A new cytotoxic cyclic pentadepsipeptide, neo-N-methylsansalvamide produced by Fusarium solani KCCM90040, isolated from potato

A new cytotoxic cyclic pentadepsipeptide, neo-N-methylsansalvamide, was produced by Fusarium solani KCCM90040, which was isolated from potato in Korea. The species of Fusarium was identified as F. solani by examining its morphological characteristics and by ITS-5.8rDNA sequence analysis. This compound was analysed for C33H52N4O6 by electrospray ionisation mass spectrometry and combined structural analysis. The one and two-dimensional NMR and the absolute configurations of amino acids spectral data allowed the resolution of five subunits linked in the following order: (S)-2-hydroxy-4-methylpentanoic acid, N-methyl-l-leucine, l-valine, l-leucine, and l-phenylalanine. The in vitro cytotoxic effect of the purified cyclic pentadepsipeptide was evaluated to establish the possibility that it would be a biohazard if present in foods. The concentrations of purified cyclic pentadepsipeptide required to inhibit cell growth in vitro by 50% for A549 (lung cancer), SK-OV-3 (ovarian cancer), SK-MEL-2 (skin melanoma), and MES-SA (uterine sarcoma) cell lines were 10.7 ± 0.15, 11.2 ± 1.23, 10.0 ± 0.53, and 14.0 ± 0.74 M, respectively (mean ± SE).