Novel Tetracyclic Azaphenothiazines with the Quinoline Ring as New Anticancer and Antibacterial Derivatives of Chlorpromazine

Phenothiazine derivatives are widely studied in various fields such as biology, chemistry, and medicine research because of their pharmaceutical effects. The first compound used successfully in the treatment of psychosis was a phenthiazine derivative, chlorpromazine. Apart from its activity in neurons, chlorpromazine has also been reported to display anticancer and antibacterial properties. In this study, we present the synthesis and research on the activity of A549, MDA, MiaPaCa, PC3, and HCT116 cancer cell lines and of S. aureus, S. epidermidis, E. coli, and P. aeruginosa bacterial strains against a series of new tetracyclic chlorpromazine analogues containing a quinoline scaffold in their structure instead of the benzene ring and various substituents at the thiazine nitrogen. The structure of these novel molecules has been determined by 1H NMR, 13C NMR, and HRMS spectral techniques. The seven most active of the twenty-four new chlorpromazine analogues tested were selected to study the mechanism of cytotoxic action. Their ability to induce apoptosis or necrosis in cancer cells was assessed by flow cytometry analysis. The results obtained confirmed the proapoptotic activity of selected compounds, especially in terms of inducing late apoptosis or necrosis in cancer cell lines A549, MiaPaCa-2, and HCT-116. Furthermore, studies on the induction of cell cycle arrest suggest that the new chlorpromazine analogues exert antiproliferative effects by inducing cell cycle arrest in the S phase and, consequently, apoptosis.

Comparative studies on the aggregate formation of synthesized zwitterionic gemini and monomeric surfactants in the presence of the amphiphilic antipsychotic drug chlorpromazine hydrochloride in aqueous solution: an experimental and theoretical approach

The formation of aggregates, which are widely used in the field of biochemistry and the medical industry, was studied with different compositions of alkyl betaine gemini surfactant (C14Ab) in conjugation with chlorpromazine hydrochloride (CPZ). The results were compared with those of a single-chain zwitterionic surfactant (C12DmCB) of the same type with CPZ. Dynamic light scattering (DLS), confocal laser scanning microscopy (CLSM), and transmission electron microscopy (TEM) methods were used to distinguish the aggregates for the CPZ/C14Ab system in aqueous solutions above a certain mole fraction of the drug CPZ (αCPZ = 0.2). Time-resolved fluorescence decay measurements of acridine orange revealed relative polarity near the head group regions of mixed micelle (CPZ/C14Ab and CPZ/C12DmCB) systems. The hydrophilic environment around the head group regions of the CPZ/C14Ab system was different from that in the case of the CPZ/C12DmCB system. On the other hand, several theoretical models were employed (Clint, Rubingh, Motomura, and SPB) for mixed micellar systems to elucidate the different interaction parameters. Such a systematic study of a zwitterionic gemini amphiphile and its interaction with other amphiphiles and an amphiphilic drug molecule is rare in the literature.

Cyclodextrin complexation studies as the first step for repurposing of chlorpromazine

The antipsychotic drug chlorpromazine (CPZ) has potential for the treatment of acute myeloid leukemia, if central nervous system side-effects resulting from its passage through the blood-brain barrier can be prevented. A robust drug delivery system for repurposed CPZ would be drug-in-cyclodextrin-in-liposome that would redirect the drug away from the brain while avoiding premature release in the circulation. As a first step, CPZ complexation with cyclodextrin (CD) has been studied. The stoichiometry, binding constant, enthalpy, and entropy of complex formation between CPZ and a panel of CDs was investigated by isothermal titration calorimetry (ITC). All the tested CDs were able to include CPZ, in the form of 1:1, 1:2 or a mixture of 1:1 and 1:2 complexes. In particular, a substituted γ-CD, sugammadex (the octasodium salt of octakis(6-deoxy-6-S-(2-carboxyethyl)-6-thio)cyclomaltooctaose), formed exclusively 1:2 complexes with an extremely high association constant of 6.37 × 10⁹ M^-2. Complexes were further characterized by heat capacity changes, one- and two-dimensional (ROESY) nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics simulations. Finally, protection of CPZ against photodegradation by CDs was assessed. This was accelerated rather than reduced by complexation with CD. Altogether these results provide a molecular basis for the use of CD in delayed release formulations for CPZ.

Investigation of metabolite-protein interactions by transient absorption spectroscopy and in silico methods

Transient absorption spectroscopy in combination with in silico methods has been employed to study the interactions between human serum albumin (HSA) and the anti-psychotic agent chlorpromazine (CPZ) as well as its two demethylated metabolites (MCPZ and DCPZ). Thus, solutions containing CPZ, MCPZ or DCPZ and HSA (molar ligand:protein ratios between 1:0 and 1:3) were submitted to laser flash photolysis and the ΔA_max value at λ = 470 nm, corresponding to the triplet excited state, was monitored. In all cases, the protein-bound ligand exhibited higher ΔAmax values measured after the laser pulse and were also considerably longer-lived than the non-complexed forms. This is in agreement with an enhanced hydrophilicity of the metabolites, due to the replacement of methyl groups with H that led to a lower extent of protein binding. For the three compounds, laser flash photolysis displacement experiments using warfarin or ibuprofen indicated Sudlow site I as the main binding site. Docking and molecular dynamics simulation studies revealed that the binding mode of the two demethylated ligands with HSA would be remarkable different from CPZ, specially for DCPZ, which appears to come from the different ability of their terminal ammonium groups to stablish hydrogen bonding interactions with the negatively charged residues within the protein pocket (Glu153, Glu292) as well as to allocate the methyl groups in an apolar environment. DCPZ would be rotated 180° in relation to CPZ locating the aromatic ring away from the Sudlow site I of HSA.

Sonochemical synthesis of iron-graphene oxide/honeycomb-like ZnO ternary nanohybrids for sensitive electrochemical detection of antipsychotic drug chlorpromazine

We report a novel electrochemical sensor for the sensitive and selective determination of the antipsychotic drug chlorpromazine (CPZ) based on the iron (Fe) nanoparticles-loaded graphene oxide (GO-Fe)/three dimensional (3D) honeycomb-like zinc oxide (ZnO) nanohybrid modified screen printed carbon electrode (SPCE). The 3D hierarchical honeycomb-like ZnO was synthesized using a novel aqueous hydrothermal method and the GO-Fe/ZnO nanohybrid was prepared based on an inexpensive and fast sonochemical method using a high-intensity ultrasonic bath (Delta DC200H, 200 W, 40 KHz). Characterizations including scanning electron microscopy, elemental mapping, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy were carried out as part of this work. The electrocatalytic oxidation behavior of CPZ at various electrodes was investigated using the cyclic voltammetry technique, through which the GO-Fe/ZnO modified SPCE was identified as the best performing electrode. The quantitative determination of CPZ was then performed using the differential pulse voltammetry technique. The as-prepared GO-Fe/ZnO/SPCE sensor exhibited a quick and sensitive response towards the oxidation of CPZ with linear concentration ranges from 0.02 to 172.74 μM and 222.48 to 1047.74 μM. The modified SPCE sensor displayed a low detection limit (LOD) of 0.02 µM and a high sensitivity of 7.56 µA µM^-1 cm^-2. The proposed sensor also showed remarkable operational and storage stability, reproducibility, and repeatability. Furthermore, the practicability of the GO-Fe/ZnO/SPCE sensor has been verified with real sample analysis using commercial antipsychotic CPZ tablets and human urine samples, and adequate recovery has been achieved.

