Solution-phase synthesis and biological evaluation of triostin A and its analogues. Issue 6 (18th January 2016)

• Record Type: Journal Article
• Authors: Hattori, Kozo; Koike, Kota; Okuda, Kensuke; Hirayama, Tasuku; Ebihara, Masahiro; Takenaka, Mei; Nagasawa, Hideko
• Is Part Of: Organic & biomolecular chemistry. Volume 14:Issue 6(2016)
• Page Start: 2090
• Page End: 2111
• Publication Date: 2016-01-18
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c5ob02505b
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : We have accomplished preparative solution-phase total syntheses of triostin A (17.5% in 13 steps) and its analogues with high yields to demonstrate their significant inhibitory activities on HIF-1 activation and cell proliferation. Abstract : Triostin A is a biosynthetic precursor of echinomycin which is one of the most potent hypoxia inducible factor 1 (HIF-1) inhibitors. An improved solution-phase synthesis of triostin A on a preparative scale has been achieved in 17.5% total yield in 13 steps. New analogues of triostin A with various aromatic chromophores, oxidized intra-peptide disulfide bridges and diastereoisomeric cyclic depsipeptide cores were also successfully synthesized. All analogues had a significant inhibitory effect on HIF-1 transcriptional activation in hypoxia and cytotoxicity on MCF-7 cells, with the exception of the derivatives containing a naphthalene chromophore or a thiosulfonate bridge. For the first time, triostin A, echinomycin and the thiosulfinate analogue of triostin A have been revealed to inhibit not only DNA binding of HIF-1 but also HIF-1α protein accumulation in MCF-7 cells. Furthermore, the thiosulfinate analogue and triostin A exhibited a hypoxia-selective cytotoxicity on MCF-7 cells. The improved solution-phase synthetic procedure described herein will contribute to the development of diverse bicyclic depsipeptide drug candidates with the potential to act as novel anti-cancer agents targeting hypoxic tumor microenvironments.