Showing papers on "Derivative (chemistry) published in 1976"

Isotope-derivative Measurements of Plasma Norepinephrine and Epinephrine in Man

Abstract: S reduced the activity of COMT, but increasing the magnesium concentration in the incubation mixture and the addition of EGTA to plasma samples improved the recoveries. Each sample was corrected for losses incurred during extraction and chromatography by using [Cjmethoxytyramine, [Cjnormetanephrine, and [CJmetanephrine that were added at the end of incubation. Several catechol compounds known to be O-methylated by COMT were examined for cross-reactivity. Of the substances tested, only dihydroxyphenylalanine (DOPA) exhibited cross-reactivity. However, the apparent 30% cross-reactivity of DOPA with dopamine was due to the presence of decarboxylase activity in the COMT preparation. As little as 50 fxl of trunk plasma from decapitated rats was sufficient for the determination of the three catecholamines. (All are verbatim summaries) Louis, W. J.; Doyle, A. E.; and Anavekar, S. N. (Univ. of Melbourne, Dept. of Med., Austin Hosp., Victoria, Australia): PLASMA NORADRENALINE CONCENTRATION AND BLOOD PRESSURE IN ESSENTIAL HYPERTENSION, PHAEOCHROMOCYTOMA AND DEPRESSION. Clin. Sci. Molec. Med. 48:239, 1975. 1. Mean plasma noradrenaline concentration was elevated in forty-four patients with established essential hypertension. Eighteen of these hypertensive patients had resting plasma noradrenaline concentrations in the normal range. 2. Patients with endogenous depression had higher mean plasma noradrenaline concentrations but significantly lower blood pressure than patients with essential hypertension. 3. Patients with phaeochromocytoma had plasma noradrenaline concentrations twenty-eight times greater than those found in essential hypertension, but blood pressures were less than 20% higher. 4. It is concluded that excess of sympathetic drive only partly explains the level of the blood pressure in essential hypertension. Ben-Jonothan, Nira; and Porter, John C. (Cecil H. and Ida Green Centr. for Reproductive Biology Sciences, the Dept. of Obstetrics and Gyn., and the Dept. of Physiology, the Univ. of Texas Health Science Centr. at Dallas, Southwestern Med. Sch., Dallas, Tex.): A SENSITIVE RADIOENZYMATIC ASSAY FOR DOPAMINE, NOREPINEPHRINE, AND EPINEPHRINE IN PLASMA AND TISSUE. Endocrinology 98:1497, 1976. A double-isotope, radioenzymatic assay for measuring dopamine, norepinephrine, and epinephrine in one sample is described. The assay procedure includes incubation, solvent extraction, and thin-layer chromatography. Dopamine, norepinephrine, and epinephrine were incubated with catechol-O-methyl transferase (COMT) and [H]S-adenosyl methionine ([H]SAM) and were converted to the O-methylated tritiated derivatives: [H]methoxytyramine, [Hjnormetanephrine, and [Hjmetanephrine, respectively. After several extraction steps, the O-methylated products were purified by means of twodimensional, thin-layer chromatography using silica gel. The thin-layer chromatographic system using silica gel. The thin-layer chromatographic system resulted in complete separation of the three O-methylated compounds with an overlap of only 1-2%. The assay was linear from 0 to 5 ng for each catecholamine and had a sensitivity of 10-30 pg. The addition of large amounts of plasma De Champlain, Jacques; Farley, Lise; Cousineau, Daniel; and Van Ameringen, Marie-Reine (Centre de Recherche en Sciences Neurologiques, Dep. de Physiologie, Faculte de Medecine, Universite de Montre'al, Quebec, Canada): CIRCULATING CATECHOLAMINE LEVELS IN HUMAN AND EXPERIMENTAL HYPERTENSION. Circ. Res 38:109, 1976. The radiometric enzymatic technique of Coyle and Henry (J. Neurochem. 21:61-67, 1973) was adapted to the measurement of serum catecholamines. This technique requires less time than other enzymatic techniques and is sensitive to quantities as small as 25 pg. In normotensive subjects lying supine for 20 minutes serum catecholamine levels averaged 0.218 ng/ml, with no obvious sex or age difference. Under these standardized conditions, the circulating catecholamine levels for a given individual are highly reproducible on different days over a period of several months. In 22 patients with essential hypertension, circulating levels were significantly higher, with an average of 0.370 ng/ml. More than 50% of the hypertensive patients had values greater than the highest value measured in normotensives. Systolic blood pressure and heart rate were significantly higher in the hypertensive group with elevated levels of circulating catecholamines than in the hypertensive group with normal levels. In one model of experimental hypertension, produced in the rat by administration of deoxycorticosterone acetate (DOCA) and saline for 4-8 weeks, serum catecholamines were significantly elevated. These findings suggest that the sympathetic system may play an important role in maintaining an elevated blood pressure in experimental hypertension and in a significant proportion of patients with essential hypertension. Johnson, David G.; Henry, David P.; Moss, Jonathan; and Williams, Robert H. (Divisions of Endocrinology and Clinical Pharmacology, Dept. of Med., Univ. of Washington, Seattle, Wash.): INHIBITION OF INSULIN RELEASE BY SCORPION TOXIN IN RAT PANCREATIC ISLETS. Diabetes 25:198, 1976. Toxin purified from venom of the scorpion Leiurus quinquestriatus was used to release norepinephrine from adrenergic nerve terminals in isolated pancreatic islets perifused in vitro. Addition of toxin (10 /xg./ml.) to the perifusion medium caused a sixfold increase in release of norepinephrine in the presence or absence of 3 X 10\"M phenoxybenzamine. During 20 minutes of stimulation with toxin, the pancreatic islets released an average of 15 pg. 1082 DIABETES, VOL. 2 5 , NO. 11