Selective adsorption and removal of drug contaminants by using an extremely stable Cu(II)-based 3D metal-organic framework

The adsorption capacity of three representative pharmaceutical drugs and personal care products (PPCPs) viz. diclofenac sodium (DCF), chlorpromazine hydrochloride (CLF) and amodiaquin dihydrochloride (ADQ), were preliminarily studied using a water-stable Cu(II)-based metal organic framework (MOF) [Cu(BTTA)]_n·2DMF (1) (H₂BTTA = 1,4-bis(triazol-1-yl)terephthalic acid). We also investigated the factors influencing the adsorption such as concentration, pH, contact time, temperature and dosages. The results show that the adsorption capacity of 1 for DCF (650 mg g-¹) from aqueous medium, which is higher in comparison to most of the reported MOFs. While the adsorption of CLF and ADQ are only 67 mg g-¹ and 72 mg g-¹, respectively. The adsorption isotherm and adsorption kinetics indicated that the adsorption of diclofenac sodium by 1 follows Freundlich model with R² value of 0.9902 and pseudo-first-order kinetics with correlation coefficient 0.9939 and K₁ value of 0.0058 min^-1, respectively. Investigations indicate that 1 could become a potential material to adsorb DCF from aqueous medium.

Fate of the drug chlorpromazine in river water according to laboratory assays. Identification and evolution over time of degradation products. Sorption to sediment

Toxic effects of the non-biodegradable drug chlorpromazine and its degradation products have been reported on microorganisms in aqueous media. Here, chlorpromazine degradation assays in forced and non-forced conditions have been done to know its persistence and degradation products in river water. Sunlight irradiation promotes the complete degradation of chlorpromazine (2 μg L(-1)) in less than 4 h, but if the exposure to sunlight is limited chlorpromazine is detected during 4 weeks in river water. Sixteen degradation products in surface water are described for first time after solid-phase extraction and analysis by ultra-pressure liquid chromatography/quadrupole time-of-flight/mass spectrometry; their structures are proposed from the molecular formulae of the fragment-ions observed in high-resolution tandem mass spectra. Hydroxylation and oxidation products such as chlorpromazine sulfoxide, 2-hydroxypromazine and 2-hydroxypromazine sulfoxide were predominant degradation products in the early stages; some benzo[1,4]thiazin-6-ol derivatives resulting from the breakdown of the phenothiazine core were the major and relatively stable products after 20 weeks under non-forced conditions. A degradation pathway of chlorpromazine in water is outlined. Moreover, it is shown that chlorpromazine is very strongly adsorbed on sediment while the degradation products that kept the promazine core have a notable capacity of sorption, too; sorption coefficients are calculated. Finally, a prediction about the toxicity of the degradation products in aquatic ecosystems suggests that some of them have toxicities similar, or even higher, than chlorpromazine.

IN VITRO MEASUREMENT OF TOTAL ANTIOXIDANT CAPACITY OF CRATAEGUS MACRACANTHA LODD LEAVES

Crataegus macracantha Lodd, family Rosaceae, is a very rare species in Europe, and unlike Crataegus monogyna is less investigated for pharmacologic activity.

AIM

To analyze the ability of the lyophilisate of extract obtained from leaves of Crataegus macracantha Lodd (single plant at the Iaşi Botanical Garden) to capture free radicals in vitro.

MATERIAL AND METHODS

The lyophilisate obtained in Department of Pharmacognosy, Faculty of Pharmacy, "Grigore T. Popa" University of Medicine and Pharmacy Iaşi. The decreased absorbance of chromophore chlorpromazine radical cation in the presence of the lyophilized solutions was studied spectrophotometrically. The indicator radical cation, obtained by oxidation of chlorpromazine by potassium persulfate, has the maximum absorbance at 525 nm. Ascorbic acid was used as a standard antioxidant.

RESULTS

The absorbance of radical solution was determined after the addition of a certain amount of lyophilisate at different time intervals. The antioxidant activity was calculated using the calibration curve obtained by plotting the variation in radical solution absorbance depending on ascorbic acid concentration. For each ascorbic acid concentration the area under the curve was calculated from plotting the percentage inhibition of the absorbance at two pre-established time intervals.

CONCLUSIONS

The results confirm the antioxidant activity of the leaves of Crataegus Macracantha Lodd and by optimizing the proposed analytical methods the antiradical activity can be quickly evaluated with minimal reagent consumption.

Characterization of mixtures of compounds produced in chlorpromazine aqueous solutions by ultraviolet laser irradiation: their applications in antimicrobial assays

The study reports an investigation of the photoproducts obtained by exposure of chlorpromazine hydrochloride in ultrapure water (concentration 2 mg/mL) to a 266-nm laser beam obtained by fourth harmonic generation from a Nd:YAG laser (6-ns full time width at half maximum, 10-Hz pulse repetition rate). The photoproducts were analyzed by steady-state UV-Vis absorption, laser-induced fluorescence, Fourier transform infrared spectroscopy, and liquid chromatography-tandem time-of-flight mass spectroscopy. Two figures showing pathways that take place during irradiation for obtaining the final products are shown. The quantum yield of singlet oxygen generation by chlorpromazine (CPZ) was determined relative to standard Zn-phthalocyanine in dimethyl sulfoxide. To outline the role of fluorescence in photoproducts formation rates, fluorescence quantum yield of CPZ during exposure to 355-nm radiation (third harmonic of the fundamental beam of Nd:YAG laser) was investigated relative to standard Coumarin 1 in ethanol. The CPZ solutions exposed 60 and 240 min to 266-nm laser beam, respectively, were tested against Staphylococcus aureus ATCC 25923 strain. For 25 μL of CPZ samples irradiated 240 min, a higher diameter of inhibition has obtained against the tested strain than for the 60-min exposed ones.

PLGA biodegradable nanoparticles containing perphenazine or chlorpromazine hydrochloride: effect of formulation and release

In our study, poly(dl-lactide-co-glycolide) (PLGA) nanoparticles loaded with perphenazine (PPH) and chlorpromazine hydrochloride (CPZ-HCl) were formulated by emulsion solvent evaporation technique. The effect of various processing variables, including PLGA concentration, theoretical drug loading, poly(vinyl alcohol) (PVA) concentration and the power of sonication were assessed systematically to obtain higher encapsulation efficiency and to minimize the nanoparticles size. By the optimization formulation process, the nanoparticles were obtained in submicron size from 325.5 ± 32.4 to 374.3 ± 10.1 nm for nanoparticles loaded with PPH and CPZ-HCl, respectively. Nanoparticles observed by scanning electron microscopy (SEM) presented smooth surface and spherical shape. The encapsulation efficiency of nanoparticles loaded with PPH and CPZ-HCl were 83.9% and 71.0%, respectively. The drug loading were 51.1% and 39.4% for PPH and CPZ-HCl, respectively. Lyophilized nanoparticles with different PLGA concentration 0.8%, 1.3% and 1.6% (w/v) in formulation process were evaluated for in vitro release in phosphate buffered saline (pH = 7.4) by using dialysis bags. The release profile for both drugs have shown that the rate of PPH and CPZ-HCl release were dependent on a size and amount of drugs in the nanoparticles.

Formulation and stability of an extemporaneously compounded oral solution of chlorpromazine HCl

Chlorpromazine is a phenothiazine antipsychotic which is often used in hospice and palliative care to treat hiccups, delirium, and nausea. With the discontinuation of the commercial oral solution concentrate, there is a need to prepare this product by extemporaneous compounding. This study was initiated to identify an easy-to-prepare formulation for the compounding pharmacist. A stability study was also conducted to select the proper storage conditions and establish the beyond-use date. Chlorpromazine HCl powder and the Ora-Sweet® syrup vehicle were used to prepare the 100 mg/mL solution. Once the feasibility was established, a batch of the solution was prepared and packaged in amber plastic prescription bottles for a stability study. These samples were stored at refrigeration (2-8°C) or room temperature (20-25°C) for up to 3 months. At each monthly time point, the samples were evaluated by visual inspection, pH measurement, and high performance liquid chromatography (HPLC). A separate forced stability study was conducted to confirm that the HPLC method was stability indicating. A clear and colorless solution of 100 mg/mL chlorpromazine HCl was obtained by dissolving the drug powder in Ora-Sweet® with moderate agitation. The stability study results indicated that this solution product remained unchanged in visual appearance or pH at both refrigeration and room temperature for up to 3 months. The HPLC results also confirmed that all stability samples retained 93.6-101.4% of initial drug concentration. Chlorpromazine HCl solution 100 mg/mL can be compounded extemporaneously by dissolving chlorpromazine HCl drug powder in Ora-Sweet®. The resulting product is stable for at least three months in amber plastic prescription bottles stored at either refrigeration or room temperature.

