Doxorubicin disaccharide analogue: apoptosis-related improvement of efficacy in vivo

BACKGROUND

Although doxorubicin remains one of the most effective agents for the treatment of solid tumors, there is an intensive effort to synthesize doxorubicin analogues (compounds with similar chemical structures) that may have improved antitumor properties. We have synthesized a novel doxorubicin disaccharide analogue (MEN 10755) and have characterized some of its relevant biochemical, biologic, and pharmacologic properties.

METHODS

The antitumor activity of this compound (MEN 10755) was studied in a panel of human tumor xenografts, including xenografts of A2780 ovarian tumor cells, MX-1 breast carcinoma cells, and POVD small-cell lung cancer cells. MEN 10755 was compared with doxorubicin according to the optimal dose and schedule for each drug. The drug's cytotoxic effects, induction of DNA damage, and intracellular accumulation were studied in A2780 cells. DNA cleavage mediated by the enzyme topoisomerase II was investigated in vitro by incubating fragments of simian virus 40 DNA with the purified enzyme at various drug concentrations and analyzing the DNA cleavage-intensity patterns. Drug-induced apoptosis (programmed cell death) in tumors was determined with the use of MX-1 and POVD tumor-bearing athymic Swiss nude mice.

RESULTS

MEN 10755 was more effective than doxorubicin as a topoisomerase II poison and stimulated DNA fragmentation at lower intracellular concentrations. In addition, MEN 10755 exhibited striking antitumor activity in the treatment of human tumor xenografts, including those of the doxorubicin-resistant breast carcinoma cell line MX-1.

CONCLUSIONS

The high antitumor activity of MEN 10755 in human tumor xenografts, including doxorubicin-resistant xenografts, and its unique pharmacologic and biologic properties make this disaccharide analogue a promising candidate for clinical evaluation.

Novel anthracycline oligosaccharides: influence of chemical modifications of the carbohydrate moiety on biological activity

Several observations highlight the importance of the carbohydrate moiety for the biological activity of antitumoural anthracyclines. Here is reported the synthesis, cytotoxicity and topoisomerase II-mediated DNA cleavage intensity of the new oligosaccharide anthracyclines 1--4 modified in the sugar residue. Evaluation of cytotoxic potency on different cell lines, resulted in quite similar values among the different analogues. On the other hand, topoisomerase II-mediated DNA breaks level was different for the various compounds, and was not related to cytotoxicity, thus supporting previous observations reported for some monosaccharide anthracyclines modified in the carbohydrate portion.

Configurational requirements of the sugar moiety for the pharmacological activity of anthracycline disaccharides

The amino sugar is recognized to be a critical determinant of the activity of anthracycline monosaccharides related to doxorubicin and daunorubicin. In an attempt to improve the pharmacological properties of such agents, novel anthracycline disaccharides have been designed in which the amino sugar, daunosamine, is separated from the aglycone by another carbohydrate moiety. In the present study, we examined the influence of the orientation of the second sugar residue on drug biochemical and biological properties in a series of closely related analogs. This structure-activity relationship study showed that the substitution of the daunosamine for the disaccharide moiety dramatically reduced the cytotoxic potency of the drug in the 4-methoxy series (daunorubicin analogs). In contrast, in the 4-demethoxy series (idarubicin analogs), the C-4 axial, but not the equatorial, configuration conferred a cytotoxic potency and antitumor activity comparable to that of doxorubicin. The configuration also influenced the drug's ability to stimulate topoisomerase II alpha-mediated DNA cleavage. Indeed, the glycosides with the equatorial orientation were ineffective as topoisomerase II poisons, whereas the compounds with axial orientation were active, although the daunorubicin analog exhibited a lower activity than the idarubicin analog. It is conceivable that the axial orientation allows an optimal interaction of the drug with the DNA-enzyme complex only in the absence of the methoxy group. Our results are consistent with a critical role of the sugar moiety in drug interaction with the target enzyme in the ternary complex.

