Synthesis and adrenergic activity of a new series of N-aryl dicyclopropyl ketone oxime ethers: SAR and stereochemical aspects.

A novel series of 31 N-aryl dicyclopropyl ketone oxime ethers were synthesized and tested for their activity at alpha- and beta-adrenergic receptors. All of the compounds showed greater affinity for beta-than for alpha1-receptor sites. Some compounds had pure antagonist effects whereas some were partial agonists. Several compounds had an antagonist effect matching that of propranolol in in vitro (binding data and pA2 values on rat heart ventricle homogenates and guinea pig spontaneously beating right and electrically driven left atrial isolated preparations, respectively) and in in vivo tests (measurement of antagonism toward isoprenaline-induced tachycardia in anesthetized rats). Furthermore, all of the compounds showed a beta1-adrenergic selectivity (beta2-affinity > 1500 nM).

[Synthesis, biological activity and encapsulation of new adrenergic beta-amino alcohols in phospholipid liposomes]. / Synthèse, activité biologique et encapsulation de nouveaux beta-amino-alcools adrénergiques dans des liposomes phospholipidiques.

New beta-amino-alcohols were synthesized and showed beta-blocking biological activity. These potential drugs, as well as natrium salicylate, have been entrapped in phospholipid liposomes. Drug-containing liposomes were prepared from egg lecithin and DPPC (Dipalmitoylphosphatidylcholine) by the injection method. Turbidity measurements and dynamic light scattering were used to characterise the liposome and to study their stability during storage. The entrapment efficiency of the drugs in liposomes was correlated to the partition coefficient of the drugs.

Determination of falintolol, a new aliphatic beta-adrenergic antagonist, in whole blood by gas chromatography with electron-capture detection: geometric isomers resolution.

Falintolol oxalate, a new beta-adrenergic antagonist, is characterized by the presence of an oxime function and exists in a racemic form as a mixture of syn- and anti- isomers in a ratio of about 8:2. This article describes a selective gas chromatographic method for the resolution of the geometric isomers and the quantitation of the drug. The unchanged falintolol and internal standard, a related compound, are separated from blood by a solvent extraction under alkaline conditions, and then the drug is derivatized. The heptafluorobutyric derivatives are chromatographed on an SE-30 capillary quartz column and detected with a nickel-63 electron-capture detector. Because the syn- and anti- isomers of falintolol display comparable chromatographic responses, the sum of the two geometrical isomers is used for the quantitation of falintolol in blood. This method allows small serial blood samples in conscious rats, and 0.05 microgram of falintolol/0.1 mL of blood can be routinely determined. A calibration curve is prepared for the blood extracts. Linearity is observed in the study range (0.05 to 1 microgram/0.1 mL of blood). No interference by endogenous substances is observed. The procedure is applied successfully to drug absorption in rats when repeated oral doses are administered.

Effects of topically applied falintolol: a new beta-adrenergic antagonist for treatment of glaucoma.

Changes in intraocular pressure (IOP) following topical administration of falintolol (0.5%-0.25%), a new beta-blocking agent, were studied in conscious albino rabbits with alpha-chymotrypsin-induced ocular hypertension. The drug produced a reduction in IOP equal to that of timolol. A longer duration of activity was noted with falintolol. The rate of transport of topically applied falintolol through the isolated bovine cornea under conditions simulating normal physiology was linear up to three hours and twice as fast as timolol from 3 to 6 hours. Since topical ocular application of beta-adrenergic antagonists useful in glaucoma therapy can also cause a number of troublesome systemic side effects, several conclusive preclinical investigations were carried out with falintolol. Of major concern was the effect falintolol might have on the pupil, cornea, and heart rate when administered topically. The results show that falintolol does not produce any noteworthy side effects and is capable of being an effective beta-blocking agent in open-angle glaucoma therapy.

New chiral and isomeric cyclopropyl ketoxime propanolamine derivatives with potent beta-adrenergic blocking properties.

The synthesis of R-(+) and S-(-) isomers of O-[3-tert-butylamino)-2-hydroxypropyl] cyclopropyl methyl ketone oxime (falintolol) is described. The syn and anti isomers of falintolol were obtained in two different ways from cyclopropyl methyl ketoxime or from falintolol. For comparison purposes, the enantiomers of the dicyclopropyl ketone oxime derivatives were also prepared. Structure-activity relationships are described.

In vitro potential measurement, anaesthetic and antimicrobial effects as indicators of beta-blocker toxicity of the cornea.

Three tests were utilized to determine and compare the toxicity of timolol, propranolol and two new aliphatic and alicyclic oxime ethers with beta-blocking activity (falintolol and compound POS 7). Effects on the electrical potential difference across the in vitro bovine corneal epithelium. Local anaesthesia on in vivo rabbit cornea. Antimicrobial activity on bacterial and fungal suspensions. In addition, partition coefficients were determined as physicochemical properties of the drugs. Falintolol, as well as timolol produced a minor change in electrophysiology at clinical concentration. They had neither local anaesthetic, nor antimicrobial effects. Conversely, propranolol and compound POS 7 showed acute corneal toxicity in the present models. It was concluded that changes in the potential difference across a perfused cornea in vitro, local anaesthesia and bacterial inhibition, might be a demonstration of the cytotoxicity of certain topical agents in terms of acute eye tissue reaction. They might represent a valuable model for the acute corneal toxicity evaluation of topical beta-blockers.

Synthesis and beta-adrenergic blocking activity of new aliphatic and alicyclic oxime ethers.

We describe the synthesis and pharmacological properties of two new series of aliphatic and alicyclic beta-adrenergic blockers, most of them containing a cyclopropyl ring. They belong either to 2-hydroxy-3-(tert-butylamino)propyl ether A or 2-hydroxy-3-tert-(butylamino)propyl ketoxime ether B derivatives. The O-[2-hydroxy-3-(tert-butylamino)propyl] dicyclopropyl ketoxime 5 exhibited a beta-adrenergic antagonist activity comparable to that of propranolol. It was found that ketoxime ethers B generally showed higher potency than the corresponding ethers A. We confirm that the presence of an aromatic nucleus is not crucial for the beta-adrenergic activity. Structure-activity relationships among these series are discussed.