Trichothecenes from the fungus Acremonium crotocinigenum BCC 20012

Two new trichothecenes (1 and 2) and a new chloroderivative of a trichothecene analogue (3) together with four known trichothecenes, crotocin, trichothecin, 8-deoxytrichothecinol B, and a trichothecene analogue, were isolated from the fungus Acremonium crotocinigenum BCC 20012. The structures of these compounds were elucidated by extensive spectroscopic analysis. Among the tested metabolites, trichothecin itself showed strongest antimalarial activity against Plasmodium falciparum K1, and cytotoxic activity against Vero cell lines with IC₅₀ values of 0.05 and 0.13 μg/mL, respectively.     

Cordylactam,a new alkaloid from the spider pathogenic fungus Cordyceps sp. BCC 12671

Cordylactam (1), a new lactam-fused 4-pyrone was isolated from the spider pathogenic fungus Cordyceps sp. BCC 12671. The structure was elucidated on the basis of NMR spectroscopic and mass spectrometry data, which was further confirmed by the spectroscopic analyses of a semisynthetic derivative. This is the first report of a new compound from spider pathogenic Cordyceps species.     

Dihydronaphthalenones from the endophytic fungus Botryosphaeria sp. BCC 8200

Five new dihydronaphthalenones (1, 2a/2b, 3a/3b), four of which were isolated as two inseparable mixtures of isomers, together with two known compounds, 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (4) and siderin (5), were identified as secondary metabolites of the endophytic fungus Botryosphaeria sp. BCC 8200. The structures were elucidated by interpretation of NMR spectroscopic and mass spectrometry data. Compounds 2a/2b, 3a/3b, and 5 exhibited weak cytotoxic activities against cancer cell lines.     

Chromone derivatives from the wood-decay fungus Rhizina sp. BCC 12292

A new chromone derivative (1), together with the known oxepino[2,3-b]chromones, microsphaeropsones A (2) and B (3), and xanthopinone (4), was isolated from the wood-decay fungus Rhizina sp. BCC 12292. The structure of 1 was elucidated on the basis of NMR spectroscopic and mass spectrometry data. Transformation of 4 into 1 occurred when a solution of 4 in MeOH was treated with p-TsOH or silica gel, which strongly suggested that 1 may be an artifact formed during the processing of the extract. Compound 1 exhibited antimalarial activity with an IC₅₀ of 5.1 μg/ml and cytotoxic activities against NCI-H187 and Vero cell lines with respective IC₅₀ of 6.4 and 1.6 μg/ml.     

Hopane triterpenes from the scale insect pathogenic fungus Aschersonia calendulina BCC 23276

Two new hopane-type triterpenenes, 6α,15α,22-trihydroxyhopane (4) and 3β-acetoxy-6α,22-dihydroxyhopane (5), together with the known 6α,22-dihydroxyhopane (1, zeorin), 15α,22-dihydroxyhopane (2, dustanin), and 3β-acetoxy-15α,22-dihydroxyhopane (3) were isolated from the scale insect pathogenic fungus Aschersonia calendulina BCC 23276. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data.     

Eremophilane and eudesmane sesquiterpenoids and a pimarane diterpenoid from the wood-decay fungus Xylaria sp. BCC 5484

Three new sesquiterpenoids (1–3) and a new pimarane-type diterpenoid (4) were isolated from the fermentation broth of the wood-decay fungus Xylaria sp. BCC 5484. The structures were elucidated by analyses of NMR spectroscopic and mass spectrometry data. The absolute configuration of eremophilane 1 was addressed by application of the modified Mosher's method.     

Antibacterial and anti-phytopathogenic substances from the insect pathogenic fungus Gibellula sp. BCC36964

Four new compounds (1–4), which were (−)-(7R)-7-O-methylsydonic acid, gibellulic acid, gibellulins A and B, together with 14 known compounds (5–17 and orcinol) were isolated from the insect pathogenic fungus, Gibellula sp. BCC36964. The chemical structures were elucidated by employing NMR spectroscopic techniques, physico-chemical data, and chemical method. These compounds were evaluated for the biological activities including anti-bacterial, anti-phytopathogenic, anti-Herpes simplex virus-type 1 activities, and cytotoxicity against both cancerous (MCF-7, KB, NCI-H187) and non-cancerous (Vero) cells.     

