Publications by authors named "Helena Boshoff"

Aim: This research aimed to develop novel indole-2-carboxamides as potential antitubercular agents using rational drug design. It also focused on identifying the critical interactions required for these compounds to exhibit effective antitubercular activity.

Materials And Methods: Novel indole-2-carboxamides targeting MmpL3 were designed based on SAR, synthesized, and tested for their antitubercular and induction properties.

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Mycobacterial species in nature are found in abundance in sphagnum peat bogs where they compete for nutrients with a variety of microorganisms including fungi. We screened a collection of fungi isolated from sphagnum bogs by co-culture with Mycobacterium tuberculosis (Mtb) to look for inducible expression of antitubercular agents and identified 5 fungi that produced cidal antitubercular agents upon exposure to live Mtb. Whole genome sequencing of these fungi followed by fungal RNAseq after Mtb exposure allowed us to identify biosynthetic gene clusters induced by co-culture.

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Mycobacterial species in nature are found in abundance in sphagnum peat bogs where they compete for nutrients with a variety of microorganisms including fungi. We screened a collection of fungi isolated from sphagnum bogs by co-culture with () to look for inducible expression of antitubercular agents and identified five fungi that produced cidal antitubercular agents upon exposure to live . Whole genome sequencing of these fungi followed by fungal RNAseq after exposure allowed us to identify biosynthetic gene clusters induced by co-culture.

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In () and (), the methylerythritol phosphate (MEP) pathway is responsible for isoprene synthesis. This pathway and its products are vital to bacterial/parasitic metabolism and survival, and represent an attractive set of drug targets due to their essentiality in these pathogens but absence in humans. The second step in the MEP pathway is the conversion of 1-deoxy-d-xylulose-5-phosphate (DXP) to MEP and is catalyzed by 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR).

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Linezolid is a drug with proven human antitubercular activity whose use is limited to highly drug-resistant patients because of its toxicity. This toxicity is related to its mechanism of action─linezolid inhibits protein synthesis in both bacteria and eukaryotic mitochondria. A highly selective and potent series of oxazolidinones, bearing a 5-aminomethyl moiety (in place of the typical 5-acetamidomethyl moiety of linezolid), was identified.

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Tuberculosis (TB) is notorious as the leading cause of death worldwide due to a single infectious entity and its causative agent, (), has been able to evolve resistance to all existing drugs in the treatment arsenal complicating disease management programs. In drug discovery efforts, natural products are important starting points in generating novel scaffolds that have evolved to specifically bind to vulnerable targets not only in pathogens such as , but also in mammalian targets associated with human diseases. Structural diversity is one of the most attractive features of natural products.

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Article Synopsis
  • * Pks13 has been identified as a crucial target for developing new growth inhibitors for TB, with prior attempts using benzofuran inhibitors halted due to safety concerns.
  • * Researchers have discovered a novel series of oxadiazole inhibitors that effectively target Pks13, showing better potency and safety profiles compared to previous compounds.
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Article Synopsis
  • The study addresses the urgent issue of drug-resistant tuberculosis, emphasizing the necessity for new drug candidates to improve treatment options.
  • Researchers discovered a potent compound, (4-benzylpiperidin-1-yl)(1-(5-phenyl-1,3,4-oxadiazol-2-yl)piperidin-4-yl)methanone, through high-throughput screening, which showed effectiveness against both drug-resistant and drug-susceptible strains of TB.
  • Analysis of resistant mutant strains identified mutations in the DprE1 gene, suggesting a new avenue for drug development and highlighting the potential of the novel oxadiazole structure as a valuable tool in TB treatment.
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Malaria, a mosquito-borne disease caused by several parasites of the genus, remains a huge threat to global public health. There are an estimated 0.5 million malaria deaths each year, mostly among African children.

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Mycobacterium tuberculosis (Mtb), perhaps more than any other organism, is intrinsically appealing to chemical biologists. Not only does the cell envelope feature one of the most complex heteropolymers found in nature but many of the interactions between Mtb and its primary host (we humans) rely on lipid and not protein mediators. Many of the complex lipids, glycolipids, and carbohydrates biosynthesized by the bacterium still have unknown functions, and the complexity of the pathological processes by which tuberculosis (TB) disease progress offers many opportunities for these molecules to influence the human response.

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Mycobacterium tuberculosis (Mtb) was responsible for approximately 1.6 million deaths in 2021. With the emergence of extensive drug resistance, novel therapeutic agents are urgently needed, and continued drug discovery efforts required.

