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At least 19 recordsLinked to original sources
PubMed1992

Synthesis and beta-adrenergic antagonist activity of novel (3-oxazolinyl-1,4-dihydropyridyl) propanolamines.

A novel class of 1-(1-[4-phenyl(n-butyl or methyl)-3-(4,4-dimethyloxazolin-2-yl)-1,4- dihydropyridyl])-3-tert-butyl(or isopropyl)amino-2-propanols (7-12) were synthesized for evaluation as beta-adrenergic antagonists. Replacement of the naphthyloxy moiety of propranolol by a 1-[1-(4-n-butyl)-3-(4,4-dimethyloxazolin-2-yl)-1,4-dihydropyrid yl] group resulted in a significant decrease in cardiac beta 1-adrenergic antagonist activity which indicates that this group is not a suitable isostere for an aryloxy moiety. 1-(1-[4-n-Butyl-3-(4,4-dimethyloxazolin-2-yl)-1,4-dihydropyridy l])-3- isopropylamino-2-propanol (10) showed a modest beta 2-adrenergic antagonist selectivity for trachea (beta 2/beta 1 = 3:1).

Adrenergic beta-Antagonists↗
PubMed1976

The mechanism of action of ethanolamine ammonia-lyase, an adenosylcobalamin-dependent enzyme. The source of the third methyl hydrogen in the 5'-deoxyadenosine generated from the cofactor during catalysis.

Ethanolamine ammonia-lyase is an adenosylcobalamin-dependent enzyme which catalyzes the conversion of ethanolamine and propanolamine to ammonia and the corresponding aldehydes. A mechanism has been proposed for this and other adenosylcobalamin-dependent reactions which involves cleavage of the carbon-cobalt bond of the cofactor followed by abstraction of a substrate hydrogen atom by the adenosyl fragment to form 5'-deoxyadenosine. In support of this proposal, a previous study demonstrated that the deamination of propanolamine by ethanolamine ammonia-lyase is accompanied by the reversible cleavage of the carbon-cobalt bond of the cofactor, with the production of 5'-deoxyadenosine (Babior, B.M., Carty, T.J., and Abeles, R.H. (1974) J. Biol. Chem. 249, 1689-1695). The present study is concerned with the origin of the third hydrogen atom on the methyl group of the 5'-deoxyadenosine produced in that reaction. The 5'-deoxyadenosine isolated from an incubation mixture initially containing enzyme, [5',5'-D2]adenosylcobalamin, and [1,1-D2]propanolamine was chemically degraded so that the 4' and 5' carbon atoms were, respectively, converted to the carbonyl and methyl carbons of acetaldehyde. Analysis of the p-nitrophenylhydrazone of the acetaldehyde by gas-liquid chromatography-mass spectroscopy revealed 3 deuterium atoms/molecule, indicating that two of the methyl hydrogens originated from adenosylcobalamin and the third was donated by substrate. This observation provides further support for the participation of 5'-deoxyadenosine in the mechanism of adenosylcobalamin-dependent reactions.

Ammonia-Lyases↗
PubMed1977

NMR and calorimetric studies of changes in phase transition of head group modified phospholipids.

The 13C- and 31P-NMR spectra and DSC thermograms of unsonicated dispersions consisting of phospholipids of varying methylation stages of the propanolamine head group were investigated. Methylation of the head group was accompanied by a corresponding reduction in the phase transition temperatures. In the liquid crystalline state the 31P-anisotropy of the chemical shift is about equal for all studied compounds, demonstrating that the motion of the phosphate group is not influenced by modifications of the propanolamine group.

Calorimetry↗
PubMed1977

Adrenergic agents. 8.1 Synthesis and beta-adrenergic agonist activity of some 3-tert-butylamino-2-(substituted phenyl)-1-propanols.

