Isolation and Characterization of the Pigment Esters of Xanthomonas juglandis (campestris)

Summary: Separation of the pigment esters of Xanthomonas juglandis (campestris) on silica gel columns yielded four bands. Two of the bands, esters 1 and 2, made up over 95% of the mixture. Both esters were phospholipids, with ester 1 containing the alcohol moieties glycerol and sorbitol, and ester 2 only glycerol. Both appeared to be mixtures containing different xanthomonadin pigment molecules but the results suggested that ester 1 consisted of one pigment molecule esterified to glycerophosphoryl sorbitol, whereas ester 2 consisted of 2 pigment molecules esterified to glycerophosphate.