Palmarumycins from the Endophytic Fungus Lasiodiplodia pseudotheobromae XSZ‐3

One new and three known spiro-dioxynaphthalene compounds, related to palmarumycins, were isolated from the extracts of fungus Lasiodiplodia pseudotheobromae XSZ-3. Their structures were established by spectroscopic methods (1D- and 2D-NMR, HR-ESI-MS, etc.). The absolute configuration of 1 was determined by comparison of quantum-chemical TDDFT (time-dependent density-functional theory) calculated and experimental ECD (electronic circular dichroism) spectra. The cytotoxic activities of 1–4 against HL-60 cell line were evaluated by trypan blue-staining assay.