RETRACTED: Identification of 3-O-acetylglycerol, a novel structural element in bacterial polysaccharides

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the author, as follow up work revealed that the work presented in this article contains two significant errors. First, the identification of 3-O-acetylglycerol in the polysaccharide repeating unit of serotype 11A is incorrect. The proper placement of the O-acetyl group is on the β-Gal O-6. Second, the conclusion that the polysaccharide is branched is incorrect. The original proposed core structure (Richards, J.C., Perry, M.B., Moreau, M.; Elucidation and comparison of the chemical structures of the specific capsular polysaccharides of Streptococcus pneumonia groups 11 (11F, 11B, 11C, and 11A), In: The Molecular Immunology of Complex Carbohydrates, Wu, A.M., Adams, L.G.; Eds.; Plenum Press: New York, 1988; pp. 595–596, ISBN 978-0-306-42818-0), with a linear subunit is correct. The conclusion for the branched structure was due to a transcription error, and the placement of the acetyl group on the glycerol side chain was due to incorrect interpretation of the NMR data. These errors were discovered while working on other polysaccharides that are structurally related to serotype 11A (Calix, J.J., Nahm, M.H., Zartler, E.R.; J. Bacteriol., 193 (2011) 5271–5278, doi:10.1128/JB.05034-11). These two corrections remove the novelty of the finding described in this report, and the authors hereby retract the article. The first author, Edward R. Zartler, takes full responsibility for this matter and apologizes for any inconvenience caused.