Preparation, characterisation and bioactivity evaluation of the inclusion complex formed between picoplatin and γ-cyclodextrin.

The inclusion complex of picoplatin with γ-cyclodextrin (γ-CD) was prepared and characterised by different analytical methods, including NMR, FTIR, TGA, phase solubility as well as SEM. All of these approaches indicated that picoplatin was able to form an inclusion complex with γ-CD, and that the picoplatin/γ-CD inclusion compounds exhibited different spectroscopic features and properties from free picoplatin. The stoichiometry of the complex was 1:1; the pyridine group of picoplatin was deeply inserted into the cavity of γ-CD and the amine platinum group of picoplatin was near the narrower rim of γ-CD. The calculated apparent stability constant of the complex was 10,318M(-1). Moreover, the water solubility of picoplatin was significantly improved, according to phase-solubility studies. The complex maintained its anticancer activity, as shown by an in vitro cell-survival assay on A549 and MCF-7 cancer cell lines. All of these results showed that inclusion complexation may be a promising strategy to design a novel formulation of picoplatin as an anticancer therapy.

cis-Diammine(glycolato-κO,O)platinum(II).

The reaction of cis-[Pt(NO(3))(2)(NH(3))(2)] and sodium glycolate yielded the title compound, [Pt(C(2)H(2)O(3))(NH(3))(2)]. The Pt(II) atom, coordinated by two N atoms of ammine and two O atoms of the carboxyl-ate and oxido groups of the glycolate ligand, is in a square-planar environment. In the crystal structure, mol-ecules are connected by inter-molecular N-H⋯O hydrogen bonds, forming a three-dimensional network.

Zinc coupling potentiates anti-HIV-1 activity of baicalin.

Baicalin (BA) has been shown with anti-HIV-1 activity. Zinc is a nutrient element. The anti-HIV-1 activity of zinc complex of baicalin (BA-Zn) in vitro was studied and compared with the anti-HIV-1 activities between BA and BA-Zn in the present study. Our results suggested that BA-Zn has lower cytotoxicity and higher anti-HIV-1 activity compared with those of BA in vitro. The CC50s of BA-Zn and BA were 221.52 and 101.73 microM, respectively. The cytotoxicity of BA-Zn was about 1.2-fold lower than that of BA. The BA and BA-Zn inhibited HIV-1 induced syncytium formation, HIV-1 p24 antigen and HIV-1 RT production. The EC50s of BA-Zn on inhibiting HIV-1 induced syncytium formation (29.08 microM) and RT production (31.17 microM) were lower than those of BA (43.27 and 47.34 microM, respectively). BA-Zn was more effective than BA in inhibiting the activities of recombinant RT and HIV-1 entry into host cells. Zinc coupling enhanced the anti-HIV-1 activity of baicalin.

[The aquation of oxaliplatin and the effect of acid].

AIM: To investigate the aquation of oxaliplatin in aqueous solution at different temperatures and gain the kinetic data. METHODS: Electronic conductometry and high performance liquid chromatography (HPLC) were used to measure the oxaliplatin content in the reaction systems at different time. RESULTS: The aquation of oxaliplatin followed a pseudo-first-order rate law. In the absence of H+, the observed rate constant kobs was 7.76 x 10(-6).min-1 and the half life t1/2 was 62 days at 25 degrees C. In the presence of H+, the aquation could be accelerated by H+ according to the equation kobs = (2.61 + 21.9 [H+]) x 10(-4).min-1. The mechanism of aquation has also been proposed in this paper. From the mechanism, the rate of aquation following to r = (k1 k2) [l-OHP]/k-1 in the absence of H+ and r = (k1 + K0k3 [H+]) [l-OHP] in the presence of H+ have been deduced, which were in perfect agreement with the experimental results. CONCLUSION: In the absence of H+, the aqueous solution of oxaliplatin is stable, which meets to the request of clinical.