Teratopyrones A–C, Dimeric Naphtho-γ-Pyrones and Other Metabolites from <i>Teratosphaeria</i> sp. AK1128, a Fungal Endophyte of <i>Equisetum arvense</i>
Ya-Ming Xu,
A. Elizabeth Arnold,
Jana M. U′Ren,
Li-Jiang Xuan,
Wen-Qiong Wang,
A. A. Leslie Gunatilaka
Affiliations
Ya-Ming Xu
Southwest Center for Natural Products Research, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 E, Valencia Road, Tucson, AZ 85706, USA
A. Elizabeth Arnold
School of Plant Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Jana M. U′Ren
School of Plant Sciences, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Li-Jiang Xuan
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
Wen-Qiong Wang
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
A. A. Leslie Gunatilaka
Southwest Center for Natural Products Research, School of Natural Resources and the Environment, College of Agriculture and Life Sciences, University of Arizona, 250 E, Valencia Road, Tucson, AZ 85706, USA
Bioassay-guided fractionation of a cytotoxic extract derived from a solid potato dextrose agar (PDA) culture of Teratosphaeria sp. AK1128, a fungal endophyte of Equisetum arvense, afforded three new naphtho-γ-pyrone dimers, teratopyrones A–C (1–3), together with five known naphtho-γ-pyrones, aurasperone B (4), aurasperone C (5), aurasperone F (6), nigerasperone A (7), and fonsecin B (8), and two known diketopiperazines, asperazine (9) and isorugulosuvine (10). The structures of 1–3 were determined on the basis of their spectroscopic data. Cytotoxicity assay revealed that nigerasperone A (7) was moderately active against the cancer cell lines PC-3M (human metastatic prostate cancer), NCI-H460 (human non-small cell lung cancer), SF-268 (human CNS glioma), and MCF-7 (human breast cancer), with IC50s ranging from 2.37 to 4.12 μM while other metabolites exhibited no cytotoxic activity up to a concentration of 5.0 μM.