Diphenylmethane diisocyanate compositions

Abstract: A diphenylmethane diisocyanate composition which comprises diphenylmethane diisocyanate, a diphenylmethane diisocyanate uretonimine group-containing derivative, a reaction product of diphenylmethane diisocyanate and a diol of molecular weight less than 175 and optionally not more than 10% by weight of methylene bridged polyphenyl polyisocyanates of isocyanate functionality higher than two, the composition having an isocyanate functionality of not more than 2.3. Methods of manufacture of such compositions, which compositions are useful for the manufacture of polyurethanes.

Cross-linked saponified absorbent polymer

Abstract: A highly absorbent polymer is obtained by saponifying a crosslinked copolymer of a vinyl ester and an ethylenically unsaturated carboxylic acid or the derivative thereof. The absorbent polymer is suitable as a material, for example, for separation and purification of substances and a seed culturing media for plants.

Some demonstrations of the effect of the heating rate on thermoanalytical curves

Abstract: Thermoanalytical curves of two parallel competitive reaction systems and of two systems in which two mutually independent reactions occur concurrently are made by simulation, as well as isothermal curves of the systems. From these curves, an effect of heating rate is illustratively shown; one peak is observed in a derivative thermoanalytical curve at one heating rate, while a shoulder or two peaks appear in another derivative curve of the same reaction system at another heating rate. An advantage of thermal analysis over isothermal experiments, and its limitations, are discussed.

Syntheses and properties of phosphino- and phosphinatopyrazoles

Abstract: The new P—N bonded phosphino- and phosphinatopyrazoles and (C2H5)2P(pz) and the arsenic derivative (pz)3As have been prepared and characterized (pz = pyrazolyl, Me2pz = 3,5-dimethylpyrazolyl).The r...

Synthesis of the germination stimulant (±)-strigol

Abstract: Two synthetic routes to the octahydroindeno[1,2-b]furanone derivative strigol (1), a germination stimulant of witchweed seeds, and its stereoisomers are described.

Process of producing ring-opening polymerization products

Abstract: A process of producing a ring-opening polymerization product of a norbornene derivative containing at least one polar group or aromatic group, a norbornadiene derivative containing at least one of said groups or a cycloolefin using a catalyst system prepared from an organometallic compound and the reaction product of tungsten oxide or molybdenum oxide and a phosphorus pentahalide or phosphorus oxytrihalide or these compounds and other third components. The catalyst system possesses a high polymerization activity.

Biosynthesis of the fungal xanthone ravenelin

Abstract: Carbon-13 and carbon-14 labelling experiments have shown that the fungal xanthone ravenelin (1) is acetatederived. Enrichment studies with [1,2–13C]acetate have demonstrated that an oxygenated benzophenone derivative is an intermediate in the biosynthetic pathway.

Malonic acid derivative composition for forming thermoparticulating coating

Abstract: A composition is disclosed of a malonic acid derivative, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the malonic acid derivative in the coating forms particles in the gas stream which are detected by a monitor.

Deactivation of catalysts of the ziegler type used for the preparation of polyethylene in high pressure, high temperature processes

Abstract: The present invention relates to a process for the continuous polymerisation and copolymerisation of ethylene under a pressure higher than 500 bars and at temperatures higher than about 160° C in the presence of a catalyst containing a derivative of a transition metal and an organic derivative of aluminium, wherein there is injected into the reaction mixture at the end of reaction at least one alkali metal salt or alkaline earth metal salt of a carboxylic acid, in an amount sufficient to bring about the deactivation of the catalyst, said salt being so chosen that its reaction products with the constituents of the catalyst remain in the polymer.

Substituted (4-carboxyphenoxy) phenyl alkane compounds

Abstract: Pharmaceutical compositions having hypolipidaemic and/or hypoglycaemic activity, contain a substituted (4-carboxyphenoxy) phenyl alkane derivative.

Complete regiospecificity in the benzylation of a cis-diol by the stannylidene procedure

Abstract: While conventional monobenzylation of benzyl 6-O-allyl-2-O-benzyl-α-D-galactopyranoside (1) gives a four component mixture, treatment of the OO′-dibutyl-stannylidene derivative of (1) with benzyl bromide provides only the 3-O-benzyl ether (2) in 66% isolated yield.

