2100760 9311139 PCTABS00022 A 6-substituted lipid A analog represented by general formula ¢I! wherein R1 represents hydrogen or hydroxy; R2 represents -C(O)R3; R3 represents linear or branched lower alkyl which may be substituted with carboxy or lower alkoxycarbonyl; l represents an integer of 5 to 17; m represents an integer of 7 to 19; n represents an integer of 4 to 16; and p represents 0 or 1.
