Chiral resolution of the enantiomers of new selective CB(2) receptor agonists by liquid chromatography on amylose stationary phases.

Analytical HPLC methods using derivatized amylose chiral stationary phases, Chiralpak AD-H and Chiralpak AS, were developed for the direct enantioseparation of eight substituted 4-oxo-1,4-dihydroquinoline-3-carboxamide derivatives with one stereogenic center. Baseline separation (Rs>1.5) was always achieved on amylose based Chiralpak AD-H column to the difference with Chiralpak AS. Using UV detection, a linear response was observed within a 180-420 micromol L(-1) concentration range (r2>0.991) for three racemic compounds 1, 3 and 4 with best pharmacological potentials; repeatability, limit of detection (LD) and quantification (LQ) were also determined: LD varied, for the solutes, from 0.36 to 2.56 micromol L(-1). Finally, the enantiopurity of these compounds was determined. Additionally, the effect of temperature variations upon isomer separations was investigated.

Novel benzothiazolin-2-one and benzoxazin-3-one arylpiperazine derivatives with mixed 5HT1A/D2 affinity as potential atypical antipsychotics.

Since it was known that 5HT properties (5HT1A agonism or 5HT2A antagonism) combined with D2 antagonism may lead to atypical antipsychotic drugs, a series of 19 benzothiazolin-2-one and benzoxazin-3-one derivatives possessing the arylpiperazine moiety was prepared, and their binding profiles were investigated. All tested compounds displayed very high affinities for the 5HT1A and D2 receptors. Therefore, further pharmacological studies were carried out on selected compounds (24, 27, 30, 46, and 47). This evaluation in rats clearly revealed potent antipsychotic properties along with a decrease of extrapyramidal side effects. These derivatives are currently under preclinical development.

Synthesis and structure-activity relationships of novel naphthalenic and bioisosteric related amidic derivatives as melatonin receptor ligands.

A series of N-naphthylethyl amide derivatives were synthesized and evaluated as melatonin receptor ligands. The affinity of each compound for the melatonin receptor was determined by binding studies using [2-125I]iodomelatonin on ovine pars tuberalis membrane homogenates. Structure-activity relationships led to the conclusion that naphthalene is a bioisostere of the indole moiety of melatonin. Moreover it appears that the affinity is strongly affected by the size of the substituent of the nitrogen of the amidic function. Many of these ligands give biphasic dose-response curves which suggests that there may be two melatonin receptor subtypes within the ovine pars tuberalis cells. The replacement of naphthalene by benzofuran or benzothiophene did not strongly alter the affinity for the melatonin receptor. In contrast, the benzimidazole analogue was a poor ligand. Compound 7, the naphthalenic analogue of melatonin, a selective ligand of the melatonin receptor and an agonist derivative, has been selected for clinical development.

Evaluation of toxicity and efficacy of 186Re-hydroxyethylidene diphosphonate in patients with painful bone metastases of prostate or breast cancer.

UNLABELLED: Twenty-eight patients (12 men with prostate cancer, 16 women with breast cancer) were included in a phase II trial to evaluate the efficacy of 186Re-hydroxyethylidene diphosphonate (HEDP) on pain from bone metastasis and the toxicity of this agent. METHODS: After intravenous administration of 1295 MBq 186Re-HEDP, the efficacy was evaluated by means of a daily log. RESULTS: We observed an objective response in 67% of prostate cancer patients and in 36% of breast cancer patients. The mean duration of response was 45 d for prostate cancer patients and 24 d for breast cancer patients. No major adverse effects were observed. Marrow toxicity did not exceed grade 2 for white blood cells and grade 3 for platelets using National Cancer Institute criteria. CONCLUSION: 186Re-HEDP provides safe symptomatic relief of pain in prostate cancer patients. The benefit of this treatment is less clear in breast cancer patients. Further studies should be conducted to evaluate treatment by 186Re-HEDP at an earlier stage of the disease.

Synthesis and preliminary pharmacological results on new naphthalene derivatives as 5-HT(4) receptor ligands.

The indole derivative GR 113808 is currently used as the reference ligand for labelling the 5-HT(4) serotoninergic receptors. Previous works in our laboratories established the bioisosteric equivalency of the indole heterocycle and naphthalene in a series of melatonin receptor ligands. Based on this knowledge we designed new analogues of GR 113808 by introducing two bioisosteric modifications: firstly, the indole ring was replaced by a naphthalene one and secondly, the ester linkage was replaced by an amide group. Compound 8 emerged within this novel series as it displayed high and selective affinity at 5-HT(4) receptors (Ki 5-HT(4) = 6 nM, Ki 5-HT(3) = 100 nM, Ki values at other 5-HT receptors were higher than 1000 nM). Compound 8 is currently undergoing further pharmacological evaluation.

