Maria Anzaldi

Synthesis and biological evaluation of novel pyrazole derivatives with anticancer activity.

We synthesized thirty-six novel pyrazole derivatives and studied their antiproliferative activity in human ovarian adenocarcinoma A2780 cells, human lung carcinoma A549 cells, and murine P388 leukemia cells. Four of these substances were selected because of their higher antiproliferative activity and further analyses showed that they were all able to induce apoptosis, although to a different extent. The expression of p53 and p21(waf1), which induce apoptosis and cell cycle arrest, was evaluated by western blot analysis in cells treated with compound 12d. The analysis of the cell cycle showed that all the selected compounds cause a partial G2/M block and the formation of polyploid cells. Furthermore, the four selected compounds were tested for their interaction with the microtubular cytoskeletal system by docking analysis, tubulin polymerization assay and immunofluorescence staining, demonstrating that the compound 12d, unlike the other active derivatives, was able to significantly bind dimers of α- and β-tubulin, probably causing a molecular distortion resulting in the disassembly of microtubules.

Simultaneous HPLC determination of multiple components in a commercial cosmetic cream

A high-performance liquid chromatographic method for the simultaneous determination of magnesium ascorbyl phosphate (I), imidazolidinylurea (II), a mixture of methyl-(III), ethyl-(IV), propyl-(V), butyl-(VI) parabens dissolved in phenoxyethanol, and ascorbyl palmitate (VII), was studied by using a cyano-propyl column and a methanol gradient at 220 and 240 nm. Calibration curves were found to be linear in the 0.05-5 mg ml(-1) range (compounds I, II, VII) and 0.9-160 mg ml(-1) (compounds III-VI). Linear regression analysis of the data demonstrates the efficacy of the method in terms of precision and accuracy. An extraction method is developed and validated in order to apply this chromatographic method to a commercial cosmetic cream. The precision of this method, calculated as the relative standard deviation (RSD) of the recoveries (1.57-2.21%) was excellent for all compounds I-VII.

HPLC determination of adenosine in human synovial fluid

A high-performance liquid chromatographic method has been developed for the quantitative determination of adenosine in human synovial fluid. The method is simple, rapid and, overall, selective. No interference with the components of the biological matrix was observed in these chromatographic conditions. An ODS (250 x 4.6 mm) 5 microm column was used with an isocratic elution of a phosphate buffer-acetonitrile mobile phase. Detection was carried out on a UV detector at 260 nm. Calibration curve was found to be linear in the 0.7--70 microg ml(-1) range. Linear regression analysis of the data demonstrates the efficacy of the method in terms of precision and accuracy. The precision of this method, calculated as the relative standard deviation (RSD) of the recoveries (1.57--2.21%), was excellent. The limits of quantitation (LOQ) and detection (LOD) were respectively 0.7 and 0.2 microg ml(-1). The method was applied to some samples of synovial effusion from patients affected by rheumatoid arthritis. The concentrations of adenosine which were found were included in the range of the calibration curve.

Synthesis and antimicrobial activity of heterocyclic ionone-like derivatives

A number of heterocyclic ionone-like derivatives 5 were prepared with appropriate bifunctional reagents by one-pot cyclisation of 3-dimethylamino-5-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2,4-pentadienal 3a, which was, in turn, obtained from α-ionone with N, N-dimethylformamide/phosphorus oxychloride. All compounds 5 possess remarkable activity against the selected Gram-positive, Gram-negative bacterial strains and against Candida albicans. Derivatives 5a2 and 5a6, acting at a high level especially against both Propionibacterium acnes and Staphylococcus aureus, could play a potential role in the treatment of acne and related skin disorders.

Antiproliferative and proapoptotic activities of a new class of pyrazole derivatives in HL-60 cells.

A series of N‐substituted pyrazole derivatives have been synthesized and tested for their anticancer effect on the HL‐60 leukaemia cell line. Four were active both in cell‐growth inhibition and in inducing apoptosis. The inhibition of cell growth mainly reflects a compound‐induced reduction in the number of cells in phases from S to M, whereas the induction of apoptosis involves inhibition of expression of Bcl‐2 and enhanced expression of Bax with consequent reduced activation of the proapoptotic caspase 3. Finally, preliminary experiments carried out with tumor cells from myelogenous leukaemic patients showed that the compounds 4c, 4l, 4m, and 4n are indeed capable of inducing apoptosis.

Amine exchange and unexpected ring-opening reactions of pyranone derivatives: Synthesis of 3-amino-substituted oxonaphthopyran-carbaldehydes and tetrahydropyrimidinethanones as new potential oligonucleotide stabilization agents

3-[(3-Aminopropyl)amino]-1-oxo-1H-naphtho[2,1-b]pyran-2-carbaldehyde (10) was synthesized by nucleophilic substitution reaction of 2-(3-dimethylamino)-1-oxo-1H-naphtho[2,1-b]pyran-2-carbaldehyde (9) and the monoprotected propane-1,3-diamine. The reaction with the unprotected reagent led to the unexpected 1-(2-hydroxynaphthalen-1-yl)-2-(tetrahydropyrimidin-2(1H)-ylidene)ethanone (6). Extension of this reaction to chromone 16 gave 1-(2-hydroxy-3-isopropyl-6-methylphenyl)-2-(tetrahydropyrimidin-2(1H)-ylidene)ethanone (7). The X-ray crystal structures of 6 and 7 were also determined.

