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Purpose: Schistosomiasis remains a parasitic disease affecting millions of people worldwide, requiring interventions like vaccination. In previous work, our group used reverse vaccinology to identify two epitopes from the Schistosoma mansoni proteins, Sm050890 (44-58) and Sm141290 (225-239). This study evaluated the immune response profile and protection induced by peptides, as a mixture of immunogens, in murine vaccination trials. Additionally, the diagnostic potential of these peptides was assessed on immunoassays., Methods: Mice were immunized with a formulation containing the mixture of the peptides, subsequently infected, and perfused for worm burden recovery and quantification. Liver and blood samples from animals were used to evaluate the effect of immunization on the formation of granulomas and specific anti-peptide antibodies (IgG). Additionally, cytokine measurement was performed in splenocyte cultures from immunized mice, and peripheral blood serum from individuals infected with S. mansoni was used to assess the recognition of the peptides by IgG antibodies., Results: The vaccine stimulated an increase in the production of IgG and IgG2c antibodies, associated with a significant reduction of 44 - 29% in worm burden. Although the vaccine did not reduce liver pathology, it enhanced the production of IFN-γ while decreasing IL-10 production by splenocytes. Furthermore, the peptides Sm050890 (44-58) and Sm141290 (225-239) were not recognized by IgG antibodies in the serum from infected individuals., Conclusion: Overall, our data suggest that the peptides Sm050890 (44-58) and Sm141290 (225-239) are promising vaccine candidates against schistosomiasis and can be used to compose a multiepitope/chimeric vaccine in future studies., Competing Interests: Declarations. Ethics Approval and Consent: This study was approved by the Animal Care and Ethics Committee of the Federal University of São João del-Rei (CEPEA–UFSJ 12/2010) and by the research ethics committee of the FUNEDI-MG (56/2009). This study obtained written informed consent from all the participants. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Nosocomial infections are an important cause of morbi-mortality worldwide. The increase in the rate of resistance to conventional drugs in these microorganisms has stimulated the search for new therapeutic options. The nitro moiety (NO 2 ) is an important pharmacophore of molecules with high anti-infective activity. We aimed to synthesize new nitro-derivates and to evaluate their antibacterial and anti-Candida potential in vitro. Five compounds [3-nitro-2-phenylchroman-4-ol (3); 3-nitro-2-phenyl-2H-chromene (4a); 3-nitro-2-(4-chlorophenyl)-2H-chromene (4b); 3-nitro-2-(4-fluorophenyl)-2H-chromene (4c), and 3-Nitro-2-(2,3-dichlorophenyl)-2H-chromene (4d)] were efficiently synthesized by Michael-aldol reaction of 2-hydroxybenzaldehyde with nitrostyrene, resulting in one β-nitro-alcohol (3) and four nitro-olefins (4a-4d). The antibacterial and anti-Candida potentials were evaluated by assaying minimal inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and minimum bactericidal concentration (MBC). Mono-halogenated nitro-compounds (4b and 4c) showed anti-staphylococcal activity with MIC values of 15.6-62.5 μg/mL and MBC of 62.5 μg/mL. However, the activity against Gram-negative strains was showed to be considerably lower and our data suggests that this effect was associated with the outer membrane. Furthermore, nitro-compounds 4c and 4d presented activity against Candida spp. with MIC values ranging from 7.8-31.25 μg/mL and MFC of 15.6-500 μg/mL. In addition, these compounds were able to induce damage in fungal cells increasing the release of intracellular material, which was associated with actions on the cell wall independent of quantitative changes in chitin and β-glucan. Together, these findings show that nitro-compounds can be exploited as anti-staphylococcal and anti-Candida prototypes.

Cancer continues to be one of the most important health problems worldwide, and the identification of novel drugs and treatments to address this disease is urgent. During recent years, marine organisms have proven to be a promising source of new compounds with action against tumoral cell lines. Here, we describe the synthesis and anticancer activity of eight new 3-alkylpyridine alkaloid (3-APA) analogs in four steps and with good yields. The key step for the synthesis of these compounds is a Williamson etherification under phase-transfer conditions. We investigated the influence of the length of the alkyl chain attached to position 3 of the pyridine ring on the cytotoxicity of these compounds. Biological assays demonstrated that compounds with an alkyl chain of ten carbon atoms (4c and 5c) were the most active against two tumoral cell lines: RKO-AS-45-1 and HeLa. Micronucleus and TUNEL assays showed that both compounds are mutagenic and induce apoptosis. In addition, Compound 5c altered the cellular actin cytoskeleton in RKO-AS-45-1 cells. The results suggest that Compounds 4c and 5c may be novel prototype anticancer agents.