A series of poly(ethylene glycol)-block-poly(allyl glycidyl ether) (PEG-b-PAGE) macroinitiators are prepared using the living anionic ring-opening polymerization (AROP) technique, and applied for further copolymerization studies. To overcome the low reactivity of the secondary hydroxyl end-group of the PAGE block, a primary hydroxyl group is introduced into the macroinitiators via trityl and tert-butyl-dimethylsilane protective groups. The modified macroinitiators are used for copolymerization by applying different amounts of PEG-b-PAGE (5, 10, and 15%) and different PLGA lengths. To study their properties, nanoparticles from selected polymers are prepared and characterized by dynamic light scattering and scanning electron microscopy showing spherical particles with diameters around 200 nm and low PDI_particle values of 0.03–0.1. An advantage of the obtained polymers is the presence of double bonds in the side chain, which enables the modification via, for example, thiol-ene reactions. For this purpose tertiary 2-(dimethylamino)ethanethiol), acetylated thiogalactose and thiomannose are attached onto the double bonds of the PAGE-blocks. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2163–2174

A series of pyridyltriazole ligands containing sugar moieties have been prepared by copper(I)-mediated 1,3-dipolar cycloaddition (“click” reaction) of azides functionalized with D-glucose, D-galactose, D-mannose, D-xylose as well as D-maltose residues, and 2-ethynylpyridine as alkyne. The peracetylated saccharide residues as well as their water-soluble deprotected derivatives were treated with Re(CO)₅Cl to obtain the corresponding mononuclear rhenium(I) carbonyl complexes [LRe(CO)₃Cl]. For comparison, one Re^I complex bearing a tert-butylbenzyl residue instead of a sugar moiety as well as two dinuclear rhenium complexes derived from a branched ligand containing two pyridyltriazole units were prepared. The structure and integrity of the ligands and complexes was established by NMR, IR, UV/Vis and fluorescence spectroscopy, mass spectrometry, and by elemental analysis. Coordination of the metal ion occurred by both the pyridyl nitrogen atoms and one of the triazole nitrogen atoms. Upon treatment with an excess of histidine, the Re^I complexes were stable for only 2.5 h. After a longer period (24 h) ligand exchange was detected by HPLC measurements. In contrast, a complex labeled with ^99mTc was found to be stable for up to 24 h against an excess of histidine. Cytotoxicity was screened for all Re^I complexes against HepG2 cells using a concentration of 100 μM. All sugar-functionalized complexes were found to be nontoxic, except for the complex derived from the pyridyl (tert-butylbenzyl)-triazole, which exhibited remarkable toxicity.

Abstract: Cisplatin analogue complexes with platinum(II) and palladium(II) starting from 3′,5′-diamino-3′,5′-dideoxy-thymidines were synthesized, both with the D-erythro- and D-threo configurations. Complexes of the general formula [MCl₂L] were obtained and characterized. NMR spectroscopic measurements and single crystal X-ray structure analysis showed that the metal centers are coordinated to the ligands by the amino groups in 3′- and 5′-positions and not through the thymine moiety. All ligands and complexes showed no significant in vitro activities except thymiplatin (cis-dichloro(3′,5′-diamino-3′,5′-dideoxy-D-threo-thymidine)platinum(II)). Detailed in vitro studies on the apoptosis pathway in lymphoma (BJAB), leukemia (NALM-6), and melanoma cells (Mel-HO) as well as on transfected or resistant cell lines were carried out. Thymiplatin significantly induced an apoptotic response, which was found to be associated with the loss of mitochondrial membrane potential and with caspase activation. The activity was shown to be independent of Fas-associated protein with death domain (FADD), but dependent on Bcl-2 expression. As a consequence, for thymiplatin a mitochondrial mode of action could be assigned. Moreover, the compound showed activity in cells resistant to common drugs, such as daunorubicin and vincristin, and showed synergistic effects with doxorubicin, vincristin, cytarabin, and daunorubicin.

Gallium and indium complexes derived from salicylaldimines of 1,1,1-tris(aminomethyl)ethane (TAME) with pendantxylose, glucose and galactose units have been synthesised as model compounds for potential application as radiotracers. The formed neutral complexes have been characterised by NMR spectroscopy, elemental analysis, mass spectrometry and, in the case of the galactose-bearing In^III complex, by single-crystal X-ray structure analysis. Octahedral coordination was observed with the appearance of an equilibrium of Λ- and Δ-isomers at the metal centre. The glucose-appended ligand was radiolabelled with ⁶⁸Ga^III ions in up to 98 % yield depending on the prevailing pH value. The in vitro stability of the radioactive complex was examined by challenge experiments against apo-transferrin and blood plasma. Very high stability was observed; even after a period of 2 h, 90 % of the complex could still be detected. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Only a small number of water-soluble iron carbonyl type model compounds for the active centre in [Fe-only] hydrogenase are known, and these models are mainly prepared by substitution of one of the CO ligands. In this publication we present new water-soluble models for [Fe-only] hydrogenase that contain a peripherally bound sugar residue. Compounds were prepared in which the 1,3-disulfanyl-2-propyltetra-O-acetyl-β-D-glucopyranoside unit is coordinated to the iron carbonyl core through either a sulfur or a selenium bridgehead atom. Electrochemical results for both types of compounds reveal hydrogen gas evolution from acetic acid and water. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)