CONSTITUENTS OFERYTHRINA SIGMOIDEA

. The study of the secondary metabolites of the chloroform extract of the stem wood of Erythrina sigmoidea afforded a new compound a -sophoradiol (1), and the known compounds: acetate of b -amyrin (2), acetate of oleanolic acid (3), n-isocosanyl-isocosanoate (4), and n-hexatetracontanol (5). Their structures were characterised by spectroscopic methods. (Received February 12, 2001, revised July 3, 2001) Bull.Chem.Soc.Ethiop. 2001, 15(2), 151-15

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

Beilschglabrines A and B: Two new bioactive phenanthrene alkaloids from the stem bark of Beilschmiedia glabra

Two new phenanthrene alkaloids, beilschglabrines A (1) and B (2) were isolated from the stem bark of Beilschmiedia glabra, together with lupeol, taraxerol, and 24-methylenelanosta-7,9-diene-3β-15α-diol. The structures of the isolated compounds were elucidated by extensive spectroscopic data analysis and comparison with respective literature data. The compounds were tested for DPPH radical scavenging, acetylcholinesterase and lipoxygenase inhibitory activities. Compound 1 displayed considerable activity in the acetylcholinesterase (IC50 50.4 μM), the DPPH radical scavenging (IC50 115.9 μM) and the lipoxygenase (IC50 32.8 μM) assays. © 2016 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved

O-Prenylated Acridone Alkaloids from the Stems of Balsamocitrus paniculata (Rutaceae)

Happi EN, Waffo AFK, Wansi JD, Ngadjui BT, Sewald N. O-Prenylated Acridone Alkaloids from the Stems of Balsamocitrus paniculata (Rutaceae). Planta Medica. 2011;77(09):934-938.Two new O-prenylated acridone alkaloids, balsacridone A (1) and B (2), together with eighteen known compounds were isolated from the methanol extract from the stems of Balsamocitrus paniculata, a Cameroonian medicinal plant. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, and chemical reactions. N-methyl-6-methoxybenzoxazolinone (16) was isolated for the first time from a natural source while compounds 13, 14, and 15 for the first time from this genus. Pure compounds were tested for their activity against bacteria, fungi, and plant pathogen oomycetes, using the paper disk agar diffusion assay. The agar diffusion test delivered low to missing antimicrobial activities, corresponding to MICs > 1 mg/mL. However, compounds 1-15 exhibited a strong suppressive effect on phagocytosis response upon activation with serum opsonized zymosan in the range of IC(50) = 0.5-7.2 mu M, and the acridone alkaloids (1-5), N-trans- p-coumaroyltyramine (13), and N-trans-p-coumaroyloctopamine (14) displayed weak cytotoxic activity against the human Caucasian prostate adenocarcinoma cell line PC-3, with IC(50) values ranging from 69.8 to 99.0 mu M

Endiandric acid derivatives from the stem bark of Beilschmiedia anacardioides

Chouna JR, Nkeng-Efouet PA, Lenta BN, Wansi JD, Kimbu SF, Sewald N. Endiandric acid derivatives from the stem bark of Beilschmiedia anacardioides. Phytochemistry Letters. 2010;3(1):13-16.Three new endiandric acid derivatives, beilschmiedic acids D, E and beilschmiedin were isolated from the stem bark of Beilschmiedia anacardioides together with the known compounds bisabolene and tricosanoic acid. Their structures were determined on the basis of spectroscopic analysis. (C) 2009 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved

Yeast-Mediated Xanthone Synthesis through Oxidative Intramolecular Cyclization

Benzoylphloroglucinol derivatives are natural products showing diverse biological activities that could be modulated by structural modifications. For this purpose, we studied the biotransformation of guttiferone A and of maclurin using a combinatorial approach for screening active microorganism strains. We found a novel and unexpected yeast-catalyzed oxidation that has selectively given a new oxy-guttiferone A and norathyriol

Constituents of <i>erythrina sigmoidea</i>

The study of the secondary metabolites of the chloroform extract of the stem wood of Erythrina sigmoidea afforded a new compound a-sophoradiol (1), and the known compounds: acetate of b-amyrin (2), acetate of oleanolic acid (3), n-isocosanyl-isocosanoate (4), and n-hexatetracontanol (5). Their structures were characterised by spectroscopic methods

Antimicrobial Furoquinoline Alkaloids from Vepris lecomteana (Pierre) Cheek &amp; T. Heller (Rutaceae)

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

A rotameric tryptamide alkaloid from the roots of Vepris lecomteana (Pierre) Cheek & T. Heller (Rutaceae)

Kouam ADK, Kenmogne SB, Lobe JS, et al. A rotameric tryptamide alkaloid from the roots of Vepris lecomteana (Pierre) Cheek &amp; T. Heller (Rutaceae). FITOTERAPIA. 2019;135:9-14.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, beta-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, H-1 and C-13 NMR spectra show two rotamers (1a and 1b) with integrated intensities of 2/3, whereas at around 60 degrees 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 Mulls and Escherichia coli with MIC values of 15.3 and 15.3 mu g/mL, respectively