Sorbifuranones A-C, sorbicillinoid metabolites from Penicillium strains isolated from Mediterranean sponges

• Published in: Tetrahedron 2010-12, Vol.66 (52), p.9894-9901
• Main Authors: Bringmann, Gerhard, Lang, Gerhard, Bruhn, Torsten, Schäffler, Katrin, Steffens, Stefan, Schmaljohann, Rolf, Wiese, Jutta, Imhoff, Johannes F.
• Format: Article
• Language: English
• Subjects: Alicyclic compounds; Alicyclic compounds, terpenoids, prostaglandins, steroids; attribution of absolute configuration; Cadmium; Chemistry; Constitution; Dichroism; Electronics; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Ircinia fasciculata; isolation of marine natural products; Mathematical analysis; Organic chemistry; Penicillium; Penicillium chrysogenum; Preparations and properties; quantum-chemical CD calculations; sorbicillinol derivatives; Sponges; Strain; structure elucidation; Tethya aurantium
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2010.10.057

Three novel natural products, sorbifuranones A-C ( 4- 6), were isolated from a Penicillium chrysogenum fungus isolated from the marine sponge Ircinia fasciculata. Sorbifuranones B ( 5) and C ( 6) and 2',3'-dihydrosorbicillin, a putative precursor to sorbifuranone B, were also found in the culture of another Penicillium strain, which was isolated from the sponge Tethya aurantia. Their constitutions were elucidated mainly by 2D NMR. NOE correlations in combination with quantum chemical calculations and comparison of experimental and calculated electronic circular dichroism (CD) spectra permitted assignment of the absolute configuration of sorbifuranone C. The structures hint at a two-step cleavage-cyclization sequence of sorbifuranone A ( 4) leading to the spiro compound sorbifuranone C, while sorbifuranone B is likely to be the respective cleavage product of a putative 2',3'-dihydrosorbifuranone A, which cannot cyclize further. ▪