Supra-amphiphilic aggregates formed by p-sulfonatocalix[4]arenes and the antipsychotic drug chlorpromazine

We report here a supramolecular strategy to directly assemble the small molecular antipsychotic drug chlorpromazine (CPZ) into nanostructures, induced by p-sulfonatocalix[4]arene (SC4A) and p-sulfonatocalix[4]arene tetraheptyl ether (SC4AH), with high drug loading efficiencies of 61% and 46%, respectively. The binary host-guest assembly process was monitored using optical transmittance measurements, and the size and morphology of these two kinds of supra-amphiphilic assemblies were identified using a combination of light scattering and high-resolution transmission electron microscopy, which showed solid spherical micelles. This strategy presents new opportunities for the development of high loading drug-containing carriers with easy processability for drug delivery.

Evaluation of free radical scavenging activity of some antioxidants

Measurement of free radical scavenging capacity of antioxidants is influenced by a number of parameters that depend on reaction rate.

AIM

A new method for assessing the free radical scavenging activity in which the influence of antioxidant concentration and reaction rate on chlorpromazine radical cation absorbance are simultaneously monitored.

MATERIALS AND METHODS

The change in radical solution absorbance at 525 nm within a fixed time at different concentrations of the standard antioxidant--ascorbic acid (AA) are determined and percent inhibition is calculated.

RESULTS

The percent inhibition of color was plotted versus time, and the area under the curve was calculated for each concentration of the standard antioxidant. The calibration curve was obtained by plotting the area under the curve versus ascorbic acid concentration. The antioxidant activity of the samples was calculated using the regression line equation (r2 = 0.9991) and expressed as ascorbic acid molar equivalents (AAE) depending on the unit of measurement chosen for the tested product.

CONCLUSIONS

The proposed method takes into account the two parameters influencing the kinetics of the reaction between antioxidant and radicals, namely the antioxidant concentration and fixed time for measuring absorbance.

The in vitro activity of products formed from exposure of chlorpromazine to a 266 nm laser beam against species of mycobacteria of human interest

Chlorpromazine (CPZ) was exposed to a 266 nm laser beam for different periods of time ranging from minutes to 24 h. At intervals, the products from irradiation were evaluated by thin-layer chromatography (TLC) and evaluated for their activity against mycobacteria of human interest (Mycobacterium tuberculosis, M. avium, M. intracellulare and their corresponding reference strains or clinical isolates). With the exception of the M. avium 47/07 clinical strain, the products produced from the irradiation of CPZ for 4 h had greater activity against M. intracellulare ATCC, M. avium ATCC, H37Rv and the Multidrug-resistant tuberculosis (MDR-TB) strains as opposed to that produced by the unirradiated control. The level of products from the 4-h exposure of CPZ remained the same throughout the next 20 h of irradiation. Of significant note is that the irradiation products of CPZ had lower in vitro cytotoxicity against human cells, suggesting that this approach may be useful for the development of compounds more bioactive than the parental species.

Importance of the interaction protein-protein of the CaM-PDE1A and CaM-MLCK complexes in the development of new anti-CaM drugs

Protein-protein interactions play central roles in physiological and pathological processes. The bases of the mechanisms of drug action are relevant to the discovery of new therapeutic targets. This work focuses on understanding the interactions in protein-protein-ligands complexes, using proteins calmodulin (CaM), human calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1A active human (PDE1A), and myosin light chain kinase (MLCK) and ligands αII-spectrin peptide (αII-spec), and two inhibitors of CaM (chlorpromazine (CPZ) and malbrancheamide (MBC)). The interaction was monitored with a fluorescent biosensor of CaM (hCaM M124C-mBBr). The results showed changes in the affinity of CPZ and MBC depending on the CaM-protein complex under analysis. For the Ca(2+) -CaM, Ca(2+) -CaM-PDE1A, and Ca(2+) -CaM-MLCK complexes, CPZ apparent dissociation constants (Kds ) were 1.11, 0.28, and 0.55 μM, respectively; and for MBC Kds were 1.43, 1.10, and 0.61 μM, respectively. In competition experiments the addition of calmodulin binding peptide 1 (αII-spec) to Ca(2+) -hCaM M124C-mBBr quenched the fluorescence (Kd  = 2.55 ± 1.75 pM) and the later addition of MBC (up to 16 μM) did not affect the fluorescent signal. Instead, the additions of αII-spec to a preformed Ca(2+) -hCaM M124C-mBBr-MBC complex modified the fluorescent signal. However, MBC was able to displace the PDE1A and MLCK from its complex with Ca(2+) -CaM. In addition, docking studies were performed for all complexes with both ligands showing an excellent correlation with experimental data. These experiments may help to explain why in vivo many CaM drugs target prefer only a subset of the Ca(2+) -CaM regulated proteins and adds to the understanding of molecular interactions between protein complexes and small ligands.

Simultaneous monitoring of photocatalysis of three pharmaceuticals by immobilized TiO2 nanoparticles: chemometric assessment, intermediates identification and ecotoxicological evaluation

In this study, the photocatalytic degradation of a mixture of three pharmaceuticals, Metronidazole (MET), Atenolol (ATL) and Chlorpromazine (CPR), was quantified simultaneously during the UV/TiO2 process. The investigated TiO2 was Millennium PC-500 immobilized on ceramic plates by sol-gel based method. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. The central composite design was applied to model and optimize the UV/TiO2 process. Predicted values of removal efficiency were found to be in good agreement with experimental values for MET, ATL and CPR (R(2)=0.947 and Adj-R(2)=0.906, R(2)=0.977 and Adj-R(2)=0.960 and R(2)=0.982 and Adj-R(2)=0.969, respectively). The optimum initial concentration of pharmaceuticals, reaction time and UV light intensity was found to be 10 mg L(-1), 150 min and 38.45 W m(-2), respectively. The main degradation intermediates of pharmaceuticals produced in this process were identified by GC-MS technique. The chronic ecotoxicity of pharmaceuticals was evaluated using aquatic species Spirodela polyrrhiza prior to and after photocatalysis. The TOC results (90% removal after 16 h) and ecotoxicological experiments revealed that the photocatalysis process could effectively mineralize and reduce the ecotoxicity of the pharmaceuticals from their aqueous solutions.

Spectrometric determination of total antioxidant activity in chlorpromazine radical cation - ascorbic acid system

Through univalent oxidation chlorpromazine forms a colored and relatively stable radical cation with maximum absorbance at 525 nm, considered a redox mediator in a number of b iochemical reactions.

AIM

To develop a spectrometric method for the determination of total antioxidant activity based on the reaction of chlorpromazine radical capture by ascorbic acid (standard antioxidant).

MATERIAL AND METHODS

The calibration curve was drawn by monitoring the decrease in the absorbance of the preformed radical solution (obtained by oxidation of chlorpromazine by potassium persulfate in an acidic environment) depending on ascorbic acid concentration.

RESULTS

The method was validated. In the ascorbic acid concentration range 10-100 microM/L linearity was good (r2 = 0.9991). Limit of detection (LOD) was 3.13 microM/L and limit of quantification (LOQ) was 9.49 microM/L. System precision (RSD = 0.75%), method precision (RSD = 4.50%) and intermediate precision (RSD = 4.63%) were determined. The average recovery of 101.7% for the concentration range 91.1 -105.9% confirmed the accuracy of the method.

