| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1221516 | Journal of Pharmaceutical and Biomedical Analysis | 2014 | 6 Pages |
•Related impurities of etimicin key intermediate P1 were detected by HPLC methods.•Four major related impurities were isolated from P1 by column chromatograpy.•Their structures were established by means of LC–MSn and NMR techniques.•Three impurities are new compounds and all NMR data were first reported.•The possible mechanism for the formation of these impurities is discussed.
Etimicin intermediate 3,2″,6″-N,N,N-triacetyl gentamicin C1a (P1), is a key intermediate of etimicin, which is a semi-synthetic aminoglycoside antibiotic effective to both gram-positive and gram-negative bacteria infections. Four major related impurities of P1 were detected by HPLC–ELSD and ESI–MSn methods. Weakly acidic cation exchange resin, CM-sephadex and silica gel column chromatography were used for the isolation and purification of four major impurities. By means of ESI–MSn and NMR analysis, related impurities were characterized as 3,2″-N,N-diacetyl gentamicin C1a (1), 3,2″,6″-N,N,N-triacetyl gentamicin C2b (2), 2″-N-acetyl gentamicin C1a (3), and 2″,6″-N,N-diacetyl gentamicin C1a (4). Impurities 1, 2, 4 are novel compounds and the NMR data of these isolates were first reported in this paper. The possible mechanism for the formation of these impurities is also discussed.
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