Heteroaromatic alkaloids, nakijinamines, from a sponge Suberites sp

• Published in: Tetrahedron 2012-10, Vol.68 (41), p.8545-8550
• Main Authors: Takahashi, Yohei, Tanaka, Naonobu, Kubota, Takaaki, Ishiyama, Haruaki, Shibazaki, Azusa, Gonoi, Tohru, Fromont, Jane, Kobayashi, Jun’ichi
• Format: Article
• Language: English
• Subjects: Alkaloids; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiinfectives and antibacterials; Biological and medical sciences; Chemistry; Conformational analysis; Conversion; Exact sciences and technology; General aspects; Heteroaromatic alkaloids; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Hybrid structures; Marine; Marine sponge; Medical sciences; Metabolites; Nakijinamines; Organic chemistry; Pharmacology. Drug treatments; Preparations and properties; Sponges; Suberites; Suberites sp; Tetrahedrons
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2012.08.018

The structures of seven new secondary metabolites isolated from an Okinawan marine sponge Suberites sp., nakijinamines A (1), B (2), and F–I (3–6) and 6-bromoconicamin (7), have been elucidated on the basis of spectroscopic analysis, chemical conversion, and conformational analysis. These analyses disclosed that 1–6 were heteroaromatic alkaloids having the hybrid structures of an aaptamine-type alkaloid and an indole alkaloid, while 7 was a bromoindole alkaloid. Nakijinamine I (6) is the first example of an aaptamine-type alkaloid possessing a 1,4-dioxane ring. Antimicrobial activities of 1–7 were evaluated. [Display omitted]