F-19848 A, a novel inhibitor of hyaluronic acid binding to cellular receptor CD44.

In the course of our screening for inhibitors of hyaluronic acid (HA) binding to cellular receptor CD44, a novel inhibitor, F-19848 A, was isolated from the cultured broth of the fungus strain Dacrymyces sp. SANK 20204. This compound inhibited the binding of CD44 and HA with an IC50 value of 23.5 microM and CD44-dependent HA degradation was inhibited with an IC50 value of 98.6 microM in a cell-based assay. The structure was elucidated by physico-chemical properties, analysis of spectral data, and decomposition experiments.