Analgesic Effects of 5-Alkyloxy-4-amino-2(5H)-furanones as Cholecystokinin-2 Antagonists.

4-Amino-2(5H)-furanones were synthesized in high yields over two synthetic steps from readily available mucochloric acid. These 5-alkyloxy-4-amino-2(5H)-furanones were screened in a ([125]) I-CCK-8 radioligand receptor binding assay for CCK2 affinity and novel active ligands in the nanomolar range were identified. SAR was optimized leading to the cyclohexyl derivative 25 with an IC50 of 27 nM. Furanone 18 was obtained as a stable crystalline material with an IC50 of 85 nM, but had a higher CCK2 selectivity. It was subsequently tested in the isolated guinea pig ileum assay with sulfated CCK8 , and the CCK antagonizing properties of the ligand were confirmed. The CCK2 selective antagonist 18 was found to potentiate analgesia in the tail flick assay in mice, for the strong opiate morphine, the partial opiate agonist tramadol and the tricyclic antidepressant desimipramine.

Novel, isoform-selective, cholecystokinin A receptor antagonist inhibits colon and pancreatic cancers in preclinical models through novel mechanism of action.

Colon and pancreatic cancers contribute to 90,000 deaths each year in the USA. These cancers lack targeted therapeutics due to heterogeneity of the disease and multiple causative factors. One important factor that contributes to increased colon and pancreatic cancer risk is gastrin. Gastrin mediates its actions through two G-protein coupled receptors (GPCRs): cholecystokinin receptor A (CCK-A) and CCK-B/gastrin receptor. Previous studies have indicated that colon cancer predominantly expresses CCK-A and responds to CCK-A isoform antagonists. However, many CCK-A antagonists have failed in the clinic due to poor pharmacokinetic properties or lack of efficacy. In the present study, we synthesized a library of CCK-A isoform-selective antagonists and tested them in various colon and pancreatic cancer preclinical models. The lead CCK-A isoform, selective antagonist PNB-028, bound to CCK-A at 12 nM with a 60-fold selectivity towards CCK-A over CCK-B. Furthermore, it inhibited the proliferation of CCK-A-expressing colon and pancreatic cancer cells without affecting the proliferation of non-cancerous cells. PNB-028 was also extremely effective in inhibiting the growth of MAC-16 and LoVo colon cancer and MIA PaCa pancreatic cancer xenografts in immune-compromised mice. Genome­wide microarray and kinase-array studies indicate that PNB-028 inhibited oncogenic kinases and angiogenic factors to inhibit the growth of colon cancer xenografts. Safety pharmacology and toxicology studies have indicated that PNB-028 is extremely safe and has a wide safety margin. These studies suggest that targeting CCK-A selectively renders promise to treat colon and pancreatic cancers and that PNB-028 could become the next-generation treatment option.

Antidepressant/anxiolytic and anti-nociceptive effects of novel 2-substituted 1,4-benzodiazepine-2-ones.

Oxazepam (4a) has been used as overall starting material in the synthesis of novel 2-substituted 1,4-benzodiazepines.By reacting Oxazepam 4a with commercially available hydrazines, hydrazides, semicarbazide, aminoguanidine and N,N-dimethylamino aniline in ethanol under acetic conditions, a series of diazenyl-1,4-benzodiazepines 5aâ5i and 2-amino-1,4-benzodiazepine 5k were obtained in good yields.These novel compounds served as new chemical entities (NCE) for testing in mice. The diazo-benzodiazepine 5d has shown a promising antidepressant effect in initial experiments in vivo at a dose of 5 mg/kg. The highly coloured 2-aminobenzodiazepine derivative 5k showed over a dose range from 5â50 mg/kg an analgesic effect in mice.

In vivo evaluation of substituted 3-amino-1,4-benzodiazepines as anti-depressant, anxiolytic and anti-nociceptive agents.

Oxazepam (CAS 604-75-1) 4a served as building block in the synthesis of substituted 3-amino-1,4-benzodiazepines, which were subsequently tested in various CNS animal models. The hydroxy group of oxazepam was either activated as a chloride (Method A) or as a phosphor-oxy derivative (Method B) giving the desired 3-amino-1,4-benzodiapines 6a-6r in high yields with primary and secondary amines in a typical nucleophilic substitution reaction. Eighteen 3-substituted 1,4-benzodiazepines were prepared and served as new chemical entities and for lead structure discovery. The mixed cholecystokinin (CCK) antagonist 6e showed anxiolytic and antidepressant effects from 10 microg/kg in mice in the elevated x-maze test and the forced swimming test. The CCK1 antagonist 6 g has shown antidepressant effects from the same dose, but lacked anxiolytic properties. Both compounds potentiated at a dose of 0.5 mg/kg morphine antinociception with a maximum possible effect (MPE) about 35%. By assessing initially the MPE of antinocipection for the 18 newly synthesised benzodiazepines in the tail-flick test, 4 other benzodiazepines were found active. In further in vive evaluation the cyclohexyl derivative 6 i displayed anxiolytic, antidepressant and antinociceptive properties as single agent at a dose of 5 mg/kg without toxicity. The benzodiazepines 6i and 6p, which initially showed a higher MPE in terms of morphine potentiation (43/44%) showed analgesic effects as single agents, without having anxiolytic or antidepressant properties. The amino-piperidinyl derivative 6p displayed a similar dose-response relationship to morphine, but was 3 times more potent.