N-arylpiperazinyl derivatives of 2,3-dihydrobenzoxazin[1,4]-3-ones synthesis and normolipemic activity.

Four series of N-arylpiperazinyl derivatives of the 7-substituted 2,3-dihydrobenzoxazin[1,4]-3-one were synthesized and preliminarily tested for hypolipemic activity. Substitutions in position 2 were performed. Hypotriglyceridemic activity was shown to be present in a number of compounds.

Pharmacomodulation of 7-(2-methylene-butyryl)-2,3-dihydrobenzoxazin-[1,4]-3-one structure and normolipemic activity.

A series of compounds from 7-(2-methylene butyryl)-2,3-dihydro benzoxazin-[1,4]-3-one was synthesized and evaluated for its lipid lowering action in animal models. Substitutions in positions 2, 4 and 7 were performed. The results of the structure-activity relationships are very difficult to be interpreted. The different modifications tested did not show any improvement in the normolipemic activity.

Synthesis and N.M.R. study of trans 2-phenoxycyclohexanol and some of its derivatives with potential antiinflammatory activity.

A number of amino-ethers, acids, amino-esters, amino-amides and carbamates was synthesized from trans-2-phenoxycyclohexanol. The configuration of the starting material was established by N.M.R. spectroscopy. Pharmacological tests showed an antiinflammatory activity for some of the derivatives.

In vitro antifilarial evaluation of phenoxycyclohexane derivatives.

Numerous potential inhibitors of the phosphoenolpyruvate-carboxylase found in Molinema dessetae were synthesized and evaluated as inhibitors of the purified enzyme and as killers, in vitro, of M. dessetae adult females and infective larvae. Phosphoenolpyruvate analogs (or derivatives) appeared disappointing whereas phenoxycyclohexane derivatives inhibited the enzyme in a non-competitive manner and killed the parasites. The compounds P2281 and P2285, for example, had Ki values of 122 and 93 microM, respectively. In vivo tests of the most effective phenoxycyclohexanes will now be carried out to check their potential as antifilarial drugs.

Microtubules as therapeutic target in Trypanosoma brucei brucei and Molinema dessetae: action of 2-(amino-methyl)acrylophenone derivatives.

2-(amino-methyl) acrylophenone derivatives as antimicrotubular agents were evaluated in vitro and in vivo against Trypanosoma brucei brucei and in vitro against infective larvae from the filaria Molinema dessetae. The compounds were active in vitro against T. b. brucei since the minimum effective concentrations were in a range from 22 to 35 microM after one hour incubation time and in a range from 10 to 35 microM after 24 hours incubation time. Nevertheless, no activity was recovered in vivo for all the compounds at 50 mumoles/kg subcutaneously administered in a single dose. Moreover, interesting activity was obtained on M. dessetae infective larvae in vitro model since EC50 range were from 0.2 to 30 microM after one day incubation time and from 0.2 to 1.5 microM after seven days incubation time. No clear-cut correlation between antimicrotubular effect and biological activity emerged; the antimicrotubular effect does not seem therefore the only mechanism of action for these compounds. Further pharmacomodulations could be studied to obtain better bioavailability and lower toxicity.

Potential anti-echinococcal activity of alkylaminoethers.

Trans 2-phenoxy cyclohexanol ethers (IA, IIA, IIIA, IVA, VA, and VIA), the cyclohexanol analog (IB) and one coumarinic compound (IC) were obtained and their activity against Echinococcus multilocularis metacestodes was studied and compared with that of trifluoperazine (TFP). All of these compounds are analogous to IA and belong to three classes. Class A comprises trans 2-phenoxycyclohexanol aminoethers whose alkylaminoether group varies; compound VIA bears one more methylene in its aminoether group than does compound IA. Class B consists of one compound exhibiting no phenoxy function. Class C comprises one coumarinic analog. In vitro assays were performed using metacestodes whose protoscoleces were attached to the germinal layer in open and in closed vesicles. Compounds IA and IIA exhibited the highest activity, but it was lower than that displayed by TFP under the same conditions. Compound IA was tested in an in vivo assay in jirds (50 mg/kg/daily beginning at 80 days p.i.); it produced results that were analogous to those obtained using TFP without inducing the neuroleptic effect associated with the latter. After 40-90 days' treatment, the percentage of diminution in the entire parasitic mass in the jirds that survived minimal treatment (71%) was about 41% as compared with that in untreated jirds. Histologic examination of the parasites in treated jirds revealed numerous dead protoscoleces and some parasitic dedifferentiated cells. This parasitic response may indicate that in alveolar echinococcosis, these drugs exhibit only a parasitostatic effect.

