Apolar chromatography on Sephadex LH-20 combined with high-speed counter-current chromatography. High yield strategy for structurally closely related analytes-Destruxin derivatives from Metarhizium anisopliae as a case study.

A novel high yield isolation procedure for lipophilic cyclic peptide derivatives is presented. Destruxin (dtx) A, B, D, E, and E-diol retrieval from Metarhizium anisopliae culture broth was achieved with a three-step purification protocol. After liquid-liquid extraction column chromatography over Sephadex LH-20 served as enrichment step. High-speed counter-current chromatography (HSCCC) was used for the final purification. Within the first chromatographic step dtx D and dtx E-diol were separated in purities exceeding 90%. The separation of dtx A, B, and E was achieved from an enriched Sephadex LH-20 fraction by a HSCCC protocol using light petroleum-ethyl acetate-methanol-water = 2:5:2:5 (v/v) as eluent system. These derivatives were obtained in purities above 98% and total yields exceeding 40%.