Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Smolková, R.; Smolko, L.; Samoľová, E.; Morgan, I.; Rennert, R.; Kaluđerović, G. N.;Novel Zn(ii), Co(ii) and Cu(ii) diflunisalato complexes with neocuproine and their exceptional antiproliferative activity against cancer cell linesDalton Trans.5317595-17607(2024)DOI: 10.1039/d4dt01736f
Three novel complexes of deprotonated diflunisal (dif) with neocuproine (neo) were synthesized and characterized via elemental, spectral (UV-vis, FTIR, fluorescence, and mass spectrometry), and single-crystal X-ray diffraction analyses. Although the compounds shared a similar composition of [MCl(dif)(neo)], where M represents Zn(II) (1), Co(II) (2) and Cu(II) (3), only 1 and 2 were isostructural, while 3 differed in both the molecular and supramolecular structures. In all three complex molecules, the central atom is coordinated by two nitrogen atoms of neo in a bidentate chelate mode, and one chlorido ligand and dif is bonded in either a monodentate mode via one oxygen atom of the carboxylate in 1 and 2 or in a bidentate chelate mode via both carboxylate oxygen atoms in 3. All three compounds demonstrated remarkable antiproliferative activity against human prostate (PC-3), colon (HCT116) and breast (MDA-MB-468) cancer cell lines with IC50 values in the nanomolar range, with the lowest values observed in the case of PC-3 and MDA-MB-468 with 2 (20.0 nM) and 3 (31.1 nM), respectively. Moreover, complex 2, as the most active, was further investigated for its potential to induce perturbations in the cell cycle of PC-3 cells. The results indicated an induction of caspase-independent apoptosis. The interaction of the complexes with genomic DNA isolated from the respective cancer cell lines was evaluated for the intercalative mode, with binding strength correlated with the antiproliferative activity against PC-3 and MDA-MB-468 cancer cell lines.
Publikation
Predarska, I.; Saoud, M.; Morgan, I.; Eichhorn, T.; Kaluđerović, G. N.; Hey-Hawkins, E.;Cisplatin−cyclooxygenase inhibitor conjugates, free and immobilised in mesoporous silica SBA-15, prove highly potent against triple-negative MDA-MB-468 breast cancer cell lineDalton Trans.51857–869(2022)DOI: 10.1039/d1dt03265h
For the development of anticancer drugs with higher activity and reduced
toxicity, two approaches were combined: preparation of platinum(IV) complexes exhibiting higher stability compared to their platinum(II)
counterparts and loading them into mesoporous silica SBA-15 with the
aim to utilise the passive enhanced permeability and retention (EPR)
effect of nanoparticles for accumulation in tumour tissues. Three
conjugates based on a cisplatin scaffold bearing the anti-inflammatory
drugs naproxen, ibuprofen or flurbiprofen in the axial positions (1, 2 and 3, respectively) were synthesised and loaded into SBA-15 to afford the mesoporous silica nanoparticles (MSNs) SBA-15|1, SBA-15|2 and SBA-15|3.
Superior antiproliferative activity of both free and immobilised
conjugates in a panel of four breast cancer cell lines (MDA-MB-468,
HCC1937, MCF-7 and BT-474) with markedly increased cytotoxicity with
respect to cisplatin was demonstrated. All compounds exhibit highest
activity against the triple-negative cell line MDA-MB-468, with
conjugate 1 being the most potent. However, against MCF-7 and BT-474 cell lines, the most notable improvement was found, with IC50
values up to 240-fold lower than cisplatin. Flow cytometry assays
clearly show that all compounds induce apoptotic cell death elevating
the levels of both early and late apoptotic cells. Furthermore,
autophagy as well as formation of reactive oxygen species (ROS) and
nitric oxide (NO) were elevated to a similar or greater extent than with
cisplatin.
Publikation
Kahsay, B. N.; Ziegler, J.; Imming, P.; Gebre-Mariam, T.; Neubert, R. H. H.; Moeller, L.;Free amino acid contents of selected Ethiopian plant and fungi species: a search for alternative natural free amino acid sources for cosmeceutical applicationsAmino Acids531105-1122(2021)DOI: 10.1007/s00726-021-03008-5
Free amino acids (FAAs), the major constituents of the natural moisturizing factor (NMF), are very important for maintaining the moisture balance of human skin and their deficiency results in dry skin conditions. There is a great interest in the identification and use of nature-based sources of these molecules for such cosmeceutical applications. The objective of the present study was, therefore, to investigate the FAA contents of selected Ethiopian plant and fungi species; and select the best sources so as to use them for the stated purpose. About 59 different plant species and oyster mushroom were included in the study and the concentrations of 27 FAAs were analyzed. Each sample was collected, lyophilized, extracted using aqueous solvent, derivatized with Fluorenylmethoxycarbonyl chloride (Fmoc-Cl) prior to solid-phase extraction and quantified using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC-ESI–MS/MS) system. All the 27 FAAs were detected in most of the samples. The dominant FAAs that are part of the NMF were found at sufficiently high concentration in the mushroom and some of the plants. This indicates that FAAs that could be included in the preparations for the management of dry skin condition can be obtained from a single natural resource and the use of these resources for the specified purpose have both economic and therapeutic advantage in addition to fulfilling customer needs.
Publikation
Böhme, B.; Moritz, B.; Wendler, J.; Hertel, T. C.; Ihling, C.; Brandt, W.; Pietzsch, M.;Enzymatic activity and thermoresistance of improved microbial transglutaminase variantsAmino Acids52313-326(2020)DOI: 10.1007/s00726-019-02764-9
Microbial transglutaminase (MTG, EC 2.3.2.13) of Streptomyces mobaraensis is widely used in industry for its ability to synthesize isopeptide bonds between the proteinogenic side chains of glutamine and lysine. The activated wild-type enzyme irreversibly denatures at 60 °C with a pseudo-first-order kinetics and a half-life time (t1/2) of 2 min. To increase the thermoresistance of MTG for higher temperature applications, we generated 31 variants based on previous results obtained by random mutagenesis, DNA shuffling and saturation mutagenesis. The best variant TG16 with a specific combination of five of seven substitutions (S2P, S23Y, S24 N, H289Y, K294L) shows a 19-fold increased half-life at 60 °C (t1/2 = 38 min). As measured by differential scanning fluorimetry, the transition point of thermal unfolding was increased by 7.9 °C. Also for the thermoresistant variants, it was shown that inactivation process follows a pseudo-first-order reaction which is accompanied by irreversible aggregation and intramolecular self-crosslinking of the enzyme. Although the mutations are mostly located on the surface of the enzyme, kinetic constants determined with the standard substrate CBZ-Gln-Gly-OH revealed a decrease in KM from 8.6 mM (± 0.1) to 3.5 mM (± 0.1) for the recombinant wild-type MTG and TG16, respectively. The improved performance of TG16 at higher temperatures is exemplary demonstrated with the crosslinking of the substrate protein β-casein at 60 °C. Using molecular dynamics simulations, it was shown that the increased thermoresistance is caused by a higher backbone rigidity as well as increased hydrophobic interactions and newly formed hydrogen bridges.