New analogues of the anticancer E7070: synthesis and pharmacology.

Cell cycle control in the G1 phase has attracted considerable attention in recent cancer research, because many of the important proteins involved in G1 progression or G1/S transition have been found to play a crucial role in proliferation, differentiation, transformation, and programmed cell death (apoptosis). E7070 is a novel antitumor sulfonamide, with a unique mode of action that affects G1 progression of the cell cycle. A series of compounds containing an N-[1-(3,4,5-trimethoxybenzyl)-1H-indol-5-yl]benzene sulfonamide, analogues of E7070, was synthesized and evaluated as potential antitumor agents. Cell cycle analysis with PC3 human prostate cancer cells revealed a cellular accumulation in the G1 phase.

Synthesis and binding studies on a new series of arylpiperazino benzazol-2-one and benzoxazin-3-one derivatives as selective D4 ligands.

A series of new arylpiperazinomethyl derivatives was designed and studied as potential D4 ligands. The synthesis of these compounds required an original synthetic route. Some of the tested compounds were found to be as potent as clozapine at D4 receptors. Moreover, compounds which displayed a high D2/D4 selectivity ratio (>122) were selected for further pharmacological evaluation.

Tetrahydronaphthalenic derivatives as new agonist and antagonist ligands for melatonin receptors.

Tetrahydronaphthalenic ligands were synthesized and evaluated as melatonin receptor ligands. Biological studies show that the aromaticity of the ring bearing the side chain is not essential for affinity and activity and that replacement of the methoxy group with the bioisostere ethyl which does not offer the possibility of H-bonding, leads to antagonist or forskoline potentiating properties.

N-phenacylthiazolium bromide decreases renal and increases urinary advanced glycation end products excretion without ameliorating diabetic nephropathy in C57BL/6 mice.

AIMS: Advanced glycation end products (AGE), which form from the non-enzymatic reaction of proteins and sugars, have been implicated in the pathogenesis of diabetic nephropathy. Recently, a compound [N-phenacylthiazolium bromide (PTB)] has been described which cleaves alpha,beta-dicarbonyl compounds. In the present study we used diabetic C57BL/6 mice to determine if PTB altered renal AGE levels and reduced diabetic glomerulosclerosis. METHODS: Mice with stable hyperglycaemia induced by streptozotocin were given daily subcutaneous injections of either PTB (10 microg/g) or saline for 12 weeks. Renal-collagen bound AGE and urinary AGE-peptides were measured by ELISA using an anti-AGE-RNase antibody. Renal collagen-released Nepsilon(carboxymethyl)lysine (CML) and pentosidine were determined by high pressure liquid chromatography (HPLC). Glomerular lesions (volume and mesangial/total surface area) were evaluated by computer-assisted image analysis. We determined urinary protein/creatinine ratio as a functional parameter. AGE localization was examined by immunohistochemistry using the anti-AGE-RNase antibody. RESULTS: Renal collagen-bound AGE were decreased and urinary AGE excretion was increased in PTB-treated diabetic mice. However, collagen-released CML and pentosidine were similar in both groups. Glomerular histology and morphometric analysis revealed also no differences between PTB-and saline-treated diabetic mice. The urinary protein/creatinine ratio was unaffected by PTB-treatment. AGE staining by anti-AGE-RNase antibody was present in Bowman's capsules, glomerular basement membranes and cortical tubules. It was decreased in all structures in PTB-treated diabetic mice. CONCLUSION: In summary, PTB decreased renal AGE accumulation but did not ameliorate glomerular lesions or proteinuria. Thus, cleavage of AGE by PTB is not sufficient to prevent development of diabetic nephropathy in C57BL/6 mice.

Synthesis and structure-activity relationships of novel naphthalenic and bioisosteric related amidic derivatives as melatonin receptor ligands.

A previous paper reported the synthesis of melatonin receptor ligands. In order to complete the structure-activity relationships and to obtain antagonists to the melatonin receptor, a new series of naphthalenic analogues of melatonin have been synthesized. Modifications include deletion of the 7-methoxy group, replacement of the ethylene moiety, replacement of the amidic function by bioisosteres, and replacement of the naphthalenic nucleus by other bicyclic rings. Almost all the structural modifications lead to decreased affinity for the melatonin receptor. However, the N-n propyl urea derivative (27) is a very potent ligand at this receptor (pKi = 14.3). Most interestingly deletion of the methoxy group resulted in the first antagonist in this series. This molecule, compound 12, or N-[2-(1-naphthyl)-ethyl]cyclobutyl carboxamide has been selected for preclinical development.