Antitumor agents from Streptomyces anandii: gilvocarcins V, M and E.

Very recently, ToMITA and coworkers' 2) have reported the fermentation, isolation and structure elucidation of gilvocarcins V (1) and M (2). They note that I was previously described under the name of toromycin by HORII et al.3) although the structure of toromycin was not elucidated. Recently we have isolated 1 and 2 and a related compound gilvocarcin E (3) from a culture of Streptomyces anandii subsp. araffinosns strain C-22437 (ATCC-31431).* The producing culture was isolated at Bristol Laboratories from a soil collected in Katpadi, Madras, India. We report here the isolation, structure elucidation and biological activities of compounds 1. 3. Isolation of Gilvocarcins V, M and E Purification of the complex extract from Streptomyces anandii (C-22437) has led to isolation of the gilvocarcins. The procedure is outlined in Scheme 1. The complex extract was obtained from methyl iso-butyl ketone whole broth extraction under slightly alkaline conditions (pH 9.5 10). In earlier