This proposal requests support to continue and expand an investigation of the natural products chemistry of coprophilous fungi. These rarely- studied fungi are ecologically, morphologically, and taxonomically distinctive, and they commonly display antagonistic effects against other fungi. Based on these considerations, and on initial positive results, coprophilous fungi show considerable promise as sources of new antifungal natural products. Compounds of this nature could be useful in the development of new treatments for fungal diseases in humans. Studies carried out in the first 2.5 years of this project have afforded several types of new antifungal agents, some of which possess unusual chemical structures. Many additional organisms that display inhibitory effects on medically relevant fungi are already available for chemical investigation. While studies of these organisms are in progress, further coprophilous species will be isolated, identified, and prescreened for antifungal activity in the laboratory of an expert in coprophilous mycology (Prof. D. Malloch). The types of fungi to be targeted are those considered most likely to exhibit antagonistic activity towards competitors, and will be selected on the basis of knowledge about their ecology and taxonomy. Isolates found to display antifungal effects will be grown in liquid culture, and extracts will be tested in-house and at a cooperating pharmaceutical company (Lilly) to prioritize cultures for chemical studies. Antifungal components will be isolated through on-site bioassay-guided fractionation, and their structures will be determined using state-of-the-art spectroscopic techniques. Antifungal potency of new metabolites will be further evaluated at Lilly. Pure compounds will also be tested for other important activities, with next priority given to cancer-relevant assays. The project has several unique aspects. The specific targeting of coprophilous fungi as sources of antifungals is unprecedented. None of the isolates to be included in this work (and few members of the genera they represent) have ever been studied chemically. The proposed approach relies upon knowledge of the ecology, taxonomy, and/or novelty of the organism prior to chemical investigation, thereby simplifying dereplication, increasing the odds of discovering new chemistry, and preventing repetitive investigation of heavily studied species. This systematic, ecology-based approach to microorganism selection represents a departure from traditional random microbial screening programs by attempting to introduce rationale at the beginning of the process. The progress made to date demonstrates the ability of the research team to perform the proposes studies, and underscores the need for continued investigation of this relatively unexplored source of potentially valuable natural products.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI027436-04
Application #
3141646
Study Section
Bio-Organic and Natural Products Chemistry Study Section (BNP)
Project Start
1990-06-01
Project End
1996-07-31
Budget Start
1993-08-01
Budget End
1994-07-31
Support Year
4
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Arts and Sciences
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Che, Yongsheng; Gloer, James B; Koster, Brenda et al. (2002) Decipinin A and decipienolides A and B: new bioactive metabolites from the coprophilous fungus Podospora decipiens. J Nat Prod 65:916-9
Hein, S M; Gloer, J B; Koster, B et al. (2001) Bombardolides: new antifungal and antibacterial gamma-lactones from the coprophilous fungus Bombardioidea anartia. J Nat Prod 64:809-12
Che, Y; Swenson, D C; Gloer, J B et al. (2001) Pseudodestruxins A and B: new cyclic depsipeptides from the coprophilous fungus Nigrosabulum globosum. J Nat Prod 64:555-8
Soman, A G; Gloer, J B; Koster, B et al. (1999) Sporovexins A-C and a new preussomerin analog: antibacterial and antifungal metabolites from the coprophilous fungus Sporormiella vexans. J Nat Prod 62:659-61
Hein, S M; Gloer, J B; Koster, B et al. (1998) Arugosin F: a new antifungal metabolite from the coprophilous fungus Ascodesmis sphaerospora. J Nat Prod 61:1566-7
Whyte, A C; Gloer, J B; Scott, J A et al. (1996) Cercophorins A-C: novel antifungal and cytotoxic metabolites from the coprophilous fungus Cercophora areolata. J Nat Prod 59:765-9
Wang, Y; Gloer, J B; Scott, J A et al. (1995) Terezines A-D: new amino acid-derived bioactive metabolites from the coprophilous fungus Sporormiella teretispora. J Nat Prod 58:93-9
Alfatafta, A A; Gloer, J B; Scott, J A et al. (1994) Apiosporamide, a new antifungal agent from the coprophilous fungus Apiospora montagnei. J Nat Prod 57:1696-702
Wang, Y; Gloer, J B; Scott, J A et al. (1993) Appenolides A-C: three new antifungal furanones from the coprophilous fungus Podospora appendiculata. J Nat Prod 56:341-4