Nocatriones A and B, Photoprotective Tetracenediones from a Marine-Derived <i>Nocardiopsis</i> sp.

Abstract

Two new tetracenedione derivatives, nocatriones A (<b>1</b>) and B (<b>2</b>), were discovered from the culture broth of a marine actinomycete, <i>Nocardiopsis</i> sp. KMF-002, which was isolated from the tissue of an unidentified dark purple marine sponge. The structures of <b>1</b> and <b>2</b>, which are tetracenediones containing α-pyrone substituents, were determined to be 3,8,10,11-tetrahydroxy-2-(4-hydroxy-2-oxo-2<i>H</i>-pyran-6-yl)-1-methyltetracene-5,12-dione (<b>1</b>) and 3,8,10,12-tetrahydroxy-2-(4-hydroxy-2-oxo-2<i>H</i>-pyran-6-yl)-1-methyltetracene-6,11-dione (<b>2</b>). Ultraviolet B (UVB)-irradiated cells treated with 10 μM nocatrione A (<b>1</b>) significantly decreased the level of MMP-1, a protein that degrades collagen and other extracelluar matrix components that comprise dermal tissue, when compared to untreated cells. These results support that nocatriones A (<b>1</b>) and B (<b>2</b>) may show antiphotoaging activity in UVB-irradiated models