TY  - JOUR
A1  - Abdelmohsen, Usama Ramadan
A1  - Szesny, Matthias
A1  - Othman, Eman Maher
A1  - Schirmeister, Tanja
A1  - Grond, Stepanie
A1  - Stopper, Helga
A1  - Hentschel, Ute
T1  - Antioxidant and Anti-Protease Activities of Diazepinomicin from the Sponge-Associated Micromonospora Strain RV115
N2  - 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.
KW  - Biologie
KW  - diazepinomicin
KW  - anti-protease
KW  - antioxidant
KW  - actinomycetes
KW  - Micromonospora
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76279
ER  - 
TY  - JOUR
A1  - Pimentel-Elardo, Sheila Marie
A1  - Grozdanov, Lubomir
A1  - Proksch, Sebastian
A1  - Hentschel, Ute
T1  - Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges
N2  - 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.
KW  - Biologie
KW  - nonribosomal peptide synthetase
KW  - NRPS
KW  - marine sponge
KW  - Porifera
KW  - metagenomics
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75990
ER  -