The HPLC analysis of the mother liquor of crystallization showed that there were two major components in the solution. Separation of these components was achieved by HPLC on a semipreparative reverse-phase column using H20-MeOH (70:30) as the mobile phase. From the first fraction (rV = 20 mL), after concentration in vacuo and crystallization of the residue from acetone, an additional 40 mg of 19 (total yield 47%) was obtained, mp 168-170 °C. The second fraction (rV = 29 mL) was concentrated and the residue crystallized from acetone. Compound 18 (80 mg, 42%) was obtained as colorless crystals: mp [172][173][174] °C; UV (MeOH) X^2 62 nm (e 7050), 230 (1520); NMR b 1.10 (3 H, d, 5'-Me), 1.83 (3 H, s, NAc), 2.03 (3 H, s, OAc), 2.15 (3 H, s, OAc), 4.28 (1 H, m, H-5'), 4.68 (1 H, m, H-3'), 4.89 (1 H, br s, H-4'), 5.00 (1 H, br s, H-2'), 5.63 (1 H, d, H-5, = 8.1 Hz), 5.92 (1 H, s, H-l', JV2! = 0 Hz), 7.45 (1 H, d, H-6), 7'.76 (1 H, br d, NHAc), 11.39 (1 H, br s, NH).