202 research outputs found
Antitumor Activity of the mixed phosphine gold species chlorotriphenylphosphine-1,3-bis(diphenylphosphine)propane gold(I)
No full textSynthesis, Molecular Structure (X-ray and DFT), and Solution Behavior of Titanium 4-Acyl-5-pyrazolonates. Correlations with Related Antitumor β-Diketonato Derivatives
No full textPreviously reported structure−activity relationships have shown two features for effective antitumor activity of titanium β-diketone complexes: (a) ligand asymmetry and (b) the presence of planar substitutents on the ligand. Mono- and dinuclear derivatives, studied with diffraction and DFT methods show that (a) is consistent with different Ti−O(β-diketonato) bond lengths, which are longer than Ti−O(oxo) and Ti−O(alkoxy) ones. π−π features observed in dinuclear derivatives correlate with strong reactivity of related complexes with DNA and support DNA intercalation by such planar groups, in agreement with (b). Large variation for Ti−O bond lengths and Ti−O−C bond angles in the ethoxy moiety is associated with the titanium withdrawing effect and oxygen bonding s character; it is confirmed through exploration of the Cambridge crystallographic database. This ethoxy geometrical flexibility also suggests versatile accommodation in protein pockets and/or other biological targets. Electrospray ionization mass spectrometry (ESI-MS) spectra show formation of di- and trinuclear Ti-4-acyl-5-pyrazolonato cationic oligomers. Hydrolysis/oligomerization is also described by NMR results
Tin(IV) and organotin(IV) derivatives of novel β-diketones. I. Dialkyltin(IV) complexes of 1-phenyl-3-methyl-4-R'(C=O)-pyrazol-5-one (R' = CCl3, O-CH3, O-C2H5, O-i-C3H7, O-C7H7). Crystal and molecular structure of trans-dimethylbis[1-phenyl-3-methyl-4-i-propoxycarbonyl-pyrazolon-5-ato]tin(IV)
No full textCampbell, Carrie (Death, 1891-09-13)
No full textAddress: 8 Genesee St.Age at death: 43178/Pg 103/1891/F W W/Ohio/Dr. N.T. Tanski/J. Gilligan/Spring Grove Cem.Original record filed in drawer labeled 'CAHILL-CAPP'
Synthesis, spectroscopy (IR, multinuclear NMR, ESI-MS), diffraction, density functional study and in vitro antiproliferative activity of pyrazole-beta-diketone dihalotin(IV) compounds on 5 melanoma cell lines
No full textNovel 4-acylpyrazolon-5-ato-dihalotin(IV) complexes, [Q2SnX2], (X = F, Cl, Br or I); HQ = HQCHPh2 (1,2-dihydro-3-methyl-1-phenyl-4-(2,2-diphenylacetyl)pyrazol-5-one), HQBn (1,2-dihydro-3-methyl-1-phenyl-4-(2-phenylacetyl)pyrazol-5-one) or HQCF3,py (4-(2,2,2-trifluoroacetyl)-1,2-dihydro-3-methyl-1-(pyridin-2-yl)pyrazol-5-one) have been synthesized and characterized by spectroscopic (IR, 1H, 13C, 19F and 119Sn NMR, electrospray ionisation mass spectrometry (ESI-MS)), analytical and structural methods (X-ray and density functional theory). 119Sn chemical shifts depend on the nature of the halides bonded to tin. Isomer conversion, detected in solution by NMR spectroscopy, is related to the acyl moiety bulkiness while the cis(Cl)-cis(acyl)-trans(pyrazolonato) scheme is found in the solid state. The in vitro antiproliferative tests of three derivatives on three human melanoma cell lines (JR8, SK-MEL-5, MEL501) and two melanoma cell clones (2/21 and 2/60) show dose-dependent decrease of cell proliferation in all cell lines. The activity correlates with the nature of the substituent on position 1 of pyrazole, decreasing in the order pyridyl > Ph ≫ methyl. The activity for (QCF3,py)2SnCl2 on the SK-MEL-5 cell line is IC50 = 50 μM
Complexes of Tin(II) with 4-acyl-5-pyrazolonates: synthesis, spectroscopic and X-ray structural characterization
No full text
Tin(II) and Lead(II) 4-Acyl-5-pyrazolonates: Synthesis, Spectroscopic and X-ray Structural Characterization
No full text4-Acyl-5-pyrazolonato)titanium Derivatives: Oligomerization, Hydrolysis, Voltammetry and DFT study
No full textTwenty 4-acyl-5-pyrazolonato (Q) titanium derivatives of varied nuclearity have been synthesized from Ti(OR) 4 or TiCl 4 and characterized with spectroscopic methods (IR, NMR, ESI-MS). While Ti-(β-diketonato) cleavage is not seen in isolated solids, Ti-O(alkoxy) (or Ti-Cl) bonds cleave upon hydrolysis, leading to several structural forms, including oligomers. Ionic Q species with no Ti, i.e., obtained after Ti-Q cleavage, are seen for some Ti-Q derivatives by ESI-MS, which also indicates a varied nuclearity for a given species, e.g., the isolated polynuclear [Q 2Ti-μ-O] n has several "n" values. Mononuclear Ti complexes are obtained under rigorous anhydrous conditions. The cis structures of the mononuclear species (Q T) 2Ti(OCH 3) 2, Q T = 3-methyl-4-(neopentylcarbonyl)-1-phenylpyrazol-5-onato have been analyzed with DFT methods. A trans influence is a major driving force that accounts for several sets of Ti-O bonds. One of the cis stereoisomers is 56 kcal/mol higher in energy than the other two. In contrast, all (Q T) 2TiCl 2 cis isomers show similar energies. Voltammetry of the mononuclear species (Q T) 2Ti(OnPr) 2 and the antitumor tetranuclear compound [(Q B) 2Ti-μ-O] 4, (Q B = 4-benzoyl-3-methyl-1-phenylpyrazol-5-onato) indicate that the Ti IV is less prone to reduction to Ti III in the latter (Ep c for the Ti IV/Ti III couple is -1.71 V and -1.46 V versus Fc +/Fc, respectively). Potential antitumor compounds having a Ti/Q ratio of 1:1 do not disproportionate, unlike the equivalent acetylacetonato derivatives, and are water-solubl
- …
