Metabolites from the sponge Pachymatisma johnstoni; L-6-bromohypaphorine, a new amino-acid (and its crystal structure)

Abstract

6-Bromohypaphorine[1-trimethylammonio-3-(6-bromoindol-3-yl)propionate], tryptophan, uracil, thymine, cholest-4-en-3-one and 24-methylenecholest-4-en-3-one have been isolated from P. johnstoni. The structure and configuration of 6-bromohypaphorine were confirmed by X-ray analysis. 6-Bromohypaphorine and related compounds show anomalous mass spectra resulting from thermal reactions in the mass spectrometer.

Pyrolysis of hypaphorine gave a mixture of products including indole, 3-methylindole, and an indolyl-tetrahydrocarbazolecarboxylic acid. Pyrolysis of diethyl(indol-3-ylmethyl)ammonium chloride yielded indole, 3-methylindole, di-indol-3-ylmethane, and related cyclic and open-chain compounds containing three indole units.