Insight into the Gd–Pt Bond: Slow Magnetic Relaxation of a Heterometallic Gd–Pt Complex

Lanthanide (Ln) compounds are common research targets in the field of magnetism and optics. Their properties arise from the electron localized in the f-orbital. Moreover, the effect of the covalency between lanthanide and ligands on magnetism attracted significant attention. We provided insight into the Gd–Pt bond (of the heterometallic Ln-Pt complexes: {[Pt(PhSAc)4]Ln[(PhSAc)4Pt]} NEt4·2DMF (Ln = Y(0), La(1), Gd(2); PhSAc = thiobenzoate, NEt4 = tetraethylammonium)); single-crystal polarized X-ray absorption near edge structure (XANES) reveal the electronic states around metal ion, where spectra of Gd-LIII edges show the Gd–Pt direction has the highest covalency (less ionic) around Gd ion in 2. In addition, calculating natural bonding (NBO) analysis, natural population analysis (NPA), LOL, and atoms in molecules (AIM), ab initio calculations reveal the role of metallic and organic ligands in the electronic and magnetic properties of Ln complexes. The slow magnetization relaxation of the Gd complex, which has not been reported previously in the Pt–Gd–Pt system, was observed up to 45K, the highest temperature reported to date among isolated Gd-complexes.

Anti-Phosphatidylserine/Prothrombin Antibodies at Two Points: Correlation With Lupus Anticoagulant and Thrombotic Risk

Antibodies to phospholipids (aPL) and associated proteins are a hallmark in the diagnosis of anti-phospholipid syndrome (APS). Those included in the classification criteria are the lupus anticoagulant (LA) and the IgG and IgM isotypes of anticardiolipin (aCL) and anti-beta-2 glycoprotein I (β2GPI) antibodies. Non-classification criteria markers such as autoantibodies that recognize the phosphatidylserine/prothrombin (aPS/PT) complex have been proposed as biomarkers for APS. Studies of aPS/PT antibodies have shown a strong correlation to clinical manifestations and LA. We aimed to study the value and the persistence of aPS/PT IgG and IgM antibodies in a cohort of consecutive patients with clinical suspicion of APS and their utility as thrombotic risk markers. Our study, with 103 patients, demonstrates that persistently positive results for aPS/PT IgG antibodies were significantly associated with APS classification, thrombosis, triple aPL positivity, LA positive result, and the Global APS Score (GAPSS) > than 9 points (p < 0.01, for each condition). On the other hand, no association was seen with pregnancy morbidity (p = 0.56) and SLE (p = 0.07). Persistence of aPS/PT antibodies, defined according to the current laboratory classification criteria, likely improves the diagnosis and clinical assessment of patients with APS.

Reactions with Proteins of Three Novel Anticancer Platinum(II) Complexes Bearing N-Heterocyclic Ligands

Three novel platinum(II) complexes bearing N-heterocyclic ligands, i.e., Pt2c, Pt-IV and Pt-VIII, were previously prepared and characterized. They manifested promising in vitro anticancer properties associated with non-conventional modes of action. To gain further mechanistic insight, we have explored here the reactions of these Pt compounds with a few model proteins, i.e., hen egg white lysozyme (HEWL), bovine pancreatic ribonuclease (RNase A), horse heart cytochrome c (Cyt-c) and human serum albumin (HSA), primarily through ESI MS analysis. Characteristic and variegate patterns of reactivity were highlighted in the various cases that appear to depend both on the nature of the Pt complex and of the interacting protein. The protein-bound Pt fragments were identified. In the case of the complex Pt2c, the adducts formed upon reaction with HEWL and RNase A were further characterized by solving the respective crystal structures: this allowed us to determine the exact location of the various Pt binding sites. The implications of the obtained results are discussed in relation to the possible mechanisms of action of these innovative anticancer Pt complexes.

Synthesis of no-carrier-added [188, 189, 191Pt]cisplatin from a cyclotron produced 188, 189, 191PtCl42− complex

We developed a novel method for production of no-carrier-added (n.c.a.) [188, 189, 191Pt]PtIICl42− from an Ir target material, and then synthesized n.c.a. [*Pt]cis-[PtIICl2(NH3)2] ([*Pt]cisplatin) from [*Pt]PtIICl42−. [*Pt]PtIICl42− was prepared as a synthetic precursor of n.c.a. *Pt complex by a combination of resin extraction and anion-exchange chromatography after the selective reduction of IrIVCl62− with ascorbic acid. The ligand-substitution reaction of Cl with NH3 was promoted by treating n.c.a. [*Pt]PtIICl42− with excess NH3 and heating the reaction mixture, and n.c.a. [*Pt]cisplatin was successfully produced without employing precipitation routes. After this treatment, [*Pt]cisplatin was isolated through preparative HPLC with a radiochemical purity of 99 + % at the end of synthesis (EOS).

Insights into the interactions between salt molecules: A combined experimental and computational study

The proton transfer (PT) complex of 2-amino 4-methoxy 6-methyl pyrimidinium (2A4M6MP) 4-aminosalicylate (4AMSA), C6H10ON3+ C7H6NO3−, (I), and 5-chlorosalicylate (5ClSA), C6H10ON3+ C7H4O3Cl− (II) were synthesized and crystallized. The crystal structures of both salt molecules were investigated by SC-XRD. Further, the calculated ∆pKa values clearly demonstrate that 2A4M6MP is a good salt former when combined with carboxylic acids. Hirshfeld surface analysis provides the quantifying interactions in the solid state and energy framework shows the stability of hydrogen bonding. QTAIM analysis reveals the nature of chemical bonding and electron density distribution of intermolecular interactions of pyrimidine based salt molecules.