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Biomedical subjects

Wee Han Ang

Publications and source records attributed to Wee Han Ang.

6 recordsLinked to original sources
PubMed2006

A supercooled imidazolium iodide ionic liquid as a low-viscosity electrolyte for dye-sensitized solar cells.

A series of allyl-functionalized imidazolium salts are reported, including 1-allyl-3-ethylimidazolium iodide and 1-allyl-3-propylimidazolium iodide, which have melting points close to room temperature and show typical properties of supercooled fluids if heated above their melting points. Their viscosities in the liquid state are considerably lower than the benchmark ionic liquid used in solar cells, viz., 1-propyl-3-methylimidazolium iodide. Electrolytes containing these new liquids provide excellent efficiencies and good stability in dye-sensitized solar cells when subjected to an accelerated-light soaking test at 60 degrees C. The structures of three of the new salts have been established in the solid state by single-crystal X-ray analysis.

Journal Article↗
PubMed2006

Development of organometallic ruthenium-arene anticancer drugs that resist hydrolysis.

With a view to develop drugs that could resist hydrolysis in aqueous media, organometallic arene-capped ruthenium(II) 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane (RAPTA) complexes bearing chelating carboxylate ligands have been prepared and studied. The new complexes, Ru(eta6-cymene)(PTA)(C2O4) (1) and Ru(eta6-cymene)(PTA)(C6H6O4) (2), were found to be highly soluble and kinetically more stable than their RAPTA precursor that contains two chloride ligands in place of the carboxylate ligands. They were also able to resist hydrolysis in water and exhibited significantly lower pKa values. Importantly, they showed a similar order of activity in inhibiting cancer cell-growth proliferation (as determined by in vitro assays) and exhibited oligonucleotide binding characteristics (as evidenced by matrix-assisted laser desorption ionization mass spectrometry) similar to those of the RAPTA precursor, hence realizing a strategy for developing a new generation of stable and highly water-soluble RAPTA adducts.

Antineoplastic Agents↗
PubMed2006

Ionic solid-state dimers and polymers derived from imidazolium dicarboxylic acids.

A series of imidazolium dicarboxylic acids have been prepared from the reaction of the 1,3-bis(carboxymethyl)imidazolium zwitterion with the Brønsted acids HX (X = F, Br, Cl, ClO4). The structures of these acids have been established in the solid state by single-crystal X-ray diffraction, which revealed that the cations and anions form strong hydrogen bonds through O-H...X interactions, leading to the formation of dimeric and polymeric networks. These acids react with elemental zinc and cobalt to form stable polymeric coordination complexes, some of which have also been characterised by X-ray diffraction.

Journal Article↗
PubMed2005

Synthesis and characterization of platinum(IV) anticancer drugs with functionalized aromatic carboxylate ligands: influence of the ligands on drug efficacies and uptake.

A series of trans-platinum(IV) complexes with functionalized aromatic carboxylate ligands, cis,cis,trans-Pt(NH3)2Cl2(CO2C6H4R)2 (R = H (3), p-vinyl (4), p-methoxy (5), p-iodo (6), p-cyano (7), or o-carboxyl (8)) was synthesized and characterized by spectroscopic methods. Crystal structures of 3, 4, 7, and 8 were obtained, which revealed that their structural conformations were influenced by intramolecular H-bonding interactions. The complexes were evaluated for cellular uptake and inhibition of cell proliferation against a panel of lung, colon, and breast carcinoma cell lines. The functionalization of the aromatic carboxylate ligand was found to have a profound influence on the uptake, and hence, efficacy, of this class of complex.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

Rational design of platinum(IV) compounds to overcome glutathione-S-transferase mediated drug resistance.

A rationally designed Pt(IV) anticancer compound is described, employing the novel concept of tethering an inhibitor of glutathione-S-transferase, an enzyme associated with Pt-based drug-resistance, to cisplatin. Its enzyme inhibition activity, investigated using spectrophotometric and mass spectrometry-based techniques, and cytotoxic profile in resistant cancer cells are described.

Cell Line, Tumor↗