Structural characterization of the trans -equatorial isomer of (aqua)(ethylenediamine- N , N , N ′-tripropionato)chromium(III) trihydrate,[Cr(edtrp)(H2O)] · 3H2O

The structure of trans-equatorial [Cr(edtrp)(H2O)] · 3H2O (edtrp3− is the anion of ethylenediamine-N,N,N′-tripropionic acid) was determined by single crystal X-ray diffraction. The chromium(III) ion is surrounded octahedrally by the two nitrogen and three oxygen atoms of the quinquedentate edtrp3−, forming a five-membered diamine ring and the three six-membered β-propionato chelate rings. The remaining coordination position is occupied by the H2O ligand. The crystal structure conformation is compared to the result of recent molecular mechanics analysis. The ring strain of R and G chelate rings was found to be in agreement with the previously proposed mechanisms for the C—N bond cleavage and recombinatio

Structural analysis of conformational flexibility in (aqua)(propanediamine-<b><i>N</i></b>,<b><i>N</i></b> '-diacetato-<b><i>N</i></b>-propionato)chromium(III) dihydrate. Crystal structure of <b><i>cis</i></b>-polar, <b><i>trans</i></b>(H₂O,O⁵)-[Cr(1,3-pddap)(H₂O)]<b>·</b>2H₂O

The quinquedentate complex trans(H₂O,O⁵)-[Cr(1,3-pddap)(H₂O)] · 2H₂O (where 1,3-pddap is the 1,3-propanediamine-N,N '-diacetate-N-3-propionate ion) was prepared and its structure established by X-ray diffraction method. It crystallizes in the orthorhombic space group Pna2₁, a = 17.290(2), b = 10.821(2), c = 7.872(1) Å, Z = 4. The metal atom is surrounded octahedrally with two nitrogen and three oxygen donors of (1,3-pddap)³⁻, forming two six-membered and two five-membered metal chelate rings, and with one water molecule occupying the trans position with respect to the oxygen of the axial glycinate ring. Conformational analysis of the five geometrical isomers of [Cr(1,3-pddap)(H₂O)], performed with the Consistent Force Field (CFF) program and recently developed edta force field, revealed that the global minimum is indeed the trans(H₂O,O⁵) isomer with the geometry in a very good agreement with the crystallographic structure. General patterns for the conformational preferences of edta-type complexes of trivalent first-row transition metals are exposed and discussed

Structural analysis of conformational flexibility in (aqua) (propanediamine-N,N'-diacetato-N-propionato)chromium(III) dihydrate. Crystal structure of cis-polar, trans(H2O, O-5)-[Cr(1,3-pddap)(H2O)]center dot 2H(2)O

The quinquedentate complex trans(H2O,O-5)-[Cr(1,3-pddap)(H2O)].2H(2)O (where 1,3-pddap is the 1,3-propanediamine-N, N '-diacetate-N-3-propioriate ion) was prepared and its structure established by X-ray diffraction method. It crystallizes in the orthorhombic space group Pna2(1), a=17.290(2), b=10.821(2), c=7.872(1) A, Z=4. The metal atom is surrounded octahedrally with two nitrogen and three oxygen donors of (1,3-pddap)(3-), forming two six-membered and two five-membered metal chelate rings, and with one water molecule occupying the trans position with respect to the oxygen of the axial glycinate ring. Conformational analysis of the five geometrical isomers of [Cr(1,3-pddap)(H2O)], performed with the Consistent Force Field (CFF) program and recently developed edta force Field, revealed that the global minimum is indeed the trans(H2O,O-5) isomer with the geometry in a very good agreement with the crystallographic structure. General patterns for the conformational preferences of edta-type complexes of trivalent first-row transition metals are exposed and discussed

Edoxaban versus warfarin in patients with atrial fibrillation

Contains fulltext : 125374.pdf (publisher's version ) (Open Access)BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing two once-daily regimens of edoxaban with warfarin in 21,105 patients with moderate-to-high-risk atrial fibrillation (median follow-up, 2.8 years). The primary efficacy end point was stroke or systemic embolism. Each edoxaban regimen was tested for noninferiority to warfarin during the treatment period. The principal safety end point was major bleeding. RESULTS: The annualized rate of the primary end point during treatment was 1.50% with warfarin (median time in the therapeutic range, 68.4%), as compared with 1.18% with high-dose edoxaban (hazard ratio, 0.79; 97.5% confidence interval [CI], 0.63 to 0.99; P<0.001 for noninferiority) and 1.61% with low-dose edoxaban (hazard ratio, 1.07; 97.5% CI, 0.87 to 1.31; P=0.005 for noninferiority). In the intention-to-treat analysis, there was a trend favoring high-dose edoxaban versus warfarin (hazard ratio, 0.87; 97.5% CI, 0.73 to 1.04; P=0.08) and an unfavorable trend with low-dose edoxaban versus warfarin (hazard ratio, 1.13; 97.5% CI, 0.96 to 1.34; P=0.10). The annualized rate of major bleeding was 3.43% with warfarin versus 2.75% with high-dose edoxaban (hazard ratio, 0.80; 95% CI, 0.71 to 0.91; P<0.001) and 1.61% with low-dose edoxaban (hazard ratio, 0.47; 95% CI, 0.41 to 0.55; P<0.001). The corresponding annualized rates of death from cardiovascular causes were 3.17% versus 2.74% (hazard ratio, 0.86; 95% CI, 0.77 to 0.97; P=0.01), and 2.71% (hazard ratio, 0.85; 95% CI, 0.76 to 0.96; P=0.008), and the corresponding rates of the key secondary end point (a composite of stroke, systemic embolism, or death from cardiovascular causes) were 4.43% versus 3.85% (hazard ratio, 0.87; 95% CI, 0.78 to 0.96; P=0.005), and 4.23% (hazard ratio, 0.95; 95% CI, 0.86 to 1.05; P=0.32). CONCLUSIONS: Both once-daily regimens of edoxaban were noninferior to warfarin with respect to the prevention of stroke or systemic embolism and were associated with significantly lower rates of bleeding and death from cardiovascular causes. (Funded by Daiichi Sankyo Pharma Development; ENGAGE AF-TIMI 48 ClinicalTrials.gov number, NCT00781391.)