Novel water-soluble phosphatriazenes: versatile ligands for Suzuki–Miyaura, Sonogashira and Heck reactions of nucleosides

Two new water-soluble phosphatriazene ligands have been synthesized as versatile ligands for complexation reactions with Pd(OAc)2 and utilized for catalyzing column-free Suzuki–Miyaura cross-coupling of various purine and pyrimidine halonucleosides in water. The water-solubility of the catalytic system simplified the isolation of the cross-coupled products to mere filtration, while the catalytically active solution in the filtrate was recycled eight times. A novel copper-free Sonogashira coupling protocol for the nucleosides has also been established via a one-pot synthesis of FV-100, a nucleoside-based drug in phase 3 clinical trials for herpes zoster or shingles treatment. Application of the Heck reaction was demonstrated by the synthesis of another antiviral drug: BVDU

Electronic structure and stability of fluorophore nitroxide radicals from ultra high vacuum to air exposure

Thin film processes of organic radicals remain widely unknown, although these materials may have a significant technological potential. In aiming at their use in applications, we explore the electronic structure of thin films of a nitronyl nitroxide radical attached to a fluorophore core. According to our findings, this molecule maintains its radical function and, consequently, its sensing capabilities in the thin films. The films are characterized by a high structural degree of the molecular arrangement, coupled to strong vacuum and air stability that make this fluorophore–nitroxide radical an extremely promising candidate for application in electronics. Our work also identifies a quantitative correlation between the results obtained by the simultaneous use of X-ray photoemission and electron paramagnetic resonance spectroscopy. This result can be used as a standard diagnostic tool in order to link the (in situ-measured) electronic structure with classical ex situ paramagnetic investigations

Effect of excess water on the desilylation of oligoribonucleotides using tetrabutylammonium fluoride.

The most commonly available 2' hydroxyl protecting group used in the synthesis of oligoribonucleotides is the tert-butyldimethylsilyl moiety. This protecting group is generally cleaved with 1 M tetrabutylammonium fluoride (TBAF) in tetrahydrofuran (THF). The efficiency of this reaction was tested on ribonucleotidyldeoxythymidine dinucleotides (AT, CT, GT, and UT). We have found that the efficiency of desilylation of uridine and cytidine is greatly dependent on the water content of the TBAF reagent. Conversely, the water content of the TBAF reagent [up to 17% (w/w)] had no detectable effect on the rate of desilylation of adenosine and guanosine. It was concluded that for effective desilylation of pyrimidine nucleosides the water content of the TBAF reagent must be 5% or less, which is readily achieved using molecular sieves. TBAF dried in such a manner was shown to be effective in deprotecting an oligoribonucleotide containing both purine and pyrimidine residues

Comparative Study of the Aftereffect of CO2 Inhalation or Tiletamine–Zolazepam–Xylazine Anesthesia on Laboratory Outbred Rats and Mice

CO2 inhalation is currently the most common method of euthanasia for laboratory rats and mice, and it is often used for further terminal blood sampling for clinical biochemical assays. Lately, this method has been criticized due to animal welfare issues associated with some processes that develop after CO2 inhalation. The stress reaction and the value of the clinical laboratory parameters significantly depend on the used anesthetics, method, and the site of blood sampling. Especially in small rodents, an acute terminal state followed by a cascade of metabolic reactions that can affect the studied biochemical profile may develop and cause unnecessary suffering of animals. The aim of this study was to compare the stability of biochemical parameters of outbred Sprague Dawley rats and CD-1 mice serum collected after CO2 inhalation or the intramuscular injection of tiletamine–zolazepam–xylazine (TZX). The serum content of total protein and albumin, cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotr ansferase (ALT), alkaline phosphatase (ALP), total bilirubin, and creatinine was decreased by the injection of TZX in comparison with CO2 inhalation. In addition, the levels of calcium, phosphates, chlorides and potassium were lowered by TZX vs. CO2 administration, while the level of sodium increased. Finally, the level of the majority of serum clinical biochemical parameters in rats and mice tend to be overestimated after CO2 inhalation, which may lead to masking the possible effect of anti-inflammatory drugs in animal tests. Injection anesthesia for small rodents with TZX is a more feasible method for terminal blood sampling, which also reduces the suffering of animals

On the finding of brachiopod in metamorphic garnet-bearing rocks on the Middle Urals

