Staplabin, a novel fungal triprenyl phenol which stimulates the binding of plasminogen to fibrin and U937 cells.

A novel triprenyl phenol, designated staplabin, has been isolated from a culture of Stachybotrys microspora IFO 30018 by solvent extraction and successive chromatographic fractionation using silica gel, Sephadex LH-20 and silica ODS columns. By a combination of spectroscopic analyses, the structure of staplabin is proposed to be 5-(2-(5,7-dihydroxy-8-methyl-8-(4,8-dimethyl-3,7-nonadienyl)-3-oxo -7, 8-dihydro-6H-pyrano[2,3-e][1,3]dihydroisoindolyl)pentanoic acid. Staplabin stimulated the binding of plasminogen, the zymogen of the fibrinolytic serine protease plasmin, to both fibrin and U937 cells. Binding was elevated 2-fold at a concentration of 0.3 approximately 0.5 mM.