Prenatal diagnosis of idiopathic neonatal hemochromatosis with MRI

Intrauterine diagnosis of perinatal hemochromatosis is difficult. Noninvasive detection of hepatic iron deposition is crucial. We report the first case diagnosed intrauterine with magnetic resonance imaging (MRI). By visual analysis, if the fetal liver is less intense than maternal or fetal fat signal for T2* gradient echo image, hemochromatosis should be suggested.

Thyroid autoregulation. Inhibition of goiter growth and of cyclic AMP formation in rat thyroid by iodinated derivatives of arachidonic acid

Thyroid autoregulation has been related to intraglandular content of an unknown putative iodocompund. Data from different laboratories have shown that the thyroid is capable of producing different iodolipids, including iodinated derivatives of arachidonic acid; such as 5-hydroxy-6-iodo-8, 11, 14-eicosatrienoic-delta-lactone (IL-delta). Previous results from our laboratory showed that a semi-purified preparation of iodinated arachidonic acid exerts an inhibitory action in vitro on calf thyroid. In the present studies three purified iodinated derivatives of arachidonic acid were synthesized: IL-delta; 14-iodo-15-hydroxy-5, 8, 11-eicosatrienoic acid (I-OH-A) and its corresponding omega-lactone (IL-omega). Their action on MMI-induced goiter was studied in rats. Administration of MMI to rats during 10 days increased thyroid weight by 124%. This effect was significantly inhibited by the simultaneous injection of 5 micrograms/day of I-OH-A (57% inhibition of MMI action), IL-W (39%), IL-delta (33%) and T3 (95%), while arachidonic acid was without action. No inhibition was found with 1.25 micrograms/day Kl, a dose equivalent to that which could be originated from total dehalogenation of the iodocompounds. These results support the idea that these iodocompounds have an intrinsic biologic activity and that there is a correlation between action and chemical structure. Serum TSH was increased around 15-20 fold after MMI administration. Chronic or acute injection of I-OH-A failed to alter TSH levels, indicating that this iodocompound exerts its action directly on the gland, without altering TSH concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Preclinical pharmacokinetics and metabolism of a potent non-nucleoside inhibitor of the hepatitis C virus NS5B polymerase

The disposition of compound A, a potent inhibitor of the hepatitis C virus (HCV) NS5B polymerase, was characterized in animals in support of its selection for further development. Compound A exhibited marked species differences in pharmacokinetics. Plasma clearance was 44 ml min-1 kg-1 in rats, 9 ml min-1 kg-1 in dogs and 16 ml min-1 kg-1 in rhesus monkeys. Oral bioavailability was low in rats (10%) but significantly higher in dogs (52%) and monkeys (26%). Compound A was eliminated primarily by metabolism in rats, with biliary excretion accounting for 30% of its clearance. Metabolism was mainly mediated by cyclohexyl hydroxylation, with N-deethylation and acyl glucuronide formation constituting minor metabolic pathways. Qualitatively, the same metabolites were identified using in vitro systems from all species studied, including humans. The low oral bioavailability of compound A in rats was mostly due to poor intestinal absorption. This conclusion was borne out by the findings that hepatic extraction in the rat was only 30%, intraperitoneal bioavailability was good, and compound A was poorly absorbed from the rat isolated intestinal loop, with no detectable intestinal metabolism. Compound A was not an inhibitor of major human cytochrome P450 enzymes, indicating minimal potential for clinical drug-drug interactions. The metabolic clearance of compound A in rat, dog and monkey hepatocytes correlated with the systemic clearance observed in these species. Since compound A was very stable in human hepatocytes, the results suggest that it will be a low clearance drug in humans.

