ABSTRACT
By establishing the procedures for sequential deprotections, reaction monitoring, purification, and handling, for the first time, we achieved the total synthesis of the proposed structure for protoaculeine B (2), which is a highly hydrophilic and polycationic amino acid. The NMR and mass spectra and chemical reactivity of the synthetic sample differed from those of natural protoaculeine B, which indicates the necessity for revision of the originally reported structure.
Subject(s)
Porifera/chemistry , Animals , Indoles/chemical synthesis , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Structure , Polyamines/chemical synthesis , StereoisomerismABSTRACT
A synthetic strategy for accessing protoaculeine B (1), the N-terminal amino acid of the highly modified peptide toxin aculeine, was developed via the synthesis of the fully protected natural homologue of 1 with a 12-mer poly(propanediamine). The synthesis of mono(propanediamine) analog 2, as well as core amino acid 3, was demonstrated by this strategy. New amino acid 3 induced convulsions in mice; however, compound 2 showed no such activity.