NEWSTICKER – Antiinfectives: aAntibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant.

D. monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. Such infections can be caused by different bacteria, including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Building on this ethnobotanical knowledge, the IPB researchers performed in vitro assays with D. monetaria extracts against ten bacterial strains, fractioned the extracts, and characterized the samples by UHPLC-HRMS/MS. While subfractions from both leaves and bark exhibited antibacterial activities, that of leaves was higher and its characterization revealed a complex profile of proanthocyanidins made up of (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The researchers were able to identify a specific fraction consisting of (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers with a minimum inhibitory concentration in the low micromolar range (64 and 32 µg/mL, respectively) against S. aureus and P. aeruginosa. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the authors conclude that the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

original publication: de Moura PHB, de Sousa AA, Porzel A, Wessjohann LA, Leal ICR, Martins RCC. Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS. Planta Med. 2020;86(12):858-866. doi:10.1055/a-1170-8016

NEWSTICKER – methods: new versatile approach for high-throughput analysis using GC-MS

IPB scientist have developed together with scientists from ISAS Dortmund a versatile high-throughput screening method that aims to accelerate catalyst discovery and development. In order to avoid long analysis time, the method combines gas chromatography-mass spectrometry (GC-MS) with the so-called MISER approach, in which several samples are injected into a chromatography system in quick succession. As proof of concept, the chemists screened different enzyme libraries. They identified promising and novel unspecific peroxygenase chimeras (UPOs) consisting of subunits from three different fungal UPO genes. The study will be published as a cover story in the ChemCatChem Journal.

original publication: Anja Knorrscheidt, Pascal Püllmann, Eugen Schell, Dominik Homann, Erik Freier and Martin J. Weissenborn. Identification of novel unspecific peroxygenase chimeras and unusual YfeX axial heme ligand by a versatile high-throughput GCMS approach. ChemCatChem DOI: 10.1002/cctc.202000618

NEWSTICKER – antiinfectives

IPB chemists recently published an extensive phytochemical study of Parmelia cetrata, a foliose lichen from Indonesia. They successfully isolated 13 phenol and depside derivatives including previously unreported ones. In assays using the gram-negative bacterium Aliivibrio fischeri and the nematode Caenorhabditis elegans, the researchers evaluated the anti-infective activity of isolated compounds. Two of the tested substances inhibited growth of A. fischeri and one of the substances, in addition, showed significant anthelmintic effects against C. elegans.

original publication: Ari Satia Nugraha, Ludmilla Fitri Untari, Annegret Laub, Andrea Porzel, Katrin Franke & Ludger A. Wessjohann (2020) Anthelmintic and antimicrobial activities of three new depsides and ten known depsides and phenols from Indonesian lichen: Parmelia cetrata Ach., Natural Product Research,DOI: 10.1080/14786419.2020.1761361

NEWSTICKER – potential Corona-drug identified

Viruses must enter cells of the human body to cause disease. For this, they attach to suitable cells and inject their genetic information into these cells. Infection biologists from the German Primate Center – Leibniz Institute for Primate Research in Göttingen, together with colleagues at Charité – Universitätsmedizin Berlin, have investigated how the novel coronavirus SARS-CoV-2 penetrates cells. They have identified a cellular enzyme that is essential for viral entry into lung cells: the protease TMPRSS2. A clinically proven drug known to be active against TMPRSS2 was found to block SARS-CoV-2 infection and might constitute a novel treatment option (Cell).

Interview with Stefan Pöhlman, head of the Infection Biology Unit at DPZ:

original publication: Hoffmann, M et al. (2020). SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a 2 clinically-proven protease inhibitor. Cell, DOI: 10.1016/j.cell.2020.02.052

NEWSTICKER – spider bite leads to new active compounds

The bite of a spider caused a severe inflammatory response and cost an Australian woman her forearm. Scientists were able to isolate a fungus from the infected forearm tissue of the patient. This tragic infection has now helped an international team of researchers find new active compounds, the so-called necroximes. These substances are produced by bacteria that live inside the fungi. The highly effective cytotoxins may provide clues for the development of new cancer drugs. The researchers published their results in the journal Angewandte Chemie.

original publication: Niehs SP, Dose B, Richter R, Pidot SJ, Dahse H-M, Stinear TP, Hertweck C (2020) Mining symbionts of spider‐transmitted fungus illuminates uncharted biosynthetic pathways to cytotoxic benzolactones. Angewandte Chemie International Edition

NEWSTICKER – synthesis of lipidated cyclo-peptides as promising anti-phytopathogenic agents

Together with Cuban and Chilean scientists, IPB chemists have developed a multicomponent-based approach for the synthesis of cyclic polycationic lipopeptides with stabilized helical structures. First bioactivity studies against model phytopathogens demonstrated a positive effect of the lipidation on the antimicrobial activity.