Synthesis and conformational preference of novel 8-fluoroanthracyclines

Analogues of daunorubicin possessing a fluorine atom at position C(8) of ring A have been synthesized with the aim of comparing their DNA-drug interaction and antitumour properties with those of the clinically useful anthracyclines doxorubicin and idarubicin. The synthesis of (8S)-8-fluoro-4-demethoxydaunorubicin, 1, is reported and molecular mechanics and NMR studies which guided towards the synthesis of the epimeric (8R)-8-fluoro-4-demethoxydaunorubicin, 2, are discussed. Both compounds were prepared by divergent routes starting from the common intermediate, 6, obtained via the Diels-Alder cyclisation between quinizarin diquinone, 3, and 2-(1-hydroxyethyl)-1,3-butadiene, 4. The synthesis of the (8S)-fluoroepimer proceeded via epoxidation of the C(8)-C(9) olefinic bond of 6, oxidation, oxirane cleavage by BF3.Et2O to give the fluorohydroxyketone, 9, followed by the introduction of the hydroxyl moiety at C(7) and glycosylation. Conversely, the synthesis of the (8R)-fluoroepimer involved the fluorobromination of the C(8)-C(9) olefinic bond of 6, formation of the C(9)-C(13) epoxide, 20 which, after regioselective hydrolysis and oxidation of the resulting fluorodiol to the epimeric fluorohydroxyketone, 21, similarly gave the desired fluoroaglycone, 25 and, hence, the corresponding glycoside, 2. The cytotoxic properties of the two 8-fluoroanthracycline analogues, 1 and 2, were markedly affected by the stereochemistry of the fluorine substituent.

Synthesis and biological evaluation of novel NK-1 tachykinin receptor antagonists: the use of cycloalkyl amino acids as a template

In the course of a program aimed at synthesizing novel, potent NK-1 tachykinin receptor antagonists, we developed upon a bioactive model by comparing the low energy structures of a series of peptide and nonpeptide Substance P antagonists. The comparison was based on the superimposition of the aromatic rings, assuming that the rest of the molecule behaves predominantly as a template to arrange the key aromatic groups in the right spatial position. A series of 2-aminocyclohexane carboxylic acid analogues were then selected as the best templates for reproducing the postulated bioactive structure, leading to several pseudo-peptides with interesting biological activity. According to the molecular modeling, these compounds exhibit a neat parallel facing of the indolyl and naphthyl groups at about 3 A distance. Ultraviolet absorption and steady state fluorescence measurements support this conclusion, showing a linear correlation between the spectral properties and the binding affinity of these analogues. Stacking of the indole ring with naphthalene gives rise to a complex characterized by a well-defined molar extinction coefficient. Consistently, steady state and lifetime fluorescence measurements suggest that the quenching process is ascribable to ground-state interactions between the chromophores. Implications of the pi stacking propensity of aromatic groups in the biological activity of the compounds examined are briefly discussed.

Thyroid autoregulation. Inhibitory effects of iodinated derivatives of arachidonic acid on iodine metabolism

Thyroid autoregulation has been linked to an organified iodocompound. Since several iodolipids are produced by the gland their possible role in thyroid autoregulation was examined. The following pure synthetic compounds were prepared: 1) 14-iodo-15-hydroxy-5,8,11-eicosatrienoic acid (I-OH-A); 2) its omega lactone (IL-omega); 3) 5-hydroxy-6-iodo-8,11,14-eicosatrienoic acid delta lactone (IL-delta). Their action on iodine metabolism was studied. Iodine uptake was measured in calf thyroid slices. At 10(-4)M I-OH-A caused a 64% decrease in the T/M ratio, while IL-omega inhibited it by 36% and IL-delta was without effect. At 10(-5)M the inhibition was 44% for I-OH-A and 19% for IL-omega, while T3 was without action. A possible isotopic dilution effect was excluded, and no change in iodine efflux was observed. The inhibition by I-OH-A of iodide uptake was observed after only 15 min preincubation. This compound also decreased 125I accumulation in rats. In calf thyroid slices, I-OH-A at 10(-4)M, inhibited PB125I formation by 80%, IL-omega by 62% and IL-delta by 37%. T3 and arachidonic acid were without action. I-OH-A also caused a dose-dependent inhibition of TSH-stimulated iodide organification. The present results demonstrate, for the first time, that iodinated derivatives of arachidonic acid inhibit thyroid function and mimic the effect of iodide on thyroid autoregulation.

