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Nature offers a huge and only partially explored variety of small molecules with potential pharmaceutical applications. Commonly used characterization methods for natural products include spectroscopic techniques such as nuclear magnetic resonance spectroscopy and mass spectrometry. In some cases, however, these techniques do not succeed in the unambiguous determination of the chemical structure of unknown compounds. To validate the usefulness of scanning probe microscopy as an adjunct to the other tools available for organic structure analysis, we used the natural product cephalandole A, which had previously been misassigned, and later corrected. Our results, corroborated by density functional theory, demonstrate that direct imaging of an organic compound with atomic-resolution force microscopy facilitates the accurate determination of its chemical structure. We anticipate that our method may be developed further towards molecular imaging with chemical sensitivity, and will become generally useful in solving certain classes of natural product structures.

Cultivation of the endophytic fungus Chaetomium globosum, which was isolated from the inner tissue of the marine red alga Polysiphonia urceolata, resulted in the isolation of chaetopyranin (1), a new benzaldehyde secondary metabolite. Ten known compounds were also isolated, including two benzaldehyde congeners, 2-(2',3-epoxy-1',3'-heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (2) and isotetrahydroauroglaucin (3), two anthraquinone derivatives, erythroglaucin (4) and parietin (5), five asperentin derivatives including asperentin (6, also known as cladosporin), 5'-hydroxy-asperentin-8-methylether (7), asperentin-8-methyl ether (8), 4'-hydroxyasperentin (9), and 5'-hydroxyasperentin (10), and the prenylated diketopiperazine congener neoechinulin A (11). The structures of these compounds were determined on the basis of their spectroscopic data analysis (1H, 13C, 1H-1H COSY, HMQC, and HMBC NMR, as well as low- and high-resolution mass experiments). To our knowledge, compound 1 represents the first example of a 2H-benzopyran derivative of marine algal-derived fungi as well as of the fungal genus Chaetomium. Each isolate was tested for its DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging property. Compounds 1-4 were found to have moderate activity. Chaetopyranin (1) also exhibited moderate to weak cytotoxic activity toward several tumor cell lines.

From the Egyptian medicinal plant Polygonum senegalense the fungal endophyte Alternaria sp. was isolated. Extracts of the fungus grown either in liquid culture or on solid rice media exhibited cytotoxic activity when tested in vitro against L5178Y cells. Chromatographic separation of the extracts yielded 15 natural products, out of which seven were new compounds, with both fungal extracts differing considerably with regard to their secondary metabolites. Compounds 1, 2, 3, 6, and 7 showed cytotoxic activity with EC 50 values ranging from 1.7 to 7.8 microg/mL. When analyzed in vitro for their inhibitory potential against 24 different protein kinases, compounds 1- 3, 5- 8, and 15 inhibited several of these enzymes (IC 50 values 0.22-9.8 microg/mL). Interestingly, compounds 1, 3, and 6 were also identified as constituents of an extract derived from healthy leaves of the host plant P. senegalense, thereby indicating that the production of natural products by the endophyte proceeds also under in situ conditions within the plant host.

Two new cyclic depsipeptide derivatives, kahalalides R (1) and S (2), together with two known congeners, kahalalides F (3) and D (4), were isolated from the Indian sacoglossan mollusk Elysia grandifolia. The structures of the new compounds were unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, HMBC) and mass spectrometric (FABMS, ESIMS, MALDI-TOF/PSD) data, which also included Marfey amino acid analyses. The new derivative kahalalide R was found to exert comparable or even higher cytotoxicity than the potential drug candidate kahalalide F toward the MCF7 human mammary carcinoma cell line.

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The metabolic profile of Streptomyces sp. strain C34, isolated from the Chilean hyper-arid Atacama Desert soil, is dependent on the culture media used for its growth. The application of an OSMAC approach on this strain using a range of cultivation media resulted in the isolation and identification of three new compounds from the rare class of 22-membered macrolactone polyketides, named chaxalactins A-C (1-3). In addition, the known compounds deferroxamine E (4), hygromycin A (5), and 5″-dihydrohygromycin A (6) were detected. The isolated compounds were characterized by NMR spectroscopy and accurate mass spectrometric analysis. Compounds 1-3 displayed strong activity against Gram-positive but weak activity Gram-negative strains tested.

Index Fungorum, Species Fungorum and MycoBank are the key fungal nomenclature and taxonomic databases that can be sourced to find taxonomic details concerning fungi, while DNA sequence data can be sourced from the NCBI, EBI and UNITE databases. Nomenclature and ecological data on freshwater fungi can be accessed on http://fungi.life.illinois.edu/, while http://www.marinespecies.org/ provides a comprehensive list of names of marine organisms, including information on their synonymy. Previous websites however have little information on marine fungi and their ecology, beside articles that deal with marine fungi, especially those published in the nineteenth and early twentieth centuries may not be accessible to those working in third world countries. To address this problem, a new website www.marinefungi.org was set up and is introduced in this paper. This website provides a search facility to genera of marine fungi, full species descriptions, key to species and illustrations, an up to date classification of all recorded marine fungi which includes all fungal groups (Ascomycota, Basidiomycota, Blastocladiomycota, Chytridiomycota, Mucromycota and fungus-like organisms e.g. Thraustochytriales), and listing recent publications. Currently, 1,257 species are listed in the marine fungi website (www.marinefungi.org), in 539 genera, 74 orders, 168 families, 20 classes and five phyla, with new taxa continuing to be described. The website has curators with specialist mycological expertise who help to provide update data on the classification of marine fungi. This article also reviews knowledge of marine fungi covering a wide range of topics: their higher classification, ecology and world distribution, role in energy transfer in the oceans, origin and new chemical structures. An updated classification of marine fungi is also included. We would like to invite all mycologists to contribute to this innovative website.Keywords Fungal classification -marine fungi website -high-throughput sequencing techniques --fungal diversity -origin of marine fungi Fungal websitesThe internet has become a major source for obtaining information worldwide. Over the last decades, fungal research has extended its horizon yielding a vast amount of data leading to the development of many websites dealing with different aspects of mycology. An integrated database, such as GenBank, provides us with a one stop solution where we can find DNA, protein, and articles. Similarly, there are some other websites which deal with specific mycological topics, and