Capillary electrophoresis for the investigation of two novel aminoalkanol derivatives of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6] dec-8-ene-3,5,10-trione as potential anticancer drugs in water solution and serum.

A simple, rapid, capillary zone electrophoresis method was developed and validated for the analysis of two novel aminoalkanol derivatives (I) and (II) of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6 ]dec-8-ene-3,5,10-trione, which were found in earlier studies as potential anticancer drugs. Samples were analyzed to demonstrate the specificity and stability indicating ability of the developed method. The samples were extracted using n-hexane-ethyl acetate mixture in the ratio of 90:10. Electrophoretic separation was performed on a eCAP fused silica capillary (37 cm length, 50 µm inside diameter) with a 50 mM tetraborate buffer as a background electrolyte adjusted to pH = 2.5. The separation time of (I) and (II) was achieved within 7 min. In addition, analysis of the two compounds in the serum was conducted. Limits of detection of (I) and (II) by UV absorbance at 200 nm were achieved in the range of 87.4-92.1 ng/mL. The sufficient recovery was observed in the range of 90.3-99.8%. The quantification limits for the compounds (I) and (II) were in the range of 279.71-291.03 ng/mL, respectively. The method has been successfully applied to the analysis of compounds (I) and (II) in serum samples.

Evaluation of species difference in peripheral lymphocyte reduction effect of CS-0777, a sphingosine 1-phosphate receptor modulator, based on a pharmacokinetic/pharmacodynamic model analysis.

Pharmacokinetic (PK) and pharmacodynamic (PD) modeling was conducted for the reduction of peripheral lymphocytes after oral administration of CS-0777 to healthy rats, monkeys and experimental autoimmune encephalomyelitis (EAE) induced rats. The phosphorylated active metabolite of CS-0777, M1, is a selective sphingosine 1-phosphate receptor-1 modulator. A linear one- and two-compartment model with a reversible metabolism process characterized the time courses of CS-0777 and M1 concentrations in rats and monkeys, respectively. The relationship between lymphocyte counts and M1 concentrations in blood was well described by an indirect response model in all animals examined. An Imax of 0.815 and an IC50 of 6.58 nM in healthy rats, an Imax of 0.807 and an IC50 of 5.09 nM in the EAE rats, an Imax of 0.789 and an IC50 of 0.484 nM in monkeys were estimated by the indirect PD model. Since the IC50 values calculated in terms of the unbound plasma concentration in rats and monkeys were within a similar range, after correction of the IC50 in blood described above with the blood to plasma concentration ratio and the plasma free fraction of M1, it was revealed that there is no species difference in the essential activity of M1 against lymphocyte reduction. The sensitivity of the lymphocytes to M1 was not affected by the EAE status. Comparison of the simulated lymphocyte reduction in EAE rats after multiple dosing with CS-0777 and the actual EAE clinical scores implies that the significant suppressive effect on EAE did not require the elimination of all lymphocytes from the blood. Copyright © 2016 John Wiley & Sons, Ltd.

Differential effect of the 17ß-aminoestrogens prolame, butolame and pentolame in anxiety and depression models in rats.

Estrogens of clinical use produce consistent antidepressant- and anxiolytic-like effects in animal models of menopause. Regulation of the hypothalamic-pituitary-adrenal (HPA) or stress axis, has been proposed as a pathway through which estrogens improve affective-like behaviors. Anticoagulant 17ß-aminoestrogens (17ß-AEs) butolame and pentolame mimic some effects of estradiol (E2), i.e., on female rodent sexual behavior, with opposite actions on coagulation. However, their psychoactive actions have not been explored. On the basis of similitude with E2's effects, we hypothesized that these 17ß-AEs would induce anxiolytic- and antidepressant-like effects, which would be reflected in a reduction of activity in the HPA axis. In ovariectomized female rats, chronic treatment with prolame (60 µg/kg), butolame (65 µg/kg) and pentolame (70 µg/kg) reduced anxiety-like behavior in the elevated plus maze (evidenced by an increase in time in open arms, E2 (40 µg/kg) +176%; prolame +201%; butolame, +237%; and pentolame +295%, in comparison to the control vehicle group 100%). Pentolame also decreased significantly anxiety-like behavior in the burying behavior test. Prolame and E2 produced a significantly antidepressant-like action, which was not induced by butolame and pentolame. Behavioral effects of 17ß-AEs (and E2) on anxiety and depression did not follow the same pattern than corticosterone or E2 levels; they also were associated to changes in locomotor activity, evaluated by the open field test. These results constitute the first evidence of specific and selective actions of butolame and pentolame as anxiolytics for females with a hypoestrogenic condition. Results also confirm the potential of prolame as an antidepressant steroid with equivalent actions to E2. Psychoactive properties of 17ß-AEs in combinations with reduced adverse effects on coagulation, suggest that 17ß-AEs may be a good alternative replacement therapy for women with symptoms associated with menopause.

Noise-Induced Mechanism for Biological Homochirality of Early Life Self-Replicators.

The observed single-handedness of biological amino acids and sugars has long been attributed to autocatalysis. However, the stability of homochiral states in deterministic autocatalytic systems relies on cross inhibition of the two chiral states, an unlikely scenario for early life self-replicators. Here, we present a theory for a stochastic individual-level model of autocatalysis due to early life self-replicators. Without chiral inhibition, the racemic state is the global attractor of the deterministic dynamics, but intrinsic multiplicative noise stabilizes the homochiral states, in both well-mixed and spatially extended systems. We conclude that autocatalysis is a viable mechanism for homochirality, without imposing additional nonlinearities such as chiral inhibition.

