Kazuaki Tanaka's research while affiliated with Hirosaki University and other places

Publications (116)

Article
A potent antifungal fusicoccane dehydroxypericonicin A (1) was isolated from Roussoella sp. along with known allantofuranone (2). The relative structure of 1 was fully elucidated by NMR spectroscopic manner. The suggested relative structure was confirmed by DFT (density functional theory)-based 13C NMR chemical shift calculations. The absolute conf...
Article
5-Dehydrodecaspirones F (1) and H (2) were isolated from Phaeoseptum sp. KT4106 along with known structurally related compounds involving palmarumycins CP4a (3) and CP5 (4). Although these were reported to be pseudo-enantiomers, our chirality reinvestigation found that both possess (2S)-configuration.
Article
The effectiveness and limitations of density functional theory (DFT) calculations in the structural determination of complexed and conformationally flexible natural products were demonstrated using the cyclohelminthols CP-1 (1) CP-2 (2), CP-3 (3), and CP-4 (4) newly isolated from Helminthosporium velutinum yone96. Prior to DFT calculations, the str...
Article
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Freshwater Dothideomycetes are a highly diverse group of fungi, which are mostly saprobic in freshwater habitats worldwide. They are important decomposers of submerged woody debris and leaves in water. In this paper, we outline the genera of freshwater Dothideomycetes with notes and keys to species. Based on multigene analyses and morphology, we in...
Article
Seiridiasteriscane A (1), pestalotiopsins L-N (2–4), and 2-O-deacetylpestalotiopsin A (5) were isolated along with known pestalotiopsins A (7), B (6), and fuscoatrol A (8) from Seiridium sp. KT3957. Their relative structures were elucidated by extensive NMR analysis and verified using DFT (density functional theory) chemical shift calculations. The...
Preprint
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This article provides an outline of the classification of the kingdom Fungi (including fossil fungi. i.e. dispersed spores, mycelia, sporophores, mycorrhizas). We treat 19 phyla of fungi. These are Aphelidiomycota, Ascomycota, Basidiobolomycota, Basidiomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomoph...
Article
Cyclopericodiol (1) and two new chlorinated melleins (2 and 3) were isolated from Periconia macrospinosa KT3863. The results of density functional theory (DFT)-based calculations while estimating the values of the ¹³C chemical shifts and the spin coupling constants allowed to determine the relative configurations of 1 and 2. The absolute configurat...
Article
Peribysins O (1), P (3), and Q (4) were isolated from Periconia macrospinosa KT3863. The relative configuration of the 6,7-epoxide of 1 was elucidated by performing quantitative NOE experiments. The structure of 2, which is a tautomer of 1 present in CDCl 3 solutions in 5% abundance, was also fully characterized by NMR analysis. Their absolute conf...
Article
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A new genus, Crassiperidium, is established to accommodate two new species, C. octosporum and C. quadrisporum, found on twigs of the Fagus crenata in Japan. Crassiperidium is characterized by globose to depressed globose ascomata with a well-developed ascomatal wall at the sides, clavate asci, broadly fusiform, hyaline ascospores, pycnidial conidio...
Article
Diaporhte species are plant pathogens rarely involved in human diseases, especially eye diseases. We report our findings in two undescribed Diaporhte species. Both were identified by their morphological characteristics and by DNA sequence analyses. In Case 1, an 81-year-old male farmer who had pterygium surgery 7 years earlier developed keratitis a...
Article
A previously undescribed mycopappus‐like fungus associated with large zonate leaf spot disease of Styrax obassia was found in Japan. Single‐propagule isolation of the fungus from necrotic areas of the diseased leaves yielded four pure cultures. Pathogenicity tests of the fungus were performed on potted S. obassia plants. Leaves were wounded with a...
Article
Apple bitter rot caused by Colletotrichum acutatum sensu lato results in fruit decay before and after harvest. We investigated the epidemiology of the disease in terms of conidial formation and dispersal as well as the change in susceptibility of fruits in Iwate, Japan. Conidia of C. acutatum were detected in rainwater collected from inside the tre...
