Publications by authors named "Ludger A Wessjohann"

Dolastatins are a class of naturally occurring antimitotic peptides that have inspired the development of some of the most active and widely used anticancer agents. Here, we report on the development of synthetic methodologies for the preparation of parallel libraries of small peptides inspired by dolastatin 15 and its analogs cemadotin and tasidotin. The approaches rely on the use of either one or multiple Ugi-multicomponent reactions to generate amide N-substituted dolastatin-like skeletons, which allow the exploration of tertiary amide chemical spaces that have not been assessed previously.

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Poly(ADP-ribose) polymerases (PARP) are a family of enzymes that were proven to play an essential role in the initiation and activation of DNA repair processes in the case of DNA single-strand breaks. The inhibition of PARP enzymes might be a promising option for the treatment of several challenging types of cancers, including triple-negative breast cancer (TNBC) and non-small cell lung carcinoma (NSCLC). This study utilizes several techniques to screen the compound collection of the Leibniz Institute of Plant Biochemistry (IPB) to identify novel hPARP-1 inhibitors.

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NMR-based Metabolomics approach assessed phytochemical profile in seed and husk of three cardamom species: Elettaria cardamomum (green), Amomum subulatum (black), and Aframomum corrorima (white). NMR Spectroscopy identified 20 metabolites belonging to sugars, amino-, organic-, fatty acids, terpenes, and phenolics. Multivariate data analyses revealed distinct metabolic profiles among the 3 species, and further in seed versus husk.

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Introduction: CIP, a broad-spectrum antibiotic, is crucial for managing bacterial infections. Its efficacy relies on maintaining high-quality standards, which can be affected by manufacturing, regulatory oversight and storage practices. This study compares the quality of CIP preparations in Vietnam and Nigeria, two nations with contrasting regulatory frameworks, to assess compliance with pharmaceutical standards and identify risks from substandard or falsified medicines.

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The ability to chemoselectively modify either the peptide backbone or specific side chains is critical to advance the fields of bioconjugation and peptide pharmaceuticals. Transition-metal catalysis has been widely used in peptide and protein derivatization but mostly under homogeneous conditions. Herein, we present a first-in-class heterogeneous catalytic approach for the site-selective functionalization of histidine-containing peptides with aryl and alkenyl moieties bearing fluorescent and affinity tags, lipids, and conjugation handles.

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Several polyphenol-rich species (Combretaceae) are known to accelerate wound healing. Recently, the Omani medicinal plant (now ) was attributed to the genus based on phylogenetic studies. Leaves, bark, and extracts of are traditionally used for various medicinal purposes, including wound treatment and personal hygiene.

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Objective: In this study, 25 synthetic cyclic lipopeptides (CLPs) were investigated for their anticancer potential against mouse melanoma (B16F10) cells, human prostate cancer (PC-3), human colorectal adenocarcinoma (HT-29) and mouse embryonic fibroblast (NIH3T3) cells.

Methods: The cytotoxic activity of investigated compounds was evaluated using MTT and CV assays. In order to examine the mechanism of action of the most potent compound cell cycle analysis, apoptosis assay, caspase activity, CFSE and DHR staining, DAF-FM, autophagy and immunocytochemistry caspase-3 assays were performed.

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Flavor is the main factor driving consumers acceptance of food products. However, tracking the biochemistry of flavor is a formidable challenge due to the complexity of food composition. Current methodologies for linking individual molecules to flavor in foods and beverages are expensive and time-consuming.

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Peptide-drug conjugates (PDCs) have recently gained significant attention for the targeted delivery of anticancer therapeutics, mainly due to their cost-effective and chemically defined production and lower antigenicity compared to ADCs, among other benefits. In this study, we designed and synthesized novel PDCs by conjugating new thiol-functionalized tubulysin analogs (tubugis) to bombesin, a peptide ligand with a relevant role in cancer research. Two tubulysin analogs bearing ready-for-conjugation thiol groups were prepared by an on-resin multicomponent peptide synthesis strategy and subsequently tested for their stand-alone anti-proliferative activity against human cancer cells, which resulted in IC values in the nanomolar range.

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Hypoxia in tumors contributes to chemotherapy resistance, worsened by acidosis driven by carbonic anhydrases (CA IX and XII). Targeting these enzymes can mitigate acidosis, thus enhancing tumor sensitivity to cytotoxic drugs. Herein, novel 4-(pyrazolyl)benzenesulfonamide ureas () were developed and evaluated for their inhibitory activity against CA IX and XII.

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Ajuga turkestanica preparations are used as anti-aging cosmeceuticals and for medicinal purposes. Herein we describe the characterization and quantification of its metabolites in different organs using UHPLC-MS and NMR spectroscopy. A total of 51 compounds belonging to various phytochemical classes (11 flavonoids, 10 ecdysteroids, 9 diterpenes, 6 fatty acids, 5 iridoids, 3 phenylpropanoids, 3 sugars, 2 phenolics, 1 coumarin, 1 triterpene) were annotated and tentatively identified by UHPLC-ESI-QqTOF-MS/MS of methanolic extracts obtained separately from the organs.

