Axinellin A and B: Two New Pyrrolactam Alkaloids from Axinella sp.
Two new pyrrolactam alkaloids, axinelline A (1) and B (2), were isolated from the n-BuOH extract of marine sponge Axinella sp. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D and 2D NMR).
Cylindradines A and B: novel bromopyrrole alkaloids from the marine sponge Axinella cylindratus.
The novel alkaloids cylindradines A and B were isolated from Axinella cylindratus, and their structures were elucidated by spectroscopic analyses. Stereochemistries of these compounds were determined by X-ray analysis. Cylindradines showed moderate inhibitory activity against the murine leukemia cell line P388.
Isolation and structure of the marine sponge cell growth inhibitory cyclic peptide phakellistatin 1.
A new cell growth inhibitory (P-388 murine leukemia ED50 7.5 micrograms/ml) cycloheptapeptide designated phakellistatin 1 was isolated from two Indo-Pacific sponges, Phakellia costata and Stylotella aurantium. Structural elucidation was accomplished utilizing high field nmr, amino acid analyses, and mass spectral techniques (fab, tandem ms/ms), followed by chiral gas chromatographic procedures for absolute configuration assignments (all S-amino acid units). By these methods phakellistatin 1 [1] was found to be cyclo (Pro-Ile-Pro-Ile-Phe-Pro-Tyr), and this assignment was finally confirmed by an X-ray crystal structure determination.