E. Gellert

The structure of alkaloid Y from Schefferomitra subaequalis

Abstract Alkaloid Y has been shown by direct comparison of samples to be identical with Aristolactam BII, the lactam of 10-amino-3,4-dimethoxyphenanthrene-1-carboxylic acid.

Steroidal alkaloids of Marsdenia rostrata

Abstract Some of the main constituents of Marsdenia rostrata , originating from two localities, were isolated and identified. The sample from the Toonumbar State Forest in northern New South Wales contains the known alkaloid anabasine and two new steroidal ester alkaloids, rostratine and dihydrorostratine. They were identified as O -acetyl- O -nicotinoylsarcostin and O -acetyl- O -nicotinoyldihydrosarcostin. The sample from the South Coast of N.S.W. yielded the two new ester alkaloids and a number of neutral polyhydroxy pregnane aglycones, one of which has been identified as metaplexigenin, but there was no anabasine.

The alkaloids ofMitrella kentii(Annonaceae)

Mitrella kentii (Bl.) Rliq. of the family Annonaceae is a tree-climbing liana, found in the oak-forests of New Guinea. The alkaloidal constituents of this species have not previously been examined though field tests1 indicated their presence in the bark. Thin-layer chromatograms of the crude alkaloid mixture (yield: 0.063% of dry weight) resembled those originating from Scheffe~oomita subaequalis,2 another New Guinean liana of the same plant family. In fact all four alkaloids isolated were also present in S, subaequalis. The three main constituents were identified as liriodenine, anonaine, and asimilobine by direct comparison with authentic specimens. The fourth, minor, alkaloid was shown to be identical with aequaline.

Constituents of a new guinea boletus isolation and identification of a new unsaturated α-amino acid

Summary A new unsaturated α-amino acid identified as L -2-amino-4-methyl-5-hexenoic Acid has been isolated from a New Guinea fungus, tentatively identified as Boletus, section Ixocomus , group Nudi ..

The absolute configuration of cryptopleurine and tylocrebrine

The absolute configurations of cryptopleurine and (-)-tylocrebrine have been established as R and S respectively by comparison of their optical rotatory dispersion and circular dichroism spectra with those of tylophorine.

The absolute configuration of the new amino acid 2-amino-4-methyl-hex-5-enoic acid from a new guinea Boletus

Abstract The absolute configuration of the 2-amino-4-methyl-hex-5-enoic acid isolated from Boletus was shown to be 2 S , 4 S , by an unambiguous synthesis of its dihydro derivative from 2 S -(−)-2-methylbutan-1-ol.

Amino acids and steroids of a new guinea Boletus

Abstract In addition to the previously reported isolation of L -2-amino-4-methylhex-5-enoic acid, eleven known amino acids, mannitol, ergosterol, and two new steroids were isolated from an allegedly hallucinogenic Boletus . A modification of the GC-MS method used for the identification of neutral α-amino acids is also reported.

Flavescin: A new 1-ketopolyhydroxypregnene from Marsdenia flavescens

Abstract A new polyhydroxy-1-ketosteroid, flavescin, was isolated from Marsdenia flavescens A. Cunn. Its structure was elucidated as 12- O -acetyl-3β,8β,12β,14β-20-pentahydroxy-Δ 5 - pregnene-1-one.