A new depsidone, termed mollicellin Z2 ( 1 ), and three known mollicellins D, H, and I ( 2 – 4 ), were isolated from cultured Chaetomium brasiliense NBRC 6548 mycelia. The structure of 1 was determined from one dimensional (1D) and 2D-NMR and high resolution electron ionization (HREI)MS spectra. It is the first 4-desmethyl mollicellin analogue found to contain a C-7 prenyl group and is likely generated via a biosynthetic pathway that is distinct from those that produce the 27 known analogues. This is the first report of mollicellin derivatives with antibacterial activity against nontuberculous mycobacteria.
Morita et al. (Thu,) studied this question.