilution method. While the methanolic stem bark extract showed good to significant activity against all bacterial test strains with MICs between 7.8 and 62.5 μg/mL, its fractions A and B were less active, indicating synergistic effects. This effect was also observed for the methanolic root extract, which gave a significant MIC against Staphylococcus aureus ATCC4330 with MIC < 3.9 μg/mL, but only MICs of 31.2 and 7.8 μg/mL for its fractions D and E. Likewise, though fractions F3 and F4 of the methanolic leaf extract displayed good MICs of 31.2 and 15.6 μg/mL, respectively, against Staphylococcus aureus ATCC4330, tested compounds were not stronger active. Interestingly, the hemi-synthesized ethylcanophyllate (3a) based on the completely antibacterial inactive canophyllic acid (3) displayed a good MIC of 15.6 μg/mL against Staphylococcus aureus ATCC4330, pointing here to a dominant role of the ester function in compound 3a in the structure-activity relationship