CONCLUSIONS

The method has a good linearity, precision, accuracy, and is easy to use for evaluation of antioxidant action of different products. Total antioxidant activity is expressed as ascorbic acid molar equivalents (AAE). The method has the advantage of using a radical involved in redox processes in the body.

[Phenothiazines are slowly oxidizable substrates of horseradish peroxidase]

Reactions of peroxidase oxidation of triftazine and thioproperazine have been investigated in the presence of horseradish peroxidase using steady state kinetic methods. It has been shown that phenothiazines are slowly oxidizable substrates for horseradish peroxidase. k(cat) and K(m) values have been determined in the range of pH from 4.5 to 7.5. The study of co-oxidation of phenothiazines and o-dianisidine (ODN) revealed that in the presence of aminazine and ODN in the reaction medium both substances follow sequential oxidation. ODN oxidation was not observed until full conversion of aminazine. At pH 4.5-5.5 thioproperazine bound to the enzyme-substrate complex and caused a nticompetitive inhibition of peroxidase. At pH>5.5 sequential substrate oxidation with preferential thioproperazine conversion occurred. In the range of pH from 4.5 to 7.5 triftazine did not influence ODN oxidation.

Study on the resonance nonlinear scattering spectra of the interactions of promethazine hydrochloride and chlorpromazine hydrochloride with 12-tungstophosphoric acid and their analytical applications

In pH 1.0 HCl medium, 12-tungstophosphoric acid (TP) reacted with promethazine hydrochloride (PMZ) and chlorpromazine hydrochloride (CPZ) to form ion-association complexes, which led to a great enhancement of the resonance nonlinear scattering such as second-order scattering (SOS) and frequency doubling scattering (FDS). Their maximum SOS and FDS peaks were located at 585 nm (TP-PMZ), 584 nm (TP-CPZ) and 388 nm (TP-PMZ), 329 nm (TP-CPZ), respectively. These results provided some indication for the determination of PMZ and CPZ by SOS and FDS methods. The linear range of TP-PMZ and TP-CPZ systems were 0.0069-2.5 microg mL(-1), 0.102-5.0 microg mL(-1) (SOS) and 0.079-6.0 microg mL(-1), 0.0133-5.0 microg mL(-1) (FDS), respectively. The detection limits (3sigma) of PMZ and CPZ were 2.08 ng mL(-1), 3.07 ng mL(-1) (SOS) and 2.22 ng mL(-1), 3.98 ng mL(-1) (FDS), respectively. In this work, the optimum reaction conditions, the influences of coexisting substances and ionic strength and analytical application have been investigated. The methods have been successfully applied to the determination of PMZ and CPZ in tablets. In addition, the composition of ion-association complexes and the reaction mechanism are also discussed.

[Functional characteristics of calcium-sensitive adenylyl cyclase of ciliate Tetrahymena pyriformis]

Calcium-sensitive forms of adenylyl cyclase (AC) were revealed in most vertebrates and invertebrates and also in some unicellular organisms, in particular ciliates. We have shown for the first time that calcium cations influence the AC activity of ciliate Tetrahymena pyriformis. These cations at the concentrations of 0.2-20 microM stimulated the enzyme activity, and maximum of catalytic effect was observed at 2 microM Ca2+. Calcium cations at a concentrations of 100 microM or higher inhibited the AC activity. Calmodulin antagonists W-5 and W-7 at the concentrations of 20-100 microM inhibited the catalytic effect induced by 5 microM Ca2+ and blocked the effect at higher concentrations of Ca2+. Chloropromazine, another calmodulin antagonist, reduced Ca2+-stimulated AC activity only at the concentrations of 200-1000 microM. AC stimulating effects of serotonin, EGF and cAMP increased in the presence of 5 microM Ca2+. AC stimulating effects of EGF, cAMP and insulin decreased in the presence of 100 microM Ca2+, and AC stimulating effect of cAMP decreased also in the presence of calmodulin antagonists (1 mM). At the same time, stimulating effect of D-glucose in the presence of Ca2+ and calmodulin antagonists did not change essentially. The data obtained speak in favor of the presence of calcium-sensitive forms of AC in ciliate T. pyriformis which mediate enzyme stimulation by EGF, cAMP, insulin, and serotonin.

[Effect of chlorpromazine combined with Platycodon grandiflorum on change of dopamine in rat striatum by microdialysis]

OBJECTIVE

To study the effects of chlorpromazine combined with Platycodon grandiflorum on the striatal extracellular dopamine level in rats and to research the interaction and the mechanism of action after combining traditional Chinese medicine with western medicine.

METHOD

Twenty four rats were randomly assigned into four groups: the control group, Platycodon group, chlorpromazine group and chlorpromazined combined with P. grandiflorum group. The level of dopamine in CSF microdialysis samples was detected with high performance liquid chromatography with electrochemical detector after administration for 10 days.

RESULT

The CSF level of DA (1.52 +/- 0.34) microg x L(-1) was significantly higher (P < 0.01) in chlorpromazine combined with P. grandiflorum group than that in the chlorpromazine group (1.25 +/- 0.22) microg x L(-1) (P < 0.05) and that in the normal control (1.06 +/- 0.24) microg x L(-1) (P < 0.01).

CONCLUSION

The combining utilization of P. grandiflorum and chlorpromazine may increase the DA concentration of monoamine neurotransmitters, which results in under the therapeutic effect is maintained, the dosage of chlorpromazine used to individuals are decreased and the incidence rate of the adverse reactions of chlorpromazine will descend.

Kinetics membrane disruption due to drug interactions of chlorpromazine hydrochloride

Drug-membrane interactions assume considerable importance in pharmacokinetics and drug metabolism. Here, we present the interaction of chlorpromazine hydrochloride (CPZ) with supported phospholipid bilayers. It was demonstrated that CPZ binds rapidly to phospholipid bilayers, disturbing the molecular ordering of the phospholipids. These interactions were observed to follow first order kinetics, with an activation energy of approximately 420 kJ mol(-1). Time-dependent membrane disruption was also observed for the interaction with CPZ, such that holes appeared in the phospholipid bilayer after the interaction of CPZ. For this process of membrane disruption, "lag-burst" kinetics was demonstrated.

Calmodulin inhibitory activity of the malbrancheamides and various analogs

The preparation and biological activity of various structural analogs of the malbrancheamides are disclosed. The impact of indole chlorination, C-12a relative stereochemistry, and bicyclo[2.2.2]diazaoctane core oxidation state on the ability of these analogs to inhibit calmodulin dependent phosphodiesterase (PDE1) was studied, and a number of potent compounds were identified.

Optimized synthesis of the melatonin metabolite N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK)

N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) is the product of oxidative pyrrole ring cleavage of melatonin. AFMK and its deformylated derivative N(1)-acetyl-5-methoxykynuramine (AMK) are compounds for which there are increasing demands because of their antioxidant, immunomodulatory and anti-inflammatory properties. Here, we sought to determine the best reaction conditions for preparation of AFMK using chlorpromazine (CPZ) as a co-catalyst in the peroxidase-mediated oxidation of melatonin. The parameters studied were pH, identity and concentration of buffers, hydrogen peroxide (H(2)O(2)) and CPZ concentrations and the presence or absence of dissolved molecular oxygen in the reaction medium. The rate and efficiency of AFMK production were compared with a noncatalyzed method which uses a high concentration of H(2)O(2). We found that by using CPZ and bubbling molecular oxygen during the course of the reaction, the yield of AFMK was significantly increased (about 60%) and the reaction time decreased (about 30 min), as compared with the noncatalyzed reaction (yield 32% and reaction time 4 hr). Based on these data, we suggest that this could be a new, easily performed and efficient route for AFMK preparation. Additionally, we provide evidence that a radical chain reaction could be responsible for the formation of AFMK.

