- Synthesis of purpurasol, a highly oxygenated coumarin from Pterocaulon purpurascens
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Purpurasol 1, a 6,7,8-trioxygenated coumarin, isolated from Pterocaulon purpurascens (Asteraceae) and Haplophyllum obtusifolium (Rutaceae), was synthesized for the first time by a three-step synthesis starting from the natural coumarin fraxetin. This synthesis confirmed unambiguously the structure of purpurasol 1 and obtusifol.
- Maes, Dominick,Syngel, Kris Van,Debenedetti, Silvia,De Kimpe, Norbert
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- Inhibitor for FcεRI expression on mast cell from Verbasucum thapsus L.
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We found out 2′,3′-dihydroxypuberulin from South American medicinal plant, V. thapsus L., as a candidate of an anti-allergic lead which inhibits the expression of high-affinity receptor of IgE (FcεRI) on the surface of mast cells. Furthermore, the analysis of structure-activity relationship by using synthesized 2′,3′-dihydroxypuberulin analogs revealed that both hydroxy groups in the side chain and both of methyl moieties on phenolic hydroxy groups were crucial for potent activity, but absolute configuration of C-3′ position wasn't. The active principle, 2′,3′-dihydroxypuberulin, was disclosed to down-regulate the mRNA level of β-chain of FcεRI, different from previous reported active natural product reducing γ-chain level.
- Tamura, Satoru,Yoshihira, Kunichika,Kawano, Tomikazu,Murakami, Nobutoshi
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p. 3342 - 3345
(2018/09/14)
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- Total syntheses of the coumarin-containing natural products pimpinellin and fraxetin using Au(I)-catalyzed intramolecular hydroarylation (IMHA) chemistry
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The title natural products (1 and 2, respectively) have been synthesized by Au(I)-catalyzed intramolecular hydroarylation (IMHA) of the relevant aryl propiolate esters (e.g., 13), which were themselves formed by reaction of the corresponding phenols with either 3-(trimethylsilyl)propiolic acid or propiolic acid and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride or dicyclohexylcarbodiimide. (±)-Purpurasol (3) was readily derived from fraxetin (2) by established procedures.
- Cervi, Aymeric,Aillard, Paul,Hazeri, Nourallah,Petit, Laurent,Chai, Christina L. L.,Willis, Anthony C.,Banwell, Martin G.
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p. 9876 - 9882
(2013/10/22)
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