Condensation of substituted 2-aminopyridine with β-ketocarboxylic esters: 4H-pyrido[1,2-a]pyrimidin-4-ones and pyridin-2-ones

We report the condensation of substituted 2-aminopyridines 5 with β-ketocarboxylic esters in polyphosphoric acid. In this reaction were obtained together with the target compounds, 4H-pyrido[1,2-a]pyrirnidin-4-ones 6 also the pyridin-2-ones 7 . All the compounds 7 were tested for their calcium-antagonistic activity but failed to evoke any vasorelaxant response.     

Exploring stereogenic phosphorus: synthetic strategies for diphosphines containing bulky,highly symmetric substituents

Diphosphine ligands bearing highly symmetric, bulky substituents at a stereogenic P atom were prepared, exploiting established protocols, which include the use of chiral synthons such as 3,4-dimethyl-2,5-diphenyl-1,3,2-oxazaphospholidine-2-borane (3a) and phenylmethylchlorophosphine borane (10) and the enantioselective deprotonation of dimethylarylphosphine boranes. However, only (Bu(t)())(Me)PCH(2)CH(2)P(Bu(t)Me (8a) could be prepared from 3a. The diphosphines (S,S)-1,2-bis(mesitylmethylphosphino)ethane, ((S,S)-8b) and (S,S)-1,2-bis(9-anthrylmethylphosphino)ethane ((S,S)-8c), which contain 2,6-disubstituted aryl P-substituents, were prepared by Evans' sparteine-assisted enantioselective deprotonation of P(Ar)(Me)(2)(BH(3)) (Ar = mesityl or 9-anthryl), but the enantioselectivity did not exceed 37% ee. The asymmetrically substituted, methylene-bridged diphosphine (2R,4R)-(Ph)(CH(3))PCH(2)P(Mes)(CH(3)) ((2R,4R)-12) (Mes = mesityl) was prepared by the newly developed stereospecific reaction of the enantiomerically pure chlorophosphine borane PCl(Ph)(Me)(BH(3)) (10) with the racemic, monolithiated dimethylmesitylphosphine borane P(Mes)(Me)(CH(2)Li)(BH(3)). Diastereomerically pure (2R,4R)-12 was obtained with 86% ee. The rhodium(I) derivatives [Rh(COD)(P-P)]BF(4) containing the diphosphine ligands 8a, 8b, and 12, as well as the previously reported (S,S)-1,2-bis(1-naphthylphenylphosphino)ethane ((S,S)-8d), were prepared and tested in the enantioselective catalytic hydrogenation of acetamidocinnamates. The best catalytic result (98.6% ee) was obtained with [Rh(COD)(8d)](+) as catalyst and methyl Z-alpha-acetamidocinnamate as substrate. Some of the catalytic results are discussed in terms of the preferred conformations of the substituents at phosphorus, as calculated by molecular modeling.     

Micro computed tomography based finite element models for elastic and strength properties of 3D printed glass scaffolds

Acta Mechanica Sinica - In this study, the mechanical properties of glass scaffolds manufactured by robocasting are investigated through micro computed tomography ( $$\mu -CT$$ ) based finite...     

Combined Treatment with PI3K Inhibitors BYL-719 and CAL-101 Is a Promising Antiproliferative Strategy in Human Rhabdomyosarcoma Cells

Rhabdomyosarcoma (RMS) is a highly malignant and metastatic pediatric cancer arising from skeletal muscle myogenic progenitors. Recent studies have shown an important role for AKT signaling in RMS progression. Aberrant activation of the PI3K/AKT axis is one of the most frequent events occurring in human cancers and serves to disconnect the control of cell growth, survival, and metabolism from exogenous growth stimuli. In the study reported here, a panel of five compounds targeting the catalytic subunits of the four class I PI3K isoforms (p110α, BYL-719 inhibitor; p110β, TGX-221 inhibitor; p110γ, {"type":"entrez-protein","attrs":{"text":"CZC24832","term_id":"994587862","term_text":"CZC24832"}}CZC24832; p110δ, CAL-101 inhibitor) and the dual p110α/p110δ, AZD8835 inhibitor, were tested on the RMS cell lines RD, A204, and SJCRH30. Cytotoxicity, cell cycle, apoptosis, and the activation of downstream targets were analyzed. Of the individual inhibitors, BYL-719 demonstrated the most anti-tumorgenic properties. BYL-719 treatment resulted in G1/G0 phase cell cycle arrest and apoptosis. When combined with CAL-101, BYL-719 decreased cell viability and induced apoptosis in a synergistic manner, equaling or surpassing results achieved with AZD8835. In conclusion, our findings indicate that BYL-719, either alone or in combination with the p110δ inhibitor, CAL-101, could represent an efficient treatment for human rhabdomyosarcoma presenting with aberrant upregulation of the PI3K signaling pathway.     

Forensic Biochemical Markers to Evaluate the Agonal Period: A Literature Review

Currently, forensic research is multidisciplinary with new methods and parameters useful to define the cause and time of death as well as survival/agony times. The identification of biochemical markers able to estimate agonal period has been studied by many forensic researchers. It is known that the estimation of agonal time in different types of death is not always easy, hence our interest in literature’s data. The studies analyzed in this review confirm the important role of thanatobiochemistry for the estimation of survival times. Regardless of the death cause, the survival/agony time between the primary event and death influences markers concentrations in biological samples (e.g., blood, urine, cerebrospinal fluid). Different biomarkers can be used for qualitative evaluations in deaths with short and long agony (e.g., C-reactive protein, ferritin, GFAP, etc.). Instead, the quantitative interpretation showed limits due to the lack of reference cut-offs. Thanatobiochemistry is a useful tool to confirm what emerged from autopsies findings (macroscopic and histological analysis), but further studies are desirable to confirm the evidence emerging from our review of the literature.