A benzyl alcohol derivative of the BDPA radical for fast dissolution dynamic nuclear polarization NMR spectroscopy

The synthesis, structural characterization and the successful application of a carbon centered radical derived from 1,3-bisdiphenylene-2-phenylallyl (BDPA), its benzyl alcohol derivative (BA-BDPA), as a polarizing agent for Dynamic Nuclear Polarization (DNP) are described. The reported BA-BDPA radical meets all the requirements to become a promising candidate for its use in in vivo DNP-NMR experiments: it is soluble in neat [1-(13)C]pyruvic acid, insoluble in the dissolution transfer solvent and is effective as a polarizing agent in fast dissolution DNP-NMR applications, without the need for using glassing agents. Moreover, it enables a simple but effective in-line radical filtration to obtain hyperpolarized solutions of [1-(13)C]pyruvic acid free of radicals that offers a better polarization performance.

Transplantation of CD34+ selected peripheral blood to HLA-identical sibling patients with aplastic anaemia: results from a single institution

We evaluated the use of CD34+ selected allogeneic peripheral blood as a source of hematopoietic progenitors for allogeneic transplantation in 11 patients with aplastic anemia (AA). The median age was 17 years (range, 6--9), and the median time between diagnosis and transplant 1 month (range, 1--4). Conditioning consisted of cyclophosphamide (50 mg/kg per day) on days--7 to--4 and antithymocyte globulin (30 mg/kg per day) on days--4 to--2 in nine patients. Total lymphoid irradiation was added to the preparative regimen for two. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and prednisone. Median doses of CD34+ and CD3+ cells infused were 3.91 x 10(6) and 0.3 x 10(6)/kg, respectively. The median time taken to achieve a neutrophil count >0.5 x 10(9)/l was 12 days and to recover a platelet count >20 x 10(9)/l, 13 days. Two patients developed acute GVHD grade I--II and one developed limited chronic GVHD. There were two treatment-related deaths. At a median follow-up of 44 months (range, 4--3), nine patients were alive with sustained and complete engraftment. This is a promising procedure in patients with AA, resulting in a rapid hematopoietic recovery, a low transplant-related mortality, and a low incidence of GVHD.

Studies of metabolism and disposition of potent human immunodeficiency virus (HIV) integrase inhibitors using19F-NMR spectroscopy

(19)F-nuclear magnetic resonance (NMR) has been extensively used in a drug-discovery programme to support the selection of candidates for further development. Data on an early lead compound, N-(4-fluorobenzyl)-5-hydroxy-1-methyl-2-(4-methylmorpholin-3-yl)-6-oxo-1,6-dihydropyrimidine-4-carboxamide (compound A (+)), and MK-0518 (N-(4-fluorobenzyl)-5-hydroxy-1-methyl-2-(1-methyl-1-{[(5-methyl-1,3,4-oxadiazol-2-yl)carbonyl]amino}ethyl)-6-oxo-1,6-dihydropyrimidine-4-carboxamide), a potent inhibitor of this series currently in phase III clinical trials, are described. The metabolic fate and excretion balance of compound A (+) and MK-0518 were investigated in rats and dogs following intravenous and oral dosing using a combination of (19)F-NMR-monitored enzyme hydrolysis and solid-phase extraction chromatography and NMR spectroscopy (SPEC-NMR). Dosing with the (3)H-labelled compound A (+) enabled the comparison of standard radiochemical analysis with (19)F-NMR spectroscopy to obtain quantitative metabolism and excretion data. Both compounds were eliminated mainly by metabolism. The major metabolite identified in rat urine and bile and in dog urine was the 5-O-glucuronide.

Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA

A BAm-BDPA radical has proved to be a quick and efficient polarizing agent, showing optimum ¹³C NMR signal enhancements per polarization time unit.

