83259-66-9 Tetrocarcin E(2) Tetronolide, 9-O-(3-O-acetyl-2,6-dideoxy-alpha-L-ribo-hexopyranosyl)-17-O-(2,3,4,6-tetradeoxy-4-((methoxycarbonyl)amino)-3-C-methyl-3-nitro-beta-D-xylo-hexopyranosyl)-