Evaluation of the anti-proliferative activity of three new pyrazole compounds in sensitive and resistant tumor cell lines

BACKGROUND In previous papers we demonstrated that the activity of short heteroretinoids as anti-proliferative and pro-apoptotic compounds was deeply linked to their heterocyclic moiety and that ionone-derived 1,5-pyrazoles had the highest anti-proliferative activity in our preliminary experiments. We then demonstrated the high and pharmacologically significant anti-proliferative and apoptotic activities of the pyrazole compounds 2-(1-(4-chlorophenyl)-1H-pyrazol-5-yl)-5-methoxyphenol (EN12-4), 5-methoxy-2-(1-(pyridin-2-yl)-1H-pyrazol-5-yl)phenol (EN12-2A) and 2-(5-(4-methoxyphenyl)-1H-pyrazol-1-yl)pyridine (EN7-2) establishing, especially for EN12-2A, a possible mechanism of action involving the cell microtubular system. METHODS Here, the anti-proliferative activity of these pyrazole compounds was analyzed in vitro by the MTT assay in six drug-resistant cell lines, five of which were selected after exposure to increasing concentrations of cisplatin (L1210/DDP), doxorubicin (A2780/DX3), 5-fluorouracil (HCT-8/5FU), taxol (A549/T24) and etoposide (MCF-7/VP), and one was obtained by transfection of the ABCG2 membrane transporter (HEK-293/R2). RESULTS Our data show that these compounds have a similar anti-proliferative activity in nearly all resistant and sensitive cell lines, demonstrating their ability to overcome the most common mechanisms of drug resistance with two exceptions regarding the MCF-7/VP cell line over-expressing the ABCC1 (MRP1) transporter, and the MDR1 over-expressing A2780/DX3 cells, with a calculated RI = 3.2 for EN12-2A, relative to their sensitive cellular counterpart. On the other hand, the taxol-resistant A549/T24 cell line showed a significantly increased sensitivity to our compounds. CONCLUSIONS Our data suggest that our pyrazole compounds are able to overcome in vitro the most common drug-resistance mechanisms demonstrating a significant anti-proliferative activity and confirming a mechanism of action involving the depolymerization of microtubules.

Synthesis of ionones and carvone analogues: olfactory properties and preliminary toxicity assays.

Vilsmeier reagents react with alpha/beta-ionones and carvone to produce aldehydes 7-11 in a one-step procedure. The indene derivative 11, which came from the double iminoalkylation of carvone and ring closure with the elimination of dimethylamine, was practically odourless, while all the others had peculiar odours which were very different from the starting material. The cytotoxicity data of 9 and 10, which are the most promising potential perfume ingredients, are also reported.

Asymmetric 4-Aryl-1,4-dihydropyridines Potentiate Mutant Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)

Some of the genetic mutations that cause cystic fibrosis (CF) impair the gating of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− ion channel. This defect can be corrected with pharmacological tools (potentiators) that belong to various chemical families, including the 1,4‐dihydropyridines (DHPs). A small set of asymmetric 4‐aryl‐DHPs was synthesized, and each racemic couple was tested in a functional assay carried out on cells expressing the G1349D, ΔF508, and G551D mutants. The most active racemates were subjected to chiral separation by HPLC, and the pure enantiomers were tested to evaluate any gains in activity. Although three enantiomers demonstrated high potency (Kd values less than 0.09, 0.1, and 0.5 μM in G1349D, ΔF508, and G551D, respectively), in general, the screening of pure enantiomers did not produce a great diversity in potency values. It is probable that the degree of DHP asymmetry considered in our analysis is still insufficient with respect to that allowed in a putative DHP binding site in CFTR, so that the site could equally accommodate both enantiomers.

Phenylhydrazones as Correctors of a Mutant Cystic Fibrosis Transmembrane Conductance Regulator.

The phenylhydrazone RDR‐1 is endowed with moderate activity as F508del‐CFTR corrector; nevertheless, its simple structure enables stimulating developments in this class of correctors. Therefore, we synthesized a number of phenylhydrazones 3 by reacting phenylhydrazine derivatives 1 with furfural derivatives 2. By the same reaction, also the pyridine derivatives 4, the thiophene derivatives 5, and the hydrazides 6 and 7 were prepared. All compounds were tested as F508del‐CFTR correctors in the cystic fibrosis (CF) bronchial epithelial cell line CFBE41o‐, using corr‐4a and VX‐809 as controls. Some of the tested compounds emerged as interesting F508del‐CFTR correctors at 20 μM (3c) and 2 μM (5d). 3c and 5d administered together with VX‐809 produced a satisfactory additivity of action. When the structure of 5d was overlapped with RDR‐1 and five other established correctors, a shared central design was clearly visible. This fact may be of interest in the search for new F508del‐CFTR correctors.