Broad Activity Research Articles

Traditionally Used Edible Flowers as a Source of Neuroactive, Antioxidant, and Anti-Inflammatory Extracts and Bioactive Compounds: A Narrative Review

Edible flowers are becoming a popular addition to diets. As science has progressed, it has been proven that in addition to their aesthetic value, they possess pharmacological effects and health-promoting properties. Several edible flowers are used in medicine, and the available literature data indicate their broad biological activity. This review focuses on pharmacological knowledge about the neuroactive, antioxidant, and anti-inflammatory potential of 15 traditionally used edible flowers. It also describes their traditionally uses and summarizes research findings on their chemical composition.

Harnessing the spatial and transcriptional regulation of monoterpenoid indole alkaloid metabolism in Alstonia scholaris leads to the identification of broad geissoschizine cyclase activities

Monoterpene indole alkaloids (MIAs) are valuable metabolites produced in numerous medicinal plants from the Apocynaceae family such as Alstonia scholaris, which synthesizes strictamine, a MIA displaying neuropharmacological properties of a potential importance. To get insights into the MIA metabolism in A. scholaris, we studied here both the spatial and transcriptional regulations of MIA genes by performing a robust transcriptomics analysis of the main plant organs, leaf epidermis but also by sequencing RNA from leaves transiently overexpressing the master transcriptional regulator MYC2. These transcriptomic studies notably demonstrated that the first steps of the MIA pathway are successively distributed in the internal phloem associated parenchyma and epidermis, and that MYC2 exert a remarkable transcriptional effect by modulating the expression of around 1000 genes. By combining these distinct datasets, we initiated the search for MIA-related genes encoding CYP71, based on the similarity of expression compared to already known MIA genes. Transient expression of these candidates in Nicotiana benthamiana leaves and yeast notably led to the identification of a related isoform of rhazimal synthase (RHS) capable of converting the MIA precursor geissoschizine into akuammicine, strictamine and 16-epi-pleiocarpamine. Investigating its catalytic mechanism revealed that strictamine results from rhazimal deformylation and that a similar mechanism may also explain 16-epi-pleiocarpamine synthesis. This prompted us to rename these enzymes geissoschizine cyclase due to their capacity of cyclizing geissoschizine into three different MIA scaffolds and to form both C-C and C-N bonds. This identification thus illustrates the potential of integrating spatial and transcriptional regulation analysis for MIA gene identification.

Dual-strategy microneedles of bio‑oxygen therapy and artificial enzyme anti-oxidation for psoriasis treatment.

Oxidative stress results from an imbalance between the production of free radicals by oxidants and their removal by antioxidants. Chronic oxidative stress is a key factor in inflammation, characterized by hypoxic microenvironments and elevated levels of reactive oxygen species (ROS). Psoriasis, a common chronic inflammatory skin disorder, profoundly impacts the physical and psychological well-being of affected individuals. In response to this, we have innovatively developed a core-shell structured Chlorella-Prussian Blue Complex (Z-PB), integrating dual therapeutic strategies of biological oxygen therapy and oxidative stress regulation to address psoriasis. The Z-PB leveraged the unique ability of Chlorella to generate dissolved oxygen under light, combined with the broad enzymatic activity of Prussian Blue (PB), to effectively ameliorate the oxidative stress in the chronic inflammatory microenvironment. Additionally, the Z-PB overcame challenges such as the survival of Chlorella in high ROS environments and the aggregation of nanoenzymes. The Z-PB-loaded hyaluronic acid microneedles (Z-PBHA/MNs) demonstrated excellent skin permeability, in vitro release profiles, and biocompatibility. These Z-PBHA/MNs had been shown to alleviate psoriasis induced by imiquimod (IMQ). Overall, the Z-PBHA/MNs incorporating both biological oxygen therapy and artificial enzyme antioxidants represented a promising and innovative therapeutic strategy for the treatment of psoriasis.

Antileishmanial and Antitrypanosomal Trends of Synthetic Tetralone Derivatives.

Leishmaniasis and trypanosomiasis are parasitic diseases that are closely linked to poverty, pose significant local burdens, and are common in tropical and subtropical regions. Various synthetic tetralone derivatives were studied as potential scaffolds for antileishmanial and antitrypanosomal activities. The compounds were studied for their effectiveness against multiple kinetoplastid protozoan pathogens: Leishmania major, Leishmania mexicana, and bloodstream trypomastigotes of Trypanosoma brucei brucei. Two different strains of T. b. brucei were used. The first strain was the wild-type Trypanosoma brucei (s427-WT), and the second strain was the multidrug resistant (MDR) strain B48, which was produced by deleting the TbAT1 gene from s427WT and subsequent adaptation to high levels of resistance to diamidines and organo-arsenical drugs. Compounds 4c, 7c, 9b, and 11b showed activity against two strains of Trypanosoma and two different Leishmania species, establishing them as versatile leads with broad anti-kinetoplastid activity. Compound 4c, a tetralone derivative with a bromo-containing trimethoxybenzylidene moiety and methyl-substituted cyclohexanone ring, was identified as the most potent inhibitor for both T. b. brucei strains, with EC50 values of 0.19 and 0.22 µM for WT and B48, respectively, showing the absence of cross-resistance with the diamidine and arsenical trypanocide classes. In addition, compound 4c exhibited more potency than both controls, eflornithine and pentamidine, against the MDR strain. We conclude that tetralone derivates could be a valuable starting point for the discovery of new antiparasitic drugs.

