Natural Occurrence of a New Aldoheptose Sugar

Abstract

AT the present time aldoheptose sugars are known to occur naturally only in bacterial polysaccharides. The first of these 7-carbon sugars was recorded by Jesiatis and Goebel¹ in a Shigella sonnei product, and during the past few years it has become increasingly clear that aldose sugars of this series are common constituents of bacterial polysaccharides². Only in three instances have aldoheptoses been isolated and identified; the aldoheptose components of both Shigella flexneri and Escherichia coli products were shown by Slein and Schnell³ and Weidel⁴ to be L-glycero-D-mannoheptose and in a Chromobacterium violaceum (BN) polysaccharide MacLennan and Davies⁵ identified D-glycero-D-galactoheptose. In many other polysaccharides the aldoheptose constituent could not be distinguished chromatographically from L-glycero-D-mannoheptose (or its optical enantiomorph D-glycero-L-mannoheptose)⁶.