The authors provide paleontological and mineralogical description of the finding of the brachiopod of Atrypinae gen. et sp. indet. of the Silurian (Llandovery) – Late Devonian (Frasnian) age in a well-formed garnet-almandine crystal. Field geologist D. L. Suslov was the one who found the brachiopod in high-aluminous gneisses in Verkholovsky garnet mine, which is a part of the Evgenie-Maximilianovsky (Palkinsky) mineral mines located in the southeastern part of the Verkhisetsky granite batholite, on the territory of the historical-landscape park "Istoki Iseti". The Verkholovsky garnet mine is located on the southern slope of Pup Mountain, about 6 km west of Ekaterinburg city, on the eastern slope of the Middle Urals. The stock of the Ural Geological Museum stores the sample containing the brachiopod imprint, its measures are 3 × 2.2 × 1.6 cm and it looks like a parallel aggregate of several garnet-almandine crystals. Main habitus forms of the garnet individuals are rhombododecahedron d{110} and tetragontrioctahedron n{211}, the latter forming thin facets of the rhombododecahedron edges. The shell imprint is not in the garnet crystals, but in the base of the sample, among the fine-grained light-brown mass, whose thickness is not more than 2–3 mm. The fine-grained mass previously probably was a carbonate matrix of the brachiopod, and during the growth of the garnet at the border of two heterogeneous media (carbonate and silicate), a local metasomatic process of substituting the garnet aggregate for the primary (carbonate) substance manifested. The article also contains a brief geological sketch of the place of the finding and an overview of information about other similar findings. Chemical U-Th-Pb-dating allowed to determine the age of monazite inclusions in garnet (344 million years)

Electronic Structure and Stability of Fluorophore–Nitroxide Radicals from Ultrahigh Vacuum to Air Exposure

Thin film processes of organic radicals remain widely unknown, although these materials may have a significant technological potential. In aiming at their use in applications, we explore the electronic structure of thin films of a nitronyl nitroxide radical attached to a fluorophore core. According to our findings, this molecule maintains its radical function and, consequently, its sensing capabilities in the thin films. The films are characterized by a high structural degree of the molecular arrangement, coupled to strong vacuum and air stability that make this fluorophore–nitroxide radical an extremely promising candidate for application in electronics. Our work also identifies a quantitative correlation between the results obtained by the simultaneous use of X-ray photoemission and electron paramagnetic resonance spectroscopy. This result can be used as a standard diagnostic tool in order to link the (in situ-measured) electronic structure with classical ex situ paramagnetic investigations

Nanosized free radicals for the use as contrast and hyperpolarization agents in ultralow-field and high-field MRI

Introduction Overhauser MRI is a technique, which could enable in vivo magnetic resonance experiments at low (100 can be achieved. This technique requires a stable free electron source in mM concentrations, usually in the form of free radicals. To enhance the stability of free radicals one can use nanosized carrier molecules. Here, we present cyclodextrines as carriers for nitroxide free radicals. The Overhauser DNP performance as well as toxicity and stability are tested. Methods We tested biotin, avidin, dendrimers, liposomes and cyclodextrines as carriers for different nitroxide free radicals. To assess the ODNP performance, the maximum enhancement Emax and the RF power P1/2, needed to reach Emax/2, were measured at 2 mM concentration (a reasonable concentration for in vivo experiments) in a homemade ULF MRI system. The stability of the selected nitroxides in the aforementioned carriers was tested in ascorbic acid solution and whole blood using EPR and ULF NMR spectroscopy. Cell viability was monitored on rat astrocyte cell cultures using the MTT assay and propidium iodide (PI) staining. Results obtained from probes with and without carriers were compared for commercially available nitroxides 3CP, 3CxP and TEMPOL and synthesized nitroxides. Results/Discussion Except for cyclodextrines all other carrier systems showed poor Overhauser DNP properties with nitroxides embedded into them. An increase of spectral line broadening, or lower tumbling rates of the larger carriers seem to be the reasons for the significant drop in ODNP performance. Cyclodextrines with nitroxides showed a reasonable enhancement with improved water solubility enabling the use of lipophilic radicals. A stability improvement of up to 30% in the presence of ascorbic acid was measured via ULF NMR spectroscopy. Some nitroxides with γ-cyclodextrin showed reduction in cell viability experiments as seen by PI staining and a decrease in metabolic activity as revealed by the MTT assay, however, these effects were ascribed mostly to the vehicle itself. Conclusions Even though most carrier systems decrease the ODNP efficiency, cyclodextrine-based radicals seem to be a promising candidate for future ultralow field Overhauser MRI in vivo experiments and high field T1 contrast agents. They show improved stability compared to nitroxides without carrier systems. Further investigations should show, if only lipophilic nitroxides benefit from being embedded into cyclodextrine. Acknowledgement This work was supported with ERA.Net RUS+ project ST2017-382: NanoHyperRadicals (including RFBR 18-53-76003-ERA-A). Disclosure I or one of my co-authors have no financial interest or relationship to disclose regarding the subject matter of this presentation

Analogs of 6-Bromohypaphorine with Increased Agonist Potency for α7 Nicotinic Receptor as Anti-Inflammatory Analgesic Agents

