PYRIDOACRIDINE ALKALOIDS FROM DEEP-WATER MARINE SPONGES OF THE FAMILY PACHASTRELLIDAE - STRUCTURE REVISION OF DERCITIN AND RELATED-COMPOUNDS AND CORRELATION WITH THE KUANONIAMINES

The single-crystal X-ray diffraction of a novel alkaloid, stellettamine (15), together with long-range H-1-C-13 coupling constants obtained by inverse detection methods, and metal chelation studies have shown that the previously reported regiochemistry of the thiazole moiety of dercitin (1) and four other related alkaloids 2-5 has to be revised. The corrected structures 10-14 are related to, and in one case identical to, those of the kuanoniamines 6-9.