Novel 12-membered non-antibiotic macrolides from erythromycin A; EM900 series as novel leads for anti-inflammatory and/or immunomodulatory agents

Herein, we report the design and synthesis of the novel 12-membered non-antibiotic macrolide (8R,9S)-8,9- dihydro-6,9-epoxy-8,9-anhydropseudoerythromycin A (EM900), which was found to be a potent anti-inflammatory and/or immunomodulatory agent, capable of promoting monocyte to macrophage differentiation. This molecule shows improved acid stability, does not exhibit any anti-bacterial activity and has relatively low cytotoxicity against THP-1 cells. In addition, one of its analogues, (8R, 9S)-4 '',13-O-diacetyl- 8,9-dihydro-6,9-epoxy-8,9-anhydropseudoerythromycin A (EM911), was found to be twice as effective as EM900. (C) 2011 Elsevier Ltd. All rights reserved.