From dioxin to drug lead--the development of 2,3,7,8-tetrachlorophenothiazine

Polychlorinated dibenzo-p-dioxins are persistent environmental pollutants. The most potent congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes a wasting syndrome and is a potent carcinogen and immunosuppressant in the rat at high doses. However, low doses cause opposite effects to some of those observed at higher doses, resulting in chemoprevention, stimulation of the immune system, and longevity in experimental animals. The new TCDD analogue, 2,3,7,8-tetrachlorophenothiazine (TCPT), was developed to take advantage of the low-dose effects of dioxins that have potential application as therapeutics. Its development marked a deviation from the traditional scope of phenothiazine drug design by deriving biological effects from aryl substituents. TCPT was synthesized in three steps. The key ring-closing step was performed utilizing a Buchwald-Hartwig amination to provide TCPT in 37% yield. Its potency to induce CYP1A1 activity over 24 h was 370 times lower than that of TCDD in vitro. The elimination half-life of the parent compound in serum was 5.4 h in the rat and 2.7 h in the guinea pig, compared to 11 and 30 days, respectively, for TCDD. These initial findings clearly differentiate TCPT from TCDD and provide the basis for further studies of its potential as a drug lead.

Interaction of chlorpromazine, fluphenazine and trifluoperazine with ocular and synthetic melanin in vitro

The aim of this study was to examine in vitro the binding capacity of three phenothiazine derivatives--chlorpromazine, fluphenazine and trifluoperazine--causing adverse effects in the eye structures, to natural melanin isolated from pig eyes as well as to synthetic DOPA-melanin used as a model polymer. The amount of drug bound to melanin was determined by UV spectrophotometry. The analysis of results for the kinetics of drug-melanin complex formation showed that the amount of drug bound to melanin increases with increasing initial drug concentration and longer incubation time, attaining an equilibrium state after about 24 h. Binding parameters, i.e. the number of binding sites (n) and association constants (K), were determined on the basis of Scatchard plots. For neuroleptic-ocular melanin and neuroleptic-DOPA-melanin complexes two classes of independent binding sites were found, with association constants K1 approximately 10(4) and K2 approximately 10(2) M (-1) for chlorpromazine and fluphenazine complexes, and K1 approximately 10(5) and K2 approximately 10(3) M(-1) for trifluoperazine complexes. The numbers of strong (n1) and weak (n2) binding sites indicate lower affinity of the drugs examined to ocular melanin compared with DOPA-melanin. The ability of chlorpromazine, fluphenazine and trifluoperazine to interact with melanin, especially the ocular melanin, in vitro is discussed in relation to the ocular toxicity of these drugs in vivo.

Photodegradation and phototoxicity of thioridazine and chlorpromazine evaluated with chemical analysis and aquatic organisms

The photochemical behaviour of chlorpromazine (CPZ) and thioridazine (THR) incubated under VIS light and a UV-A lamp was investigated with a high-performance liquid chromatography photodiode array detector (HPLC-PAD) and two bioassays. VIS light caused the decrease of CPZ and THR to 25% and 34% of the initial level, respectively, while UV-A degraded the drugs almost totally. CPZ and THR were very toxic to the protozoan Spirostomum ambiguum (Spirotox) and anostracan crustacean Thamnocephalus platyurus (Thamnotoxkit F) with 24-h LC50 values of around 0.5 mg l(-1). In spite of the drastic decrease of the concentration of the drugs, the irradiated samples were toxic to the protozoan, especially when a sublethal end-point was taken into consideration. Contrary to the protozoan the crustacean was not sensitive to the products of photodegradation. Mass spectrometry analysis showed the presence of dimers and trimers of the CPZ and mono-, di-, and tri-oxygenated derivatives of THR. The presented data give a strong indication of the importance of the investigation of the environmental fate of drugs, especially those known to be phototoxic.

Simultaneous measurements of K+ and calcein release from liposomes and the determination of pore size formed in a membrane

The changes induced by biologically active substances in the permeability to K+ and calcein of liposomes composed of egg phosphatidylcholine and cholesterol were measured simultaneously in order to rapidly screen the sizes of pores formed in a membrane, using different sized markers. The substances examined in the present study were classified into three types based on differences in the rates at which K+ and calcein were released. The first type released only K+, and included gramicidin A. The second type predominantly released K+, preceding the release of calcein, and included amphotericin B and nystatin. The third type, including antimicrobial peptides, such as gramicidin S, alamethicin, and melittin, and several membrane-active drugs, like celecoxib (non-steroidal anti-inflammatory drug), 1-dodecylazacycloheptan-2-one (named azone; skin permeation enhancer), and chlorpromazine (tranquilizer), caused the release of K+ and calcein simultaneously. Thus, the sizes of pores formed in a liposomal membrane increased in the following order: types one, two, and three. We determined the size more precisely by conducting an osmotic protection experiment, measuring the release of calcein in the presence of osmotic protectants of different sizes. The radii of pores formed by the second type, amphotericin B and nystatin, were 0.36 - 0.46 nm, while the radii of pores formed by the third type were much larger, 0.63 - 0.67 nm or more. The permeability changes induced by substances of the third type are discussed in connection with a transient pore formed in a lipid packing mismatch taking place during the phase transition of dipalmitoylphosphatidylcholine liposomes.

The Singlet Oxygen Oxidation of Chlorpromazine and Some Phenothiazine Derivatives. Products and Reaction Mechanisms

A kinetic and product study of the reactions of chlorpromazine 1, N-methylphenothiazine 2, and N-ethylphenothiazine 3 with singlet oxygen was carried out in MeOH and MeCN. 1 undergoes exclusive side-chain cleavage, whereas the reactions of 2 and 3, in MeOH, afforded only the corresponding sulfoxides. A mechanism for the reaction of 1 is proposed where the first step involves an interaction between singlet oxygen and the side-chain dimethylamino nitrogen. This explains why no side-chain cleavage is observed for 2 and 3.

The drug binding site of human α1-acid glycoprotein: Insight from induced circular dichroism and electronic absorption spectra

Human alpha(1)-acid glycoprotein (AGP) is an important drug binding plasma protein which affects pharmacokinetical properties of various therapeutic agents. For the first time, interpretation of the induced circular dichroism (ICD) spectra of drug-AGP complexes is presented yielding valuable information on the protein binding environment. ICD spectra were obtained by novel ligands of which AGP induced optical activity have never been reported (primaquine, mefloquine, propranolol, terazosin, carbamazepine, rhodamine B) and by re-investigation of ICD spectra of protein-bound drugs published earlier (chlorpromazine, dipyridamole, prazosin). Spectroscopic features of the ICD and absorption bands of drugs combined with native AGP indicated chiral non-degenerate exciton coupling between the guest chromophore and the indole ring of an adjacent tryptophan (Trp) residue. Results of additional CD experiments performed by using recombinant AGP mutants showed no changes in the ligand binding ability of W122A in sharp contrast with the W25A which was unable to induce extrinsic CD signal with either ligand. Thus, these findings unequivocally prove that, likely via pi-pi stacking mechanism, Trp25 is essentially involved in the AGP binding of drugs studied here as well as of related compounds. Survey of the AGP binding data published in the literature support this conclusion. Our results provide a fast and efficient spectroscopic tool to determine the inclusion of ligand molecules into the beta-barrel cavity of AGP where the conserved Trp25 is located and might be useful in ligand-binding studies of other lipocalin proteins.

A versatile method for determining the molar ligand-membrane partition coefficient

A novel method for the quantitative assessment of the membrane partitioning of a ligand from the aqueous phase is described, demonstrated here with the thoroughly studied antipsychotic chlorpromazine (CPZ). More specifically, collisional quenching of the fluorescence of a pyrene labeled fluorescent lipid analog 1-palmitoyl-2[10-(pyren-1-yl)]decanoyl-sn-glycero-3-phosphocholine (PPDPC) by CPZ was utilized, using 1-palmitoyl-2-oleyl-sn-glycero-3-phosphocholine and -serine (POPC and POPS) liposomes as model membranes. The molar partition coefficient is obtained from two series of titrations, one with constant [phospholipid] and increasing [drug] and the other with constant [drug] and varying total [phospholipid], the latter further comprising of large unilamellar vesicles (LUVs) of POPC/POPS/PPDPC at a constant concentration of 10 microM and indicated concentrations of POPC/POPS LUVs. Notably, the approach described is generic and can be employed in screening for the membrane partitioning of compounds, providing that a suitable fluorescence parameter can be incorporated into one population of liposomes utilized as model membranes.

