Spiroapplanatumines A-Q (1-12, 14-16, 18, and 20), new spiro meroterpenoids respectively bearing a 6/5/7 or 6/5/5 ring system, along with three known compounds, spirolingzhines A, B, and D, were isolated from the fruiting bodies of the fungus Ganoderma applanatum. Their structures including absolute configurations were assigned by using spectroscopic methods, ECD and 13C NMR calculations, and single-crystal X-ray diffraction analysis. Biological evaluation of all the compounds disclosed that compounds 7 and 8 inhibited JAK3 kinase with IC50 values of 7.0 ± 3.2 and 34.8 ± 21.1 μM, respectively.