Cyclopiamines C (1) and D (2) were isolated from the extract of Penicillium sp. CML 3020, a fungus sourced from an Atlantic Forest soil sample. Their structures and relative configuration were determined by 1D and 2D NMR, HRMS, and UV/vis data analysis. Cyclopiamines C and D belong to a small subset of rare spiroindolinone compounds containing an alkyl nitro group and a 4,5-dihydro-1H-pyrrolo[3,2,1-ij]quinoline-2,6-dione ring system. NMR and MS/HRMS data confirmed the presence of an epoxide unit (C-17-O-C-18) and a hydroxy group at C-5, not observed for their known congeners. Cytotoxic and antimicrobial activities were evaluated.
Kildgaard, S., de Medeiros, L. S., Phillips, E., Gotfredsen, C. H., Frisvad, J. C., Nielsen, K. F., ... Larsen, T. O. (2018). Cyclopiamines C and D: Epoxide Spiroindolinone Alkaloids from Penicillium sp. CML 3020. Journal of Natural Products, 81(4), 785-790. https://doi.org/10.1021/acs.jnatprod.7b00825