PENTATHIEPINS AND TRITHIANES FROM 2 LISSOCLINUM SPECIES AND A EUDISTOMA SP - INHIBITORS OF PROTEIN-KINASE-C

The ascidian Lissoclinum japonicum from Palau contained the antimicrob ial and antifungal metabolites N,N-dimethyl-5-(methylthio)varacin (6) and N-dimethylaminoethyl)-5-(methylthio)benzotrithiane (7), both of wh ich were isolated as the trifluoroacetate salts. An inseparable 2:3 mi xture of 5-(methylthio)varacin (8) and the corresponding trithiane 9 w as isolated from a different Lissoclinum species from Pohnpei and 3,4- desmethylvaracin (10), isolated as the trifluoroacetate salt, was obta ined from a species of Eudistoma from Pohnpei. The pentathiepins and t rithianes selectively inhibit protein kinase C.