Metabolism-related liabilities of a potent histone deacetylase (HDAC) inhibitor and relevance of the route of administration on its metabolic fate

Compound A [1-methyl-N-{(1S)-1-[5-(2-naphthyl)-1H-imidazol-2-yl]-7-oxooctyl}piperidine-4-carboxamide is a potent class I histone deacetylase (HDAC) inhibitor that demonstrated good antiproliferative activity against human tumour cell lines of different origin. This compound showed high in vivo clearance in rats (160 ml min(-1) kg(-1)) due to metabolism. The main metabolite detected in urine after intravenous dosing was characterized as a dihydrohydroxy S-mercapturic acid conjugate. Following oral dosing, however, the mercapturic acid derivative was no longer the main metabolite but the major metabolites were mono- and di-glucuronide conjugates of oxidized species having a mass shift of +34 m/z with respect to the parent. Comparison of plasma concentration after intra-arterial infusion and intravenous infusion and incubation with microsomes from different tissues (liver, kidney, small intestine and lung) in the presence of beta-nicotinamide adenine dinucleotide phosphate (NADPH) indicated that the compound was highly cleared by the lung. Oxidation of the naphthalene moiety was demonstrated to be the cause of the high in vivo clearance of compound A and the potential for bioactivation of this group was flagged.

Ethylone: A synthetic cathinone emerging in Barcelona

Introduction

Synthetic cathinones, the active component in “bath salts”, have surfaced as a popular alternative to other illicit drugs of abuse, such as cocaine, MDMA (ecstasy), and methamphetamine, due to their potent psychostimulant and empathogenic effects.

Objectives

To describe the presence of Ethylone in samples delivered to energy control from 2014 to 2015 in Spain.

Methods

The total number of samples analyzed from 2014 to 2015 was 8324. Only those samples containing ethylone were studied. They were analyzed by energy control, a Spanish harm reduction NGO that offers the possibility of analysing the substances that users report. Analysis was done by gas chromatography-mass spectrometry.

Results

From June 2014 to December 2015, 8324 samples were delivered to EC. From this samples 28 (0.336%) contained ethylone. Twelve (0.144%) were delivered as MDMA, representing a 0.783% of the samples delivered as such, and only one sample (0.012%) delivered as MDMA presented ethylene as an adulterant along with MDMA. Other 6 samples (0.072%) were delivered as ethylone and 10 samples (0.120%) were delivered as unknown pills.

Discussion

Ethylone consumption is found to be an emerging issue according to the results of our samples, an increase of such is found during 2015. This might be traduced as an increase of ethylone in the drug market, but a sample selection bias should be considered as samples were voluntary delivered by consumers. An alarming phenomenon is that in some occasions ethylone is sold as MDMA, but effects take longer to occur and last longer, which may lead to an overdose if used as MDMA.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The effects of actors vocal exercises for relaxation on fluency: A preliminary study

PURPOSE

To determine the efficacy of treatment based on Kristin Linklater's technique for vocal preparation for performance for use with people who stutter.

METHOD

A protocol for a treatment for stuttering involving breathing exercises, relaxation techniques, and focus on awareness was designed by the first author from Linklater's published exercises in her book Freeing the Natural Voice (2006). Four adults who stutter participated in a 12-week, single-case reversal design study. Treatment efficacy was determined by baseline and post-treatment measures on the OASES, self-report naturalness, tension and severity scale, and percentage of stuttering-like disfluency (SLD). Qualitative measures included a daily tension and practice log, a program completion questionnaire, and accounts from the clinicians administering the treatment protocol.

RESULTS

Three of four participants scored lower on the OASES post-treatment, suggesting that the impact of stuttering on their daily lives had decreased. All four experienced a reduction in the number of SLD counted throughout treatment sessions compared to baseline data.

CONCLUSION

A treatment for stuttering based on Linklater's work including regulation of breathing, relaxation, and awareness of breath may be effective in improving fluency and decreasing the impact of stuttering and warrants further study.

