In the course of discovering new metabolites from co-culture of Penicillium pinophilum FKI-5653 and Trichoderma harzianum FKI-5655, a new compound, designated secopenicillide C, and four known compounds, penicillide, MC-141, pestalasin A and stromemycin were isolated. The production of these compounds, except pestalasin A, was enhanced in co-culture to be two to six times higher than in pure culture of Penicillium pinophilum FKI-5653, which was the producer of these compounds.