title: Bioactive bis-naphtho-γ-pyrones from rice false Smut pathogen Ustilaginoidea virens.
abstract: Ustilaginoidins were bis-naphtho-γ-pyrones mycotoxins possessing an aR configuration of the chiral axis previously reported from the false smut balls of rice infected by the fungal pathogen Ustilaginoidea virens. To investigate the chemical diversity of these metabolites and their bioactivities, we fermented this fungus on solid rice media, which afforded the isolation of 13 ustilaginoidins, including seven new compounds, namely ustilaginoidins K-P, 1-6, and E1, 7, together with the known ustilaginoidins A, 8, D, 9, E, 10, F, 11, and G, 12, and isochaetochromin B2, 13. The structures of the new compounds were elucidated by using (1D, 2D) NMR, high-resolution mass spectrometry, UV, and circular dichroism, as well as by comparison with the literature data. A plausible biosynthesis pathway was proposed for these dimeric polyketides. The isolated compounds were evaluated for their antibacterial, cytotoxic, and radicle elongation inhibitory activities. Ustilaginoidins K, 1 and L, 2 showed cytotoxic activities on the A2780 human ovarian cancer cell line with IC50 values of 4.18 and 7.26 μM, respectively. Ustilaginoidins N, 4, D, 9, E, 10, and G, 12 were active against the tested pathogenic bacteria with MIC values in the range of 16-64 μg/mL. Ustilaginoidins O, 5, E, 10, and F, 11, and isochaetochromin B2, 13 displayed moderate inhibitory activity on the radicle elongation of rice seeds.
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Shiqiong
authors.initials: S
authors.lastname: Lu
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Weibo
authors.initials: W
authors.lastname: Sun
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Meng
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Ali
authors.initials: A
authors.lastname: Wang
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Wang
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Tian
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Fu
authors.forename: Jungui
authors.initials: J
authors.lastname: Dai
authors.affiliation: §Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Daowan
authors.initials: D
authors.lastname: Lai
authors.affiliation: †MOA Key Laboratory of Plant Pathology, Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D045744:Cell Line, Tumor; D005260:Female; D005285:Fermentation; D006801:Humans; D006999:Hypocreales / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D009183:Mycotoxins / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry*; D009281:Naphthalenes / Q000032:analysis* / Q000737:chemistry; D012275:Oryza / Q000382:microbiology*; D010051:Ovarian Neoplasms; D010935:Plant Diseases / Q000382:microbiology; D011753:Pyrones / Q000032:analysis* / Q000737:chemistry; D012639:Seeds / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D009183:Mycotoxins; D009281:Naphthalenes; D011753:Pyrones
keywords: Ustilaginoidea virens; Villosiclava virens; bis-naphtho-γ-pyrone; mycotoxin; rice false smut; rice false smut pathogen; ustilaginoidin