Diclavatol and tetronic acids from Penicillium griseoroseum

Abstract

In our continuous studies on the chemistry of the endophytic fungus Penicillium griseoroseum, an endophyte isolated from fruits of Coffea arabica, we isolated clavatol, a dimethylated tetraketide, and its dimer which appears to be a novel natural compound. The studies also resulted in the identification of two known tetronic acids, viridicatic acid and terrestric acid, found in ethyl acetate and n-butanol extracts. Spectroscopic studies using 1-D and 2-D NMR and MS/MS analysis were performed to determine the structures of these compounds, first reported by this Penicillium. Two other tetronic acids congeners were identified through HPLC/MS/MS studies, based on fragmentation pattern of ions produced from ionised tetronic acids, and UV light absorptions.

Keywords:

• diclavatol
• Penicillium griseoroseum
• endophytic fungi
• tetronic acids

Acknowledgements

The authors are grateful to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES) for their financial support.