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Resistance of bacterial pathogens against antibiotics is declared by WHO as a major global health threat. As novel antibacterial agents are urgently needed, we re-assessed the broad-spectrum myxobacterial antibiotic myxovalargin and found it to be extremely potent against . To ensure compound supply for further development, we studied myxovalargin biosynthesis in detail enabling production via fermentation of a native producer.

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The emergence of drug resistant Mycobacterium tuberculosis, the causative agent of tuberculosis, demands the development of new drugs and new drug targets. We have recently reported that the d-phenylalanine benzoxazole Q112 has potent antibacterial activity against this pathogen with a distinct mechanism of action from other antimycobacterial agents. Q112 and previously reported derivatives were unstable in plasma and no free compound could be observed.

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Tuberculosis is a major global cause of both mortality and financial burden mainly in low and middle-income countries. Given the significant and ongoing rise of drug-resistant strains of Mycobacterium tuberculosis within the clinical setting, there is an urgent need for the development of new, safe and effective treatments. Here the development of a drug-like series based on a fused dihydropyrrolidino-pyrimidine scaffold is described.

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Tuberculosis (TB) is an air-borne infectious disease and is the leading cause of death among all infectious diseases globally. The current treatment regimen for TB is overtly long and patient non-compliance often leads to drug resistant TB resulting in a need to develop new drugs that will act via novel mechanisms. In this research work, we selected membrane protein large (MmpL3) as the drug target and indole-2-carboximide as our molecule of interest for further designing new molecules.

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As a result of a high-throughput compound screening campaign using Mycobacterium tuberculosis-infected macrophages, a new drug candidate for the treatment of tuberculosis has been identified. GSK2556286 inhibits growth within human macrophages (50% inhibitory concentration [IC] = 0.07 μM), is active against extracellular bacteria in cholesterol-containing culture medium, and exhibits no cross-resistance with known antitubercular drugs.

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Described here is a series of spiropyrimidinetrione (SPT) compounds with activity against Mycobacterium tuberculosis through inhibition of DNA gyrase. The SPT class operates via a novel mode of inhibition, which involves Mg-independent stabilization of the DNA cleavage complex with DNA gyrase and is thereby not cross-resistant with other DNA gyrase-inhibiting antibacterials, including fluoroquinolones. Compound 22 from the series was profiled broadly and showed cidality as well as intracellular activity against M.

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Tuberculosis (TB) is one of the world's most deadly infectious diseases resulting in nearly 1.3 million deaths annually and infecting nearly one-quarter of the population. para-Aminosalicylic acid (PAS), an important second-line agent for treating drug-resistant Mycobacterium tuberculosis, has moderate bioavailability and rapid clearance that necessitate high daily doses of up to 12 g per day, which in turn causes severe gastrointestinal disturbances presumably by disruption of gut microbiota and host epithelial cells.

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Rising antimicrobial resistance challenges our ability to combat bacterial infections. The problem is acute for tuberculosis (TB), the leading cause of death from infection before COVID-19. Here, we developed a framework for multiple pharmaceutical companies to share proprietary information and compounds with multiple laboratories in the academic and government sectors for a broad examination of the ability of β-lactams to kill (Mtb).

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Natural products provide a rich source of potential antimicrobials for treating infectious diseases for which drug resistance has emerged. Foremost among these diseases is tuberculosis. Assessment of the antimycobacterial activity of nargenicin, a natural product that targets the replicative DNA polymerase of , revealed that it is a bactericidal genotoxin that induces a DNA damage response in () and inhibits growth by blocking the replicative DNA polymerase, DnaE1.

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New drugs and new targets are urgently needed to treat tuberculosis. We discovered that d-phenylalanine-benzoxazole displays potent antibacterial activity against () in multiple media and in macrophage infections. A metabolomic profiling indicates that has a unique mechanism of action.

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Article Synopsis
  • * Researchers discovered a new class of anthranilate-like compounds, especially benzohydrazides, that show improved effectiveness against Mycobacterium tuberculosis (Mtb) compared to a known compound, 6-FABA.
  • * These new compounds not only demonstrate strong antimycobacterial activity (with minimal toxic effects on human cells) but also inhibit tryptophan biosynthesis, suggesting their potential for development as TB treatments.
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Mycobacterium tuberculosis thymidylate kinase (MtTMPK) has emerged as an attractive target for rational drug design. We recently investigated new families of non-nucleoside MtTMPK inhibitors in an effort to diversify MtTMPK inhibitor chemical space. We here report a new series of MtTMPK inhibitors by combining the Topliss scheme with rational drug design approaches, fueled by two co-crystal structures of MtTMPK in complex with developed inhibitors.

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