Novel anti-bacterials against MRSA: synthesis of focussed combinatorial libraries of tri-substituted 2(5H)-furanones.

Mucobromic and mucochloric acid were used as building blocks for the construction of a chemical combinatorial library of 3,4,5-trisubstituted 2(5H)-furanones. With these 2 butenolide building blocks, and eight alcohols a sublibrary of 16 dihalogenated 5-alkoxy-2(5H)-furanones was prepared. This sublibrary of 5-alkoxylated furanones was reacted with 16 amines generating a full size focussed combinatorial library of 256 individual compounds. This three dimensional combinatorial library of 3-halogen-4-amino-5-alkoxy-2(5H)-furanones was prepared around the benzimida-zolyl furanone lead structure by applying a solution phase combinatorial chemistry concept. Typical representatives of the library were purified and fully characterized and one x-ray structures was recorded, additionally. The 3-bromo-4-benzimizazolyl-5-methoxy-2(5H)furanone, Br-A-l, showed an MIC of 8 microg/ml against the multiresistant Staphylococcus aureus (MRSA).

Synthesis of substituted 3-anilino-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepine-2-ones and their evaluation as cholecystokinin-ligands.

3-Amino-1,4-benzodiazepines as well as chemically related diverse amines were prepared from oxazepam and subsequently screened on the cholecystokinin receptor in a radiolabel binding assay. Oxazepam 2 was activated via its 3-chloro-1,4-benzodiazepine intermediate 3 and was reacted with a large series of aliphatic and aromatic amines. The substituted 3-anilino-1,4-benzodiazepine structure was identified as lead structure in a diverse series of 3-amino-1,4-benzodiazepines 4-38 and the full SAR (structure-activity relationship) optimisation provided 3-anilinobenzodiazepines 16-38 with CCK1 receptor selectivity to CCK2. The compounds 18, 24, 28 and 33 have shown affinities at the CCK1 receptor of 11, 10, 11 and 9 nM, respectively. These equipotent CCK1 ligands were fully evaluated in behaviour pharmacological essays. An antidepressant effect was identified in the tail suspension- and the Porsolt swimming-test. The ED50 values for 24 and 28 were determined in these assays as 0.46 and 0.49 mg/kg. The mixed antagonist 37 showed in addition to the antidepressant effects anxiolytic properties.

Synthesis and evaluation of N-(3-oxo-2,3-dihydro-1H-pyrazol-4-yl)-1H-indole-carboxamides as cholecystokinin antagonists.

The structure-activity relationship optimization of the pyrazoline template 3a resulted in novel 3-oxo-1,2-diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-indole carboxamides 4a-4e. These non-peptidal CCK ligands have been shown to act as potent CCK1 ligands in a [125]I-CCK-8 receptor binding assay. The best amides (4c and 4d) of this series displayed an IC50 of 20/25 nM for the CCK1 receptor. In a subsequent in-vivo evaluation using various behaviour pharmacological assays, an anxiolytic effect of these novel 3-oxo-1,2-diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-indole carboxamides was found at high doses in the elevated plus-maze. In the despair swimming test, a model for testing antidepressants, an ED50 of 0.33/0.41 mg kg(-1) was determined for amide 4c/4d and the antidepressant effect had a magnitude comparable to desimipramine.

Synthesis and evaluation of N-(5-methyl-3-oxo-1,2- diphenyl-2,3-dihydro-1H-pyrazol-4-yl)-N'-phenylureas as cholecystokinin antagonists.

In the search for new cholecystokinin (CCK) ligands, ureidopyrazolines were identified in combinatorial libraries using 168 chemically diverse amines. The structure-activity relationship optimisation of this pyrazoline template 4a resulted in novel 3-oxo-1,2-diphenyl-2,3-di-hydro-1H-pyrazol-4-yl)-N'-phenylureas 5a-5o. These novel CCK ligands have shown to act as mixed CCK-A/CCK-B ligands in a [125]I-CCK-8 receptor binding assay. The best pyrazoline 5e of this series displayed an IC50 of 20 and 25 nmol/L for the CCK-A, and CCK-B receptor, respectively. In a subsequent in vivo evaluation using various behavior pharmacological assays, an anxiolytic effect of these novel diphenylpyrazolinyl ureas was found in the elevated x-maze with an ED50 of 1.7 mg/kg. In the despair swimming test, a model for testing antidepressants, an ED50 of 0.69 mg/kg was determinated for urea 5e and the antidepressant effect had a magnitude comparable to desimipramine.