Three new metabolites from the endophytic fungus Climacocystis montana isolated from the root bark of Paeonia ostia

Abstract Two new pyridine derivatives climacomontaninates A–B ( 1 – 2 ), and a new sesquiterpenoid derivative climacomontanetate ( 3 ), together with twelve known compounds ( 4 – 15 ) were isolated from the culture extract of the fungal strain Climacocystis montana from the root bark of Paeonia ostii . The structures of these compounds were determined through spectroscopic methods such as NMR and HRMS. Moreover, we expound the absolute configuration of 1 using the organic synthesis method. The cytotoxicity against five human cancer cell lines of new compounds were evaluated by SRB assay.