Article
Cyclohelminthols Y1-Y4 (1-4) were isolated from the culture broth of Helminthosporium velutinum yone96. These compounds are diastereomers to each other featuring 3-azabicyclo[3.1.0]hexane-6-spirocyclopentane linked with a cyclopentanespirocyclopropane framework. Their planar structures were established via the comparison of their spectra with the s...
Thesis
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We conducted the biotransformation of 4-chromanone and 4-chromanol using two kinds of fungi, Botrytis cinerea and Colletotrichum acutatum, as biocatalysts. The biotransformation of 4-chromanone using B. cinerea yielded 98.6% 4-chromanol by day 3. This chiral compound was identified as (R)-4-chromanol (76.4% yield) and its enantiomer excess was 52.8...
Article
Full-text available
We conducted the biotransformation of 4-chromanone and 4-chromanol using two kinds of fungi, Botrytis cinerea and Colletotrichum acutatum, as biocatalysts. The biotransformation of 4-chromanone using B. cinerea yielded 98.6% 4-chromanol by day 3. This chiral compound was identified as (R)-4-chromanol (76.4% yield) and its enantiomer excess was 52.8...
Article
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Knowledge of the relationships and thus the classification of fungi, has developed rapidly with increasingly widespread use of molecular techniques, over the past 10–15 years, and continues to accelerate. Several genera have been found to be polyphyletic, and their generic concepts have subsequently been emended. New names have thus been introduced...
Article
A new genus, Brevicollum, is established for two new species, B. hyalosporum on Syzygium samarangense and B. versicolor on Volkameria inermis, in Japan. This genus is characterized by the presence of immersed ascomata with an excentric to central, short cylindrical ostiolar neck, thin ascomatal wall, clavate asci with a shallow ocular chamber, and...
Article
Helminthosporium velutinum yone96 produces cyclohelminthol X (1), a unique hexa-substituted spirocyclopropane. Although its molecular formula and NMR spectral data resemble those of AD0157, being isolated from marine fungus Paraconiothyrium sp. HL-78-gCHSP3-B005, our detailed analyses disclosed totally different structure. Chemical shift calculatio...
Article
We describe an 82-year-old male farmer who had diabetes mellitus with no history of ocular trauma by soil or plants and who developed a corneal infection due to a fungus. The organism was identified as Roussoella solani based on both the morphological characteristics and phylogenetic analysis using LSU and ITS nrDNA sequences. The sexual stage of R...
Article
During an assessment of biodiversity of ascomycetous fungi in the South China Karst area in Guizhou Province, China, a novel species of Prosthemium was collected. We isolated the taxon and sequenced the ITS, LSU and TUB gene regions. The novel taxon is characterized by immersed, globose or depressed globose ascomata, flattened, papillate ostioles,...
Article
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Synnemapestaloides rhododendri, the type species of the genus Synnemapestaloides, is a pathogen of Rhododendron brachycarpum. This fungus produces six-celled conidia with appendages at both end cells, and are generated by annellidic conidiogenous cells on the synnema. These conidial structures are similar to those of the genus Pestalotia. The monot...
Article
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The fungi Botrytis cinerea and Colletotrichum acutatum were used to convert acetophenone to 1-phenylethanol. B. cinerea produced a 98.5% yield of 1-phenylethanol with an enantiomeric excess of 93.8%. Conversely, addition of 1-phenylethanol did not change the reaction rate or product composition. In contrast, the reaction catalyzed by C. acutatum wa...
Article
This is a continuity of a series of taxonomic papers where materials are examined, described and novel combinations are proposed where necessary to improve our traditional species concepts and provide updates on their classification. In addition to extensive morphological descriptions and appropriate asexual and sexual connections, DNA sequence dat...
Article
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Notes on 113 fungal taxa are compiled in this paper, including 11 new genera, 89 new species, one new subspecies, three new combinations and seven reference specimens. A wide geographic and taxonomic range of fungal taxa are detailed. In the Ascomycota the new genera Angustospora (Testudinaceae), Camporesia (Xylariaceae), Clematidis, Crassiparies (...
