Blar i forfatter "Pandey, Sunil Kumar"
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A Concise Total Synthesis of Breitfussin A and B
Pandey, Sunil Kumar; Guttormsen, Yngve; Haug, Bengt Erik; Hedberg, Christian; Bayer, Annette (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)The first total synthesis of breitfussin A and B is described. The approach features two palladium-catalyzed cross-couplings installing the indole and pyrrole onto the oxazole core and selective lithiation/iodination of a common indole–oxazole fragment providing 2,4-diiodinated or 2-iodinated oxazoles as potential precursors for breitfussin A and B, respectively. An unexpected acid promoted deiodination ... -
Kinase chemodiversity from the Arctic: the breitfussins
Østnes Hansen, Kine; Andersen, Jeanette hammer; Bayer, Annette; Pandey, Sunil Kumar; Lorentzen, Marianne; Jørgensen, Kåre Bredeli; Sydnes, Magne Olav; Guttormsen, Yngve; Baumann, Matthias; Koch, Uwe; Klebl, Bert; Eickhoff, Jan; Haug, Bengt Erik; Isaksson, Johan; Hansen, Espen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-24)In this work, we demonstrate that the indole-oxazole-pyrrole framework of the breitfussin family of natural products is a promising scaffold for kinase inhibition. Six new halogenated natural products, breitfussin C–H (3 – 8) were isolated and characterized from the Arctic, marine hydrozoan Thuiaria breitfussi. The structures of two of the new natural products were also confirmed by total synthesis. ... -
Total Synthesis of Phorbazole B
Guttormsen, Yngve; Fairhurst, Magnus John Espeland; Pandey, Sunil Kumar; Isaksson, Johan; Haug, Bengt Erik; Bayer, Annette (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-21)Phorbazoles are polychlorinated heterocyclic secondary metabolites isolated from a marine sponge and several of these natural products have shown inhibitory activity against cancer cells. In this work, a synthesis of the trichlorinated phorbazole B using late stage electrophilic chlorination was developed. The synthesis relied on the use of an oxazole precursor, which was protected with an iodine ... -
Unequivocal structure confirmation of a breitfussin analog by anisotropic NMR measurements
Ndukwe, Ikenna E.; Lam, Yu-hong; Pandey, Sunil Kumar; Haug, Bengt Erik; Bayer, Annette; Sherer, Edward C.; Blinov, Kirill A.; Williamson, R. Thomas; Isaksson, Johan; Reibarkh, Mikhail; Liu, Yizhou; Martin, Gary E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-21)Structural features of proton-deficient heteroaromatic natural products, such as the breitfussins, can severely complicate their characterization by NMR spectroscopy. For the breitfussins in particular, the constitution of the five-membered oxazole central ring cannot be unequivocally established via conventional NMR methods when the 4′-position is halogenated. The level of difficulty is exacerbated ...