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ABSTRACT: Seven stilbenes and one alkylresorcinol were isolated from the orchid Phragmipedium calurum during a screen for anticancer compounds. They were evaluated for antiproliferative activity against multiple human cancer cell lines, and two displayed moderate activity against several cell lines.
Phytochemistry 07/2012; 82:172-5. · 3.35 Impact Factor
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ABSTRACT: High-throughput natural products chemistry methods have facilitated the isolation of eight new (1-8) and two known (9 and 10) beilschmiedic acid derivatives from the leaves of a Gabonese species of Beilschmiedia. Compounds 3-10 were isolated in microgram quantities, and the NMR data for structure elucidation and dereplication were acquired utilizing a Bruker BioSpin TCI 1.7 mm MicroCryoProbe. All of the compounds were screened for cytotoxic and antibacterial activity against NCI-H460 human lung cancer cells and a clinical isolate of methicillin-resistant Staphylococcus aureus, respectively. This is the first report of cytotoxic activity for the endiandric/beilschmiedic acid class of compounds.
Journal of Natural Products 07/2012; 75(7):1319-25. · 3.13 Impact Factor
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Russell B Williams,
Steven M Martin,
Jin-Feng Hu,
Eliane Garo,
Stephanie M Rice,
Vanessa L Norman,
Julie A Lawrence,
Grayson W Hough,
Matt G Goering,
Mark O'Neil-Johnson,
Gary R Eldridge, Courtney M Starks
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ABSTRACT: High-throughput natural product research produced a suite of anticancer hits among several species of the Orchidaceae family (Oncidium microchilum, O. isthmi, and Myrmecophila humboldtii). A commercial Oncidium sp. was also examined as a convenient source of additional material. Isolation and structure elucidation led to the identification of fifteen stilbenoids including a new phenanthraquinone and two new dihydrostilbenes. NMR data for structure elucidation and dereplication were acquired utilizing a Bruker BioSpin TCI 1.7-mm MicroCryoProbe or a 5-μL CapNMR capillary microcoil. Several compounds inhibited proliferation of NCI-H460 and M14 cancer cell lines. All compounds were also examined for their ability to induce apoptosis. Apoptosis induction was determined by measuring caspase 3/7 activation and LDH release in a NCI-H460 cell line. Based on these results, a portion of the extract from a commercially available Oncidium sp. was chemically modified in an attempt to obtain additional phenanthraquinones.
Planta Medica 01/2012; 78(2):160-5. · 2.15 Impact Factor
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ABSTRACT: A phytochemical investigation of Monanthotaxis congoensis afforded eight polyoxygenated cyclohexenes as well as the known crotepoxide. Structures were determined using NMR, MS, and optical rotation analyses. One compound displayed moderate antiproliferative activity against NCI-H460 and M14 cancer cells.
Phytochemistry 11/2011; 74:185-9. · 3.35 Impact Factor
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ABSTRACT: A high-throughput phytochemical investigation of Abronia villosa afforded a new rotenoid designated abronione (1) along with the known compounds boeravinone C and lupeol. The structure of 1 was determined using NMR, MS, and optical analysis with < 400 µg of material. Compound 1 displayed moderate cytotoxicity against NCI-H460 and HL-60 human cancer cell lines with IC(50) values of 14 and 36 µM, respectively.
Phytochemistry Letters 06/2011; 4(2):72-74. · 1.22 Impact Factor
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ABSTRACT: One method that bacteria employ to reduce their susceptibility to antibiotics is the formation of biofilms. We developed a robust 6-well plate biofilm assay to evaluate early-stage discovery compounds against methicillin-resistant Staphylococcus aureus (MRSA). Tissue culture-treated 6-well plates were selected for this assay because they facilitate the adherence of MRSA and enable accurate determination of the number of CFU in each well. The MRSA biofilms formed in this assay exhibit increased tolerances to clinically used antibiotics. Using this biofilm assay, we identified a novel potentiator of gentamicin against MRSA biofilms. The combination of gentamicin and pentadecenyl tetrazole is superior to clinically used MRSA antibiotics against these MRSA biofilms. This novel combination also exhibits synergistic effects on MRSA planktonic cells. This plant-derived compound reveals promise for its effectiveness and warrants further lead optimization as an antibiotic and aminoglycoside potentiator.
Antimicrobial Agents and Chemotherapy 06/2011; 55(8):3691-5. · 4.84 Impact Factor
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ABSTRACT: High-throughput natural products chemistry methods have led to the isolation of three new (1-3) and two known indole sesquiterpene alkaloids (4, 5) from Greenwayodendron suaveolens. Their structures were determined using CapNMR and MS. Pentacyclindole (1) was determined to possess a new natural product framework. Pentacyclindole (1) and polyalthenol (4) showed activity against clinical isolates of Staphylococcus aureus with polyalthenol (4) demonstrating a MIC(90) of 4 microg/mL.
Journal of Natural Products 05/2010; 73(5):1008-11. · 3.13 Impact Factor
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ABSTRACT: Bioassay-guided fractionation of the antibacterial ethyl acetate-ethanol (50 : 50) extract obtained from the aerial parts of Penstemon centranthifolius led to the isolation of six phenylethanoid glycosides (1-6) and eleven iridoid glycosides (7-17). Their structures were determined on the basis of spectroscopic analysis and comparison with the literature. Among them, two phenylethanoid glycosides, 4'''-O-acetylverbascoside (1) and verbascoside (2), were found to show significant inhibition of the formation of bacterial biofilms by Escherichia coli UTI89. Compound 1 showed 77% biofilm inhibition at 2.5 microg/mL, and compound 2 showed 60% inhibition at 5 microg/mL.
Phytotherapy Research 10/2009; 24(5):778-81. · 2.09 Impact Factor
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ABSTRACT: Nine clerodane diterpenes, solidagoic acids C-I (1-7), cleroda-3,13(14)-dien-16,15:18,19-diolide (8) and cleroda-3,13(14)-dien-15,16:18,19-diolide (9) were isolated and characterised from the ethanol-ethyl acetate (1:1) extract of Solidago virgaurea. The structures were determined by NMR spectroscopic analysis. Several displayed moderate antibacterial activity against Staphylococcus aureus.
Phytochemistry 10/2009; 71(1):104-9. · 3.35 Impact Factor
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Helvetica Chimica Acta 02/2009; 92(2):273 - 280. · 1.48 Impact Factor
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ABSTRACT: The unsymmetrical 2,5-diaryl-tetrahydrofuran type lignan, 2-(3'-methoxy-4'-hydroxyphenyl)-3,4-dihydroxymethyl-5-(3''-methoxy-5''-hydroxyphenyl)-tetrahydrofuran, laxanol (1), was obtained from Justicia laxa via high-throughput natural product chemistry methods as a mass-limited sample and its structure was elucidated by capillary scale NMR and HR-/LR-ESIMS analyses.
Journal of Chemical Research 12/2007; 2008(1):20-21. · 0.04 Impact Factor
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ABSTRACT: Trichodermamides A (1) and B (2), two modified dipeptides, have been isolated from cultures of the marine-derived fungus Trichoderma virens. The trichodermamides possess a rare cyclic O-alkyl-oxime functionality incorporated into a six-membered ring. The structure of trichodermamide B was established by X-ray diffraction analysis, while the structure assignment of trichodermamide A, and determination of the absolute stereochemistry, was accomplished by spectral and chemical methods. Trichodermamide B displayed significant in vitro cytotoxicity against HCT-116 human colon carcinoma with an IC(50) of 0.32 microg/mL.
Journal of Natural Products 04/2003; 66(3):423-6. · 3.13 Impact Factor
