ABSTRACT
A previously unreported heterodetic cyclic peptide, homophymamide A (1), was isolated from a Homophymia sp. marine sponge. The structure of homophymamide A was determined to be a lower homologue of anabaenopeptins by spectroscopic analysis, chemical degradation, and chemical synthesis. Analysis of the acidic hydrolysate showed that the racemization of Lys took place, leading us to pose a cautionary note on the configurational assignment of peptides that contain a ureido bond.
Subject(s)
Peptides, Cyclic/chemistry , Porifera/chemistry , Animals , Japan , Molecular StructureABSTRACT
New sesquiterpene quinones, metachromins X (1) and Y (2), together with the known metachromins C (3), J (4), and T (5), were isolated as inhibitors of cell cycle progression in the HeLa/Fucci2 cells. The structure of 1 was assigned by spectroscopic data and confirmed by a total synthesis. The planar structure of 2 was determined by interpretation of spectroscopic data, whereas its absolute configuration was analyzed by a combination of chiral HPLC and CD spectroscopy. Metachromins X (1) and C (3) arrested the cell cycle progression of HeLa/Fucci2 cells at S/G2/M phase.
Subject(s)
Antineoplastic Agents/pharmacology , Porifera/chemistry , Sesquiterpenes/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Cycle/drug effects , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HeLa Cells , Humans , Molecular Structure , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Structure-Activity Relationship , Tumor Cells, CulturedABSTRACT
N6-Isopentenyladenosine (i6A) was isolated from a marine sponge Oceanapia sp. as the major cytotoxic constituent along with N6-isopentenyladenosine 5'-monophosphate (i6AP) which was inactive. The structures of i6A and i6AP were assigned by a combination of the analysis of NMR spectroscopy and mass spectrometry. This is the first isolation of i6A and i6AP from a marine sponge.
