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Genetic polymorphisms in CYP3A5 and MDR1 genes and their correlations with plasma levels of tacrolimus and cyclosporine in renal transplant recipients

Immunosuppressive drugs, such as tacrolimus (FK506) and cyclosporine (CsA), play an essential role in graft survival, preventing rejection. Large interindividual differences in drug-metabolizing enzymes as well as in drug transporters make the task of reaching the optimal concentrations difficult. The bioavailability of CsA and FK506 seems to be associated with the cytocrhome P450 IIIA (CYP3A) gene. It has also been described that the Multi Drug Resistance 1 (MDR1) gene that encodes for polyglycoprotein-P (P-gp) may influence the metabolizing action of FK506 and CsA. Therefore, we sought, to correlate single nucleotide polymorphisms (SNPs) in the CYP3A and MDR1 genes with the concentrations of FK506 and CsA. For this purpose we analyzed 2 groups of renal transplant recipients by sequencing: one receiving a CsA immunosuppressive regime, and other, an FK506-immunosuppression. This study showed that subjects in the FK506 group who had encoded the 1236C>T substitution in the MDR1 gene displayed 44.4% higher drug concentrations compared with ("wild-type") individuals. Individuals carrying the 2677G>T,A mutation showed FK506 concentrations that were 44.7% higher than the wild-type individuals. Concerning the CsA group, individuals carrying the 22915A>C substitution displayed CsA concentrations 52.1% higher than wild-type individual

Troubles in the Systematic Prediction of Transition Metal Thermochemistry with Contemporary Out-of-the-Box Methods

The recently developed DLPNO-CCSD(T) method and seven popular DFT functionals (B3LYP, M06, M06L, PBE, PBE0, TPSS, and TPSSh) with and without an empirical dispersion term have been tested to reproduce 111 gas phase reaction enthalpies involving 11 different transition metals. Our calculations, corrected for both relativistic effects and basis set incompleteness, indicate that most of the methods applied with default settings perform with acceptable accuracy on average. Nevertheless, our calculations also evidenced unexpected and nonsystematic large deviations for specific cases. For group 12 metals (Zn, Cd, Hg), most of the methods provided mean unsigned errors (MUE) less than 5.0 kcal/mol, with DLPNO-CCSD(T) and PBE methods performing excellently (MUE lower 2.0 kcal/mol). Problems started with group 4 metals (Ti and Zr). The best performer for Zr complexes with MUE of 1.8 kcal/mol, PBE0-D3, provides MUE larger than 8 kcal/mol for Ti. DLPNO-CCSD(T) provides a reasonable MUE of 3.3 kcal/mol for Ti reactions but gives MUE a larger than 14.4 kcal/mol for Zr complexes, with all the larger deviations for reactions involving ZrF4. Large and nonsystematic errors have been obtained for group 6 metals (Mo and W.), for eight reactions containing Fe, Cu, Nb, and Re complexes. Finally, for the whole set of 111 reactions, the DLPNO-CCSD(T), B3LYP-D3, and PBE0-D3 methods turned out to be the best performers, all providing MUE below 5.0 kcal/mol. Since DFT results cannot be systematically improved and large nonsystematic deviations of 20-30 kcal/mol were obtained even for best performers, our results indicate that current DFT methods are still unable to provide robust predictions in transition metal thermochemistry, at least for the functionals explored in this work. The same conclusion holds for both DLPNO-CCSD(T) and canonical CCSD(T) methods when used entirely as out-of-the-box. However, if careful investigation of core correlation is performed, relativistic effects are properly included and the quality of the reference wave function is properly checked, CCSD(T) methods can still provide good quality results that might even be used to validate DFT methods due to paucity of accurate thermodynamic data for realistic-sized transition metal complexes

O-H Bond dissociation enthalpies in hydroxyphenols. A time-resolved photoacoustic calorimetry and quantum chemistry studyy

Time-resolved photoacoustic calorimetry (TR-PAC) was used to investigate the energetics of O-H bonds of phenol, catechol, pyrogallol, and phloroglucinol. Values of À27.1 AE 3.9, À44.1 AE 4.4 and À1.6 AE 3.8 kJ mol À1 , respectively, were obtained for the solution-phase (acetonitrile) O-H bond dissociation enthalpies of the last three compounds relative to the O-H bond dissociation enthalpy in phenol, A value of 388.7 AE 3.7 kJ mol À1 was determined for the PhO-H bond dissociation enthalpy in acetonitrile. Density functional theory (MPW1PW91/aug-cc-pVDZ) calculations and complete basis set (CBS-4M) calculations were carried out to analyse intramolecular hydrogen bonding and to predict gas-phase O-H bond dissociation enthalpies, DH o (ArO-H). A microsolvation model, based on the DFT calculations, was used to study the differential solvation of the phenols and their radicals in acetonitrile and to bridge solution-and gas-phase data. The results strongly suggest that DDH o sln (ArO-H) % DDH o (ArO-H). Hence, to calculate absolute gas-phase O-H bond dissociation enthalpies in substituted phenols from the corresponding solution-phase values, the solvation enthalpies of the substituted phenols and their radicals are not required