First Total Synthesis of Vialinin A, a Novel and Extremely Potent Inhibitor of TNF-α Production
摘要:
Vialinin A, a powerful inhibitor (IC50 90 pM) of TNF-alpha production, was synthesized from sesamol in 11 steps with 28% overall yield. The key reactions include a double Suzuki coupling of electron-rich aryl triflate with phenylboronic acid and an oxidative deprotection of bis-MOM ether. In addition, the related synthetic studies also suggest the necessity for structural revision of ganbajunin C, a positional isomer of vialinin A.
First Total Synthesis of Vialinin A, a Novel and Extremely Potent Inhibitor of TNF-α Production
摘要:
Vialinin A, a powerful inhibitor (IC50 90 pM) of TNF-alpha production, was synthesized from sesamol in 11 steps with 28% overall yield. The key reactions include a double Suzuki coupling of electron-rich aryl triflate with phenylboronic acid and an oxidative deprotection of bis-MOM ether. In addition, the related synthetic studies also suggest the necessity for structural revision of ganbajunin C, a positional isomer of vialinin A.
This paper describes the total synthesis of thelephantin G, thus revising the proposedstructure 1 to 2. The key steps involved a double Suzuki−Miyaura coupling and an esterification reaction. By a similar strategy, ganbajuninsD and E (3 and 4) were also prepared. Compound 2 strongly inhibited TNF (tumor necrosis factor)-α production in rat basophilic leukemia (RBL-2H3) cells: IC50 = 3.5 nM, while
A powerful inhibitor of TNF-α production, vialinin A, was synthesized from sesamol through a series of reactions involving double Suzuki-Miyaura coupling, 2,3-dichloro-5,6-dicyano-1,4-benzoquino (DDQ) mediated de-methoxymethylation and oxidative removal of methylene acetal by lead tetraacetate. The synthetic method also made it possible to prepare a related compound, terrestrin B.
Kynapcin-12 is a prolyl oligopeptidase (POP) inhibitor isolated from Polyozellus multiplex, and its structure was assigned as 1 having a p-hydroquinone moiety by spectroscopic analyses and chemical means. This Letter describes the total syntheses of the proposed structure 1 for kynapcin-12 and 2',3'-diacetoxy-1,5',6',4 ''-tetrahydroxy-p-terphenyl 2 isolated from Boletopsis grisea, revising the structure of kynapcin-12 to the latter. These syntheses involved double Suzuki-Miyaura coupling, CAN oxidation, and LTA oxidation as key steps. The inhibitory activities of synthetic compounds against POP and cancer cells were also evaluated. (C) 2014 Elsevier Ltd. All rights reserved.