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.

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 enterohemorrhagic Escherichia coli (EHEC) strains. Phylogeny and physiological characteristics of the active strains were investigated. First insights into the chemical basis of the antibacterial activity indicated the biosynthetic production of the known compounds ariakemicin, kocurin, naphthyridinomycin, pumilacidins, resistomycin, and surfactin. However, most compounds remained elusive until now. Hence, the obtained results implicate that the microbiome present at the various habitats at the Peruvian coastline is a promising source for heterotrophic bacterial strains showing high potential for the biotechnological production of antibiotics.

Context: Given the growing public health crisis caused by viral diseases, traditional medicine stands as one of the fundamental pillars for the study and discovery of phytometabolites with antiviral properties. It is necessary to investigate and evaluate these compounds, mostly phenolic, that could be used as drugs. Aims: To identify the polyphenols by UPLC-MS/MS and the potential in silico antiviral activity of medicinal plants in Trujillo, Peru. Methods: The ethnobotany of the eight most widely used medicinal plants in the city of Trujillo was described (Azadirachta indica A. Juss. “paradise”, Caesalpinia spinosa (Molina) Kuntze “tara”, Citrus limon (L.) Osbeck “lemon”, Clinopodium pulchellum (Kunth) Govaerts "panizara", Cordia lutea Lam. "overo", Ocimum basilicum L. "basil", Schinus molle L. "molle", and Taraxacum campylodes G.E. Haglund "dandelion"). The phytometabolites responsible for the antiviral activity were identified by LC-MS and evaluated in silico against the viral proteins NS2B/NS3 (DENV-2), NS5B (HCV), and ICP27 (HSV-1) by molecular docking using Chimera 1.16 software and molecular interaction by Maestro 13.1 software to identify the position and type of interaction. Results: Five polyphenols (chlorogenic acid, gallic acid, caffeic acid, rosmarinic acid, and rutin) were found, and in the in-silico test, the antiviral activity of chlorogenic acid stood out against DENV-2 and HCV, rutin against HCV and HSV-1, rosmarinic acid against DENV-2 and HCV. Conclusions: It is demonstrated that the medicinal plants studied contain phytometabolites that make them possible antiviral candidates, which would support their use in the traditional medicine of the province of Trujillo, Peru.