Unraveling the antifungal composition of bitter orange decoction against the melon pathogen Fusarium jinanense.

Bitter orange (Citrus aurantium) is an important source of essential oils with high antimicrobial activities, however the composition and antifungal potential of the decoction peels is little explored. This study assessed the peel decoction's chemical profile at the secondary metabolism level and its antifungal activity against the melon phytopathogen Fusarium jinanense. The decoction's antifungal potential was investigated using a bioassay-guided fractionation approach based on Solid-Phase Extraction (SPE) and LC-HRMS/MS analysis. Coumarins and flavones were the most abundant classes of compounds in the high-value fractions responsible for up to 61% of the mycelial inhibition of F. jinanense. Overall, this study has presented for the first time the chemical composition, the antifungal potential of the decoction of C. aurantium peels and the compounds associated with these results. This strategy can guide the exploration of under-explored food sources and add value to compounds or fractions enriched with bioactive compounds.

Chemical-Biology and Metabolomics Studies in Phage-Host Interactions.

For many years, several studies have explored the molecular mechanisms involved in the infection of bacteria by their specific phages to understand the main infection strategies and the host defense strategies. The modulation of the mechanisms involved in the infection, as well as the expression of key substances in the development of the different life cycles of phages, function as a natural source of strategies capable of promoting the control of different pathogens that are harmful to human and animal health. Therefore, this chapter aims to provide an overview of the mechanisms involved in virus-bacteria interaction to explore the main compounds produced or altered as a chemical survival strategy and the metabolism modulation when occurring a host-phage interaction. In this context, emphasis will be given to the chemistry of peptides/proteins and enzymes encoded by bacteriophages in the control of pathogenic bacteria and the use of secondary metabolites recently reported as active participants in the mechanisms of phage-bacteria interaction. Finally, metabolomics strategies developed to gain new insights into the metabolism involved in the phage-host interaction and the metabolomics workflow in host-phage interaction will be presented.

Musa spp. cultivars as a neutralising source against some toxic activities of Bothrops and Crotalus genus snake venoms.

Accidents involving snakes from Bothrops spp. and Crotalus spp. constitute the most important cause of envenomation in Brazil and Argentina. Musa spp. (banana) have been reported to be used in popular medicine against snakebite by the members of the Canudos Settlement, located in Goiás. In this way, the aim of this work was to evaluate the antivenom effect of the Ouro (AA), Prata (AAB), Prata-anã (AAB) and Figo (ABB) cultivars against in vitro (phospholipase, coagulation and proteolytic) and in vivo (lethality and toxicity) activities caused by the venoms and toxicity (Artemia salina nauplii and Danio rerio embryos) of Musa spp. as well as the annotation of chemical compounds possibly related to these activities. From the in vitro antiophidic tests with the sap, we observed 100% inhibition of the phospholipase and coagulant activities with the cultivars Prata-anã and Figo against the venoms of B. alternatus and C. d. collineatus, B. diporus and B. pauloensis, respectively, and neutralisation of the lethality against the B. diporus venom. It was observed that the cultivars of Musa spp. did not show toxicity against Artemia salina nauplii and Danio rerio embryos. The sap analysis via HPLC-MS/MS allowed the annotation of the 13 compounds: abscisic acid, shikimic acid, citric acid, quinic acid, afzelechin, Glp-hexose, glucose, sucrose, isorhamnetin-3-O-galactoside-6-raminoside, kaempferol-3-glucoside-3-raminoside, myricetin-3-O-rutinoside, procyanidin B1 and rutin. Therefore, it can be seen that Musa spp. is a potential therapeutic agent that can act to neutralise the effects caused by snakebites.

Evaluation of antimicrobial and antiproliferative activities of Actinobacteria isolated from the saline lagoons of northwestern Peru.

Extreme environments Morrope and Bayovar Salt lagoons, several ecosystems and microhabitats remain unexplored, and little is known about the diversity of Actinobacteria. We suggest that the endemic bacteria present in this extreme environment is a source of active molecules with anticancer, antimicrobial, and antiparasitic properties. Using phenotypic and genotypic characterization techniques, including 16S rRNA sequencing, we identified these bacteria as members of the genera Streptomyces, Pseudonocardia, Staphylococcus, Bacillus, and Pseudomonas. Actinobacteria strains were found predominantly. Phylogenetic analysis revealed 13 Actinobacteria clusters of Streptomyces, the main genus. Three Streptomycetes, strains MW562814, MW562805, and MW562807 showed antiproliferative activities against three tumor cell lines: U251 glioma, MCF7 breast, and NCI-H460 lung (non-small cell type); and antibacterial activity against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 10536, and the multidrug resistant Acinetobacter baumannii AC-972. The antiproliferative activities (measured as total growth inhibition [TGI]) of Streptomyces sp. MW562807 were 0.57 µg/mL, for 0.61 µg/mL, and 0.80 µg/mL for glioma, lung non-small cell type, and breast cancer cell lines, respectively; the methanolic fraction of the crude extract showed a better antiproliferative activity and could inhibit the growth of (U251 (TGI = 38.3 µg/mL), OVCAR-03 (TGI = 62.1 µg/mL), and K562 (TGI = 81.5 µg/mL)) of nine tumor cells types and one nontumor cell type. Extreme enviroments, such as the Morrope and Bayovar Salt saloons are promising sources of new bacteria, whose compounds may be useful for treating various infectious diseases or even some types of cancer.

