Two New Tryptamine Derivatives Leptoclinidamide and (-)-Leptoclinidamine B from an Indonesian Ascidian Leptoclinides dubius

摘要

Two new tryptamine-derived alkaloids, named as leptoclinidamide (>1) and (-)-leptoclinidamine B (>2), were isolated from an Indonesian ascidian Leptoclinides dubius together with C²-α-D-mannosylpyranosyl-L-tryptophan (>3). The structure of >1 was assigned on the basis of spectroscopic data for >1 and its N-acetyl derivative (>4). Compound >1 was an amide of tryptamine with two β-alanine units. Although the planar structure of >2 is identical to that of the known compound (+)-leptoclinidamine B (>5), compound >2 was determined to be the enantiomer of >5 based on amino acid analysis using HPLC methods. Compounds >1 to >4 were evaluated for cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells, but none of the compounds showed activity.