Novel antiproliferative chimeric compounds with marked histone deacetylase inhibitory activity

Given our interest in finding potential antitumor agents and in view of the multifactorial mechanistic nature of cancer, in the present work, taking advantage of the multifunctional ligands approach, new chimeric molecules were designed and synthesized by combining in single chemical entities structural features of SAHA, targeting histone deacetylases (HDACs), with substituted stilbene or terphenyl derivatives previously obtained by us and endowed with antiproliferative and pro-apoptotic activity. The new chimeric derivatives were characterized with respect to their cytotoxic activity and their effects on cell cycle progression on different tumor cell lines, as well as their HDACs inhibition. Among the other, trans -6 showed the most interesting biological profile, as it exhibited a strong pro-apoptotic activity in tumor cell lines in comparison with both of its parent compounds and a marked HDAC inhibition.

Berberine and its metabolites: relationship between physicochemical properties and plasma levels after administration to human subjects

Berberine (1) is an alkaloid used widely in the treatment of several diseases. However, its physicochemical properties, pharmacokinetics, and metabolism remain unclear, and conflicting data have been reported. In this study, the main physicochemical properties of 1 and its metabolites were evaluated, including lipophilicity, solubility, pKa, and albumin binding. A sensitive HPLC-ESIMS/MS method was developed and validated to identify 1 and its main metabolites in human plasma. This method was used to quantify their levels in the plasma of healthy volunteers and hypercholesterolemic patients following a single dose and chronic administration, respectively. In both cases, berberrubine (2) was found to be the main metabolite. Surprisingly, 2 is more lipophilic than 1, which suggests that this compound tautomerizes to a highly conjugated, electroneutral quinoid structure. This was confirmed by NMR studies. These results indicate that the higher plasma concentration of 2 was a consequence of a more efficient intestinal absorption, suggesting that berberrubine is potentially more pharmacologically active than berberine.

Trace metals speciation in coastal particulate matter for marine environmental studies in Antarctica

Solid speciation of some trace metals (Pb, Cd, Fe, Mn, Cu) having environmental relevance was studied in coastal particulate sampled during the Austral Spring 2000/2001. A nearshore station situated in the Gerlache Inlet of Terra Nova Bay (Ross Sea, Antarctica) was sampled from November to February. Samples were collected using the in situ filtration system FIS500, equipped with polycarbonate membrane filters having different pore sizes (10 microm, 2 microm and 0.4 microm) for the size fraction analysis of particles. The total concentration of metals was determined both in dissolved and particulate fractions, while speciation was determined on particulate by applying a sequential extraction procedure. Concerning the surface and sub-surface layers, it has been observed that concentration of elements is mainly affected by the dynamic of the pack ice melting and by phytoplankton activity. The solid speciation in November and December is similar for all the studied elements, while some differences can be noted in February, when the pack has completely melted and phytoplankton bloom occurs. With the exception of iron, during this sampling period the quantity of metal associated to the labile fraction increases.

Distribution of polycyclic aromatic hydrocarbons in the sediments of the Adriatic Sea

Distribution of the sixteen polycyclic aromatic hydrocarbons (PAHs) indicated from USEPA as priority pollutants was studied in surface sediments of two coastal areas of the Adriatic Sea. PAHs were recovered from the sediments by solvent extraction and then analyzed by means of gas chromatography-mass spectrometry. Total concentrations of the analytes in the range 24.1-501.1 ng/g were detected. The observed distribution has been discussed taking into account different aspects, such as the fluvial inputs and the grain size of the sediments. By using a molecular marker approach and characteristic compositional patterns it was possible to ascribe to combustion processes the main source of PAHs. Furthermore a good correlation between benzo[a]pyrene and the total concentration of PAHs (r=0.953) has been pointed out.

Evaluation and comparison of two selective extraction procedures for heavy metal speciation in sediments

Two sequential extraction procedures (the former proposed by the Standard, Measurements and Testing-SM&T-program of European Union and the latter derived from those of Tessier and Forstner with various modifications) have been compared, by analyzing a reference material (CRM 601) certified for the content of heavy metals in the three solutions resulting from the SM&T procedure. Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) was used to evaluate the composition of the residues after various extractions. Reliable results, both in terms of precision and accuracy, were obtained for the first two steps of the SM&T scheme. As regards the third step, because it was modified during this work, a direct comparison of our results with those certified is not possible. SEM analysis confirmed that the scheme previously used in the laboratory was more aggressive compared to the SM&T procedure, which has also the advantage that the only CRM available for metal partitioning in sediments is certified using this method.

Determination of porphyrins and metalloporphyrins using liquid chromatography-diode array detection and mass spectrometry

A HPLC procedure has been optimized and successfully applied to porphyrins of environmental interest, such as etio and octaethylporphyrins and their VO and Ni compounds. The use of UV-Vis diode array allowed the detection of the analytes within the 5-15 ng/ml range. In order to achieve greater specificity and some structural information, the coupling of liquid chromatography with mass spectrometry was investigated, and the particle beam interface conditions were optimized. Electron impact (EI) spectra, comparable to those reported in the literature were obtained. The entire procedure has been applied to a real marine sediment, previously spiked with porphyrins to resemble oil-contaminated samples. The results pointed out that the method is suitable for such levels of analytes (5-10 microg/ml), allowing their identification and quantification with no need for purification steps.