Replacement of the benzylic hydroxyl group of N-tert-butylnorepinephrine with a hydroxymethyl substituent affords a propanolamine homologue which retains a high degree of beta-adrenergic agonist activity. As modification of the meta substituent of catecholic ethanolamines, such as N-tert-butylnorepinephrine, often provides compounds that exert a more pronounced effect in relaxing tracheobronchial smooth muscle (beta2-adrenergic agonist) than in stimulating cardiac muscle (beta1-adrenergic response), a series of 3-tert-butylamino-2-(3-substituted 4-hydroxyphenyl)-1-propanols was prepared. The 3-meta substituents included HOCH2 (1b), H2NCONH (1c), MeSO2NH (1d), H (le), and NH2 (1f). These phenylpropanolamine derivatives were compared with their phenylethanolamine counterparts in in vitro tests that measure the ability of these compounds to relax spontaneously contracted guinea pig tracheal smooth muscle (a measure of potential bronchodilating activity) and to increase the rate of contraction of a spontaneously beating guinea pig right atrial preparation (an indicator of potential cardiac stimulating activity). In these tests all of the propanolamine derivatives included in the study were less potent than their ethanolamine relatives. In both series replacement of the catecholic m-hydroxyl group with the indicated substituents usually resulted in compounds with increased selectivity for tracheobronchial vs. cardiac muscle.

Adrenergic beta-Agonists↗
PubMed1992

Flavones. 3. Synthesis, biological activities, and conformational analysis of isoflavone derivatives and related compounds.

A series of 2-alkylisoflavone derivatives 1 was prepared with the intent to study the importance of the phenyl group (at the 3-position) of the isoflavone in imparting antihypertensive activity and the substitution effects at the 2-position of isoflavone. With the exception of the 2-isopropyl analog, the antihypertensive activity of these compounds appears to have a slow onset and long duration. None of the analogs appears better than the corresponding flavone (3) and 3-phenylflavone (2) analogs. An unsuccessful attempt to correlate the relationship between antihypertensive activity and the calculated torsional angle of C2-C3-C1'-C2' is discussed. Antiinflammatory activities of these compounds along with 7-(oxypropylamine)flavones were also evaluated and found to be not very potent. The antiinflammatory activity appears to be sensitive to steric effects of the alkyl group on the nitrogen and of substituents at the 2-position of the isoflavones, while the hydroxyl group of the propanolamine side chain is not essential.

Animals↗
PubMed1979

Aromatic hydroxylation of beta-adrenergic antagonists. Formation of 4'- and 5'-hydroxy-1-(isopropylamino)-3-[2'-allyloxy)phenoxy]-2-propanol from oxprenolol.

The metabolic aromatic hydroxylation of oxprenolol [1-(isopropylamino)-3-[2'-(allyloxy)phenoxy]-2-propanol] in rats was examined. Synthesis of the isomeric ring methoxyoxprenolols (3b-6b) was accomplished from the isomeric methoxysalicylaldehydes by O-allylation, followed by Baeyer-Villiger oxidation. The propanolamine side chain was elaborated by O-alkylation of the Bayer-Villiger product with epichlorohydrin and subsequent oxirane opening with isopropylamine. Gas chromatography-mass spectra of the trifluoroacetyl derivatives of these standards was compared with urinary metabolites obtained from the rat, after methylation with diazomethane and derivatization with trifluoroacetic anhydride. Both 4'- and 5'-hydroxyoxprenolol (4a and 5a) were present in an approximate 4:1 ratio. No 3'- or 6'-hydroxyoxprenolol (3a and 6a) was detected. The metabolites obtained from a human urine treated in the same manner gave similar results with both 4a and 5a present.

Animals↗
PubMed1979

Synthesis of 4'- and 5'-hydroxyoxprenolol:pharmacologically active ring-hydroxylated metabolites of oxprenolol.

Synthesis and preliminary pharmacological activity data for 4'- and 5'-hydroxyoxprenolol (2 and 3) are reported. The synthetic routes make use of the isomeric 2-pyranyl monoether derivatives of 4-hydroxysalicylaldehyde and 2,5-dihydroxyacetophenone. The corresponding O-allyl ethers were converted to substituted phenols by Baeyer-Villiger oxidation and the propanolamine side chain elaborated using epichlorohydrin, followed by oxirane ring opening with isopropylamine. Each of the hydroxylated metabolites is about ten times less potent than oxprenolol as an antagonist to the isoproterenol-induced relaxation of guinea pig tracheal strips.