Açai (Euterpe oleracea Mart.) Seed Extract Induces ROS Production and Cell Death in MCF-7 Breast Cancer Cell Line.

Euterpe oleracea Mart. (açai) is a native palm from the Amazon region. There are various chemical constituents of açai with bioactive properties. This study aimed to evaluate the chemical composition and cytotoxic effects of açai seed extract on breast cancer cell line (MCF-7). Global Natural Products Social Molecular Networking (GNPS) was applied to identify chemical compounds present in açai seed extract. LC-MS/MS and molecular networking were employed to detect the phenolic compounds of açai. The antioxidant activity of açai seed extract was measured by DPPH assay. MCF-7 breast cancer cell line viability was evaluated by MTT assay. Cell death was evaluated by flow cytometry and time-lapse microscopy. Autophagy was evaluated by orange acridin immunofluorescence assay. Reactive oxygen species (ROS) production was evaluated by DAF assay. From the molecular networking, fifteen compounds were identified, mainly phenolic compounds. The açai seed extract showed cytotoxic effects against MCF-7, induced morphologic changes in the cell line by autophagy and increased the ROS production pathway. The present study suggests that açai seed extract has a high cytotoxic capacity and may induce autophagy by increasing ROS production in breast cancer. Apart from its antioxidant activity, flavonoids with high radical scavenging activity present in açai also generated NO (nitric oxide), contributing to its cytotoxic effect and autophagy induction.

In silico characterization of linoleic acid biotransformation to rumenic acid in food derived Lactobacillus plantarum YW11.

Lactobacillus plantarum YW11 capability to convert linoleic acid into conjugated linoleic acid and other metabolites was studied in a dose-dependent manner by supplementing LA at different concentrations. L. plantarum YW11 displayed a uniform distinctive growth curve of CLA and other metabolites at concentrations of LA ranging from 1% (w/v) to 10% (w/v), with slightly increased growth at higher LA concentrations. The biotransformation capability of L. plantarum YW11 evaluated by GC-MS revealed a total of one CLA isomer, i.e. 9-cis,11-trans-octadecadienoic acid, also known as the rumenic acid (RA), one linoleic acid isomer (linoelaidic acid), and LA metabolites: (E)-9-octadecenoic acid ethyl ester, trans, trans-9,12-octadecadienoic acid, propyl ester and stearic acid. All the metabolites of linoleic acid were produced from 1 to 10% LA supplemented MRS media, while surprisingly the only conjugated linoleic acid compound was produced at 10% LA. To assess the presence of putative enzymes, responsible for conversion of LA into CLA, in silico characterization was carried out. The in silico characterization revealed presence of four enzymes (10-linoleic acid hydratase, linoleate isomerase, acetoacetate decarboxylase and dehydrogenase) that may be involved in the production of CLA (rumenic acid) and LA isomers. The biotransformation ability of L. plantarum YW11 to convert LA into RA has great prospects for biotechnological and industrial implications that could be exploited in the future scale-up experiments.

Antifungal potential of secondary metabolites involved in the interaction between citrus pathogens.

Numerous postharvest diseases have been reported that cause substantial losses of citrus fruits worldwide. Penicillium digitatum is responsible for up to 90% of production losses, and represent a problem for worldwide economy. In order to control phytopathogens, chemical fungicides have been extensively used. Yet, the use of some artificial fungicides cause concerns about environmental risks and fungal resistance. Therefore, studies focusing on new approaches, such as the use of natural products, are getting attention. Co-culture strategy can be applied to discover new bioactive compounds and to understand microbial ecology. Mass Spectrometry Imaging (MSI) was used to screen for potential antifungal metabolites involved in the interaction between Penicillium digitatum and Penicillium citrinum. MSI revealed a chemical warfare between the fungi: two tetrapeptides, deoxycitrinadin A, citrinadin A, chrysogenamide A and tryptoquialanines are produced in the fungi confrontation zone. Antimicrobial assays confirmed the antifungal activity of the investigated metabolites. Also, tryptoquialanines inhibited sporulation of P. citrinum. The fungal metabolites reported here were never described as antimicrobials until this date, demonstrating that co-cultures involving phytopathogens that compete for the same host is a positive strategy to discover new antifungal agents. However, the use of these natural products on the environment, as a safer strategy, needs further investigation. This paper aimed to contribute to the protection of agriculture, considering health and ecological risks.