The constitution of primycin. Part II. The mass spectra of the secoprimycins

Abstract

The structures of secoprimycins A and C have been established by application of high resolution mass spectrometry to the secoprimycins themselves, to their chemical degradation. Similarly the carbon skeleton and the oxygenation pattern of secoprimycin B have been established, but the position of the arabinose unit associated with this fragment has been only tentatively assigned. The structure of a minor component formed along with the secoprimycins in some experiments has also been resolved by mass spectrometry. A structure is proposed for the amino-ester that yields the secoprimycins on ozonolysis and reduction.