Interactions of chlorpromazine with phospholipid monolayers: effects of the ionization state of the drug

Molecular dynamics simulations have been performed to investigate the interactions between chlorpromazine (CPZ) and Langmuir monolayers of the zwitterionic dipalmitoylphosphatidylcholine (DPPC) and the anionic dipalmitoylphosphatidylglycerol (DPPG). Simulations for a fixed surface density and different charge states - neutral and protonated CPZ - were able to capture important features of the CPZ-phospholipid monolayer interaction. Neutral CPZ is predominantly found in the hydrophobic tail region, whereas protonated CPZ is located at the lipid-water interface. Specific interactions (hydrogen bonds) between protonated CPZ and the lipid head groups were found for both zwitterionic and anionic monolayers. We computed lipid tail order parameters and investigated the effects of the drug upon tail ordering. We also computed electrostatic surface potentials and found qualitative good agreement with experimental results.

Effect of electrolytes on the cloud point of chlorpromazine hydrochloride solutions

Cloud point (CP) phenomenon occurring in amphiphilic drug chlorpromazine hydrochloride (CPZ) solutions with and without salts is reported herein. The CP of a 50mM CPZ solution (prepared in 10mM sodium phosphate, SP, buffer) was found to decrease with increasing pH, both in the absence as well as presence (50mM) of added salts (NaCl, NaBr, LiBr, KBr, tetra-n-butylammonium bromide). Whereas, at a fixed concentration of NaCl, the CP increased with increasing CPZ concentration, addition of increasing amounts of salts (NaF, NaCl, NaBr, LiCl, KCl) to 50 mM CPZ solution (at pH 6.7) caused continuous increase in CP. On the basis of these studies the binding-effect orders of counterions and co-ions have been deduced, respectively, as: Br(-) > Cl(-) > F(-) and Li+ >Na+ >K+. The similar trend of increasing CP with addition of increasing amounts of quaternary bromides (tetramethylammonium bromide, TMeAB; tetraethylammonium bromide, TEtAB; tetra-n-propylammonium bromide, TPrAB; tetra-n-butylammonium bromide, TBuAB; tetra-n-pentylammonium bromide, TPeAB) to 50 mM CPZ solutions (at pH 6.7) was found to be dependent upon the alkyl chain length of the particular salt. The overall behaviour has been discussed in terms of electrostatic interactions, micellar growth, and mixed micelle formation.

Thermodynamic and Infrared Analyses of the Interaction of Chlorpromazine with Phospholipid Monolayers

An investigation has been made of the interaction between chlorpromazine (CPZ) and monolayers of 1,2-dipalmitoyl-sn-3-glycerophosphatidylcholine (DPPC) and 1,2-dipalmitoyl-sn-3-glycero[phospho-rac-(1-glycerol)] (DPPG), both at the air/water interface and in transferred Langmuir-Blodgett films. The Gibbs free energy, DeltaG, and the compressibility modulus (C(S)(-1)), obtained from the surface pressure isotherms, indicated changes in the in-plane interactions of CPZ/DPPG mixed monolayers, with positive values of DeltaG. The arrangement of CPZ in the zwitterionic DPPC monolayers causes a weaker interaction in CPZ/DPPC mixed monolayers, with the DeltaG fluctuating around zero. IR measurements in transferred monolayers showed that CPZ did not affect the conformational order of the acyl chains, its effects being limited to the bands corresponding to the headgroups. Furthermore, since no shift was observed for the acyl chain bands, the phase transition induced by CPZ is not a liquid expanded (LE) to liquid condensed (LC) transition, as the latter is associated with chain ordering. Taken together, the IR and compressibility results demonstrate that the effect from CPZ cannot be correlated with temperature changes in the subphase for pure monolayers, in contrast to models proposed by other authors.

Bacterial efflux systems and efflux pumps inhibitors

It is now well established that bacterial resistance to antibiotics has become a serious problem of public health that concerns almost all antibacterial agents and that manifests in all fields of their application. Among the three main mechanisms involved in bacterial resistance (target modification, antibiotic inactivation or default of its accumulation within the cell), efflux pumps, responsible for the extrusion of the antibiotic outside the cell, have recently received a particular attention. Actually, these systems, classified into five families, can confer resistance to a specific class of antibiotics or to a large number of drugs, thus conferring a multi-drug resistance (MDR) phenotype to bacteria. To face this issue, it is urgent to find new molecules active against resistant bacteria. Among the strategies employed, the search for inhibitors of resistance mechanisms seems to be attractive because such molecules could restore antibiotic activity. In the case of efflux systems, efflux pump inhibitors (EPIs) are expected to block the pumps and such EPIs, if active against MDR pumps, would be of great interest. This review will focus on the families of bacterial efflux systems conferring drug resistance, and on the EPIs that have been identified to restore antibiotic activity.

Investigation of the electrochemical oxidation products of zotepine and their fragmentation using on-line electrochemistry/electrospray ionization mass spectrometry

When zotepine, an antipsychotic drug, was electrochemically oxidized using electrospray ionization mass spectrometry (ESI-MS) coupled with a microflow electrolytic cell, [M + 16 + H]+ (m/z 348), [M-H]+ (m/z 330) and [M-14 + H]+ (m/z 318) were observed as electrochemical oxidation product ions (M represents the zotepine molecule). Although a major fragment ion that was derived from the dimethyl aminoethyl moiety was observed only at m/z 72 in the collision-induced dissociation (CID) spectrum of zotepine, new fragments such as m/z 315 and 286 ions could be generated in the CID spectrum by combining electrochemical oxidation and CID. Since these fragments were relatively specific with high ion strength, it was thought that they would be useful for developing a sensitive LC-MS/MS assay. The S-oxide and N-demethylated products were detected by electrolysis assuring that a portion of P450 metabolites of zotepine could be mimicked by the electrochemistry/electrospray ionization mass spectrometry (EC/ESI-MS) system.

Molecular Dynamics Simulations of Neutral Chlorpromazine in Zwitterionic Phospholipid Monolayers

Molecular dynamics simulations have been performed to investigate the interactions between chlorpromazine (CPZ), a neuroleptic drug used in the treatment of psychiatric disorders, and dipalmitoylphosphatidylcholine (DPPC), a zwitterionic phospholipid, in Langmuir monolayers. The results from simulations carried out at different monolayer surface densities were able to capture important features of the CPZ-lipid interaction. We find that neutral (unprotonated) CPZ is preferentially located in the lipid tail region of the phospholipids, in little contact with the aqueous phase, and that the orientation of its rigid ring structure and tail conformation vary with lipid surface density. CPZ is found to promote ordering of the lipid tails for all surface densities because of a reduction in the effective surface area per lipid upon addition of the drug. Similar effects have been observed in previous studies of cholesterol in DPPC monolayers, in which lipid tails were seen to order around the solute. This feature, however, is quite distinct from what we observe for the most dense monolayer considered here (area per lipid of 50 A(2)), for which we find that CPZ promotes a local distortion of the lipid tails in its immediate vicinity and a concomitant ordering of lipid tails located further away from the solute. This view is further supported by the results obtained for an approximated nonlinear vibrational sum frequency generation susceptibility, which showed greater tail disorder close to CPZ.

