Anthony J. S. Whalley

The xylariaceous way of life

This paper outlines current positions on systematic arrangements of the Xylariaceae, discusses the value of the different characters used in attaining these arrangements, and reviews the activities of members of the family in nature. The taxonomic significance and potential ecological role of the many secondary metabolites produced by xylariaceous taxa is evaluated. The importance of the Xylariaceae in wood decomposition and as agents of disease is discussed. Aspects of their distribution in relation to host, habitat and climate are presented.

Application of Toxocara canis excretory–secretory antigens and IgG subclass antibodies (IgG1-4) in serodiagnostic assays of human toxocariasis

A major problem in the serodiagnosis of human toxocariasis in tropical countries is cross-reaction with antibodies to other helminthic diseases and a lack of sensitivity. The majority of tests currently available use total IgG and, in this study, the use of peroxidase-conjugated anti-human IgG subclass antibodies (IgG1-4) was compared with total IgG for the diagnosis of human toxocariasis by using Toxocara excretory-secretory (TES) antigens in an enzyme-linked immunosorbent assay (ELISA) format. All four IgG subclass antibodies gave approximately 10-fold increases in optical density (OD) values for 50 toxocariasis patients compared to 29 healthy normals; this was significantly greater than the approximate doubling of OD values seen in the total IgG-ELISA format. IgG2 gave by far the greatest sensitivity (values: IgG, 50%; IgG1, 60%; IgG2, 98%; IgG3, 78%; IgG4, 64%). Significant cross-reactivity using all IgG subclasses in the TES ELISA was seen with 141 serum samples from patients with 10 other helminthic infections. However, IgG3 gave the best specificity (values: IgG, 73%; IgG1, 76%; IgG2, 71%; IgG3, 81%; IgG4, 71%). Thus, of the IgG subclass antibodies, IgG2 appeared best and employing this subclass can improve the serodiagnosis of human toxocariasis since it recognises carbohydrate epitopes of TES antigens.

Metabolites of the higher fungi. Part 21. 3-Methyl-3,4-dihydroisocoumarins and related compounds from the ascomycete family xylariaceae

Culture solutions of members of the ascomycete family Xylariaceae produce a series of 5-substituted 8-hydroxy-3-methyl-3,4-dihydroisocoumarins as major metabolites. Ramulosin, iso-ochracein, and mellein are produced by three Hypoxylon species and 4-hydroxy iso-ochracein by one species. The antibiotic pyrenophorin is produced by Nummularia broomeiana. The synthesis of 7-formylmellein from mellein is described and the products from the alkaline rearrangement of 5-formylmellein are studied spectroscopically.

Endophytic fungi from mangrove plant species of Thailand: their antimicrobial and anticancer potentials

Abstract We examined the distribution of endophytic fungi in the leaves of mangrove forest trees growing at three different locations (Chanthaburi Province, Prachuap Khiri Khan Province and Ranong Province) in Thailand. Three thousand and nine-hundred leaf segments from 10 different hosts belonging to seven families, Rhizophoraceae (Rhizophora apiculata, R. mucronata, Ceriops decandra), Sonneratiaceae (Sonneratia alba), Combretaceae (Lumnitzera littorea), Avicenniaceae (Avicennia alba), Acanthaceae (Acanthus ilicifolius), Meliaceae (Xylocarpus granatum and Xylocarpus moluccensis) and Malvaceae (Thespesia populneoides), were screened for the presence of fungal endophytes. The dominant endophytes varied by host type. Phyllosticta was the most frequently isolated fungus from plants at all sites. The common fungal endophyte genera were Cladosporium, Colletotrichum, Phomopsis and Xylaria. Most endophytic isolates in mangrove leaves were recovered from Ranong Province. The antimicrobial potential of 71 endophytic fungi isolated from mangrove plants towards selected bacteria (Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus) was tested using ethyl acetate extracts of fungi cultivated under static conditions. All test bacteria were inhibited by a Cladosporium sp. isolated from the leaves of T. populneoides and an endophytic Xylaria sp. 1 isolated from A. ilicifolius leaves caused considerable inhibition to Gram-positive and Gram-negative bacteria. Additionally, the crude extracts of 84 endophytic fungi were tested for anticancer activities by the MTT assay against A375 (human malignant melanoma), SW620 (human colorectal adenocarcinoma), Kato III (human gastric carcinoma), HepG2 (human liver hepatoblastoma) and Jurkat (human acute T cell leukemia). Most extracts had cytotoxicity against some cancer cell lines.

Metabolites of the higher fungi. Part 19. Serpenone, 3-methoxy-4-methyl-5-prop-1-enylfuran-2(5H)-one, a new γ-butyrolactone from the fungus Hypoxylon serpens(Barrons strain)(Persoon ex Fries)Kickx

Culture solutions of the fungus Hypoxylon serpens(Barrons strain) contain a new butyrolactone as the major metabolite, which has been identified as 3-methoxy-4-methyl-5-prop-1-enylfuran-2(5H)-one (2), and small quantities of the reduced analogue, 3-methoxy-4-methyl-5-propylfuran-2(5H)-one (3); the structures have been established by synthesis of compound (3). A new rapid synthesis of the isomeric 4-methoxy-3,5-disubstituted analogues is described and the two groups of compounds are compared spectroscopically.

