Isolation of Peptide Components of Bacitracin by Preparative HPLC and Solid Phase Extraction (SPE)

Pathways of Chemical Degradation of Polypeptide Antibiotic Bacitracin

“…21,22) As found by our experiments the favoured pathway of degradation of Bc stored at elevated temperatures in neutral water solutions is oxidation (Fig. 2).…”

“…6 min) on the new type of monolithic silica reversed phase column. 22) Using stress stability tests on the isolated Bc components we were able to identify the decomposition processes and individual oxidative and nonoxidative desamido degradation products. The peak that was eluted before each microbiologically active component (B1, B2, B3, A) corresponded to hydrolytic-desamido degradation product (Fig.…”

“…1). 21,22) In several papers on HPLC separation of Bc carried out up to the present we frequently pointed out that under certain experimental conditions (especially when mobile phases with lower pH were used) the peaks of degradation products may be asymmetric or may even split into two subunits (e.g. F splits into FЈ and FЉ).…”

“…6) In our recently published HPLC method for Bc, the mentioned oxidative degradation products H1, H2 and H3 were chromatographically clearly defined for the first time. 21,22) We used mainly the new type monolithic silica reversed-phase Chromolith RP-18e (100ϫ4.6 mm I.D.) column which dramatically reduced analysis time.…”

“…3) Pure microbiological active components of Bc: A, B1, B2, B3; oxidative degradation products: F, H1, H2, H3 and hydrolytic products of component A: Xa1, Xa were isolated by preparative HPLC method. 22) All solutions with Bc (ZnBc) or with individual components of Bc were filtered through a membrane filter with pore diameter of 0.45 mm before HPLC measurements.…”