original publication: Aldrin V. Vasco, Martina Brode, Yanira Méndez, Oscar Valdés, Daniel G. Rivera & Ludger A. Wessjohann. Synthesis of Lactam-Bridged and Lipidated Cyclo-Peptides as Promising Anti-Phytopathogenic Agents. Molecules 2020, 25(4), 811;

NEWSTICKER – metabolomics

First metabolite profiling of roasted date pits proves their suitability as a coffee substitute. Date pits are used as animal feed and their oils have proved to be an excellent biofuel source. Their use as a coffee substitute is particularly widespread in the Arab countries.

original publication: Mohamed A. Farag, Asmaa M. Otify, Aly M. El-Sayed, Camilia G. Michel, Shaimaa A. ElShebiney, Anja Ehrlich & Ludger A. Wessjohann, Sensory Metabolite Profiling in a Date Pit Based Coffee Substitute and in Response to Roasting as Analyzed via Mass Spectrometry Based Metabolomics. Molecules 2019, 24(18), 3377;

NEWSTICKER – detection of anthraquinones in complex mixtures

IPB chemists have recently published an efficient approach for the detection of anthraquinones in complex mixtures of compounds. As a proof of concept, the scientists used this approach to detect well-known anthraquinones such as emodin or skyrin in raw extracts of Chilean Cortinarii fungi. Anthraquinones are coloring agents and chemotaxonomically important marker compounds. They also show a variety of pharmaceutical effects and are widespread in medicinal plants, such as aloe and rhubarb.

original publication: Annegret Laub, Ann-Katrin Sendatzki, Götz Palfner, Ludger A. Wessjohann, Jürgen Schmidt & Norbert Arnold, HPTLC-DESI-HRMS-Based Profiling of Anthraquinones in Complex Mixtures—A Proof-of-Concept Study Using Crude Extracts of Chilean Mushrooms. Foods 2020, 9(2), 156;

NEWSTICKER – bioactives from Ethiopian torch lilies

With the participation of the IPB, scientists have published a study on bioactives from Ethiopian torch lilies (Kniphofia foliosa Hochst). They analyzed the biological activity of the phenylanthraquinone derivatives knipholone and knipholone anthrone in human cell lines and pathogens.

original publication: Feilcke R., Arnouk G., Raphane B., Richard K., Tietjen I., Andrae-Marobela K., Erdmann F., Schipper S., Becker K., Arnold N., Frolov A., Reiling N., Imming P. and Fobofou S. A. T.  Biological activity and stability analyses of knipholone anthrone, a phenyl anthraquinone derivative isolated from Kniphofia foliosa Hochst. Journal of Pharmaceutical and Biomedical Analysis, 2019. 174:277-285.

NEWSTICKER – bioactive compounds

Novel organic selenides with increased cytotoxic selectivity for hepatocellular carcinoma and breast adenocarcinoma:

original publication:!

NEWSTICKER – ethnopharmacology

Fideloside, a Novel Bioactive 8-C-glycosyl 2,3-Dihydroflavonol:

original publication:Antonio Francioso, Katrin Franke, Claudio Villani, Luciana Mosca, Maria D’Erme, Stefan Frischbutter, Wolfgang Brandt, Angel Sanchez-Lamar & Ludger Wessjohann. Insights into the Phytochemistry of the Cuban Endemic Medicinal Plant Phyllanthus orbicularis: Fideloside, a Novel Bioactive 8-C-glycosyl 2,3-Dihydroflavonol. Molecules 24, 2019

NEWSTICKER – bioactive compounds

Synthetic Tubulysin derivative, Tubugi-1, against invasive melanoma cells: The cell death triangle:

original publication: DIJANA DRAČA, SANJA MIJATOVIĆ, TAMARA KRAJNOVIĆ, GORAN N. KALUĐEROVIĆ, LUDGER A. WESSJOHANN & DANIJELA MAKSIMOVIĆ-IVANIĆ. Synthetic Tubulysin derivative, Tubugi-1, against invasive melanoma cells: The cell death triangle. Anticancer Research, 2019

NEWSTICKER – neuroactive compunds

Memory enhancement by ferulic acid ester across species:

original publication: Birgit Michels, Hanna Zwaka, Ruth Bartels, Oleh Lushchak, Katrin Franke, Thomas Endres, Markus Fendt, Inseon Song, May Bakr, Tuvshinjargal Budragchaa, Bernhard Westermann, Dushyant Mishra, Claire Eschbach, Stefanie Schreyer, Annika Lingnau, Caroline Vahl, Marike Hilker, Randolf Menzel, Thilo Kähne, Volkmar Leßmann, Alexander Dityatev, Ludger Wessjohann, Bertram Gerber. (2018) Memory enhancement by ferulic acid ester across species. Science Advances DOI: 10.1126/sciadv.aat6994