Novel acyl glyco-carotenoic acids, diapolycopenedioic acid xylosyl esters A, B, and C, were isolated as red pigments by using chromatographic methods from a marine bacterium, Rubritalea squalenifaciens, belonging to subdivision 1 of Verrucomicrobia. The structures of these diapolycopenedioic acid xylosyl esters were determined to be 4-[2-O-acyl-b -D-xylopyranosyl] hydrogen 4,4Ј-diapo-Y ,Y -carotene-4,4Ј-dioate by spectroscopic analysis. Diapolycopenedioic acid xylosyl ester A showed potent antioxidative activity in a 1 O 2 suppression model.