Endophytic fungus Penicillium chrysogenum, a new source of hypocrellins

Subject and source

Endophytic fungi have proven to be a rich source of novel secondary metabolites with interesting biological activities and a high level of chemical diversity (Schulz and Boyle, 2005, Zhang et al., 2006). In our ongoing screening for biologically active secondary metabolites from endophytic fungi (Zhang et al., 2008a, Zhang et al., 2008b, Zhang et al., 2008c, Zhang et al., 2009), we investigated metabolites produced by the endophytic fungus Penicillium chrysogenum, isolated from Fagonia cretica,

Previous work

Penicillium chrysogenum is widely distributed in nature, and is often found to live on foods and in indoor environments. It is an important filamentous fungus because of its ability to produce large amounts of penicillin (Elander, 2003). The secondary metabolites of P. chrysogenum include various penicillins, chrysogine, xanthocillins, secalonic acids, sorrentanone, and PR-toxin (Hoog et al., 2000). Recently, Singh et al. (2003) reported two novel polyketides xanthoviridicatins E and F from

Present work

The endophytic fungus P. chrysogenum was isolated following surface sterilization from the plant F. cretica, and was cultivated on 12 L of 5% w/v biomalt solid agar medium at room temperature for 28 days (Schulz et al., 1995). The cultures were then extracted with ethyl acetate to afford 19.8 g of residue after removal of the solvent under reduced pressure. A portion of crude extract (1.5 g) was subjected to a silica column chromatography (CC) and separated into 10 fractions, using a gradient

Ecological significance

It is commonly accepted that microorganisms associated with plants in nature are one of the richest sources of new compounds having phytotoxic and plant growth-regulating properties (Greaves, 1996, Tringali, 2001). Secondary metabolites of endophytic microorganisms play very important ecological roles as parasiticides, insect antifeedants, and pathogen inhibitors.

In the present research, the mixture of hypocrellins B and C were isolated as main metabolites of endophytic fungus P. chrysogenum,

Acknowledgments

This research work was financially supported by Natural Science Foundation of China (No. 30873200, 41076082), STCSM Projects (No. 08JC1405600), Shanghai Leading Academic Discipline Project (B906), and Shanghai Pujiang Program (PJ2008). The authors are grateful to Kathrin Meier and Tatjana Stolz for excellent technical assistance.