Chemical analyses of fungi aid identification and classification of fungi, and predict, select and explore fungal species and strains in solving problems facing ecosystems, environment and industries.
Direct detection of antifungal metabolites in fungal extracts on identical developed TLC plates: compounds revealed using chemical detection (anisaldehyde spray, heat; Top), areas of inhibition of fungal growth shown as white spots on grey background (con
Microorganisms including fungi represent traditionally the most productive sources of biologically active substances, yet until 2000 virtually none of the living fungal collections at Kew had been systematically tested for biologically active secondary metabolites. In order to evaluate the importance of the collections as sources of valuable metabolites a systematic survey of the collection was started in 2000. By the end of 2005, 762 strains that originated in the UK have been studied. The fungi of Basidiomycota were the most represented, reflecting Kew’s long-standing interest in this group of fungi. Each strain was grown in various growth media and the production of bioactive metabolites examined. The extracts were screened against a panel of test organisms (insects, fungi and bacteria) for their effects such as growth stimulation or retardancy in assay systems available in-house, and when appropriate, with external collaborators including universities and industrial collaborators. Those registered as highly active were selected for further study. Following large scale cultivation of these species over 50 compounds were isolated. Many of these were responsible for the observed activities and often explained the mechanisms of interactions between the producing fungi and competing fungi, plants and insects. Their chemical structures were determind with a multitude of spectroscopic analyses, and additional biological properties examined for possible applied use.
Work has been extended in the last five years to cover fungi of various ecological niches, including endophytes and lichens. The scope of chemical analyses has been widened to documenting of chemical markers that may be used as biochemical characters in classification of fungi. Beside genetic analyses the chemical profiles of these fungi have been helping recognise and classify otherwise indistinguishable fungal species. These groups of fungi also appear to have interesting unique secondary metabolites, particulary rich in diversity. The chemistry of lichens have been explored for application in fighting against various drug-resistant strains of bacteria.
Smaller sub-projects and work, originated from enquiries, were also undertaken. These may be internal (from within Kew) and external enquiries, most of which resulted in preparation of analysis reports.
In the long term studies the chemistry of fungi are predicted to yield a deeper understanding of the life histories of plant-fungal interactions, where chemistry is the language of mutual benefit at one extreme and a cause of disease at the other, below- and above-ground. High-value materials that may find use in enhancing quality of life, not only in medical, pharmaceutical and agronomical fields but also in the areas of food and drink, and cosmetic applications, are expected to be discovered.
Key publications 2006-2011:
Kokubun, T., Irwin, D., Legg, M., Veitch, N.C. & Simmonds, M.S.J. (2007). Serialynic acid, a new phenol with an isopentenyne side chain from Antrodia serialis. Journal of Antibiotics 60: 285-288.
Kokubun, T., Rozwadowski, T. & Duddeck, H. (2007). Benzaldehyde derivatives from Sarcodontia crocea. Journal of Natural Products 70: 1531-1541.
Kokubun, T., Shiu, W.K.P. & Gibbons, S. (2007). Inhibitory activities of lichen-derived compounds against methicillin-and multidrug-resistant Staphylococcus aureus. Planta Medica 73: 176-179.
Aguirre-Hudson, B., Kokubun, T., Spooner, B.M. & Tibell, L. (2007). Taxonomy of Calicium victorianum (F. Wilson) Tibell (Caliciaceae, Lecanorales), a lichenized ascomycete new to Europe. Lichenologist 39: 401-407.
Project partners and collaborators
School of Pharmacy, University of London
Leibniz University of Hannover
Iwokrama International Centre
Szczecin University of Technology