title: Spiroscytalin, a new tetramic acid and other metabolites of mixed biogenesis from Scytalidium cuboideum.
abstract: Spiroscytalin (1), a new tetramic acid that possesses an uncommon spiro-ring fusion between a polyketide-derived octalin ring system and a 2,4-pyrrolidinedione, along with two known compounds, leporin B (2) and purpactin A (3), were isolated from a solid phase culture of the fungus Scytalidium cuboideum (MSX 68345). The molecular connectivity of 1-3 was determined using NMR spectroscopy and mass spectrometry. The relative configurations of 1 and 2 were determined by NOESY experiments. The absolute configuration of 1 was determined by electronic circular dichroism (ECD) via a combination of experimental measurements and computational calculations. While leporin B was known, it displayed activities that had not been reported previously, including cytotoxicity against three human tumor cell lines and antibacterial activity against Candida albicans and Staphylococcus aureus.
authors.affiliation: University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States.
authors.forename: Arlene A
authors.initials: AA
authors.lastname: Sy-Cordero
authors.affiliation: Facultad de Química, Universidad Nacional Autónoma de México, Mexico DF 04510, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Figueroa
authors.affiliation: University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States.
authors.forename: Huzefa A
authors.initials: HA
authors.lastname: Raja
authors.affiliation: University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States.
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Meza Aviña
authors.affiliation: University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States.
authors.forename: Mitchell P
authors.initials: MP
authors.lastname: Croatt
authors.affiliation: Department of Pharmaceutical Sciences, BRITE, North Carolina Central University, Durham, NC 27707, United States.
authors.forename: Audrey F
authors.initials: AF
authors.lastname: Adcock
authors.affiliation: Department of Pharmaceutical Sciences, BRITE, North Carolina Central University, Durham, NC 27707, United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kroll
authors.affiliation: Natural Products Laboratory, Research Triangle Institute, Research Triangle Park, NC 27709, United States.
authors.forename: Mansukh C
authors.initials: MC
authors.lastname: Wani
authors.affiliation: Mycosynthetix, Inc., Hillsborough, NC 27279, United States.
authors.forename: Cedric J
authors.initials: CJ
authors.lastname: Pearce
authors.affiliation: University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, United States.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Oberlies
keywords: Leporin B; Purpactin A; Scytalidium cuboideum; Tetramic acid