Characterization and genome analysis of lytic Vibrio phage VPK8 with potential in lysing Vibrio parahaemolyticus isolates from clinical and seafood sources

BackgroundVibrio parahaemolyticus is a marine bacterium causing seafood-associated gastrointestinal illness in humans and acute hepatopancreatic necrosis disease (AHPND) in shrimp. Bacteriophages have emerged as promising biocontrol agents against V. parahaemolyticus. This study characterizes Vibrio phage VPK8, focusing on host specificity, efficiency of plating (EOP) variability across V. parahaemolyticus isolates from diverse sources and other Vibrio species, morphology, genomic features, and bacteriolytic potential.MethodsVibrio phage VPK8 was isolated from blood cockles in Thailand using a mixed-host approach and purified via the double-layer agar method. Host specificity was evaluated using spot assays and EOP measurements against 120 Vibrio strains, including AHPND-associated, clinical, and seafood isolates. Phage morphology was characterized by transmission electron microscopy (TEM), while genomic features were analyzed using next-generation sequencing. Lytic characteristics, including latent period and burst size, were determined through one-step growth curves, and bacterial growth reduction was evaluated over a 24-h.ResultsVibrio phage VPK8 is a lytic phage with a 42,866 bp linear double-stranded genome, G + C content of 49.4%, and 48 coding sequences. Phylogenetic analysis grouped it within the Autographiviridae family, showing 95.96% similarity to Vibrio phage vB_VpaP_MGD1. Viral proteomic analysis placed VPK8 within the Pseudomonadota host group. Spot assays indicated broad lytic activity, but EOP analysis revealed high infectivity in clinical and seafood V. parahaemolyticus isolates, as well as some V. cholerae and V. mimicus strains. TEM revealed an icosahedral head (~ 60 nm) and a short tail. At a multiplicity of infection of 0.01, VPK8 exhibited a latent period of 25 min, a burst size of 115, and effectively inhibited the reference host V. parahaemolyticus PSU5124 within 6 h, maintaining its lytic activity and stability for over 24 h.ConclusionsThis study provides a detailed characterization of Vibrio phage VPK8 which exhibits targeted infectivity with high EOP in clinical and seafood V. parahaemolyticus isolates, as well as selected Vibrio species. Its stable lytic performance, rapid replication, and genomic safety suggest its potential for phage-based applications. Further studies should explore its in vivo efficacy and the genetic features contributing to phage resistance mechanisms, enhancing its potential applicability in managing Vibrio-related diseases.

P-1099. Correlation Analysis of Cefiderocol In vitro Activity and In vivo Efficacy Against Acinetobacter baumannii Strains with Difficult-to-Read MIC Endpoints

