In the preceding communication, the production, extraction and some biological properties of the detoxin complex, a metabolite of Streptomyces caespitosus var. detoxicus 7072, were reported. This study focused on the separation and characterization of two main active principles, detoxin Cx and Dx, from the detoxin complex. The detoxin complex (5.0 g, 530 u/mg) was first separated into eight groups (A-H) by buffered resin chromatography on Dowex 50Wx2 using 0.2 M and 0.3 M pyridine-acetic acid buffers (pH 5.0). Groups C and D, which exhibited higher specific activities, were selected for further purification. Crude detoxin C group (120 mg, 1250 u/mg) was separated into C1, C2, and C3 by partition chromatography on a silica gel column with butanol-acetic acid-water (3:1:1). Detoxin C1 was further purified by Sephadex G-10 chromatography to afford a semicrystalline powder (18 mg, 2200 u/mg), identified as detoxin Cx, with microneedles (m.p. 142~144°C), [α]D²⁵ = -23° (c 1, MeOH), elemental analysis consistent with C₂₉H₄₄O₉N₄ or C₃₀H₄₆O₉N₄, pKa values of 8.0 and 3.9, UV absorption maxima (H₂O) at 248, 253, 259, 265, and 269 mμ, and IR absorption at 3300, 1740, 1670, 1580, etc., cm⁻¹. Crude detoxin D group (300 mg, 2500 u/mg) was purified by Sephadex G-10 chromatography to obtain detoxin Dx (150 mg, 5500 u/mg), whose homogeneity was confirmed by countercurrent distribution. Detoxin Dx had a m.p. of 168°C, [α]D²⁵ = -16° (c 1, MeOH), elemental analysis consistent with C₃₀H₄₆O₉N₄ or C₃₀H₄₈O₉N₄, pKa values of 8.0 and 4.0, UV absorption maxima (H₂O) at 253, 258, 265, and 268 mμ, and IR absorption at 3300, 1740, 1660, 1570, etc., cm⁻¹. Further isolation of detoxin homologues and structural elucidation of detoxin Cx and Dx are in progress.