Myxotyrosides A and B, Unusual Rhamnosides from Myxococcussp.

Myxobacteria are gliding bacteria of the δ-subdivision of the Proteobacteria and known for their unique biosynthetic capabilities. Two examples of a new class of metabolites, myxotyrosides A (1) and B (2), were isolated from a Myxococcussp. The myxotyrosides have a tyrosine-derived core structure glycosylated with rhamnose and acylated with unusual fatty acids such as (Z)-15-methyl-2-hexadecenoic and (Z)-2-hexadecenoic acid. The fatty acid profile of the investigated Myxococcussp. (strain 131) is that of a typical myxobacterium with a high similarity to those described for M. fulvusand M. xanthus,with significant concentrations of neither 15-methyl-2-hexadecenoic acid nor 2-hexadecenoic acid being detected.