102647-16-5 A 64922 AIDS-031950 AIDS031950 Antibiotic A 649 D-threo-2-pentulose, 1-C-[(2S,3S)-7-[[3-O-acetyl-2,6-dideoxy-4-O-(2,6-dideoxy-4-O-methyl-.alpha.-D-lyxo-hexopyranosyl)-.beta.-D-lyxo-hexopyranosyl]oxy]-3-[[O-2,6-dideoxy-3-C-methyl-4-O-(2-methyl-1-oxopropyl)-.alpha.-L-arabino-hexopyranosyl-(1-