The molecule is a lipid A derivative in which the phospho group at the anomeric carbon is esterified with a 4-amino-4-deoxy-beta-L-arabinopyranosyl group. It is a conjugate acid of a lipid IIA(3-) and a lipid IIA(2-).
[(2R,3R,4R,5S,6R)-2-[[(2R,3R,4S,5S)-5-amino-3,4-dihydroxyoxan-2-yl]oxy-hydroxyphosphoryl]oxy-5-hydroxy-6-[[(2R,3R,4R,5S,6R)-6-(hydroxymethyl)-3-[[(3R)-3-hydroxytetradecanoyl]amino]-4-[(3R)-3-hydroxytetradecanoyl]oxy-5-phosphonooxyoxan-2-yl]oxymethyl]-3-[[(3R)-3-hydroxytetradecanoyl]amino]oxan-4-yl] (3R)-3-hydroxytetradecanoate