Production of red pigments by the insect pathogenic fungus Cordyceps unilateralis BCC 1869

Production of red pigments (naphthoquinones) by the insect pathogenic fungus Cordyceps unilateralis BCC 1869 was investigated in this study. Cultivation conditions, including temperature, intitial pH of medium, and aeration, were optimised to improve the yield of total naphthoquinones in shake-flask culture of C. unilateralis. The highest yield of total naphthoquinones (3 g L^–1) was obtained from a 28-day culture grown in potato dextrose broth with an initial pH of 7.0, at 28°C with shaking-induced aeration at 200 rpm. An extraction process for isolation of the targeted naphthoquinone, 3,5,8-trihydroxy-6-methoxy-2-(5-oxohexa-1,3-dienyl)-1,4-naphthoquinone (3,5,8-TMON), from a culture of C. unilateralis, was also developed. The yield of 3,5,8-TMON obtained was about 1.2 g L^–1 or 40% of total naphthoquinones. The stability of 3,5,8-TMON was very high, even upon exposure to strong sunlight (70,000 lx), high temperature up to 200°C, and acid and alkali solutions at concentrations of 0.1 M     

Sulcatine,a norsesquiterpene from the fungus Laurilia sulcata

The structure of sulcatine, a novel protoilludene norsesquiterpene isolated from a culture of Laurilia sulcata, has been assigned on the basis of a detailed study of its ¹H NMR and ¹³C NMR spectra and chemical evidence. The relative configuration was deduced from the observed ¹H {¹H} nuclear Overhauser effects (NOEs) and from the values of ¹H¹H coupling constants. The application of the exciton chirality method on the dibenzoate permitted establishment of the absolute configuration of sulcatine as 2S,3R,7S,8S,9R.     

Garvieacin Q, a novel class II bacteriocin from Lactococcus garvieae BCC 43578

Lactococcus garvieae BCC 43578 produces a novel class II bacteriocin, garvieacin Q (GarQ), 70 amino acids in length and containing a 20-amino-acid N-terminal leader peptide. It is cleaved at the Gly-Gly site to generate the mature GarQ (5,339 Da), which is especially inhibitory against Listeria monocytogenes ATCC 19115 and other L. garvieae strains.     

一株源于南极土壤的耐冷真菌Sistotrema brinkmannii(英文)

从南极Dry Valleys Feyxell Basin湖土壤中分离获得一株具有锁状联合的耐冷担子菌,核糖体DNAITS区序列分析将该菌株鉴定为Sistotrema brinkmannii。形态特征研究表明该菌株产生裸担子,其上生4-8个小梗,每个梗上产生一个肾形担孢子,丝状担子菌在南极少有报道,该菌株的生物学及生态学值得进一步研究。     

Ravenelia cenostigmatis, a new rust fungus from Brazil

Ravenelia cenostigmatis is described as a new species of plant rust (Uredinales) onCenostigma gardnerianum (Caesalpiniaceae) from Brazilian Cerrado. Teliospore heads ofR. cenostigmatis exhibit an unusually complex structure with four different kinds of cells: teliospore cells, sterile apical cells (intercalary between pedicel hyphae and teliospores), sterile hygroscopic cysts, and morphologically distinct border cells. The last are flattened, elaborately ornamented and probably sterile cells that are wedged between the teliospores and the cysts.Ravenelia cenostigmatis probably belongs to a natural assemblage of ravenelias that occur on caesalpiniaceous hosts and exhibit similar morphological traits. Part 179 of the series “Studies in Heterobasidiomycetous Fungi” of the Botanical Institute, University of Tübingen     

Scopulariopsis murina,a new fungus from self-heated compost

Summary A new species of Scopulariopsis, S. murina Samson and Klopotek, is described. This species is closely related to S. sphaerospora and S. carbonaria, but differs from them in having smaller, cylindrical conidia and chlamydospores. In addition Paecilomyces fuscatus Inagaki is redescribed and the new name Scopulariopsis gracilis Samson is proposed for it.     

Opegrapha cladoniicola,a new lichenicolous fungus from Hawaii

A new species Opegrapha cladoniicola, lichenicolous on the podetia of Cladonia ochrochlora, is described from Hawaii. It is the first known Opegrapha species found growing on Cladonia.     

DNA polymerases from a dimorphic fungus,Histoplasma capsulatum

DNA polymerases from the yeast and mycelial phases of a fungus,Histoplasma capsulatum, were partially purified and analyzed. Two classes of enzymes were identified in each morphological form. No significant differences were found among polymerases Ia and Ib from mycelia and I from yeast; similarly, polymerases II from both phases were almost identical. (Numbering refers to the order of elution from phosphocellulose.) However, all of the class I polymerases differed significantly from the class II enzymes. DNA polymerases I (M_r 122,000) were unaffected by 0.2m KCl and resistant to 10 mmN-ethylmaleimide; their levels fluctuated significantly in relation to cell growth, and they showed no nuclease activity. All of the enzymes had similar template dependence and Mg²⁺ requirements. These results are compared to data on other eucaryotic DNA polymerases. Possible roles for class I and class II polymerases are discussed.     

Diversity of type I polyketide synthase genes in the wood-decay fungus Xylaria sp. BCC 1067

Fungal type I polyketide (PK) compounds are highly valuable for medical treatment and extremely diverse in structure, partly because of the enzymatic activities of reducing domains in polyketide synthases (PKSs). We have cloned several PKS genes from the fungus Xylaria sp. BCC 1067, which produces two polyketides: depudecin (reduced PK) and 19,20-epoxycytochalasin Q (PK-nonribosomal peptide (NRP) hybrid). Two new degenerate primer sets, KA-series and XKS, were designed to amplify reducing PKS and PKS-NRP synthetase hybrid genes, respectively. Five putative PKS genes were amplified in Xylaria using KA-series primers and two more with the XKS primers. All seven are predicted to encode proteins homologous to highly reduced (HR)-type PKSs. Previously designed primers in LC-, KS-, and MT-series identified four additional PKS gene fragments. Selected PKS fragments were used as probes to identify PKS genes from the genomic library of this fungus. Full-length sequences for five PKS genes were obtained: pks12, pks3, pksKA1, pksMT, and pksX1. They are structurally diverse with 1-9 putative introns and products ranging from 2162 to 3654 amino acids in length. The finding of 11 distinct PKS genes solely by means of PCR cloning supports that PKS genes are highly diverse in fungi. It also indicates that our KA-series primers can serve as powerful tools to reveal the genetic potential of fungi in production of multiple types of HR PKs, which the conventional compound screening could underestimate.     

Identification and expression of cellobiohydrolase (CBHI) gene from an endophytic fungus, Fusicoccum sp. (BCC4124) in Pichia pastoris

A gene encoding a cellobiohydrolase (CBHI) was isolated from Fusicoccum sp. (BCC4124), an endophytic fungus belongs in phylum Ascomycota, using 5' and 3' rapid amplification of cDNA end (RACE) technique. This CBHI gene contains 1395 nucleotides and encodes a 465-amino acid protein with a molecular weight of approximately 50 kDa. The deduced amino acid sequence showed significant similarity to those of other fungal CBHI belonging to family 7 of glycosyl hydrolase. Interestingly, the result from the amino acid alignment revealed that this CBHI does not contain the cellulose binding domain nor the linker region. The CBHI gene was successfully expressed in Pichia pastoris KM71. The purified recombinant CBHI has ability to hydrolyze Avicel, filter paper and 4-methylumbelliferyl beta-d-cellobioside (MUC) but not carboxymethylcellulose (CMC). It showed an optimal working condition at 40 degrees C, pH 5 with K(m) and V(max) toward MUC of 0.57 mM and 3.086 nmol/min/mg protein, respectively. The purified enzyme was stable at pH range of 3-11. The enzyme retained approximately 50% of its maximal activity after incubating at 70-90 degrees C for 30 min. Due to its stability through wide range of pH, and moderately stable at high temperature, this enzyme has potential in various biotechnology applications.     

Unguisin C,a GABA-containing cyclic peptide from the fungus Emericella unguis

Besides the known unguisins A and B, a new cyclic heptapeptide, unguisin C, containing a GABA-derived moiety in the ring, was isolated from the fungus Emericella unguis. The structure was determined by 1D and 2D NMR techniques. Marfey's method was used to determine the absolute stereochemistry. Precursor-directed biosynthesis of the unguisins was performed by supplementation of the culture medium with amino acids (L-Ala, L-Ser, L-Phe and L-Leu). A related cyclic heptapeptide, unguisin D, was detected by HPLC and characterized by sequence analysis using LC-QITMS.