Dicymalides A–C: Three New Phthalide Derivatives From the Mangrove Endophytic Fungus <i>Dicyma</i> sp. L6B1

Three new phthalide derivatives, named dicymalides A-C (1-3), were isolated from the mangrove endophytic fungus Dicyma sp. L6B1, together with eight known compounds. The structures of these compounds were elucidated by high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopic data, single-crystal X-ray diffraction analysis, and specific rotation quantum-chemical calculations. Inhibitory activities of 1-11 against nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells were evaluated. Compound 8 exhibited potent inhibitory activity with a half-maximal inhibitory concentration value of 1.0 µM.