Natural Products Discovery Group
Natural Products Discovery Group
Motley J.L.,Natural Products Discovery Group |
Motley J.L.,University of Oklahoma |
Stamps B.W.,University of Oklahoma |
Mitchell C.A.,Natural Products Discovery Group |
And 11 more authors.
Journal of Natural Products | Year: 2017
Few secondary metabolites have been reported from mammalian microbiome bacteria despite the large numbers of diverse taxa that inhabit warm-blooded higher vertebrates. As a means to investigate natural products from these microorganisms, an opportunistic sampling protocol was developed, which focused on exploring bacteria isolated from roadkill mammals. This initiative was made possible through the establishment of a newly created discovery pipeline, which couples laser ablation electrospray ionization mass spectrometry (LAESIMS) with bioassay testing, to target biologically active metabolites from microbiome-associated bacteria. To illustrate this process, this report focuses on samples obtained from the ear of a roadkill opossum (Dideiphis virginiana) as the source of two bacterial isolates (Pseudomonas sp. and Serratia sp.) that produced several new and known cyclic lipodepsipeptides (viscosin and serrawettins, respectively). These natural products inhibited biofilm formation by the human pathogenic yeast Candida albicans at concentrations well below those required to inhibit yeast viability. Phylogenetic analysis of 16S rRNA gene sequence libraries revealed the presence of diverse microbial communities associated with different sites throughout the opossum carcass. A putative biosynthetic pathway responsible for the production of the new serrawettin analogues was identified by sequencing the genome of the Serratia sp. isolate. This study provides a functional roadmap to carrying out the systematic investigation of the genomic, microbiological, and chemical parameters related to the production of natural products made by bacteria associated with non-anthropoidal mammalian microbiomes. Discoveries emerging from these studies are anticipated to provide a working framework for efforts aimed at augmenting microbiomes to deliver beneficial natural products to a host. © 2016 The American Chemical Society and American Society of Pharmacognosy.
Wang X.,Natural Products Discovery Group |
Sena Filho J.G.,Natural Products Discovery Group |
Sena Filho J.G.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária |
Hoover A.R.,Natural Products Discovery Group |
And 3 more authors.
Journal of Natural Products | Year: 2010
Chemical epigenetic manipulation of Penicillium citreonigrum led to profound changes in the secondary metabolite profile of its guttate. While guttate from control cultures exhibited a relatively simple assemblage of secondary metabolites, the guttate collected from cultures treated with 50 μM 5-azacytidine (a DNA methyltransferase inhibitor) was highly enriched in compounds representing at least three distinct biosynthetic families. The metabolites obtained from the fungus included six azaphilones (sclerotiorin (1), sclerotioramine (6), ochrephilone (2), dechloroisochromophilone III (3), dechloroisochromophilone IV (4), and 6-((3E,5E)-5,7-dimethyl-2-methylenenona-3, 5-dienyl)-2,4-dihydroxy-3-methylbenzaldehyde (5)), pencolide (7), and two new meroterpenes (atlantinones A and B (9 and 10, respectively)). While pencolide was detected in the exudates of both control and 5-azacytidine-treated cultures, all of the other natural products were found exclusively in the guttates of the epigenetically modified fungus. All of the metabolites from the P. citreonigrum guttate were tested for antimicrobial activity in a disk diffusion assay. Both sclerotiorin and sclerotioramine caused modest inhibition of Staphylococcus epidermidis growth; however, only sclerotioramine was active against a panel of Candida strains. © 2010 The American Chemical Society and American Society of Pharmacognosy.
Cichewicz R.H.,Natural Products Discovery Group |
Hambright K.D.,Plankton Ecology Laboratory
Toxicon | Year: 2010
A reconsideration of the pKa values proposed by Valenti et al. (Theodore W. Valenti et al., A mechanistic explanation for pH-dependent ambient aquatic toxicity of Prymnesium parvum carter. Toxicon (2010) 55, 990-998) suggests that the ionization status of the C-14 amino group in prymnesins will not substantially influence the toxicity of these compounds over a pH range of 6.5-8.5. A revised pKa value and ionization state distribution for the prymnesins in aqueous systems is proposed. © 2010.