Year

1972

Degree Name

Doctor of Philosophy

Department

Department of Chemistry

Abstract

The constituents of the bark and leaves of Schefferomitra subaequalis belonging to the family Annonaceae and those of an allegedly hallucinogenic Boletus species, section Ixocomus, group Nudi, both originating from New Guinea, were investigated.

Eight alkaloids were isolated from the bark of Sch. subaegualis. Two of these: liriodenine and anonaine, were already known to be present in Sch. subaegualis. In this investigation three other aporphine alkaloids, asimilobine, isoboldine and anolobine were isolated and identified. In addition two new tetrahydroprotoberberine type alkaloids, aequaline and schefferine and a third new alkaloid, described as alkaloid "Y" have been isolated. The structures of aequaline and schefferine were elucidated as L-3, 9-dihydroxy-2, 10-dimethoxy tetrahydroprotoberberine and L-9-hydroxy-2,3,10-trimethoxy tetrahydroprotoberberine respectively, and their absolute configurations established as S. The structure of the alkaloid "Y" is not yet known.

From the leaves of Sch. subaequalis six of the above eight alkaloids viz. anonaine, asimilobine, isoboldine, anolobine, aequaline and schefferine were isolated. Only the two coloured alkaloids: liriodenine and alkaloid "Y" were absent.

From the Boletus species there were isolated mannitol and ergosterol and the known amino acids: leucine, isoleucine, valine, methionine, tyrosine, alanine, threonine, glycine, arginine, lysine and histidine.

One of the major constituents of the free amino acid pool in this Boletus was found to be a new unsaturated α-amino acid, the structure of which has been elucidated as 2(S)-amino-4-methylhex-5-enoic acid.

In addition two apparently new steroids have been isolated and characterised but due to shortage of available material no structural assignments have been made for these compounds.

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