Abstract Background Cefiderocol (FDC) is a siderophore-conjugated cephalosporin with broad activity against Gram-negative bacteria, including Acinetobacter baumannii. For some isolates, determining the minimum inhibitory concentration (MIC) endpoints for FDC can be difficult due to the trailing growth phenomenon. Recently guidance on how to determine the MIC when trailing occurs has been updated in the CLSI M100 document, to enhance MIC reproducibility. In this study, we determined MICs of A. baumannii strains that show difficult to determine MIC endpoint due to trailing according to the updated CLSI guidance and analyzed correlations between MICs and in vivo efficacy. In vivo bacterial growth or reduction from start of treatment with cefiderocol against Acinetobacter baumannii in the neutropenic murine thigh infection model using humanized pharmacokinetic exposure of cefiderocol. In vivo (S): mean of reduction in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change <0 log10 colony forming unit (CFU) /thigh) CFU/thigh), in vivo (R): mean of increase in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change ≥0 log10 CFU/thigh). MIC values shown blue, orange, and red indicate susceptible, intermediate, and resistant, respectively, according to CLSI guideline 2024. Methods MICs were determined according to the 2024 CLSI guidance using iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB) from BD-BBL for 43 A. baumannii isolates, including 13 strains that show severe trailing. All strains had been evaluated in vivo in the murine thigh infection model using humanized pharmacokinetic exposure of FDC (1). Categorical agreements between MICs and in vivo efficacy in murine thigh infection model Susceptible (S), Non-susceptible (NS), breakpoints as published by CLSI (2024), In vivo (S): mean of reduction in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change <0 log10 colony forming unit (CFU)/thigh, in vivo (R): mean of increase in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change ≥0 log10 CFU/thigh). Results FDC MIC range of tested A. baumannii strains was 0.12 to >32 μg/mL. Among 19 strains that showed a reduction in bacterial load after treatment with FDC in the murine thigh infection model, 94.7% (18/19 strains) were categorized as FDC susceptible (Figure and Table 1). Among 24 strains that showed increase in bacterial load after treatment with FDC in vivo, 87.5% (21/24 strains) were categorized as FDC non-susceptible. The categorical agreement of MICs and in vivo efficacy was 90.7% (39/43). As for the 13 strains that showed severe trailing, the categorical agreement of MICs and in vivo efficacy was 84.6% (11/13, Table 2). The updated CLSI guidance did not impact the overall agreement that was obtained earlier using the previous CLSI guidance (Table 1, 2). Categorical agreements between MICs and in vivo efficacy in murine thigh infection model for 13 strains that showed severe trailing Susceptible (S), Non-susceptible (NS), breakpoints as published by CLSI (2024), In vivo (S): mean of reduction in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change <0 log10 colony forming unit (CFU)/thigh, in vivo (R): mean of increase in bacterial cell number at 24 hours after initial treatment with cefiderocol (mean of change ≥0 log10 CFU/thigh). Conclusion Our correlation analysis between MICs and in vivo efficacy in thigh infection model confirms the validity of MIC endpoint determinations described in CLSI M100 document, including strains that show severe trailing. Reference: 1. Monogue L, et al. Antimicrob Agents Chemother. 2017;61(11):e01022-17. Disclosures Hidenori Yamashiro, Shionogi & Co., Ltd.: Employee Motoyasu Onishi, PhD, Shionogi & Co., Ltd.: Employee Naomi Anan, MSc, Shionogi & Co., Ltd.: Employee Boudewijn L. DeJonge, PhD, Shionogi Inc.: Employee Christopher M. Longshaw, PhD, Shionogi BV: Employee Miki Takemura, n/a, Shionogi & Co., Ltd.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee

P-314. A Retrospective Review of Long-Acting Lipoglycopeptide Utilization at a VA Tertiary Teaching Medical Center

Abstract Background Dalbavancin and oritavancin are long-acting lipoglycopeptides (LA-LGPs) approved by the Food and Drug Administration (FDA) for acute skin and soft tissue infections (ASSTIs). With their long-acting pharmacokinetics and broad activity against gram-positive bacteria, LA-LGPs are ideal options for patients with serious infections, such as bone, joint, and bloodstream, who (1) require prolonged antimicrobial therapy, (2) are not candidates for long-term intravascular catheter access, (3) prefer to avoid hospital admission, and/or (4) need early discharge. Methods A retrospective chart review was conducted on patients ages older than 18 with a medication order of dalbavancin or oritavancin from September 2020- August 2023 at the Atlanta VA Medical Center. Patients were excluded if the patient did not have an active infection or a LA-LGP was ordered but not administered. Pertinent demographic, clinical, and microbiological data were collected from the patient’s medical record. Results Resolution of infection in 3 months with LA-LGPs was found to be 76% (35/46) effective in lower extremity osteomyelitis and 74% (72/98) effective for all indications. The mean total length of stay (inpatient) after LA-LGP infusion was 3.9 days. The most common adverse events were nausea and vomiting, which occurred at a rate of 6.1% (6/98). Conclusion The utilization of LA-LGPs showed to be effective in infection resolution in a 3-month period in majority of patients. Specifically, lower extremity osteomyelitis, a non-FDA approved use, showed promising results in resolution of infection. The use of LA-LGPs can be beneficial in shortening hospital length of stay and prevention of hospitalizations with minimal adverse events. This can possibly lead to decreased health care cost and hospital acquired infections. In all, the use of LA-LGPs has significant potential use in other serious infections other than ASSTIs with a variety of benefits from the patient and healthcare perspective. Disclosures All Authors: No reported disclosures

P-1484. In vitro Activity of Cefiderocol and Comparator Agents Against Non-fermentative Gram-negative Bacilli Isolated from Patients Hospitalized with Pneumonia as part of the SENTRY Global Surveillance Program (2020-2022)