Article
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Coelomycetous fungi are an artificial taxonomic group which produce conidia inside a cavity i.e. conidiomata. Coelomycetes comprise about, 1000 genera and 7000 species, which can be endophytic, pathogenic or saprobic. Traditional classification of coelomycetes was previously based on morphology, such as the shape of conidiomata and mode of conidiog...
Article
Species of Cryptocoryneum were taxonomically reassessed on the basis of morphological observations and the results of molecular phylogenetic analysis. Eighteen isolates of Cryptocoryneum species, namely two strains from Africa, three from Europe, and 13 from Japan, were phylogenetically analysed using sequences of nuclear rDNA internal transcribed...
Article
Dictyosporiaceae fam. nov. is introduced to accommodate a holomorphic group of Dothideomycetes that are saprobes on decaying wood and plant debris in terrestrial and freshwater habitats. The sexual morph comprises Dictyosporium meiosporum, D. sexualis, Gregarithecium curvisporum, Pseudocoleophoma calamagrostidis and P. polygonicola. The sexual morp...
Article
Cyclohelminthols I–V (1–4) were isolated from Helminthosporium velutinum yone96. The positions of the carbons attached to chlorine atoms in 2–4 were determined by signal splitting due to isotopes in high resolution fully proton decoupled 13C NMR spectra. Although these natural products gave poor electron circular dichroism (ECD) spectrum because of...
Article
trans- and cis-Homojesterone (1 and 2, respectively), vinylogous analogs of jesterone, were isolated from Helminthosporium velutinum TS28. The relative configurational relationship between H-6 and H-7 was determined by comparing their 3JH-6/H-7 values with those of jesterones in literature, as well as with structurally related natural products. The...
Article
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Astrosphaeriella sensu lato is a common genus occurring on bamboo, palms and stout grasses. Species of Astrosphaeriella have been collected from various countries in tropical, subtropical or temperate regions. In Asia, species have been collected in Brunei, China, Indonesia, Japan, Philippines and Vietnam. There have been several morphological stud...
Article
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This paper is a compilation of notes on 142 fungal taxa, including five new families, 20 new genera, and 100 new species, representing a wide taxonomic and geographic range. The new families, Ascocylindricaceae, Caryosporaceae and Wicklowiaceae (Ascomycota) are introduced based on their distinct lineages and unique morphology. The new Dothideomycet...
Article
Full-text available
This paper is a compilation of notes on 142 fungal taxa, including five new families, 20 new genera, and 100 new species, representing a wide taxonomic and geographic range. The new families, Ascocylindricaceae, Caryosporaceae and Wicklowiaceae (Ascomycota) are introduced based on their distinct lineages and unique morphology. The new Dothideomycet...
Article
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We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank...
Article
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Minutisphaera is a recently established genus of freshwater Dothideomycetes characterized by small, globose to subglobose or apothecioid, erumpent to superficial, brown ascomata; fissitunicate, eight-spored, ovoid to obclavate asci; and 1–2- septate, clavate to broadly fusiform, hyaline to pale brown ascospores with or without a gelatinous sheath a...
Article
A C3-O-acylated analogue of achaetolide (2) was isolated from phytopathogenic fungus Helminthosporium velutinum TS28. The relative configuration involving the C3-O-acyl side chain was determined by NMR spectroscopic analysis combined with conformational analysis computer-assisted chemical shift calculations. The absolute configuration was establish...
Article
The structures of epoxyroussoenone (1) and epoxyroussoedione (3) isolated from a culture broth of Roussoella japanensis KT1651 were determined. Although NMR spectra provided insufficient structural information, computation of the theoretical chemical shifts with DFT EDF2/6-31G* enabled us to elucidate not only the planar structure, but also the rel...
Article
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This paper is a compilation of notes on 110 fungal taxa, including one new family, 10 new genera, and 76 new species, representing a wide taxonomic and geographic range. The new family, Paradictyoarthriniaceae is introduced based on its distinct lineage in Dothideomycetes and its unique morphology. The family is sister to Biatriosporaceae and Rouss...
Article
The taxonomic relationships of three coelomycetous genera, Dinemasporium, Diarimella and Stauronema, were assessed. A total of 43 isolates/specimens of Dinemasporium-like fungi were examined by phylogenetic analysis of internal transcribed spacer sequences of the nuclear rRNA gene and morphological comparisons. Species highly consistent with Diarim...
Article
The taxonomy of Pseudolachnea and Pseudolachnella is controversial. Some authors have regarded them as congeneric, whereas others have considered them to be distinct genera differentiated merely on the number of conidial septa. A total of 26 isolates of Pseudolachnea-like fungi were subjected to morphological examination and phylogenetic analyses o...
Article
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The genera Lophiostoma, Misturatosphaeria and several other allied taxa in Lophiostomataceae are revisited. Accounts of these taxa, including their history, morphology, and family placement, based on molecular phylogeny, are provided. Type or representative specimens of Lophiostoma and Misturatosphaeria were examined and fresh specimens were obtain...
Article
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Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this...
Article
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Roussoella and Roussoellopsis species are mostly known from monocotyledons (large grasses, bamboo and palms). Detailed phylogenies for this group are lacking and thus their family placement and relationships with other genera are unclear. Fresh collections of several Roussoella-like species, including the type species Roussoella nitidula were made...
Article
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The ascomycetous families, Didymosphaeriaceae and Montagnulaceae, have been treated in Pleosporales, Dothideomycetes, and both include saprobes, endophytes and pathogens associated with a wide variety of substrates worldwide. Didymosphaeriaceae was characterized by 1-septate ascospores and trabeculate pseudoparaphyses, mainly anastomosing above the...
Article
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DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects us...
Article
The 'Lambertellin system' was disclosed which rationally explains the fungal replacement (mycoparasitism) of Monilinia fructigena (M. f., the host) with Lambertella corni-maris (L. corni-maris, the parasite) without competitive inhibition in the simultaneous incubations on agar media. The 'Lambertellin system' involves; (a) L. corni-maris secretes...
Article
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Dothideomycetes comprise a highly diverse range of fungi characterized mainly by asci with two wall layers (bitunicate asci) and often with fissitunicate dehiscence. Many species are saprobes, with many asexual states comprising important plant pathogens. They are also endophytes, epiphytes, fungicolous, lichenized, or lichenicolous fungi. They occ...
Article
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During ongoing investigations of freshwater ascomycetes we found one interesting taxon from Aomori (Japan), as well as three additional taxa from North Carolina (USA), which were morphologically similar to Minutisphaera, a recently described freshwater fungus in the Dothideomycetes. The ascomata of all the collections showed dark hair-like structur...
Article
The structures of the tetracyclic fusicoccanes roussoellols A (1) and B (2) from Roussoella hysterioides KT1651 are described. NMR spectroscopic analyses involving NOESY experiments revealed that these molecules possessed unique bent structures that were supported by chemical derivatizations as well as chemical shift comparisons with theoretical sh...
Article
Overwintering of the brown leaf spot fungus, Mycochaetophora gentianae, in infected gentian leaves was studied in Iwate, northern Japan. Sporophores were produced on overwintered, infected leaves when they were sampled from January to July, but not in August after incubation in high humidity at 15 °C. Symptoms developed on gentian plants grown in s...
Article
Stereochemistries of the C2C8 double bond in photinides A and B were corrected to be reversed forms. The present studies also revised their absolute configurations by comparing the CD spectra of the degradation product with the corresponding synthetic sample. Discosia sp. SH 125 produced novel derivatives photinides X and Y, of which stereochemistr...
Article
In July 2003, a new disease occurred on leaves of highbush blueberry (Vaccinium corymbossum L.) in Iwate, Japan. Leaves initially had brownish spots, which subsequently developed into large lesions with concentric rings, resulting in premature defoliation. Teardrop-shaped conidia infecting leaves were visible by the naked eye as small protuberances...
Article
Plipastatin A1 and fengycin IX were experimentally proven to be identical compounds, while these had been considered as diastereomers due to the permutation of the enantiomeric pair of Tyr in most papers. The (1)H NMR spectrum changed to become quite similar to that of plipastatin A1, when the sample which provided resembled spectrum of fengycin IX...
