title: An endophytic Coniochaeta velutina producing broad spectrum antimycotics.
abstract: An endophyte (PC27-5) was isolated from stem tissue of Western hemlock (Tsuga heterophylla) in a Pacific Northwest temperate rainforest. Phylogenetic analyses, based on ITS-5.8S rDNA and 18S rDNA sequence data, combined with cultural and morphological analysis showed that endophyte PC27-5 exhibited all characteristics of a fungus identical to Coniochaeta velutina. Furthermore, wide spectrum antimycotics were produced by this endophyte that were active against such plant pathogens as Sclerotinia sclerotiorum, Pythium ultimum, and Verticillium dahliae and lethal to Phythophthora cinnamomi, Pythium ultimum, and Phytophthora palmivora in plate tests. The bioactive components were purified through organic solvent extraction, followed by silica column chromatography, and finally preparative HPLC. The minimum inhibitory concentration of the active fraction to Pythium ultimum, which was gained from preparative HPLC, was 11 μg/ml. UPLC-HRMS analysis showed there were two similar components in the antimycotic fraction. Their molecular formulae were established as C30H22O11 (compound I) and C30H22O10 (compound II) respectively, and preliminary spectral results indicate that they are anthroquinone glycosides. Other non-biologically active compounds were identified in culture fluids of this fungus by spectral means as emodin and chrysophanol--anthroquinone derivatives. This is the first report that Coniochaeta velutina as an endophyte produces bioactive antifungal components.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, 400715, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xie
authors.forename: Gary A
authors.initials: GA
authors.lastname: Strobel
authors.forename: Tao
authors.initials: T
authors.lastname: Feng
authors.forename: Huishuang
authors.initials: H
authors.lastname: Ren
authors.forename: Morgan T
authors.initials: MT
authors.lastname: Mends
authors.forename: Zeyang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Brad
authors.initials: B
authors.lastname: Geary
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D001203:Ascomycota / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002853:Chromatography, Liquid; D016000:Cluster Analysis; D003600:Cytosol / Q000737:chemistry; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D060026:Endophytes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008828:Microbiological Techniques; D008969:Molecular Sequence Data; D010802:Phylogeny; D018547:Plant Stems / Q000382:microbiology; D011775:Pythium / Q000187:drug effects; D011809:Quinones / Q000032:analysis; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017422:Sequence Analysis, DNA; D028225:Tsuga / Q000382:microbiology
chemical_list: D000935:Antifungal Agents; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D011809:Quinones; D012337:RNA, Ribosomal, 18S; D012340:RNA, Ribosomal, 5.8S