[Progression to AIDS among HIV-seropositive hemophiliacs]

PURPOSE

To assess the incidence of AIDS, along with its origin and mortality rate, in a group of sero-positive haemophiliacs with long follow-up.

MATERIAL AND METHODS

The progression into AIDS in 94 HIV-seropositive haemophiliacs (88 with haemophilia A and 6 with haemophilia B) followed since 1986 has been analyzed. The mean age was 19 years and 64% of the patients had severe haemophilia. All of them had been previously treated with non virus-inactivated factor concentrates. Was detected HIV antigen in 13 of them and 32 were treated with zidovudine. Actuarial analysis started from seroconversion date or from the first positive result and the average observation time was 90 months (5-97).

RESULTS

Sixteen patients developed AIDS, resulting in an eight-years accumulative actuarial indice of about 24%. AIDS incidence was lower (p less than 0.0001) in haemophilia A (21%) than in haemophilia B (67%). The eight-years progression rate to AIDS showed a significant dependence on patient age, it being higher in patients aged greater than 30 (77%) than in those aged 15-30 (30%) and less than 15 (9%). Patients who presented CD4+ counts lower than 0.5 x 10(9)/L or CD4/CD8 ratios lower than 0.5 at the beginning of the observation period had a greater 8-year AIDS incidence (63% and 57% respectively) than the remaining patients (16% and 12%). At AIDS diagnosis, all patients had CD4+ lymphocyte counts lower than 0.2 x 10(9)/L, two had detectable HIV antigenaemia and six had been previously treated with zidovudine. The cause of AIDS was an opportunistic infection in all the cases namely, P. carinii pneumonia and candidiasis, but no secondary neoplasia was registered. Nineteen patients died during the follow-up, 12 because of AIDS and 7 because of other reasons unrelated to HIV-infection.

CONCLUSION

Our results suggest that 25% of the haemophiliacs will develop AIDS eight years after seroconversion, and a decreasing incidence is not observed. Lower progression rate to AIDS in children than in adults is confirmed.

What are sweet dreams made of? Analysis of psychoactive substances into “gummies”: A retrospective descriptive study

Introduction

Although psychoactive substances has a long history in recreational settings, research on its composition has focused only on tablets, crystal and powder, even though new formulation for new psychoactive substances are readily available for users.

Objectives

To describe the presence of psychoactive substances and its characteristics in new formulations which had not previously been found in samples delivered to Energy Control from 2014 to 2015 in Spain.

Methods

A total of 8324 samples were analysed from June 2014 to December 2015. Only those samples in gummy formulation were studied (n = 9). Samples were analyzed by energy control, a Spanish harm-reduction NGO that offers analysis of substances to users. Analysis was done by gas chromatography-mass spectrometry.

Results

From 9 samples of psychoactive substances in gummy formulation, the analysis detected that 55.5% contained multiple psychoactive substances: 6 samples contained 25N-NBOMe (66.7%), 1 2C-E (11.1%), 1 2C-D (11.1%). Two allylescaline (20%), 1 cocaine (11.1%), 1 THC (11.1%), 1 canabinol (11.1%), 1 ketamine (11.1%), 1 caffeine (11.1%), 1 MDMA (11.1%), 1 N-acetyl-MDMA (11.1%), 1 metoxetamine (11.1%), 1 N-acetyl-MDMA), 1 2C-N (11.1%). The only substance found in active dosage was 25N-NBOMe. Six samples (66.67%) did not contain the substance expected by the consumer.

Discussion

Incipient presence of gummies as new psychoactive formulation was found. The most prevalent drug was 25N-NBOMe; 66.7% did not contain the substance expected. This may pose a risk for potential harmful effects. All the gummies were known to be drug-carriers when bought. This could represent the presence of new formulations from June 2014 in the Spanish recreational market.

Disclosure of interest

The authors have not supplied their declaration of competing interest.