Unstable Tetramic Acid Derivatives from the Deep-Sea-Derived Fungus Cladosporium sphaerospermum EIODSF 008.

ABSTRACT: Seven new unstable tetramic acid derivatives, cladosporiumins I-O (1⁻7), together with the known analogue cladodionen (8) were isolated from the extract of the deep-sea-derived fungus Cladosporium sphaerospermum EIODSF 008. Their structures were elucidated by spectroscopic analysis, quantum chemical calculations and ECD spectra. Compound 4 was a Mg complex of tetramic acid derivative. In acidic solvent, 4 could change to 1 and 6, and 7 could change to 5. In addition, 1, 5 and 8 existed as two exchangeable isomers, respectively. The structures of cladosporiumins E-H were reassigned as their Na complexes. The antibacterial and cytotoxic activities of 1⁻8 were also evaluated. However, beca

SUBMITTER: Liang X 

PROVIDER: S-EPMC6266709 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature