30 research outputs found
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
Melanin production inhibitors from the West African 'Cassipourea congoensis'
Cassipourea congoensis (syn. Cassipourea malosana) is used in African countries as a skin-lightening agent. Two previously unreported cycloartane triterpenoids, 26-hydroxy-3-keto-24-methy lenecycloartan-30-oic acid 1 and 24-methylene-cycloartan-3β,26,30-triol 2 along with the known mahuannin B 3, 7-methoxymahuannin B 4, 7-methoxygeranin A 5, methyl-3-(4-hydroxy-3-methoxyphenyl)-2E-propenoate, glycerol-1-alkanoate, (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal 6, (-)-syringaresinol 7, and stigmast-5-en-3-O-β-D-glucoside, were isolated from the roots of C. congoensis. The crude extract and compounds 1 and 5 were found to inhibit the production of melanin at 10 μM with low cytotoxicity validating the ethno-medicinal use of this plan
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
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
The chemical constituents of Penianthus longifolius Miers
Fourteen compounds were isolated from the roots, leaves and twigs of Penianthus longifolius Miers (Menispermaceae), including two previously unreported neo-clerodane diterpenoids, penianthin (1), its C-8 epimer (2). In addition, the previously reported O-methylmoschatoline (3), taraxerol (4), taraxerone (5), rubrosterone, (6), panuosterone (7), 22-epi-20-hydroxyecdysone (8), ergosterol peroxide (9), stigmast-5-ene-3,7-dione (10), stigmasterol (11), β-sitosterol (12), stigmasterol glucoside (13) and β-sitosterol glucoside (14) were isolated. The structures of the compounds were determined by means of NMR spectroscopic and mass spectrometric analysis. The absolute configurations of 1 and 2 were determined by circular dichroism analysis. Compounds 1 and 2 were screened against the NCI60 cancer cell panel but showed no significant activity at 10 μM
Antimicrobial Furoquinoline Alkaloids from Vepris lecomteana (Pierre) Cheek & 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
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
Antimycobacterial cycloartane derivatives from the roots of Trichilia welwistchii C. DC (Meliaceae).
Chemical investigation of the roots of yielded a cycloartane type terpenoid 28,29-bis-norcycloart-24-en-3 ,4 ,6 -triol ( ), isolated as pure compound for the first time, three coumarins and three sterols. New cycloartane derivatives ( ) and ( + ) were obtained by hemi-synthetic reaction of compound . The structures of – were established by spectroscopic methods including 1D and 2D-NMR analysis, HR-EIMS, chemical transformations and by comparison of these data with those of related compounds. Evaluated for their antimycobacterial potential, compound and + were determined to show significant activities against MIC values of 6.25 μg mL while compound displayed weak activity showing MIC > 100 μg mL . Compounds – displayed moderate activity with MIC values range from 12.5 to 50 μg mL
Oxidative burst inhibition, cytotoxicity and antibacterial acriquinoline alkaloids from Citrus reticulate (Blanco)
Fomani M, Ngeufa Happi E, Nouga Bisoue A, et al. Oxidative burst inhibition, cytotoxicity and antibacterial acriquinoline alkaloids from Citrus reticulate (Blanco). Bioorganic & Medicinal Chemistry Letters. 2015;26(2):306-309
A New Antimicrobial Phenylpropanol from the Leaves of Tabernaemontana inconspicua Stapf. (Apocynaceae) Inhibits Pathogenic Gram-Negative Bacteria.
A chemical investigation of the leaves of Tabernaemontana inconspicua Stapf. led to the isolation of a new phenylpropanol derivative, namely irisdichototin G (1), together with nine known compounds, including one polyol derivative, dambonitol (2); three alkaloids, 10-hydroxycoronaridine (3), voacristine (4) and vobasine (5); two triterpenes lupeol (6), betulinic acid (7) and three sterols, sitosterol (8), sitosterol-3-O-β-D-glucopyranoside (9) and stigmasterol (10). The structure of the new compound, as well as those of the known ones, was established by means of spectroscopic methods: NMR analysis (1H and 13C NMR, 1H-1H-COSY, HSQC, HMBC and NOESY), high-resolution mass spectrometry (HR-ESI-MS) and comparisons with previously reported data. Among the known compounds, compound 2 was firstly reported from the family Apocynaceae. Compounds 1–5 were tested for their antimicrobial effects against three Gram-negative organisms associated with human wound and systemic infections, namely Haemophilus influenzae 9435337A, Klebsiella pneumoniae 17102005 and Pseudomonas aeruginosa 2137659B. Compounds 1, 3, and 5 showed significant antimicrobial effects with minimum inhibitory concentrations (MIC) of 62.5 μg/mL, 62.5 μg/mL and 7.81 μg/mL, respectively, against Haemophilus influenzae, whereas compounds 1 and 5 showed significant antimicrobial effects, with a MIC value of 31.25 μg/mL against Pseudomonas aeruginosa. In addition, compound 3 showed significant antimicrobial activity, with a MIC value of 31.25 μg/mL against Klebsiella pneumoniae