International Union of Pure and Applied Chemistry

The Xylariaceae: A case study in biological and chemical diversity*

A.J.S. Whalley¹and R.L. Edwards²1. School of Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, U.K.
2. School of Chemistry and Chemical Technology, University of Bradford, Bradford, U.K.
E-mail: [email protected]

Abstract: The Xylariaceae is a large family of ascomycete fungi with worldwide distribution but exhibiting a far greater representation in the tropics. A total of 40 or more genera are considered likely and these are represented by perhaps as many as a thousand species. During our studies over the past 25 years we have investigated secondary metabolites produced in liquid, static culture by members of the Xylariaceae representing over 100 species from 14 genera. Taking a biological viewpoint the Xylariaceae are taxonomically a difficult family because of extreme variation in morphological form and a general lack of modern studies on the tropical genera. However over the past 10 years Rogers and his coworkers in the USA have made considerable progress on the systematics of the family whilst here in South East Asia studies by Khun Surang Thienhirun in conjunction with the authors have resulted in the recognition of many new species in Thailand. We now believe that current models showing a biodiversity index difference of over 2:1 (for the Xylariaceae) between the neotropics and Thailand is likely to be greatly exaggerated since between 30% and 50% of the xylariaceous taxa from Thailand appear to be new.

Taking a chemical viewpoint there are exciting prospects for the discovery of novel chemicals associated with these new taxa since the track record for new metabolite discovery from members of the Xylariaceae is impressive. To date dihydroisocoumarins, succinic acid derivatives, butyrolactones, cytochalasins, punctaporonis, griseofulvin and derivatives, and naphthalene derivatives have been characterised, with many proving to be novel structures. Examination of xylariaccous endophytes from teak leaves has revealed a series of species producing previously unknown compounds. Since the Xylariaceae are known to be prominent endophytes of tropical plants and since only a small proportion of the likely 1000 species have been investigated the future certainly looks promising.

Download full text (11 pages) - PDF file (110KB)