Abstract Background Cefiderocol (CFDC) is a siderophore-conjugated cephalosporin with broad activity against Gram-negative bacteria including non-fermenters resistant to carbapenems. The in vitro activity of CFDC and comparators was evaluated against glucose non-fermenting Gram-negative bacteria isolated from patients hospitalized with pneumonia.Table 1:Activity of cefiderocol and comparator agents against Pseudomonas aeruginosa, Acinetobacter baumannii-calcoaceticus complex, and Stenotrophomonas maltophilia isolates from patients hospitalized with pneumonia from 2020-2022 Methods 5,995 isolates were collected between 2020-2022 from pneumonia patients as part of the global SENTRY Antimicrobial Surveillance Program, including: 3,809 Pseudomonas aeruginosa (PSA), 1,092 Acinetobacter baumannii-calcoaceticus complex (ABC), 808 Stenotrophomonas maltophilia (STM), 104 Achromobacter spp. (ACHR), 81 Burkholderia cepacia complex (BURK), and 101 other isolates. Minimum inhibitory concentrations (MIC) were assessed by CLSI guidelines using broth microdilution with cation-adjusted Mueller-Hinton broth (CAMHB) for comparators and iron-depleted CAMHB for CFDC. Susceptibility was assessed according to 2024 CLSI, FDA, and EUCAST breakpoints. Carbapenem resistance (CR) was defined as resistant to meropenem and imipenem by CLSI breakpoints. Results Against PSA, CFDC and β-lactam/β-lactamase inhibitor combinations all had susceptibility >95%. However only CFDC maintained high susceptibility against CR-PSA with 99.3% of the isolates being susceptible by CLSI breakpoints. No other comparator had > 90% susceptibility against CR-PSA (Table 1). Against ABC, CFDC demonstrated 97.5% susceptibility by CLSI breakpoints. This high susceptibility was maintained against CR-ABC with 96.1% susceptibility using CLSI breakpoints. Colistin showed 75.5% susceptibility per EUCAST breakpoint, but ceftazidime and ampicillin-sulbactam had no appreciable activity. CFDC, trimethoprim-sulfamethoxazole, and minocycline all showed >90% susceptibility against STM. Against ACHR and BURK, CFDC had high activity, with MIC50/90 values of 0.03/0.5 and 0.06/1 mg/L, respectively. Conclusion CFDC demonstrated high in vitro activity against glucose non-fermenters isolated from hospitalized patients with pneumonia. In particular, CFDC maintained high susceptibility against CR isolates making it an important treatment option for pneumonia patients at risk of infection with a CR non-fermenter. Disclosures Frank Kung, PhD, Shionogi Inc: Employee Sean T. Nguyen, PharmD, Shionogi Inc.: Employee Boudewijn L. DeJonge, PhD, Shionogi Inc.: Employee Christopher M. Longshaw, PhD, Shionogi BV: Employee Jason J. Bryowsky, PharmD, MS, Shionogi: Employee Rodrigo E. Mendes, PhD, GSK: Grant/Research Support Miki Takemura, n/a, Shionogi & Co., Ltd.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee

P-1100. Activity of Cefiderocol and Comparator Agents Against Global Isolates of Stenotrophomonas maltophilia from the SENTRY Antimicrobial Surveillance Program (2020–2023)