Existence of lipid microdomains in bilayer of dipalmitoyl phosphatidylcholine (DPPC) and 1-stearoyl-2-docosahexenoyl phosphatidylserine (SDPS) and their perturbation by chlorpromazine : A 13C and 31P solid-state NMR study

The polyunsaturated fatty acid docosahexaenoic acid (DHA, 22:6, n-3) is found at a level of about 50% in the phospholipids of neuronal tissue membranes and appears to be crucial to human health. Dipalmitoyl phosphatidylcholine (DPPC, 16:0/16:0 PC) and the DHA containing 1-stearoyl-2-docosahexenoyl phosphatidylserine (SDPS) were used to make DPPC (60%)/SDPS (40%) bilayers with and without 10 mol% chlorpromazine (CPZ), a cationic, amphiphilic phenothiazine. Resonances that are present in 13C NMR spectrum of the DPPC (60%)/SDPS (40%) sample and that disappear in presence of 10% CPZ most probably are due to the special interface environment, e.g. the hydrophobic mismatch, at the interface of DPPC and SDPS microdomains in the DPPC/SDPS bilayer. In itself the appearance of resonances at novel chemical shift values is a clear demonstration of a unique chemical environment in the DPPC (60%)/SDPS (40%) bilayer. The findings of the study presented here suggest CPZ bound to the phosphate of SDPS will slow down and partially inhibit such a DHA acyl chain movement in the DPPC/SDPS bilayer. This would affect the area occupied by a SDPS molecule (in the bilayer) and probably the thickness of the bilayer where SDPS molecules reside as well. It is quite likely that such CPZ caused changes can affect the function of proteins embedded in the bilayer.

Chronic inhibition of cardiac Kir2.1 and HERG potassium channels by celastrol with dual effects on both ion conductivity and protein trafficking

A high percentage of drugs and drug candidates has been found to cause cardiotoxicity by reducing potassium conductance, more commonly known as QT prolongation. However, some compounds do not show direct block of ionic flow, suggesting that other mechanisms may also lead to reduction of potassium currents. Using the functional recovery after chemobleaching (FRAC) assay, we have examined a collection of drugs and drug-like compounds for potential perturbation of cardiac potassium channel trafficking. Here we report that a significant number of inhibitory compounds displayed effects on channel expression on the cell surface. Further investigation of celastrol (3-hydroxy-24-nor-2-oxo-1 (10),3,5,7-friedelatetraen-29-oic acid), a cell-permeable dienonephenolic triterpene compound, revealed its potent inhibitory activity on both Kir2.1 and hERG potassium channels, causal to QT prolongation. In addition to acute block of ion conduction, celastrol also alters the rate of ion channel transport and causes a reduction of channel density on the cell surface. In contrast, celastrol has no effects on trafficking of either CD4 or CD8 membrane proteins. Furthermore, the potency for reducing surface expression is approximately 5-10-fold more effective than that for either direct acute inhibition or reported cytoprotectivity via activation of the heat shock transcription factor 1. Because the reduction of potassium channel activity is a common form of druginduced cardiotoxicity, the potent inhibition of cell surface expression by celastrol underscores a need to evaluate drug candidates for their chronic effects on biogenesis of potassium channels. Our results suggest that chronic exposure to certain drugs may be an important aspect of acquired QT prolongation.

Chiral Ionic Liquid that Functions as Both Solvent and Chiral Selector for the Determination of Enantiomeric Compositions of Pharmaceutical Products

We have successfully synthesized both enantiomers of a novel chiral ionic liquid, (R)- and (S)-[(3-chloro-2-hydroxypropyl) trimethylammonium][bis((trifluoromethyl)sulfonyl)amide] ((R)- and (S)-[CHTA]+[Tf2N]-) in optically pure form by a simple ion exchange reaction from corresponding chloride salts that are commercially available. In addition to the ease of preparation, this chiral IL has relatively high thermal stability (up to 300 degrees C), is liquid at room temperature (glass transition temperature of -58.4 degrees C), and exhibits strong enantiomeric recognition. The high solubility power and strong enantiomeric recognition ability make it possible to use this chiral IL to solubilize an analyte and to induce diastereomeric interactions for the determination of enantiomeric purity. In fact, we have successfully developed a novel method based on the near-infrared technique with this chiral IL serving both as solvent and as a chiral selector for the determination of enantiomeric purity. Enantiomeric compositions of a variety of pharmaceutical products and amino acids with different shape, size, and functional groups can be sensitively (milligram concentration) and accurately (enantiomeric excess as low as 0.6%) determined by use of this method.

Effects of Inorganic Ions on the Binding of Triflupromazine and Chlorpromazine to Bovine Serum Albumin Studied by Spectrometric Methods

The effects of inorganic salts, NaCl, NaBr, NaI, Na2SO4, KCl, KBr, KI, on the binding constants (Ks) of psychotropic phenothiazine drugs, triflupromazine (TFZ) and chlorpromazine, to bovine serum albumin (BSA) were examined by using second-derivative spectrophotometry. All of the salts examined, with the exception of Na2SO4, decreased the K values significantly, depending on the concentration of the salt, e.g., the decrease in the K values of both drugs were about 40% for 0.1 M NaCl. The results obtained with Na2SO4 indicated that neither Na+ nor SO4(2-) had any affect on the binding of the phenothiazines to BSA. Based on the Na2SO4 results and the finding that the effect of each potassium salt on binding was quite similar to that of the corresponding sodium salt, the effects of these halogen salts can be considered to be derived from their anions, although the phenothiazines are positively charged at pH 7.4. The effectiveness of the anions was determined to occur in the following order: I->>Br->Cl-; these results coincided with the published order of the binding affinity of these anions to albumin. The 19F-NMR spectra of TFZ in the presence of each of these halogen salts revealed a concentration-dependent decrease in the intensity of the signal at 13.8 ppm that had previously been assigned to the TFZ bound to Site II. Consequently, the effects of these anions on the binding of positively charged phenothiazine drugs are thought to be local steric effects caused by the binding of these anions to Site II.

Importance of polyunsaturated acyl chains in chlorpromazine interaction with phosphatidylserines: a 13C and 31P solid-state NMR study

The polyunsaturated fatty acid docosahexaenoic acid (DHA, c22:6, n-3) is found at a level of about 50% in the phospholipids of neuronal tissue membranes and appears to be crucial to human health. Dipalmitoyl phosphatidylcholine (DPPC, 16:0/16:0 PC), 1-palmitoyl-2-oleoyl phosphatidylserine (POPS) and the DHA containing 1-stearaoyl-2-docosahexenoyl phosphatidylserine (SDPS) were used to make DPPC (60%)/POPS (29%)/SDPS (11%) bilayers with and without 10 mol% chlorpromazine (CPZ), a cationic, amphiphilic phenothiazine. The T1 relaxation measurements make it clear that the saturated acyl chains carbons (palmitic, stearic and most of the oleic chain) and the choline head group are not affected by CPZ addition. The observed increased signal intensity and T1-values of DHA indicate reduced mobility of C4 and C5 due to CPZ binding. 31P NMR spectra confirm that CPZ binding to the phosphatidylserines in the bilayer enhances phospholipid head group mobility.

Antitrypanosomal, Antileishmanial, and Antimalarial Activities of Quaternary Arylalkylammonium 2-Amino-4-Chlorophenyl Phenyl Sulfides, a New Class of Trypanothione Reductase Inhibitor, and of N-Acyl Derivatives of 2-Amino-4-Chlorophenyl Phenyl Sulfide

Quaternization of the nitrogen atom of 2-amino-4-chlorophenyl phenyl sulfide analogues of chlorpromazine improved inhibition approximately 40-fold (3',4'-dichlorobenzyl-[5-chloro-2-phenylsulfanyl-phenylamino)-propyl]-dimethylammonium chloride inhibited trypanothione reductase from Trypanosoma cruzi with a linear competitive Ki value of 1.7 +/- 0.2 microM). Molecular modelling explained docking orientations and energies by: (i) involvement of the Z-site hydrophobic pocket (roughly bounded by F396', P398', and L399'), (ii) ionic interactions for the cationic nitrogen with Glu-466' or -467'. A series of N-acyl-2-amino-4-chlorophenyl sulfides showed mixed inhibition (Ki, Ki' = 11.3-42.8 microM). The quaternized analogues of the 2-chlorophenyl phenyl sulfides had strong antitrypanosomal and antileishmanial activity in vitro against T. brucei rhodesiense STIB900, T. cruzi Tulahuan, and Leishmania donovani HU3. The N-acyl-2-amino-4-chlorophenyl sulfides were active against Plasmodium falciparum. The phenothiazine and diaryl sulfide quaternary compounds were also powerful antimalarials, providing a new structural framework for antimalarial design.

