Phenylhydrazone and Quinazoline Derivatives from the Cold-Seep-Derived Fungus .

Three new phenylhydrazones, penoxahydrazones A-C (compounds -), and two new quinazolines, penoxazolones A (compound ) and B (compound ), with unique linkages were isolated from the fungus obtained from the deep sea cold seep. Their structures and relative configurations were assigned by analysis of 1D/2D NMR and mass spectroscopic data, and the absolute configurations of , , and were established on the basis of X-ray crystallography or ECD calculations. Compound represents the first natural phenylhydrazone-bearing steroid, while compounds and are rarely occurring phenylhydrazone tautomers. Compounds and are enantiomers that feature quinazoline and cinnamic acid units. Some isolates exhibited inhibition of several marine phytoplankton species and marine-derived bacteria.