Hypaphorines, tryptophan derivatives, have anti-inflammatory activity, but their mechanism of action was largely unknown. Marine alkaloid L-6-bromohypaphorine with EC50 of 80 μM acts as an agonist of α7 nicotinic acetylcholine receptor (nAChR) involved in anti-inflammatory regulation. We designed the 6-substituted hypaphorine analogs with increased potency using virtual screening of their binding to the α7 nAChR molecular model. Fourteen designed analogs were synthesized and tested in vitro by calcium fluorescence assay on the α7 nAChR expressed in neuro 2a cells, methoxy ester of D-6-iodohypaphorine (6ID) showing the highest potency (EC50 610 nM), being almost inactive toward α9α10 nAChR. The macrophages cytometry revealed an anti-inflammatory activity, decreasing the expression of TLR4 and increasing CD86, similarly to the action of PNU282987, a selective α7 nAChR agonist. 6ID administration in doses 0.1 and 0.5 mg/kg decreased carrageenan-induced allodynia and hyperalgesia in rodents, in accord with its anti-inflammatory action. Methoxy ester of D-6-nitrohypaphorine demonstrated anti-oedemic and analgesic effects in arthritis rat model at i.p. doses 0.05–0.26 mg/kg. Tested compounds showed excellent tolerability with no acute in vivo toxicity in dosages up to 100 mg/kg i.p. Thus, combining molecular modelling and natural product-inspired drug design improved the desired activity of the chosen nAChR ligand

Russian multicenter experience of using talazoparib in the treatment of patients with BRCA-associated metastatic breast cancer

Introduction. The presence of a germinal BRCA mutation occurs in 3–4% of all breast cancer (BC) patients with various biological subtypes, but significantly with a high frequency in patients with a triple negative biological subtype (in 10–20% of cases). For the treatment of patients with HER2-negative metastatic breast cancer associated with gBRCA mutation, the effectiveness of biologically targeted drugs from the group of PARP inhibitors (olaparib and talazoparib) has been proven.Purpose. Comparison of the results of our experience with the use of talazoparib in patients with HER2-gBRCA+ + mBC with the data of the EMBRACA registration study.Materials and methods. As part of the multicenter compassionate use program (CUP) with the support of Pfizer, 24 patients with HER2-negative metastatic gBRCA-associated mutation metastatic breast cancer (HER2-gBRCA+ breast cancer) received biologically targeted therapy with the PARP inhibitor talazoparib at a standard oral dose of 1 mg per day for vital indications . The average age of patients with HER2-gBRCAm+ breast cancer was 50 years (29–90 years).Results. Objective response (OR) was registered in 29% of cases, disease control (OR+stabilization) – in 71% of cases. The median progression-free survival (PFS) was 6.5 months (95% CI [3–10]). Objective response, disease control, and median PFS were evaluated depending on the biological subtype, the number of lines of previous therapy, and the presence of platinum-containing agents in the anamnesis.Objective response and disease control were evaluated depending on the biological subtype: in patients with ER+HER2-mBC versus patients with triple negative subtype, OR was 33% vs 22%, and disease control was 83% vs 61%, respectively. In the presence of < 3 vs ≥ 3 lines of therapy for metastatic disease in the anamnesis, OR was 31% vs 12.5%, disease control – 75% vs 50% of cases, respectively. In the presence or absence of platinum-containing agents in the anamnesis, OR was observed in 22% vs 33% of cases, and disease control – 67% vs 67%, respectively.In patients with the luminal subtype versus patients with the triple negative subtype, the PFS was 9 months vs 5 months, respectively (HR = 0.705; 95% CI [0.231–2.147]; p = 0.5208). Median PFS in the presence of <3 vs ≥3 lines of therapy for metastatic disease in the anamnesis was 9 months vs 4 months, respectively (HR = 4,216; 95% CI [1,334–13,327]; p = 0.0056). In the presence or absence of platinum-containing agents in previous lines of therapy 5 months vs 9.5 months, respectively (HR =1.484; 95% CI [0.48–4.582]; p = 0.4750).During the treatment with talazoparib adverse events of the 3rd-4th grades were observed in 5 patients (20,8%). These include moderate and severe anemia in 3 patients (12.5%), thrombocytopenia in 1 patient (4%), and neutropenia in 1 patient (4%). The majority of patients (79,5%), which received talazoparib, did not require dose adjustment. The need to reduce the dose to 0.75 mg was noted in 3 patients (12.5%), to 0.5 mg – in 2 patients (8%). Hemotransfusion was performed in 3 patients. For effective therapy safety management regular monitoring of blood parameters is necessary.Conclusion. Thus, targeted therapy with talazoparib is an effective treatment option for HER2-gBRCA+ mBC