Article
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Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes l...
Article
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To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. First, we isolated culturable fungi and bacteria from apple or...
Article
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Premise of study: This research seeks to advance understanding of conditions allowing movement of fungal pathogens among hosts. The family Clavicipitaceae contains fungal pathogens exploiting hosts across three kingdoms of life in a pattern that features multiple interkingdom host shifts among plants, animals, and fungi. The tribe Ustilaginoideae...
Article
The absolute stereochemistry of altersolanol A (1) was established by observing a positive exciton couplet in the circular dichroism (CD) spectrum of the C3,C4-O-bis(2-naphthoyl) derivative 10 and by chemical correlations with known compound 8. Before the discussion, the relative stereochemistry of 1 was confirmed by X-ray crystallographic analysis...
Article
A novel isochromanone, (S)-8-hydroxy-6-methoxy-4,5-dimethyl-3-methylene-isochromen-1-one (1), known 2 and previously reported metabolites from Leptosphaeria sp. KTC 727 (JCM 13076 = MAFF 239586) were isolated from the same source by culturing for a relatively long period. The results of the present study disclose their structures involving the abso...
Article
Lophiostoma and Lophiotrema share several morphological and ecological features. They have been regarded as closely related genera within the family Lophiostomataceae, but their morphological circumscriptions have been uncertain. To clarify the generic definitions of Lophiostoma and Lophiotrema, we conducted phylogenetic analyses of 29 isolates of...
Article
During independent surveys of freshwater ascomycetes in Japan and USA two new species of Lindgomyces were collected from submerged wood in freshwater. These species are described and illustrated based on morphological data and phylogenetic relationships based on analyses of nuclear ribosomal sequence data (partial SSU and LSU, and ITS). Lindgomyces...
Article
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Species in the present study were compared based on their morphology, growth characteristics in culture, and DNA sequences of the nuclear ribosomal RNA gene operon (including ITS1, ITS2, 5.8S nrDNA and the first 900 bp of the 28S nrDNA) for all species and partial actin and translation elongation factor 1-alpha gene sequences for Cladosporium speci...
Article
Two new metabolites, (R)-3,4-dihydro-4,6,8-trihydroxy-4,5-dimethyl-3-methyleneisochromen-1-one (1) and (R)-7-hydroxy-3-((S)-1-hydroxyethyl)-5-methoxy-3,4-dimethylisobenzofuran-1(3H)-one (2), were isolated along with two structurally known related compounds (3 and 4) from the culture broth of Leptosphaeria sp. KTC 727 (JCM 13076 = MAFF 239586). Thes...
Article
Prosthemium (teleomorph Pleomassaria) and Asterosporium (teleomorph unknown) are coelomycetous genera with stellate conidia on Fagales trees. Their morphological resemblance suggests their close relationship, but phylogenetic relatedness remains unknown. They have been distinguished on the basis of either conidiomatal morphology (pycnidia in Prosth...
Article
When the influence of host species, inoculum density, temperature, leaf wetness duration, and leaf position on the incidence of gentian brown leaf spot caused by Mycochaetophora gentianae, was examined, the fungus severely infected all seven Gentiana triflora cultivars, but failed to infect two cultivars of G. scabra and an interspecific hybrid cul...
Article
A 303-nucleotide viroid was isolated from an apple tree (Malus×domestica, ‘Fuji’) cultivated in Japan. The viroid had 84.9% overall nucleotide sequence homology to Apple dimple fruit viroid (ADFVd), a member of Pospiviroidae, reported from Italy. This viroid differed from the Italian variant by 47 mutations (38 substitutions, six deletions and thre...
Article
Diadema ahmadii sp. nov. is described, illustrated, and compared with similar taxa. This species was collected from dead branches of Rosa moschata in Kaghan Valley, an alpine region in Pakistan. Diadema ahmadii is most similar to D. tetramerum, the type species of the genus, in that it has asci and ascospores of similar dimensions. However, D. ahma...