Brominated tyrosine-derived metabolites from the sponge Ianthella basta

Abstract

Seven novel metabolites, each originating from four bromotyrosine units, have been isolated from the sponge Ianthella basta. Bastadin-1 (2), bastadin-2(3) and bastadin-3(4) are derived from a single phenol oxidative coupling whilst the macrocyclic compounds bastadin-4(5), bastadin-5(6), bastadin-6(8) and bastadin-7(7) are formed by two phenol oxidative coupling reactions. Compounds (2)-(8) showed potent in vitro antimicrobial activity against Gram-positive organisms.

Bromoalterochromides A and A′, Unprecedented Chromopeptides from a Marine Pseudoalteromonas maricaloris Strain KMM 636T†

“…The pattern of three aromatic 1 H NMR signals indicated protons in 1,2,4-position of a benzene ring. On comparison with 1b/1bЈ, the third substituent must be bromine, whose position at C-3Ј of the benzene ring was further confirmed by HMBC spectra and by comparison with reference data of aplysillin A [4] and bastadin-1 [5]. The expected olefin signals of 1d/1dЈ appeared at dϭ6.83 and 6.02, which is explained best by a double bond in a -position to the carbonyl group.…”

Bastadin 10 Stabilizes the Open Conformation of the Ryanodine-sensitive Ca2+ Channel in an FKBP12-dependent Manner

“…Structural differences between B5 and B10 undoubtedly underlie both their ability to interact with a novel binding domain requiring the integrity of the RyR1-FKBP12 complex and the different manner in which each alters channel function. The solution conformation of each molecule can be approximated by the x-ray structure of B5 tetra-O-methyl ether which has been previously reported (20). Each solution conformation is, of necessity, nonplanar as a consequence of non-bonded steric interactions between aryl ring substituents (especially bromine) and torsional constraints within the macrocyclic ring (Fig.…”

“…The unique actions of bastadin 10 (B10) were originally predicted to exist from results obtained with extracts containing a mixture of bastadins (17,19 13 C NMR, and matrix-assisted laser desorption, ionization Fourier transfer mass spectrometry data and compared with literature data (20).…”

The Marine Bromotyrosine Derivatives

“…The remaining 20 bastadins possess a macrocyclic system, which was given a name bastarane and numbered as shown (129). According to the oxidative cyclization, there are two structural classes, i.e.…”

“…The majority of the bastadins were isolated from the marine sponge Ianthella basta (class Demospongiae, order Verongida, family Inthellidae) with several obtained from I. flabelliformis, I. quadrangulata, Ianthella sp., and Psammaplysilla purpurea. Bastadins 1-7 (204)(205)(206)(207)(208)(209)(210)(211) were isolated from the Australian sponge I. basta, as antimicrobial agents against Gram positive organisms in 1980 (128,129). Their structures were determined by spectroscopic methods and alcoholic KOH hydrolysis.…”