A.G. Paul

The isolation and synthesis of dolichotheline

Abstract An imidazole alkaloid named dolichotheline has been isolated from Dolichothele sphaerica (Dietrich) Britton and Rose, and characterized as 4(5)-[2- N -isovalerylaminoethyl[imidazole ( N -isovalerylhistamine) (I). Its structure has been confirmed by synthesis and a biogenetic pathway is proposed.

DIRECTED BIOSYNTHESIS OF UNNATURAL ALKALOIDS IN DOLICHOTHELE SPHAERICA

Abstract Using appropriate precursors, the two unnatural alkaloids 4(5)-[ N -isocaproylaminomethyl]imidazole and 3-[2- N -isovalerylaminoethyl]pyrazole were produced by Dolichothele sphaerica . The former compound represents an unnatural alkaloid formed by the simultaneous introduction of two unnatural precursors, namely isocaproic acid and 4(5)-aminomethylimidazole. The latter compound represents an aberrant alkaloid formed by the introduction of a precursor of different heterocyclic entity, 3-aminoethylpyrazole.

Biosynthesis of phenolic tetrahydroisoquinoline alkaloids of peyote.

Abstract Data are presented supporting a proposed pathway of biosynthesis of the phenolic tetrahydroisoquinoline alkaloids of peyote from dopamine. It is suggested that meta - O -methylation of dopamine, hydroxylation in the 5-position, para - O -methylation and finally cyclizations yield anhalamine, anhalidine, anhalonidine and pellotine.