(6R)-2-{(1S)[(4S,3R,5R)-5-(Aminomethyl)-3,4-dihydroxyoxolan-2-yloxy][(3S,4R)-5-(2,4-dioxo(1,3-dihydropyrimidinyl))-3,4-dihydroxyoxolan-2-yl]methyl}-6-hexadecanoyloxy-1,4-dimethyl-3-oxo-1,4-diazaperhydroepine-(5S)-carboxylic acid AIDS-181972 AIDS181972