Synthesis of prodigiosene–estrogen conjugates: optimization of protecting group strategies and anticancer properties
Canadian Journal of Chemistry, e-First Articles. <br/> The tripyrrolic prodigiosene skeleton was conjugated to several estrogen ligands. The conjugation was achieved via an ester linker that proved to be unusually sensitive to hydrolysis during synthesis. This work describes the determination of an appropriate protecting group for the hydroxy groups of the estrogen linker. The anticancer properties of the target prodigiosene–estrogen conjugates were evaluated against breast cancer cells and some show selectivity for ER+ breast cancer cell lines.
Lanthanide-dependent RNA-cleaving DNAzymes as metal biosensors
Canadian Journal of Chemistry, e-First Articles. <br/> Lanthanides represent a group of very important but challenging analytes for biosensor development. These 15 elements are very similar in their chemical properties. So far, limited success has been realized using the rational ligand design approach. My laboratory has successfully accomplished the task of carrying out combinatorial selection to isolate lanthanide-dependent RNA-cleaving DNAzymes. We report two new DNAzymes, each discovered in a different selection condition and both are highly specific to lanthanides. When both DNAzymes are used together, it is possible to identify the last few heavy lanthanides. Upon introducing a phosphorothioate modification, one of the abovementioned DNAzymes becomes highly active with many toxic heavy metals. With the selection of more DNAzymes with different activity patterns cross the lanthanide series, a sensor array might be produced for identifying each ion. This article is a minireview of the current developments on this topic and some of the historical aspects. It reflects the main content of the Fred Beamish Award presentation delivered at the 2014 Canadian Society for Chemistry Conference in Vancouver. Future directions in this area are also discussed.
Part 1 (January 2015 issue) / Partie 1 (numéro janvier 2015)
Canadian Journal of Chemistry, Volume 93, Issue 2, Page iii-iii, February 2015. <br/>
Phosphine chalcogenide complexes of antimony(III) halides
Canadian Journal of Chemistry, e-First Articles. <br/> Three series of phosphine chalcogenide complexes of the antimony(III) halides SbX3 (X = F, Cl, Br, or I) have been synthesized and characterized by spectroscopic and crystallographic methods. Complexes of the generic formulae (Cy3PO)SbX3 (X = F (1a), Cl (1b), or Br (1c)), (Cy3PO)2SbX3 (X = F (2a), Cl (2b), or Br (2c)), and (Cy3PS)SbX3 (X = Cl (3b), Br (3c), or I (3d)) were synthesized via the treatment of solutions of SbX3 with OPCy3 and SPCy3, respectively. Derivatives of (Cy3PO)SbX3 were characterized by single crystal X-ray diffraction for 1a and 1b and crystallize as dimers through symmetry related intermolecular Sb–X interactions, providing the first structurally characterized examples of this class of complex. Derivatives of (Cy3PS)SbX3 (3b–3c) adopt analogous dimeric structures in the solid state. The solid-state structure of (Cy3PO)2SbCl3 (2b) is consistent with the previously reported structures of bis-phosphine oxide complexes of antimony(III), with a square pyramidal Sb center and cis-configured OPCy3 ligands. The phosphine chalcogenide complexes of SbX3 display configurations that are consistent with the perceived trans-labilizing properties of the ligands/substituents.
A volumetric and NMR study of cyclodextrin-inhalation anesthetic complexes in aqueous solutions
Canadian Journal of Chemistry, e-First Articles. <br/> The apparent molar volumes (Vϕ) of two anesthetics (halothane and forane) have been determined in water and in binary solvent (H2O + cyclodextrin) systems at 25 °C. The results show that the magnitudes of Vϕ are greater in ternary solutions than in the binary aqueous systems. The apparent molar volumes at infinite dilution (Vϕo) of halothane in ternary solutions are observed to depend on the following factors: (i) the magnitude of the binding constant (K1:1), (ii) the lipophilicity of the anesthetic, (iii) the mole ratio of the host/halothane system, and (iv) the topology (i.e., facial vs. inclusion) of the host/guest complex. The volumetric properties of the ternary systems have been analyzed in terms of the complexed and uncomplexed species by application of Young’s rule. The formation of 1:1 CD–halothane complexes was successfully modeled using a two-state model. The binding affinity of the various cyclodextrins toward halothane is listed in descending order as follows: DM-β-CD > HP-β-CD > β-CD > α-CD > TM-β-CD.