This research was funded by Fondo Nacional de Desarrollo Cient?fico, Tecnol?gico y de Innovaci?n Tecnol?gica (FONDECYT) del Consejo Nacional de Ciencia Tecnolog?a e Innovaci?n Tecnol?gica (CONCYTEC) del Gobierno de Per? (Convenio de Subvenci?n 153-2015-FONDECYT). The authors would like to thank Dr. Pedro Alva-Plasencia, principal researcher of the project PIC 06-2014, for providing the laboratory equipment.

Este trabajo fue financiado por el CONCYTEC-FONDECYT en el marco de la convocatoria E041-01 [114-2018-FONDECYT-BM-IADT-MU].

The antibiotically bioactive thiopeptide compound kocurin was identified in extracts from a newly isolated Kocuria rosea strain. The axenic strain was retrieved from a soil sample of the intertidal area at the Paracas National Park, Peru. The genetic basis of this promising natural product with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains was revealed by comparative genome analysis of this new isolate and other reported thiopeptide producer strains. The functionality of the predicted gene locus was experimentally proven by heterologous expression in Streptomyces coelicolor M1146. Expression of the gene cluster under the control of a constitutive promoter enabled the transgenic strain to produce kocurin in selected media. The kocurin biosynthetic gene cluster comprises nine open reading frames and spans around 12 kbp of the genome.

Bacterial aminophenylpyrrole-derived alkaloids (APPAs) represent high value lead compounds. Pyrrolnitrin, which was developed into globally important fungicides, is the only reported APPA produced by Proteobacteria. Recently, various APPAs showing diverse bioactivities were discovered from Bacteroidetes. Here, a bioinformatics and phylogenetic approach enabled the elucidation of the biosynthesis of the highly diverse APPAs in Cytophagales bacteria and their chemical diversification strategy. The biosynthetic gene clusters were identified in producer strains, and the biosynthesis was experimentally validated by heterologous expression experiments in E. coli. First, one enzyme-dependent biosynthetic step yields the tryptophan-derived precursor 3-(2′-aminophenyl)-pyrrole. Second, a spontaneous Pictet–Spengler-like coupling reaction enables the bacterial producer strains to create a libr...

The microbiome of three different sites at the Peruvian Pacific coast was analyzed, revealing a lower bacterial biodiversity at Isla Foca than at Paracas and Manglares, with 89 bacterial genera identified, as compared to 195 and 173 genera, respectively. Only 47 of the bacterial genera identified were common to all three sites. In order to obtain promising strains for the putative production of novel antimicrobials, predatory bacteria were isolated from these sampling sites, using two different bait organisms. Even though the proportion of predatory bacteria was only around 0.5% in the here investigated environmental microbiomes, by this approach in total 138 bacterial strains were isolated as axenic culture. 25% of strains showed antibacterial activity, thereby nine revealed activity against clinically relevant methicillin resistant Staphylococcus aureus (MRSA) and three against enteroh...

Pineapple peels has several beneficial properties including antioxidant activity. We investigated the antioxidant effect of five different peels of pineapple lyophilized extracts, not adsorbed and adsorbed onto Amberlite. They were examined using total phenolic contents (TPC), antioxidant effect by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP). In addition, we analyzed the chemical composition by HPLC-ESI-QTOF-MS/MS. The main constituents of pineapple peels were tentatively identified as quercetin glycosides and N,N’-diferuloylspermidine. We conclude that the antioxidant activity in pineapple peels from District of Poroto, Province of Trujillo, Region of La Libertad, can be associated with the presence of flavonoid and spermidines. © 2019, Universidad de Santiago de Chile. All rights reserved.

The chemical composition of Mangifera indicaL. cv. "Kent" leaves was determined by HPLC-ESI-QTOF-MS/MS. Polyphenolic compounds characterized as benzophenone derivatives were the main components found in extracts and xanthones. The estrogenic and antioxidant effects of aqueous extracts from Mangifera indica L. cv. "Kent" leaves on ovariectomized rats were determined by uterotrophic assay and malondialdehyde (MDA) levels in erythrocytes, bone, liver, and stomach. We conclude that the polyphenolic compounds from extracts act as exogenous antioxidant agents against oxidative damage in ovariectomized rats.