Koninginins N-Q, Polyketides from the Endophytic Fungus Trichoderma koningiopsis Harbored in Panax notoginseng

Endophytic microorganisms, residing in the living tissues of the host plant and forming complex relationships with the host, are to be found in every plant on earth. Species of Trichoderma , ubiquitous in the environment including plant and soil, produce a plethora of substances with potential use for modern agriculture, and industry [ 1 , 2 ]. Some Trichoderma species can be used to enhancing plant growth and resistance to the biotic and abiotic stresses, such as antagonizing plant-pathogenic fungi, stimulating plant growth and defense responses, and inducing salt tolerance [ 3 , 4 ]. At global level, Trichoderma species are widely used as a powerful biocontrol agent for plant diseases [ 5 ]. Chemical exploitation of Trichoderma spp. afforded a diverse of bioactive secondary metabolites [ 6 – 9 ]. Over the course of our ongoing search for new naturally occurring bioactive products from endophytic fungi associated with famous Chinese traditional medicine, Panax notoginseng [ 10 ], the chemical investigation of endophytic fungus Trichoderma koningiopsis YIM PH30002 was found with inhibiting the growth of some phytopathogenic fungi [ 11 ]. Four new metabolites named koninginins N-Q ( 1 – 4 ), together with four known koninginins B ( 5 ), E ( 6 ), J ( 7 ), and 7- O -methylkoninginin D ( 8 ) were isolated [ 9 , 12 – 14 ] (Fig. 1 ). In the present paper, we report the isolation, structural elucidation and bioactivities of these fungal polyketides.