Tenuecyclamides A-D, cyclic hexapeptides from the cyanobacterium Nostoc spongiaeforme var. tenue.
Four modified cyclic hexapeptides, tenuecyclamides A-D (1-4), were isolated along with the known antibiotic, borophycin (5), from the methanol extract of Nostoc spongiaeforme var. tenue (TAU strain IL-184-6). The planar structure of tenuecyclamides A-D (1-4) was determined by homonuclear and inverse-heteronuclear 2D-NMR techniques as well as by high-resolution mass spectrometry measurements. The absolute configuration of the asymmetric centers was studied by Marfey's method for HPLC. The stereochemistry of the asymmetric centers in tenuecyclamides A and B (1 and 2) could not be fully determined, while that of tenuecyclamides C and D (3 and 4) was unambiguously determined.
Banker
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School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
Carmeli
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D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000458:Cyanobacteria / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012617:Sea Urchins
D000900:Anti-Bacterial Agents; D009842:Oligopeptides; D010456:Peptides, Cyclic