Four new compounds: diaporthichalasins A-C (1-3) and biatriosporin N (7), along with six known compounds (4-6 and 8-10) were separated from the culture of the fungus Diaporthe sp. GZU-1021. The absolute configurations of 1-3 were determined by quantum chemical calculations, X-ray diffraction, and spectroscopic analysis. The structure of 4 was analyzed by X-ray crystallography analysis for the first time. All of the isolates were evaluated on the production of nitric oxide in lipopolysaccharide-induced microglial cells (RAW 264.7 cells). Compounds 5-10 exhibited significant inhibitory effects against nitric oxide production with IC