Abstract Background Stenotrophomonas maltophilia is a ubiquitous multidrug-resistant opportunistic pathogen. Infections caused by S. maltophilia have limited antibiotics treatment options due to the intrinsic resistant mechanisms such as the production of chromosomal L1 metallo-type carbapenemase and L2 extended-spectrum type β-lactamase. Cefiderocol (FDC) is a siderophore-conjugated cephalosporin with broad activity against Gram-negative bacteria, including S. maltophilia. In this study, the in vitro activities of cefiderocol and comparators were investigated against S. maltophilia clinical isolates that were collected from the US and Europe in 2020-2023 as part of the SENTRY Antimicrobial Surveillance Program. Susceptibility of Stenotrophomonas maltophilia to cefiderocol and comparator agents Cefiderocol (FDC), levofloxacin (LVFX), trimethoprim-sulfamethoxazole (TMP-SMX), minocycline (MIN), ceftazidime (CAZ), imipenem-relebactam (I/R), ceftazidime-avibactam (CZA), non-susceptible (NS), susceptible (S), intermediate (I), resistant (R), N/A (not applicable), a cefiderocol S ≤1, levofloxacin S ≤2, trimethoprim-sulfamethoxazole S ≤2/38, minocycline S ≤1, breakpoints as published by CLSI (2024), b cefiderocol S ≤2, levofloxacin S ≤0.5, ceftazidime S≤4, imipenem-relebactam S ≤2, ceftazidime-avibactam S ≤8, PK-PD breakpoints as published by EUCAST (2023) Methods A total of 1782 S. maltophilia isolates were consecutively collected from the US and Europe from 2020-2023. The most common infection type from which isolates were collected was pneumonia (n=1193), followed by skin and skin structure (n=166), bloodstream infection (n=208), and urinary tract infections (n=56). Minimum inhibitory concentrations (MICs) of FDC and comparators were determined by using iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB) for cefiderocol and CAMHB for comparators. MIC50, MIC90, and MIC range were calculated. Susceptibility rates were determined by using CLSI breakpoints (2024) and EUCAST PK-PD breakpoints (2023). Results FDC was the most potent agent tested against S. maltophilia, showing the lowest MIC90 value of 0.25 µg/mL (Table). The MIC90 values of levofloxacin (LVFX), trimethoprim-sulfamethoxazole (TMP-SMX), and minocycline (MIN) were 4, 0.5, and 1 µg/mL, respectively. The MIC90 values of other comparator agents were >8 µg/mL. Susceptibilities of FDC, LVFX, SMT, and MIN were 99.3, 83.0, 97.0, and 93,0%, respectively. The susceptibility to FDC was the highest against LVFX-, TMP-SMX- or MIN-non-susceptible isolates according to both CLSI and EUCAST breakpoint (Table). Conclusion FDC showed potent in vitro activity against S. maltophilia collected in the US and Europe from 2020-2023, including isolates non-susceptible to LVFX, TMP-SMX, or MIN, suggesting that FDC is an important therapeutic option for S. maltophilia infections. Disclosures Motoyasu Onishi, PhD, Shionogi & Co., Ltd.: Employee Hidenori Yamashiro, Shionogi & Co., Ltd.: Employee Rodrigo E. Mendes, PhD, GSK: Grant/Research Support Boudewijn L. DeJonge, PhD, Shionogi Inc.: Employee Sean T. Nguyen, PharmD, Shionogi Inc.: Employee Christopher M. Longshaw, PhD, Shionogi BV: Employee Miki Takemura, n/a, Shionogi & Co., Ltd.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee

87. Machine Learning-Guided Generation of a Potent Combination of Broadly Neutralizing Sarbecovirus Antibodies with a High Barrier to Resistance

Abstract Background The elderly and immunocompromised remain at high risk of severe COVID-19 due to suboptimal immune responses. Monoclonal antibodies to SARS-CoV-2 spike were highly effective for both prophylaxis and treatment, but quickly became ineffective due to viral escape. Using a machine learning-guided optimization approach, we identified two antibodies against highly conserved epitopes, one targeting the spike S2 stem helix (GB-0669) and the other against the class 4 RBD site on S1 (PRO-37587) with the goal of developing a combination for prophylaxis that would be less susceptible to viral escape. Methods GB-0669 and PRO-37587 were characterized for breadth through binding and neutralization assays against a panel of SARS-CoV-2 variants and related sarbecoviruses. We also assessed the barrier to resistance, both individually and in combination using SARS-CoV-2 Omicron BA.1 in live virus escape studies in Vero E6 cells. Passaged viruses were sequenced and assessed for viral replication. The prevalence of any observed mutations was analyzed for conservation in the SARS-CoV-2 lineages and across the sarbecovirus family. Results Both antibodies exhibited potent neutralization across SARS-CoV-2 variants including those that had not yet emerged during development of our antibodies, while displaying activity against non-SARS-CoV-2 viruses. During passage with BA.1, escape from GB-0669 was observed in passage 3 (H1156Y), while escape from PRO-37587 emerged in passage 10 through two mutations (P381S, D402G) that impaired viral replication. By the end of passage 10, neither complete nor partial escape were observed for the combination of GB-0669 and PRO-37587. These escape mutations were observed in fewer than 1% of circulating variants from the beginning of the pandemic, probably due to low selective pressure and/or their impact on viral replication. With the exception of P381S, these mutations were not observed across a range of sarbecoviruses. Conclusion We demonstrate that the combination of GB-0669 and PRO-37587 has potent and broad neutralization activity. The robust viral escape profile and conservation of these epitopes suggest that this combination is more likely to remain effective in the face of ongoing viral evolution. Disclosures Alex Ramos, PhD, Generate Biomedicines: Stocks/Bonds (Private Company) Alan Leung, PhD, Generate Biomedicines: Stocks/Bonds (Private Company) Brett T. Hannigan, PhD, Generate Biomedicines: Employee|Generate Biomedicines: Stocks/Bonds (Private Company) Adam Root, MS, MBA, Generate Biomedicines: Grant/Research Support|Generate Biomedicines: Stocks/Bonds (Private Company) Heather A. Van Epps, PhD, Generate Biomedicines: Stocks/Bonds (Private Company) Kristen Hopson, Ph.D., Generate Biomedicines: Stocks/Bonds (Private Company) Gevorg Grigoryan, PhD, Generate Biomedicines, Inc.: Employee and shareholder|Generate Biomedicines, Inc.: Stocks/Bonds (Private Company) Gavin CKW Koh, PhD, AstraZeneca: Stocks/Bonds (Public Company)|Generate:Biomedicines: Stocks/Bonds (Private Company)|GlaxoSmithKline: Stocks/Bonds (Public Company) Daria Hazuda, PhD, Generate Biomedicines: Stocks/Bonds (Private Company)

Screening a 681-membered yeast collection for the secretion of proteins with antifungal activity.