Metabolites of the higher fungi. Part 29. Maldoxin, maldoxone, dihydromaldoxin, isodihydromaldoxin and dechlorodihydromaldoxin. A spirocyclohexadienone, a depsidone and three diphenyl ethers: keys in the depsidone biosynthetic pathway from a member of the fungus genus Xylaria

2-(3′-Chloro-2′-hydroxy-4′-methoxy-6′-methoxycarbonylphenoxy)-6-hydroxy-4-methylbenzoic acid (dihydromaldoxin 1), 2-(3′-Chloro-4′-hydroxy-2′-methoxy-6′-methoxycarbonylphenoxy)-6-hydroxy-4-methylbenzoic acid (isodihydromaldoxin 2), dechlorodihydromaldoxin 3, a new chlorinated depsidone (maldoxone 4) and a new spirocyclohexadienone (maldoxin 5) have been isolated from the culture medium of an as yet unidentified Xylaria species. The structures have been determined by physical and chemical methods and the positions of the substituents in dihydromaldoxin 1 have been confirmed by a single crystal X-ray structure determination. Their role in the grisan–depsidone biosynthetic pathway is discussed.

Metabolites of the higher fungi. Part 24. Cytochalasin N, O, P, Q, and R. New cytochalasins from the fungus Hypoxylon terricola Mill

Punctaporonin B, cytochalasin C and D, and five new cytochalasins have been isolated from the culture medium and mycelium of the fungus Hypoxylon terricola. Cytochalasin C is the major metabolite. Cytochalasin N is the 5,6-epoxide of cytochalasin C, and cytochalasins O and P are two epimeric 6-hydroxy analogues. Cytochalasin Q is a 6,7-epoxide and R is a 6,7,13,14-diepoxide. The epoxides formed by cytochalasin C and D are described and the acid- and BF3-induced rearrangement products of cytochalasin N are identified.

Daldinia concentrica versus Daldinia vernicosa

A comparative study of the perfect and imperfect states of Daldinia concentrica and D. vernicosa confirm their separate identity. Furthermore, the smaller stromatal forms of the former occurring on Betula and occasionally on Fagus were not found to differ significantly from typical D. concentrica growing on Fraxinus , its common host.

Fungi in Thailand: a case study of the efficacy of an ITS barcode for automatically identifying species within the Annulohypoxylon and Hypoxylon genera.

Thailand, a part of the Indo-Burma biodiversity hotspot, has many endemic animals and plants. Some of its fungal species are difficult to recognize and separate, complicating assessments of biodiversity. We assessed species diversity within the fungal genera Annulohypoxylon and Hypoxylon, which produce biologically active and potentially therapeutic compounds, by applying classical taxonomic methods to 552 teleomorphs collected from across Thailand. Using probability of correct identification (PCI), we also assessed the efficacy of automated species identification with a fungal barcode marker, ITS, in the model system of Annulohypoxylon and Hypoxylon. The 552 teleomorphs yielded 137 ITS sequences; in addition, we examined 128 GenBank ITS sequences, to assess biases in evaluating a DNA barcode with GenBank data. The use of multiple sequence alignment in a barcode database like BOLD raises some concerns about non-protein barcode markers like ITS, so we also compared species identification using different alignment methods. Our results suggest the following. (1) Multiple sequence alignment of ITS sequences is competitive with pairwise alignment when identifying species, so BOLD should be able to preserve its present bioinformatics workflow for species identification for ITS, and possibly therefore with at least some other non-protein barcode markers. (2) Automated species identification is insensitive to a specific choice of evolutionary distance, contributing to resolution of a current debate in DNA barcoding. (3) Statistical methods are available to address, at least partially, the possibility of expert misidentification of species. Phylogenetic trees discovered a cryptic species and strongly supported monophyletic clades for many Annulohypoxylon and Hypoxylon species, suggesting that ITS can contribute usefully to a barcode for these fungi. The PCIs here, derived solely from ITS, suggest that a fungal barcode will require secondary markers in Annulohypoxylon and Hypoxylon, however. The URL http://tinyurl.com/spouge-barcode contains computer programs and other supplementary material relevant to this article.

Metabolites of the higher fungi. Part 23. The punctaporonins. Novel bi-, tri-, and tetra-cyclic sesquiterpenes related to caryophyllene, from the fungus Poronia punctata(Linnaeus:Fries) Fries

Six new sesquiterpenes have been isolated from the culture medium of the fungus Poronia punctata. Punctaporonins A, D, E, and F are isomeric allylic alcohols possessing a tricyclic carbon skeleton not previously found in nature. Punctaporonin B is a related trihydroxycaryophyllene isomer, and punctaporonin C is a novel tetracyclic hemisuccinate. An additional major metabolite has been identified as (E)-methyl 3-(4-methoxyphenoxy)propenoate.