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Quinazolinones, particularly 9-azaglycophymines, and closely related derivatives and precursors were tested in vitro against various breast cancer cell lines representing the major types of breast tumors. Among the 49 compounds tested, azaglycophymine derivative 19 with an electron-withdrawing substituent demonstrated the most significant anti-proliferative effects, with IC values of around 4 µM. Extensive cell-based investigations revealed that compound 19 induced caspase-dependent apoptosis in HCC1937 (human TNBC), BT-474 (human HER2+/HR+), and 4T1 (mouse TNBC) cells.

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Article Synopsis
  • The development of new anti-cancer drugs is hindered by challenges in identifying their mode of action (MoA), but a combination of metabolomics and machine learning has been used to predict MoAs for new drug candidates targeting prostate cancer cells.
  • In a study of 38 drugs affecting cancer metabolism, distinct metabolic patterns enabled accurate predictions of MoAs, and these predictions were validated across other cancer types such as breast cancer and Ewing's sarcoma, albeit with some loss in prediction quality.
  • This approach not only enhances understanding of drug effects on cellular processes, such as mitochondrial dysfunction, but also opens up new avenues for optimizing drug combinations to improve treatment outcomes.
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Introduction: Climate change poses various threats to marine life, particularly in shallow tropical waters.

Objective: The impact of increased temperature and ultraviolet (UV) exposure on two photosymbiotic cnidarians, a common bubble-tip anemone and an upside-down jellyfish, was investigated.

Methods: To illustrate the response of aquatic organisms, the metabolomes of unstressed Entacmaea quadricolor and Cassiopea andromeda were compared for detailed metabolite profiling.

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Two connected histopathological hallmarks of Alzheimer's disease (AD) are chronic neuroinflammation and synaptic dysfunction. The accumulation of the most prevalent posttranslationally modified form of Aβ1-42, pyroglutamylated amyloid-β (Aβ3(pE)-42) in astrocytes is directly linked to glial activation and the release of proinflammatory cytokines that in turn contribute to early synaptic dysfunction in AD. At present, the mechanisms of Aβ3(pE)-42 uptake to astrocytes are unknown and pharmacological interventions that interfere with this process are not available.

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In Vietnam, the stems and roots of the Rutaceous plant Paramignya trimera (Oliv.) Burkill (known locally as "Xáo tam phân") are widely used to treat liver diseases such as viral hepatitis and acute and chronic cirrhosis. In an effort to search for Vietnamese natural compounds capable of inhibiting coronavirus based on molecular docking screening, two new dimeric coumarin glycosides, namely cis-paratrimerin B (1) and cis-paratrimerin A (2), and two previously identified coumarins, the trans-isomers paratrimerin B (3) and paratrimerin A (4), were isolated from the roots of P.

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Tubulysins are among the most recent antimitotic compounds to enter into antibody/peptide-drug conjugate (ADC/PDC) development. Thus far, the design of the most promising tubulysin payloads relied on simplifying their structures, e. g.

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Piper sarmentosum Roxb. (Piperaceae) is a traditional medicinal and food plant widely distributed in the tropical and subtropical regions of Asia, offering both health and culinary benefits. In this study the secondary metabolites in different organs of P.

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The 2-pyrone moiety is present in a wide range of structurally diverse natural products with various biological activities. The plant biosynthetic routes towards these compounds mainly depend on the activity of either type III polyketide synthase-like 2-pyrone synthases or hydroxylating 2-oxoglutarate dependent dioxygenases. In the present study, the substrate specificity of these enzymes is investigated by a systematic screening using both natural and artificial substrates with the aims of efficiently forming (new) products and understanding the underlying catalytic mechanisms.

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L. (black and white peppercorn) is one of the most common culinary spices used worldwide. The current study aims to dissect pepper metabolome using H-NMR targeting of its major primary and secondary metabolites.

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Introduction: The genus Clusia L. is mostly recognised for the production of prenylated benzophenones and tocotrienol derivatives.

Objectives: The objective of this study was to map metabolome variation within Clusia minor organs at different developmental stages.

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The development of potent adjuvants is an important step for improving the performance of subunit vaccines. CD1d agonists, such as the prototypical α-galactosyl ceramide (α-GalCer), are of special interest due to their ability to activate iNKT cells and trigger rapid dendritic cell maturation and B-cell activation. Herein, we introduce a novel derivatization hotspot at the α-GalCer skeleton, namely the N-substituent at the amide bond.

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The archipelagic country of Indonesia is populated by the densest marine biodiversity in the world which has created strong global interest and is valued by both Indigenous and European settlements for different purposes. Nearly 1000 chemicals have been extracted and identified. In this review, a systematic data curation was employed to collate bioprospecting related manuscripts providing a comprehensive directory based on publications from 1988 to 2022.

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The production of fine-flavor cocoa represents a promising avenue to enhance socioeconomic development in Colombia and Latin America. Premium chocolate is obtained through a post-harvesting process, which relies on semi-standardized techniques. The change in the metabolic profile during cocoa processing considerably impacts flavor and nutraceutical properties of the final product.

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