Fungal pathogens pose a threat to human health and food security. Few antifungals are available and resistance to all has been reported. Novel strategies to control plant and human pathogens as well as food spoilers are urgently required. Environmental yeasts provide a functionally diverse, yet underexploited potential for fungal control based on their natural competition via the secretion of proteins and other small molecules such as iron chelators, volatile organic compounds or biosurfactants. However, there is a lack of standardized workflows to systematically access application-relevant yeast-based compounds and understand their molecular functioning. Towards this goal, we developed a workflow to identify and characterize yeast isolates that are active against spoilage yeasts and relevant human and plant pathogens, herein focusing on discovering yeasts that secrete antifungal proteins. The workflow includes the classification of the secreted molecules and cross-comparison of their antifungal capacity using an independent synthetic calibrant. Our workflow delivered a collection of 681 yeasts of which 212 isolates (31%) displayed antagonism against at least one target strain. While 57.5% of the active yeasts showed iron-depended antagonism, likely due to pulcherrimin-like iron chelators, 31.7% secreted antifungal proteins. Those yeast candidates clustered within twelve OTUs, showed narrow and broad target spectra, and several showed a broad pH and temperature activity profile. Given the tools for yeast biotechnology and protein engineering available, our collection can serve as a rich starting point for genetic and molecular characterization of the various antifungal phenotypes, their mode of action and their future exploitation.

Fc-binding nanodisc restores antiviral efficacy of antibodies with reduced neutralizing effects against evolving SARS-CoV-2 variants

Passive antibody therapies, typically administered via parenteral routes, have played a crucial role in the initial response to the COVID-19 pandemic. However, the ongoing evolution of SARS-CoV-2 has revealed significant limitations of this approach, primarily due to mutational escape and the inadequate delivery of antibodies to the upper respiratory tract. To overcome these challenges, we propose a novel prophylactic strategy involving the intranasal delivery of an antibody in combination with an Fc-binding nanodisc. This nanodisc, engineered to specifically bind to the Fc regions of IgG antibodies, served two key functions: extending the antibody's half-life in the larynx and trachea, and enhancing its neutralization efficacy. Notably, Sotrovimab, an FDA-approved monoclonal antibody that has experienced a significant decline in neutralizing potency due to viral evolution, exhibited robust antiviral activity when complexed with the nanodisc against all tested Omicron variants. Furthermore, the Fc-binding nanodisc significantly boosted the antiviral efficacy of the soluble angiotensin-converting enzyme 2 (sACE2) Fc fusion protein, which possesses broad but modest antiviral activity. In ACE2 transgenic mice, the Fc-binding nanodisc protected better than sACE2-Fc alone with two more log reduction in lung viral titer. Therefore, the intranasal Fc-binding nanodisc offers a promising and powerful approach to counteract the diminished antiviral activity of neutralizing antibodies caused by mutational escape, effectively restoring antiviral efficacy against various evolving SARS-CoV-2 variants.

The Application of the Pyrazole Structure in the Structural Modification of Natural Products.

Most natural products in nature have broad but not exceedingly good biological activities. The pyrazole structure has been introduced into natural products due to its suitability for various synthetic methods and its broad pharmacological activities. This article provides a detailed introduction to the anti-inflammatory, antibacterial, antifungal, antiviral, and anti-Alzheimer disease activities of pyrazole-modified natural product derivatives, particularly their anti-tumor activity. It is worth noting that compared to lead compounds, most natural product derivatives modified with pyrazole exhibit excellent pharmacological activity. Some of these derivatives exhibit outstanding anti-tumor activity, with IC50 values reaching nanomolar levels. This review provides more research directions and choices for future studies on natural products.

Nuclear Magnetic Resonance Fingerprinting and Principal Component Analysis Strategies Lead to Anti-Tuberculosis Natural Product Discovery from Actinomycetes.

