Electrospray mass spectrometric analysis of new alpha-MSH analogues carrying nitrogen mustard at their amino terminus.
Two different chlorinated drugs, chlorambucil and melphalan, have been linked to the carrier alpha-melanocyte-stimulating hormone at the end of the solid-phase peptide synthesis of the hormone. The [Nle4, D-Phe7] and the [Nle4, L-Phe7] derivatives of the hormone have both been used. It was found by electrospray mass spectrometric analysis that the products undergo hydrolysis of the chlorinated moiety of the drugs, most likely due to the acidic conditions necessary for cleavage of the peptide from the resin. Only the melphalan-O(ethyl)-N(succinyl)-derivative of alpha-melanocyte-stimulating hormone [Nle4, L-Phe7] did not show a bis-hydroxylated form. It was proven by blank experiments with commercially available melphalan that this mustard occurs for some 45%-50% in the mono-hydroxylated form, which is known to be pharmacologically poorly active.
Van Beeumen
J
J
State University of Gent, Belgium.
Devreese
B
B
Ghanem
G
G
Lejeune
F
F
Deknop
C
C
Faignet
C
C
Toch
I
I
Jacquemotte
F
F
D000595:Amino Acid Sequence; D002247:Carbon Isotopes; D002699:Chlorambucil / Q000032:analysis / Q000138:chemical synthesis; D004337:Drug Carriers; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D008558:Melphalan / Q000032:analysis / Q000138:chemical synthesis; D008969:Molecular Sequence Data; D009588:Nitrogen Mustard Compounds / Q000032:analysis* / Q000138:chemical synthesis; D009842:Oligopeptides / Q000032:analysis / Q000138:chemical synthesis; D000521:alpha-MSH / Q000031:analogs & derivatives* / Q000032:analysis* / Q000138:chemical synthesis
D002247:Carbon Isotopes; D004337:Drug Carriers; D009588:Nitrogen Mustard Compounds; D009842:Oligopeptides; D002699:Chlorambucil; D000521:alpha-MSH; D008558:Melphalan