Total synthesis of burkholdacs A and B and 5,6,20-tri-epi-burkholdac A: HDAC inhibition and antiproliferative activity

  • Eur J Med Chem. 2014 Apr 9:76:301-13. doi: 10.1016/j.ejmech.2014.02.044.
Yurie Fukui  1 Koichi Narita  1 Singo Dan  2 Takao Yamori  3 Akihiro Ito  4 Minoru Yoshida  4 Tadashi Katoh  5
Affiliations
  • 1. Laboratory of Synthetic and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
  • 2. Division of Molecular Pharmacology, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550, Japan.
  • 3. Division of Molecular Pharmacology, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550, Japan; Pharmaceuticals and Medical Devices Agency (PMDA), 3-3-2 Kasumigaseki, Chiyoda-ku, Tokyo 100-0013, Japan.
  • 4. Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
  • 5. Laboratory of Synthetic and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan. Electronic address: [email protected].
Abstract

The bicyclic depsipeptide histone deacetylase (HDAC) inhibitors burkholdacs A and B were efficiently synthesized in a highly convergent and unified manner. The synthesis features the amide coupling of a D-valine-D-cysteine- or D-allo-isoleucine-D-cysteine-containing segment with a D-methionine-containing segment to directly assemble the corresponding seco-acids, key precursors for macrolactonization. Using the same methodology, 5,6,20-tri-epi-burkholdac A was also synthesized. HDAC inhibitory assays and cell-growth inhibition analyses of the synthesized depsipeptides demonstrated the potency order of this class of bicyclic depsipeptides as compared to the clinically approved depsipeptide FK228 (romidepsin). Novel structure-activity relationships within this class of compounds were also revealed.

Keywords
Bicyclic depsipeptide; Burkholdacs; Histone deacetylase inhibitors; Natural products; Total synthesis.