The increasing prevalence of drug-resistant tuberculosis (TB) underscores the urgent need for novel antimicrobial agents. This study integrates cultivation optimization, nuclear magnetic resonance (NMR) fingerprinting, and principal component analysis (PCA) to explore microbial secondary metabolites as potential anti-TB agents. Using the combined approach, 11 bioactive compounds were isolated and identified, all exhibiting anti-Mycobacterium bovis BCG activity. Notable findings include borrelidin, a potent threonyl-tRNA synthetase inhibitor with broad biological activities, and L-O-Lac-L-Val-D-O-Hiv-D-Val, a peptide isolated for the first time from a plant endophyte, demonstrating broad-spectrum antimicrobial activity. Additionally, elaiophylin and polycyclic tetramate macrolactams (PTMs) displayed significant bactericidal effects, with elaiophylin achieving complete BCG inhibition at 72 h and PTMs marking their first reported anti-TB activity. The study also identified bafilomycins as potent scaffolds for anti-TB drug development, showcasing rapid bactericidal activity at low MIC values. These findings emphasize the value of microbial metabolites as a reservoir of bioactive compounds and provide new avenues for developing next-generation anti-TB therapies.

Effects of Echinacea purpurea and Alkylamides on Respiratory Virus Replication and IL-8 Expression In Vitro.

Echinacea purpurea is a perennial medicinal herb with important immunomodulatory and anti-inflammatory properties, especially purported for the alleviation of cold and flu symptoms. Different classes of secondary metabolites of the plant, such as alkylamides, caffeic acid derivatives, polysaccharides, flavonoids, and glycoproteins, are believed to be biologically and pharmacologically active. Although previous research suggests that the alkylamides present in Echinacea may be responsible for reducing the symptoms associated with the common cold or flu through their immunomodulatory activity, the roles of specific alkylamides and their targets (i.e., immune and/or antiviral) have not been well-elucidated or established. This study tested the antiviral and cytokine regulatory activity of various specific alkylamides that are present predominantly in Echinacea root extracts and found that one specific alkylamide, Dodeca-2E,4E-Dienoic acid isobutylamide, had potent antiviral activity against rhinovirus (the causative agent of most common colds) and influenza virus, as well as potent inhibition of IL-8 cytokine production. IL-8 is responsible for many of the symptoms associated with the common cold and is upregulated in other common respiratory infections. The broad activity and low cytotoxicity of this specific alkylamide support its potential use for treating rhinovirus and influenza virus infections.

Classification and Mechanism of Action of Anti-Parasitic Drugs: A Review Article

The action of antiparasitic drugs is critical in the treatment of infections caused by parasites and that have devastating effects on millions of individuals worldwide. This paper consolidates different research findings on the classification and mechanisms of action of these drugs, highlighting new therapies and natural products. In particular, this special class of heterocyclic compounds, known as Benzimidazoles, has garnered a wide interest in medicinal chemistry due to their broad pharmacological activities. It recognizes the important contribution normally made by these drugs in the treatment of a wide range of different diseases, including cancer, bacterial infection, and parasitic disease. Drug-resistant parasites are now increasingly prevalent and have greatly impeded the management of parasitic infections; thus, there is an increasing demand for new therapeutic approaches. Anti-parasitic metallodrugs have emerged as another auspicious mode of intervention that carefully exploits the unique chemical features of metal ions and their complexes to affect the biological pathways important for the survival of the parasite. In this paper, we will draw up a range of knowledge gaps identified up-to-date and propose future research directions that would enhance the understanding and, what is more important, the efficiency of anti-parasitic therapies.

Pharmacological action of Angelica sinensis polysaccharides: a review.

Angelica sinensis, a traditional Chinese herbal medicine and food, which has a long history of clinical application, is used to improve health conditions and treat various diseases. Angelica sinensis polysaccharides (ASP), the main active component of this traditional Chinese medicine, have multicomponent, multitarget characteristics and very broad pharmacological activities. They play important roles in the treatment of several diseases. In addition, the effect is significant, which may provide a more comprehensive database and theoretical support for applying ASP in the treatment of disease and could be considered a promising candidate for preventing disease. This review summarizes the research progress on the extraction, chemical structure, pharmacological effects, and mechanisms of ASP and its derivatives by reviewing relevant national and international literature and provides comprehensive information and a reliable basis for the exploration of new treatment strategies involving botanical drugs for disease therapy. Literature information was obtained from scientific ethnobotany and ethnomedicine databases (up to September 2024), mainly from the PubMed, Web of Science, and CNKI databases. The literature has explored the extraction, purification, structure, and pharmacological effects of Angelica sinensis polysaccharides. The search keywords for such work included "Angelica sinensis" or "Angelica sinensis polysaccharides," and "pharmacological effects," "extraction" and "structure." Multiple studies have shown that ASP has important pharmacological effects, such as antitumor, anemia-improving, anti-inflammatory, antioxidative, immunomodulatory, hepatoprotective, antifibrotic, hypoglycemic, antiradiation, and antiviral effects, the mechanisms of which appear to involve the regulation of inflammation, oxidative stress, and profibrotic signaling pathways. As a natural polysaccharide, ASP has potential applications as a drug. However, further research should be undertaken to clarify the unconfirmed regulatory mechanisms, conduct standard clinical trials, and evaluate the possible side effects. This review establishes a theoretical foundation for future studies on the structure, mechanism, and clinical use of ASP.

