Linear and Polyvalent Peptides with Potent Antimicrobial Activity Against Sensitive and Multidrug-Resistant E. c oli Clinical Isolates.

Peptides containing the sequences RRWQWR and RRWQWRMKKLG derived from Bovine lactoferricin (LfcinB) were synthesized and their antibacterial effect against reference strains and sensitive and resistant clinical isolates of E. coli was evaluated. Tetra-branched multiple antigen peptide (MAP) ((RRWQWR)-K-Ahx-C) exhibited significant antibacterial activity against sensitive, resistant, and multidrug-resistant clinical isolates of E.

Antifungal Synergy: Mechanistic Insights into the R-1-R Peptide and Extract as Potent Therapeutics against spp. through Proteomics.

Previous reports have demonstrated that the peptide derived from LfcinB, R-1-R, exhibits anti- activity, which is enhanced when combined with an extract from the plant. However, the mechanism of action remains unexplored. In this research, a proteomic study was carried out, followed by a bioinformatic analysis and biological assays in both the SC5314 strain and a fluconazole-resistant isolate of after incubation with R-1-R.

Unmasking the Antifungal Activity of Leaf Extract against .

Invasive fungal disease causes high morbidity and mortality among immunocompromised patients. Resistance to conventional antifungal drugs and the toxicity associated with high doses highlight the need for effective antifungal therapies. In this study, the antifungal potential of the ethanolic extract of (Cashew Leaf) leaves were evaluated against and .

Exploring the Potential Mechanism of Action of Piperine against and Targeting Its Virulence Factors.

Plant-derived compounds have proven to be a source of inspiration for new drugs. In this study, piperine isolated from the fruits of showed anti- activity. Furthermore, the mechanisms of action of piperine and its impact on virulence factors in , which have not been comprehensively understood, were also assessed.

Combining the Peptide RWQWRWQWR and an Ethanolic Extract of Enhances the Activity against Sensitive and Resistant and Strains.

The antifungal activity of palindromic peptide RWQWRWQWR and its derivatives was evaluated against clinical isolates of and . Also, ethanolic extracts of leaves and stem were evaluated. Furthermore, combinations of peptide, extract, and/or fluconazole (FLC) were evaluated.

Non-natural amino acids into LfcinB-derived peptides: effect in their (i) proteolytic degradation and (ii) cytotoxic activity against cancer cells.

The dimeric peptide [F]: (RRWQWRKKLG)-K-Ahx has exhibited a potent cytotoxic effect against breast cancer cell lines, with position 26 (F) being the most relevant for anti-cancer activity. In this investigation, six analogues of the [F] peptide were synthesized in which the 26th position was replaced by non-natural hydrophobic amino acids, finding that some modifications increased the resistance to proteolytic degradation exerted by trypsin or pepsin. Additionally, these modifications increased the cytotoxic effect against breast cancer cells and generated cell death mediated by apoptosis pathways, activating caspases 8 and 9, and did not compromise the integrity of the cytoplasmic membrane.

Emergence and circulation of azole-resistant , and bloodstream isolates carrying Y132F, K143R or T220L Erg11p substitutions in Colombia.

Methods: Over a four-year period, 123 Candida bloodstream isolates were collected at a quaternary care hospital. The isolates were identified by MALDI-TOF MS and their fluconazole (FLC) susceptibility patterns were assessed according to CLSI guidelines. Subsequently, sequencing of ERG11, TAC1 or MRR1, and efflux pump activity were performed for resistant isolates.

Changes in Length and Positive Charge of Palindromic Sequence RWQWRWQWR Enhance Cytotoxic Activity against Breast Cancer Cell Lines.

Breast cancer is one of the main causes of premature death in women; current treatments have low selectivity, generating strong physical and psychological sequelae. The palindromic peptide R-1-R (RWQWRWQWR) has cytotoxic activity against different cell lines derived from cancer and selectivity against noncancerous cells. To determine if changes in the charge/length of this peptide increase its activity, six peptides were obtained by SPPS, three of them with addition of Arg at the N, C-terminal or both and three with deletion of Arg at the N, C-terminal or both.

In Vitro Antifungal Activity of Chimeric Peptides Derived from Bovine Lactoferricin and Buforin II against var. .

Cryptococcosis is associated with high rates of morbidity and mortality. The limited number of antifungal agents, their toxicity, and the difficulty of these molecules in crossing the blood-brain barrier have made the exploration of new therapeutic candidates against a priority task. To optimize the antimicrobial functionality and improve the physicochemical properties of AMPs, chemical strategies include combinations of peptide fragments into one.

Chimeric Peptides Derived from Bovine Lactoferricin and Buforin II: Antifungal Activity against Reference Strains and Clinical Isolates of spp.

Antimicrobial peptides (AMPs) are considered to be a valuable source for the identification and/or design of promising candidates for the development of antifungal treatments, since they have advantages such as lower tendency to induce resistance, ease of production, and high purity and safety. Bovine lactoferricin (LfcinB) and buforin II (BFII) are AMPs to which great antimicrobial potential has been attributed. The minimum motives with antimicrobial activity derived from LfcinB and BFII are RRWQWR and RLLR, respectively.

Evaluation of Anti- Potential of Extract in Inhibiting Growth, Yeast-Hyphal Transition, Virulent Enzymes, and Biofilm Formation.

Due to the increased incidence of fungal infections and the emergence of antifungal resistance mainly by species, the need for safe and effective novel therapies is imperative. Consequently, plants and herbs are a powerful source to combat infections. Here, we evaluated the anti- potential of an ethanolic extract from The phytochemical analysis of revealed bioactive compounds such as alkaloids, terpenoids, and tannis.

Designing Chimeric Peptides: A Powerful Tool for Enhancing Antibacterial Activity.

Chimeric peptides containing short sequences derived from bovine Lactoferricin (LfcinB) and Buforin II (BFII) were synthetized using solid-phase peptide synthesis (SPPS) and characterized via reversed-phase liquid chromatography and mass spectrometry. The chimeras were obtained with high purity, demonstrating their synthetic viability. The chimeras' antibacterial activity against Gram-positive and Gram-negative strains was evaluated.

Synergistic bactericide and antibiotic effects of dimeric, tetrameric, or palindromic peptides containing the RWQWR motif against Gram-positive and Gram-negative strains.

Dimeric and tetrameric peptides derived from LfcinB (20-25): RRWQWR, LfcinB (20-30): RRWQWRMKKLG, LfcinB (17-31): FKARRWQWRMKKLGA, or the palindromic sequence LfcinB (21-25): RWQWRWQWR were obtained by means of the SPPS-Fmoc/Bu methodology. The antibacterial activity of these molecules was evaluated against (ATCC 25922 and ATCC 11775), (ATCC 25923), (ATCC 29212), and (ATCC 27853). The dimer LfcinB (20-25): (RRWQWR)K-Ahx, the tetramer LfcinB (20-25): (RRWQWR)K-Ahx-C, and the palindromic sequence LfcinB (21-25) exhibited the highest antibacterial activity against the tested bacterial strains.

Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines.

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides.

Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076.

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against ATCC 11775, ATCC 13636, and ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined.