Gerfelin, a novel inhibitor of geranylgeranyl diphosphate synthase from Beauveria felina QN22047. II. Structural elucidation.

Sir: Protein geranylgeranylation of small GTP-binding proteins, such as Rho, Rac, Cdc42 and Rab1), is essential for the function of the modified proteins. Protein geranylgeranylation is a key target for chemotherapeutic intervention in a number of diseases. Because geranylgeranyl diphosphate synthase (GGPP synthase)2,3) is involved in a pathway for protein geranylgeranylation, we screened an inhibitor of GGPP synthase, and we have isolated gerfelin (1a) from a culture broth of Beauveria felina QN22047. In the preceding paper4), the taxonomy, fermentation, isolation and biological activities were reported. In this paper, we describe the physico-chemical properties and structural elucidation of 1a. The physico-chemical properties of 1a are summarized in Table 1. 1a was isolated as a white powder. 1a is readily soluble in methanol and acetone, but insoluble in chloroform and acetonitrile. The UV spectrum acquired