Discovery and mechanistic exploration of promiscuous xylosyltransferase based on protein engineering.

Glycosylation is an effective means to alter the structure and properties of plant compounds, influencing the pharmacological activity of natural products (NPs) to obtain highly active NPs. In nature, glucosides are the most widely distributed, while other glycosides such as xylosides are less common and present in lower quantities. This is due to the scarcity of xylosyltransferases with substrate promiscuity in nature, and the modification of their catalytic function is also quite challenging. In this study, we first performed a phylogenetic analysis of reported UDP-glycosyltransferases (UGTs) of plant and microbiological origin and identified a unique motif region from the UGTs of the Bacillus genus, which may be responsible for the broad sugar donor catalytic activity of the UGTs in the Bacillus genus. Then, utilizing protein engineering techniques, we have evolved a xylosyltransferase M3-2, which exhibited high substrate promiscuity, sugar donor promiscuity, and site selectivity, enabling the synthesis of a variety of O-glycosides. In addition, another mutant M3-1 has been engineered to alter the sugar donor specificity of the UGT, enabling the switch from UDP-Glc donor to UDP-Xyl. The improved enzymatic activity is likely attributed to stable hydrophobic interactions and hydrogen bonding interactions between the enzyme and the substrate. In order to synthesize xylosylated products more economically and efficiently, an in vitro synthetic pathway that utilizes NPs and inexpensive glucuronic acid as starting materials was designed. Through this pathway, we successfully synthesized a variety of unnatural xylosylated products belonging to O-glycosides, one of which 10a possesses excellent anti-inflammatory activity. We anticipate that this work will contribute to the future discovery and industrial production of unnatural glycosides.

A Predicted Helix-Turn-Helix Core Is Critical for Bacteriophage Kil Peptide to Disrupt Escherichia coli Cell Division.

Background/objectives: FtsZ, a eukaryotic tubulin homolog and an essential component of the bacterial divisome, is the target of numerous antimicrobial compounds as well as proteins and peptides, most of which inhibit FtsZ polymerization dynamics. We previously showed that the Kil peptide from bacteriophage λ inhibits Escherichia coli cell division by disrupting FtsZ ring assembly, and this inhibition requires the presence of the essential FtsZ membrane anchor protein ZipA. Methods: To investigate Kil's molecular mechanism further, we employed deletions, truncations, and molecular modeling to identify the minimal residues necessary for its activity. Results: Modeling suggested that Kil's core segment folds into a helix-turn-helix (HTH) structure. Deleting either the C-terminal 11 residues or the N-terminal 5 residues of Kil still allowed the inhibition of E. coli cell division, but removing both termini nearly abolished this activity, indicating that a minimal region within the Kil HTH core is essential for its structure and function. Another Kil-like peptide from a closely related enterobacterial phage also disrupted FtsZ ring assembly and required ZipA for this activity. Consistent with its broader activity against FtsZ, λ Kil was able to efficiently inhibit cell division of a uropathogenic E. coli (UPEC) strain. Conclusions: Understanding the structure and function of Kil and similar peptides can potentially reveal additional ways to target FtsZ for antimicrobial therapies and elucidate how FtsZ functions in bacterial cell division.

Enhancing vaccine half-life as a novel strategy for improving immune response durability of subunit vaccines.

Vaccines are widely regarded as one of the most effective strategies for combating infectious diseases. However, significant challenges remain, such as insufficient antibody levels, limited protection against rapidly evolving variants, and poor immune durability, particularly in subunit vaccines, likely due to their short in vivo exposure. Recent advances in extending the half-life of protein therapeutics have shown promise in improving drug efficacy, yet whether increasing in vivo persistence can enhance the efficacy of subunit vaccines remains underexplored. In this study, we developed two trimeric SARS-CoV-2 subunit vaccines with distinct pharmacokinetic profiles to evaluate the impact of vaccine persistence on immune efficacy. A self-assembling trimeric subunit vaccine (RBD-HR/trimer) was designed, followed by an extended-persistence variant (RBD-sFc-HR/trimer) incorporating a soluble monomeric IgG1 fragment crystallizable. We demonstrated that RBD-sFc-HR/trimer elicited more robust and higher levels of neutralizing antibodies, with potent and broad neutralization activity against multiple SARS-CoV-2 variants. Notably, RBD-sFc-HR/trimer induced a durable immune response, significantly increasing the number of memory B cells and T cells. This study provides critical insights for designing vaccines that achieve potent and long-lasting immune responses against infectious diseases.