Binding of chemicals to melanins re-examined: adsorption of some drugs to the surface of melanin particles

This work presents a first attempt to study the interaction of some drugs with melanins, realistically considered as solid aggregates of primary particles. This situation appears similar to the adsorption of organic molecules onto the surface of colloidal absorbers, as active carbon, zeolites or titanium dioxide. We have applied some of the most popular theoretical models used in technological applications with the aim to give a more realistic picture of the melanin-drug interaction responsible for some observed side effects in vivo. Moreover, this approach can simplify the problem of the search of the physical parameters dominating the binding processes, by reducing the phenomenon to a simple physisorption/chemisorption, at least in a first approximation. We have studied the binding to melanin of gentamicin, methotrexate and chlorpromazine, molecules with different physico-chemical and structural characteristics. Our study demonstrates the possibility to fit experimental adsorption data with Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich equations. In such a way we obtain binding parameters useful to characterize the drug-surface interaction in terms of energy and of mean affinity.

Effects of chlorpromazine with and without UV irradiation on gene expression of HepG2 cells

Damage to DNA can trigger a variety of stress-related signals that alter the expression of genes associated with numerous biological pathways. In this study, we have used a cDNA microarray representing 1089 genes related to DNA damage and repair, cell cycle, transcription, metabolism and other toxicologically important cell functions to identify genes regulated in response to DNA damage in HepG2 cells induced by UV-activated chlorpromazine (CPZ). CPZ itself is not genotoxic but, upon UV irradiation with a non-genotoxic dose in the UVA range, it produces reactive free radical intermediates with DNA damaging properties. Genotoxicity in HepG2 cells was assessed concomitantly to gene expression profiling using the Comet assay. Kinetic studies were performed at a non-cytotoxic but clearly photogenotoxic concentration of CPZ (1.25 microg/ml) to characterize gene expression profiles at four different time points (3, 7, 15, 23 h) post short-term treatment. The results obtained from repeated experiments display a time-dependent expression pattern of up-regulated and repressed genes with distinct peaks in the number of differentially expressed genes at the 7 and 23 h time points. Most of the genes with altered expression belonged to the functional categories of cell cycle regulation and cell proliferation. A comparison with published expression profiles established in response to other genotoxic compounds showed low levels of concordance, which is most likely caused by the fact that extremely different testing conditions were used.

Effects of phosphatidylserine and phosphatidylethanolamine content on partitioning of triflupromazine and chlorpromazine between phosphatidylcholine-aminophospholipid bilayer vesicles and water studied by second-derivative spectrophotometry

To assess the affinity of psychotropic phenothiazine drugs, triflupromazine (TFZ) and chlorpromazine (CPZ), for the membranes of central nervous system and the other organs in the body, the partition coefficients (Kps) of these drugs to phosphatidylcholine (PC)-phosphatidylserine (PS) and PC-phosphatidylethanolamine (PE) small and large unilamellar vesicles (SUV, LUV) were examined by a second-derivative spectrophotometric method, since PS is abundantly contained in the membranes of the central nervous system and PE is distributed widely in the membranes of the organs in the body. Size and preparation methods of the vesicles did not affect the Kp values at each aminophospholipid content suggesting that the partition of the phenothiazine drugs was not affected by the structural differences in the vesicles such as their curvature or asymmetric distribution of the phospholipids between the outer and inner layers of the bilayer membranes. However, the Kp values of both drugs increased remarkably according to the PS content in the bilayer membranes, i.e., the Kp values for the vesicles of 30 mol% PS content were about 3 times of that for the vesicles of PC alone, while both Kp values slightly reduced with the increase in the content of PE in the bilayer membranes of PC-PE vesicles. The results indicate that both drugs have higher affinity for the PC-PS bilayer membranes than for the PC and PC-PE membranes, which can offer an evidence for the fact that TFZ and CPZ are predominantly distributed and accumulated in the brain and nerve cell membranes that contain PS abundantly.

Ion-pair complex-based solvent extraction combined with chemiluminescence determination of chlorpromazine hydrochloride with luminol in reverse micelles

A new chemiluminescence (CL) method is proposed for the determination of chlorpromazine hydrochloride, which is based on the dichloromethane solvent extraction of ion-pair complex of tetrachloroaurate(III) with chlorpromazine hydrochloride and luminol chemiluminescence detection in a reversed micellar medium formed by the cation surfactant cetyltrimethylammonium bromide in a dichloromethane-cyclohexane (1:1 V/V)-water (0.3 mol/L Na2CO3 buffer solution with the pH of 11.5). The ion-pair complex of tetrachloroaurate(III) with chlorpromazine hydrochloride produced an analytical chemiluminescence signal when it entered the reversed micellar water pool. In the optimum conditions, CL intensities are proportional to concentrations of the studied drug over the range 0.05 approximately 10 microg/mL with a detection limit (DL) of 6 ng/mL. The relative standard deviation (R.S.D.) is 2.6% for 1.25 microg/mL chlorpromazine hydrochloride (n = 11). R.S.D. (precision) of inter-day and intra-day is less than 6%, and accuracy of inter-day and intra-day is satisfactory. The method has been applied to the determination of studied drug in pharmaceutical preparations and biological fluids with satisfactory results.

Spectroelectrochemical determination of chlorpromazine hydrochloride by flow-injection analysis

An original, simple and sensitive flow-injection spectroelectroanalytical method for the determination of chlorpromazine in pure form or in pharmaceutical formulations is described. The method is based on the formation of a stable cationic radical by electro-oxidation in sulfuric acid medium (0.1 mol l(-1)), monitored in situ at lambda=524 nm. The determination of chlorpromazine hydrochloride in pure form or in pharmaceutical formulations was explored, considering the amperometric and the absorptiometric signal. The association of these two signals enhanced the selectivity of the analysis and proved decisive when other electroactive compounds or excipients like ascorbic acid were present in the formulation. The analytical parameters have been evaluated and the results obtained using standard additions are in agreement with the reference methods.

Compatibility of nitroglycerin, diazepam and chlorpromazine with a new multilayer material for infusion containers

The stability and compatibility of three drugs: nitroglycerin, diazepam and chlorpromazine, with a new multilayer infusion bag were studied. The study was carried out comparatively with PVC bags with which these drugs are incompatible. The drugs were diluted in 5% dextrose or in 0.9% sodium chloride isotonic solutions. Solutions were stored during 8 or 48 h with or without any protection against light. Remaining concentrations of drug were determined by high-performance liquid chromatography (HPLC) during the storage. The admixtures were also monitored for precipitation, color change and pH. Whatever the isotonic solution used, the loss of drugs is in discredit of the use of PVC bags for their storage. So, these three drugs would not be stored in PVC bags. In multilayer bags, no loss of drugs and no color change were detected throughout the storage period. pH values were stable during the same storage period. These three drugs were compatible with multilayer bags in all tested conditions for 8 or 48 h. The leaching of the plasticizer di-(2-ethylhexyl) phthalate (DEHP), that is incorporated into PVC to make the bags soft and pliable was not detected in the three drug solutions during storage period. Our study confirms that these three drugs are incompatible with PVC bags, on the contrary the new materiel tested was proved to be interesting for drug storage.