A set of 8-methylene-, 8-methyl-, and 8-methyl-9-dihydro-oleandomycin derivatives having different combinations of stereochemistries at positions C-8 and/or C-9 have been prepared in a chemoselective and stereoselective manner and tested in vitro for antibacterial activity and inhibition of IL-6 production. Configurations of the stereocenters at C-8 and C-9 were determined using 2D NMR techniques. We have shown that change of stereochemistry at these positions can exert a major influence on antibacterial activity as well as IL-6 inhibition, providing novel macrolide derivatives with diminished antibacterial and potent anti-inflammatory activity. In addition, the anti-inflammatory activity observed in vitro was confirmed in an in vivo model of lipopolysaccharide-induced inflammation. (C) 2012 Elsevier Ltd. All rights reserved.
An Enantioselective Synthesis of a Macrolide from the Polyketide Lactone Derived from Oleandomycin
The polyketide lactone, 8-methyl-3,5,11-trioxo-oleandolide, which is obtained from a new aglycone of oleandomycin by ruthenium tetraoxide oxidation, is stereoselectively reduced by zinc borohydride in the presence of magnesium bromide to give a macrolide, (5R,8R,9R)-9-dihydro-8-methyl-epi-oleandolide in a good yield.