Airway Resistance↗
PubMed1977

Timolol. A beta-adrenergic blocking agent for the treatment of glaucoma.

Timolol maleate, a beta-adrenergic blocking agent, was studied in 30 patients with glaucoma. Significant intraocular pressure lowering was achieved with 0.5% and 1.5% solution of the drug. At seven hours following treatment, the IOP was lowered 50% from the pretreatment pressure with both strengths of timolol. There were no subjective or objective ocular or systemic side effects detected. Visual acuity and pupil response were unchanged from pretreatment levels throughout the study. beta-Adrenergic blocking agents and specifically timolol may be an important breakthrough for the medical management of glaucoma.

Clinical Trials as Topic↗
PubMed1977

Timolol, dose response and duration of action.

Timolol maleate, a beta-adrenergic blocking agent, was used in a study of 20 adult patients with chronic open-angle glaucoma. This single-dose study demonstrated a dose response for this drug using concentrations of 0.1%, 0.25%, 0.5%, and 1.0%. Timolol, 0.5%, appears to give the maximal ocular hypotensive effect; however, each concentration of the drug produced an ocular hypotensive effect for at least 24 hours. No local or systemic side effects were discovered throughout the study. Timolol may be an effective, innocuous, once-a-day, topical agent for the treatment of glaucoma.

Adult↗
PubMed1978

Timolol. A new drug for management of chronic simple glaucoma.

Timolol maleate, a potent beta-adrenergic antagonist, reduces intraocular pressure in rabbits. With topical application in one eye, a significant reduction in pressure is seen in the contralateral, untreated eye also. When used in conjunction with timolol, other adrenergic amines, such as norepinephrine and epinephrine, produce an additional hypotensive response. On the other hand, pretreatment with timolol does inhibit the ocular hypotensive response to topically applied albuterol. No further reduction in pressure is seen after application of this beta-adrenergic agonist to eyes pretreated with timolol. In a double-blind study with patients who had previously been receiving various medications for control of elevated intraocular pressures, timolol was as effective as pilocarpine in reducing intraocular tension. Many common complaints associated with pilocarpine therapy, including miosis, ocular irritation, and blurred vision, were not encountered with timolol therapy.

Adult↗
PubMed1978

The mechanism of timolol in lowering intraocular pressure. In the normal eye.

A single-drop, double-masked, randomized, placebo-controlled study of the mechanism of the ocular-pressure lowering property of timolol maleate, a beta-adrenergic blocker, was carried out in 23 normal subjects, using fluorophotometry. Timolol suppressed aqueous formation in all subjects. The range of suppression was 13% to 48%, with a mean +/- SD of 34% +/- 9%. The drug had no effect on anterior chamber volume or endothelial permeability to fluorescein and, apparently, had no effect on outflow resistance. No differences were observed between its effect on men and women or between eyes with light and dark irides.

Adult↗
PubMed1979

Timolol maleate: efficacy and safety.

A randomized, double-masked trial of various concentrations of timolol maleate ophthalmic solution (0.1%, 0.25%, 0.5%, and 1.0%) vs placebo demonstrated that all concentrations of timolol effectively lowered intraocular pressure (IOP). A 0.5% solution of timolol was as effective in reducing IOP as the 1.0% concentration. Blood pressure, visual acuity, and pupillary diameter were not altered significantly by any concentration of timolol tested during this study. There was a dose-dependent decrease in resting pulse rate with increasing concentrations of timolol. No objective signs of drug intolerance were found on external ocular examination, nor were any subjective symptoms elicited on questioning the subjects. Timolol applied topically twice daily in concentrations of 0.1% to 0.5% appeared to be an effective and safe ocular hypotensive agent.

Adult↗
PubMed1975

Programmed "trendscription." A new approach to electrocardiographic monitoring.

A new approach to monitoring of episodic but frequently recurring arrhythmias has been developed, consisting of condensation of electrocardiographic information on a special drum recorder, a programmer that permits selection of intervals and durations for monitoring, and a telemetry unit for transmission of the electrocardiographic signal. We used this system to manage three selected cases.

Adrenergic beta-Antagonists↗