RESUMO
There are several examples of marine organisms whose metabolic profiles differ among conspecifics inhabiting the same region. We have analyzed the metabolic profile of each colony of a Theonella swinhoei marine sponge with a yellow interior and noticed the patchy distribution of one metabolite. This compound was isolated and its structure was studied by a combination of spectrometric analyses and chemical degradation, showing it to be a congener in the theonellamide class of bicyclic peptides. Theonellamides had previously been isolated by us only from T. swinhoei with a white interior and not from those with a yellow interior.
Assuntos
Peptídeos Cíclicos/isolamento & purificação , Theonella/química , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Peptídeos Cíclicos/químicaRESUMO
Nazumazoles D-F (1-3) were isolated from the marine sponge Theonella swinhoei. The compounds gave extremely broad peaks by reversed-phase HPLC using an ODS column. HPLC using a gel permeation column was instrumental for the separation of the three compounds. Their planar structures were determined by interpretation of NMR data to be cyclic pentapeptides. Nazumazoles D-F contained one residue each of α-keto-l-norvaline (l-Knv) {or α-keto-d-leucine (l-Kle)}, l-alanyloxazole (l-Aox), d-Abu (or d-Ser), N-α-CHO-ß-l-Dpr, and cis-4-methyl-l-proline. The absolute configuration of each amino acid residue was determined by Marfey's method in combination with conversion of the α-keto-ß-amino acid to the α-amino acid by oxidation. Nazumazoles D-F are not cytotoxic against P388 cells at 50 µM, but inhibit chymotrypsin.
Assuntos
Peptídeos Cíclicos/isolamento & purificação , Theonella/química , Animais , Cromatografia Líquida de Alta Pressão , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos Cíclicos/químicaRESUMO
A mixture of nazumazoles A-C (1-3) was purified from the extract of the marine sponge Theonella swinhoei. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation of the NMR data and chemical degradations. Nazumazoles contain one residue each of alanine-derived oxazole and α-keto-ß-amino acid residue. Nazumazoles exhibited cytotoxicity against P388 cells.
