title: Bioactive Dibenzo-α-pyrone Derivatives from the Endophytic Fungus Rhizopycnis vagum Nitaf22.
abstract: Six new dibenzo-α-pyrones, rhizopycnolides A (1) and B (2) and rhizopycnins A-D (3-6), together with eight known congeners (7-14), were isolated from the endophytic fungus Rhizopycnis vagum Nitaf22 obtained from Nicotiana tabacum. The structures of the new compounds were unambiguously elucidated using NMR, HRESIMS, TDDFT ECD calculation, and X-ray crystallography data. Rhizopycnolides A (1) and B (2) feature an uncommon γ-butyrolactone-fused dibenzo-α-pyrone tetracyclic skeleton (6/6/6/5), while rhizopycnin B (4) was the first amino group containing dibenzo-α-pyrone. Rhizopycnolides A (1) and B (2) are proposed to be biosynthesized from polyketide and tricarboxylic acid cycle pathways. The isolated compounds were tested for their antibacterial, antifungal, and cytotoxic activities. Among them, rhizopycnolide A (1), rhizopycnins C (5) and D (6), TMC-264 (8), penicilliumolide D (11), and alternariol (12) were active against the tested pathogenic bacteria Agrobacterium tumefaciens, Bacillus subtilis, Pseudomonas lachrymans, Ralstonia solanacearum, Staphylococcus hemolyticus, and Xanthomonas vesicatoria with MIC values in the range 25-100 μg/mL. Rhizopycnin D (6) and TMC-264 (8) strongly inhibited the spore germination of Magnaporthe oryzae with IC50 values of 9.9 and 12.0 μg/mL, respectively. TMC-264 (8) showed potent cytotoxicity against five human cancer cell lines (HCT-116, HepG2, BGC-823, NCI-H1650, and A2780) with IC50 values of 3.2-7.8 μM.
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Daowan
authors.initials: D
authors.lastname: Lai
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Ali
authors.initials: A
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Yuheng
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Kaiyi
authors.initials: K
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Ziling
authors.initials: Z
authors.lastname: Mao
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Dong
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.|National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences , Beijing 100101, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Tian
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Science & Peking Union Medical College , Beijing 100050, People's Republic of China.
authors.forename: Jungui
authors.initials: J
authors.lastname: Dai
authors.affiliation: Technical Centre of Hunan Tobacco Industry Co. Ltd. , Changsha 410014, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Key Laboratory of Plant Pathology, Ministry of Agriculture/Department of Plant Pathology, College of Plant Protection, China Agricultural University , Beijing 100193, People's Republic of China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Processing, Ministry of Agriculture , Beijing 100193, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D015107:4-Butyrolactone / Q000737:chemistry; D016960:Agrobacterium tumefaciens / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001203:Ascomycota / Q000737:chemistry*; D001412:Bacillus subtilis / Q000187:drug effects / Q000378:metabolism; D002867:Chromones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D056945:Hep G2 Cells; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007783:Lactones / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D061065:Polyketides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D011549:Pseudomonas / Q000187:drug effects; D043368:Ralstonia solanacearum / Q000187:drug effects; D013210:Staphylococcus / Q000187:drug effects; D014026:Nicotiana / Q000382:microbiology; D044184:Xanthomonas vesicatoria / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D002867:Chromones; D006575:Heterocyclic Compounds, 3-Ring; D007783:Lactones; D061065:Polyketides; C476504:TMC-264; C005197:alternariol; D015107:4-Butyrolactone