@article{PimentelElardoBubackGulderetal.2011,
  author    = {Pimentel-Elardo, Sheila M. and Buback, Verena and Gulder, Tobias A. M. and Bugni, Tim S. and Reppart, Jason and Bringmann, Gerhard and Ireland, Chris M. and Schirmeister, Tanja and Hentschel, Ute},
  title     = {New Tetromycin Derivatives with Anti-Trypanosomal and Protease Inhibitory Activities},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75465},
  year      = {2011},
  abstract  = {Four new tetromycin derivatives, tetromycins 1-4 and a previously known one, tetromycin B (5) were isolated from Streptomyces axinellae Pol001T cultivated from the Mediterranean sponge Axinella polypoides. Structures were assigned using extensive 1D and 2D NMR spectroscopy as well as HRESIMS analysis. The compounds were tested for antiparasitic activities against Leishmania major and Trypanosoma brucei, and for protease inhibition against several cysteine proteases such as falcipain, rhodesain, cathepsin L, cathepsin B, and viral proteases SARS-CoV Mpro, and PLpro. The compounds showed antiparasitic activities against T. brucei and time-dependent inhibition of cathepsin L-like proteases with Ki values in the low micromolar range.},
  subject      = {Biologie},
  language  = {en}
}
@article{AbdelmohsenPimentelElardoHanoraetal.2010,
  author    = {Abdelmohsen, Usama Ramadan and Pimentel-Elardo, Sheila M. and Hanora, Amro and Radwan, Mona and Abou-El-Ela, Soad H. and Ahmed, Safwat and Hentschel, Ute},
  title     = {Isolation, Phylogenetic Analysis and Anti-infective Activity Screening of Marine Sponge-Associated Actinomycetes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68307},
  year      = {2010},
  abstract  = {Terrestrial actinomycetes are noteworthy producers of a multitude of antibiotics, however the marine representatives are much less studied in this regard. In this study, 90 actinomycetes were isolated from 11 different species of marine sponges that had been collected from offshore Ras Mohamed (Egypt) and from Rovinj (Croatia). Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. Fourteen putatively novel species were identified based on sequence similarity values below 98.2\% to other strains in the NCBI database. A putative new genus related to Rubrobacter was isolated on M1 agar that had been amended with sponge extract, thus highlighting the need for innovative cultivation protocols. Testing for anti-infective activities was performed against clinically relevant, Gram-positive (Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, fungi (Candida albicans) and human parasites (Leishmania major, Trypanosoma brucei). Bioactivities against these pathogens were documented for 10 actinomycete isolates. These results show a high diversity of actinomycetes associated with marine sponges as well as highlight their potential to produce anti-infective agents.},
  subject      = {Biologie},
  language  = {en}
}
@article{PimentelElardoKozytskaBugnietal.2010,
  author    = {Pimentel-Elardo, Sheila Marie and Kozytska, Svitlana and Bugni, Tim S. and Ireland, Chris M. and Moll, Heidrun and Hentschel, Ute},
  title     = {Anti-Parasitic Compounds from Streptomyces sp. Strains Isolated from Mediterranean Sponges},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68312},
  year      = {2010},
  abstract  = {Actinomycetes are prolific producers of pharmacologically important compounds accounting for about 70\% of the naturally derived antibiotics that are currently in clinical use. In this study, we report on the isolation of Streptomyces sp. strains from Mediterranean sponges, on their secondary metabolite production and on their screening for anti-infective activities. Bioassay-guided isolation and purification yielded three previously known compounds namely, cyclic depsipeptide valinomycin, indolocarbazole alkaloid staurosporine and butenolide. This is the first report of the isolation of valinomycin from a marine source. These compounds exhibited novel anti-parasitic activities specifically against Leishmania major (valinomycin IC50 < 0.11 μM; staurosporine IC50 5.30 μM) and Trypanosoma brucei brucei (valinomycin IC50 0.0032 μM; staurosporine IC50 0.022 μM; butenolide IC50 31.77 μM). These results underscore the potential of marine actinomycetes to produce bioactive compounds as well as the re-evaluation of previously known compounds for novel anti-infective activities.},
  subject      = {Biologie},
  language  = {en}
}
@article{AbdelmohsenSzesnyOthmanetal.2012,
  author    = {Abdelmohsen, Usama Ramadan and Szesny, Matthias and Othman, Eman Maher and Schirmeister, Tanja and Grond, Stepanie and Stopper, Helga and Hentschel, Ute},
  title     = {Antioxidant and Anti-Protease Activities of Diazepinomicin from the Sponge-Associated Micromonospora Strain RV115},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76279},
  year      = {2012},
  abstract  = {Diazepinomicin is a dibenzodiazepine alkaloid with an unusual structure among the known microbial metabolites discovered so far. Diazepinomicin was isolated from the marine sponge-associated strain Micromonospora sp. RV115 and was identified by spectroscopic analysis and by comparison to literature data. In addition to its interesting preclinical broad-spectrum antitumor potential, we report here new antioxidant and anti-protease activities for this compound. Using the ferric reducing antioxidant power (FRAP) assay, a strong antioxidant potential of diazepinomicin was demonstrated. Moreover, diazepinomicin showed a significant antioxidant and protective capacity from genomic damage induced by the reactive oxygen species hydrogen peroxide in human kidney (HK-2) and human promyelocytic (HL-60) cell lines. Additionally, diazepinomicin inhibited the proteases rhodesain and cathepsin L at an IC50 of 70-90 μM. It also showed antiparasitic activity against trypomastigote forms of Trypanosoma brucei with an IC50 of 13.5 μM. These results showed unprecedented antioxidant and anti-protease activities of diazepinomicin, thus further highlighting its potential as a future drug candidate.},
  subject      = {Biologie},
  language  = {en}
}
@article{PimentelElardoGrozdanovProkschetal.2012,
  author    = {Pimentel-Elardo, Sheila Marie and Grozdanov, Lubomir and Proksch, Sebastian and Hentschel, Ute},
  title     = {Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75990},
  year      = {2012},
  abstract  = {Genomic mining revealed one major nonribosomal peptide synthetase (NRPS) phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows highest similarities to NRPS genes that were previously assigned, by ways of single cell genomics, to a Chloroflexi sponge symbiont. Genomic mining studies such as the one presented here for NRPS genes, contribute to on-going efforts to characterize the genomic potential of sponge-associated microbiota for secondary metabolite biosynthesis.},
  subject      = {Biologie},
  language  = {en}
}