Bactoprenol also known as dolichol-11 and (isomerically vaguely) C55-isoprenyl alcohol (C55-OH) is a lipid first identified in certain species of lactobacili. It is a hydrophobic alcohol that plays a key role in the growth of cell walls (peptidoglycan) in Gram-positive bacteria. The double bonds all have the Z configuration except for the three ω-terminal ones, which are biosynthetically derived from (E,E)-farnesyl diphosphate.