Application of cation-exchange solid-phase extraction for the analysis of amino alcohols from water and human plasma for verification of Chemical Weapons Convention.

The analysis of nitrogen containing amino alcohols, which are the precursors and degradation products of nitrogen mustards and nerve agent VX, constitutes an important aspect for verifying the compliance to the CWC (Chemical Weapons Convention). This work devotes on the development of solid-phase extraction method using silica- and polymer-based SCX (strong cation-exchange) and MCX (mixed-mode strong cation-exchange) cartridges for N,N-dialkylaminoethane-2-ols and alkyl N,N-diethanolamines, from water. The extracted analytes were analyzed by GC-MS (gas chromatography-mass spectrometry) in the full scan and selected ion monitoring modes. The extraction efficiencies of SCX and MCX cartridges were compared, and results revealed that SCX performed better. Extraction parameters, such as loading capacity, extraction solvent, its volume, and washing solvent were optimized. Best recoveries were obtained using 2 mL methanol containing 10% NH(4)OH and limits of detection could be achieved up to 5 x 10(-3) microg mL(-1) in the selected ion monitoring mode and 0.01 microg mL(-1) in full scan mode. The method was successfully employed for the detection and identification of amino alcohol present in water sample sent by Organization for Prohibition of Chemical Weapons (OPCW) in the official proficiency tests. The method was also applied to extract the analytes from human plasma. The SCX cartridge showed good recoveries of amino alcohols from human plasma after protein precipitation.

Characterization of interactions between human serum albumin and tumor-inhibiting amino alcohol platinum(II) complexes using capillary electrophoresis.

Platinum(II) complexes with amino alcohol ligands are of growing interest as anticancer agents capable of changing their reactivity toward biomolecules at different pH values. The binding of such compounds to the transport protein, human serum albumin (HSA), under simulated physiological conditions (pH 7.4, 100mM chloride, 37 degrees C) has been studied by capillary electrophoresis (CE), with the objective to acquire and compare their binding parameters. The association constants and stoichiometric ratios of the platinum-HSA adducts were determined by measuring the concentration changes of the peak area response of the Pt complex (after a 48 h incubation of the reaction mixture to attain equilibrium), constructing the binding isotherms, and their mathematical analysis. The investigated Pt(II) compounds were found to show moderate affinity toward HSA, with association constants ranging from 1.0 x 10(3) to 2.4 x 10(4)M(-1). Such binding behavior was attributed to a distinctive structural feature of bis(amino alcohol)platinum(II) complexes, that is, existence of an equilibrium between ring-opened and ring-closed forms in solution.

Comparison of extraction of a beta-blocker from plasma onto a molecularly imprinted polymer with liquid-liquid extraction and solid phase extraction methods.

An optimised solid phase extraction (SPE) method developed for the extraction of a structural analogue of the beta-blocking drug propranolol from plasma utilising a molecularly imprinted polymer (MIP) has been compared with methods based on conventional liquid-liquid extraction (LLE), and SPE using C18-bonded and immobilised phenyl boronic acid (PBA). All four methods could be used for the extraction of the analyte with acceptable accuracy and precision. The MIP-based method, unlike the other methods required a protein precipitation step prior to extraction to eliminate the effects of co-extracted protein. The best performance was seen with the LLE method followed by SPE on the C18 phase. The MIP-based method represented no advantage over the comparator methods for this analyte. Indeed the performance of the MIP-based method was marginally worse as leaching of low level template impurities prevented detection of the target analyte at low concentrations (5 ngmL(-1)). This relatively poorer performance was evident as worse accuracy at low concentrations with a consequent higher limit of quantification than the conventional methods.

Liquid chromatographic assay of heptaminol in serum and its oral pharmacokinetics in the dog.

In order to investigate the pharmacokinetics of heptaminol in dogs, a high-performance liquid chromatographic assay of the drug was devised and it was evaluated in a general purpose validation design through analysis of variance. Heptaminol and its internal standard n-propylamine were salted out from plasma together with acetonitrile, the previously proposed "solvent demixing " extraction procedure. Both amines were derivatised in acetonitrile with the o-phthaldialdehyde, 2-mercaptoethanol procedure of Roth. The adducts were quantitated by reversed-phase high-performance liquid chromatography on Radial-Pak cartridges with ultraviolet detection. Peak height ratios were linearly related to concentrations up to 250 mumol l-1 with a 2% coefficient of variation. Sensitivity was 3.5 mumol l-1 (signal-to-noise ratio of 5). Means of the usual pharmacokinetic parameters in four dogs were: elimination half-life 3.75 h, apparent distribution volume 2.18 l kg-1 and total clearance 0.402 l kg-1 h-1, similar to the results obtained in humans by other authors using radiolabelled heptaminol .

Determination of isoetharine in plasma by reversed-phase chromatography with amperometric detection.

A reversed-phase liquid chromatographic method for the determination of isoetharine in blood plasma, utilizing amperometric detection, is described. Plasma samples were extracted utilizing an ion-pair reagent, di-(2-ethylhexyl)phosphoric acid, to concentrate the catecholamine. Only minor differences were observed in the relative bioavailability of isoetharine hydrochloride and isoetharine mesylate after oral administration to rats. Observed plasma levels, at 1 hr after oral medication, were highly variable in dose-ranging studies at doses of 800-2500 mg/kg/day for 2 weeks.