Photochemische Synthese von 4‐Phenyl‐3‐oxazolin‐5‐onen und deren thermische Dimerisierung. 45. Mitteilung über Photoreaktionen

Abstract: Photochemical Synthesis of 4-Phenyl-3-oxazolin-5-ones and their Thermal Dimerization. Irradiation of 3-phenyl-2H-azirines affords reactive benzonitrilemethylide intermediates, which can be trapped by carbon dioxide to yield 4-phenyl-3-oxazolin-5-ones (Scheme 1). The first section of the paper deals with the experimental description of this reaction, which already has been preliminarily communicated. Upon irradiation the 3-oxazolin-5-ones undergo photoextrusion of carbon dioxide to reform the corresponding benzonitrile-methylides, which can be trapped by dimethyl acetylenedicarboxylate. In the second section of the paper, reactions of 2-methyl-4-phenyl-3-oxazolin-5-one (3c) are described. Upon heating to 130°, this compound is partially converted to 2-methyl-4-phenyl-2-oxazolin-5-one (azlactone 4e). Prolonged heating of 3c affords the dimer 7 (Scheme 3) as well as the imidazole derivative 9 (Scheme 4). Compound 7 is related to the ‘Rugheimer compound’ C18H14N2O4, formed from hippuric acid methylester. The structure of 7 was determined by X-ray crystallography and this supports the formula assigned earlier to the ‘Rugheimer compound’ (12) and related pyrrolidin-2,4-diones. The possible mechanism of the thermal formation of 7, which is also base catalysed, is represented in Scheme 3, the one for the formation of the imidazol 9 in Scheme 4. Under the influence of oxygen the 2,4-diphenyl-3-oxazolin-5-one (3b) undergoes a dehydrodimerization to yield compound 16 (Scheme 7). Section three contains the structure elucidation of compound 16 and a mechanistic proposal for the formation of the pyrazine 19 upon thermolysis of 2,4-diphenyl-2-oxazolin-5-on (4b, Scheme 7).

Preparation of phenolic resin

Abstract: PURPOSE: To obtain a phenolic resin capable of lowering the softening point without degrading the properties of molded articles, by reacting a reaction product, prepared from a phenol and an aldehyde in the presence of an acid catalyst, with an epoxy alkyl compound. CONSTITUTION: One mole of a phenol is reacted with an aldehyde in the presence of an acid catalyst to give a reaction product, which is reacted with a monofunctional epoxy alkyl compound in an epoxy equivalent of 0.001W0.1 to form a phenolic resin having a low softening point. The softening point is adjusted by the amount of the epoxy alkyl compound. A tertiary amine, a quaternary ammonium salt, or an imidazole derivative as a catalyst may be added to the reaction mixture together with the epoxy alkyl compound to make the reaction proceed rapidly. COPYRIGHT: (C)1979,JPO&Japio

Coating composition containing an alkylated glycoluril, a polymeric non-self-crosslinking compound and an acid catalyst

Abstract: An organic solvent based composition comprising a blend of certain quantities of a partially or fully alkylated glycoluril blended with certain organic solvent dispersible non-gelled, non-self-crosslinking polymeric materials containing only certain reactive groups and catalyzed with small quantities of an acid catalyst which will cause the glycoluril derivative to crosslink with the polymeric material, when subjected to heat.

Photochemische Synthese von 4-Phenyl-3-oxazolin-5-onen und deren thermische Dimerisierung

Abstract: Irradiation of 3-phenyl-2H-azirines affords reactive benzonitrile-methylide intermediates, which can be trapped by carbon dioxide to yield 4-phenyl-3-oxazolin-5-ones (Scheme 1). The first section of the paper deals with the experimental description of this reaction, which already has been preliminarily communicated. Upon irradiation the 3-oxazolin-5-ones undergo photoextrusion of carbon dioxide to reform the corresponding benzonitrile-methylides, which can be trapped by dimethyl acetylenedicarboxylate. In the second section of the paper, reactions of 2-methyl-4-phenyl-3-oxazolin-5-one (3c) are described. Upon heating to 130°, this compound is partially converted to 2-methyl-4-phenyl-2-oxazolin-5-one (azlactone 4e). Prolonged heating of 3c affords the dimer 7 (Scheme 3) as well as the imidazole derivative 9 (Scheme 4). Compound 7 is related to the ‘Rugheimer compound’ C18H14N2O4, formed from hippuric acid methylester. The structure of 7 was determined by X-ray crystallography and this supports the formula assigned earlier to the ‘Rugheimer compound’ (12) and related pyrrolidin-2,4-diones. The possible mechanism of the thermal formation of 7, which is also base catalysed, is represented in Scheme 3, the one for the formation of the imidazol 9 in Scheme 4. Under the influence of oxygen the 2,4-diphenyl-3-oxazolin-5-one (3b) undergoes a dehydro-dimerization to yield compound 16 (Scheme 7). Section three contains the structure elucidation of compound 16 and a mechanistic proposal for the formation of the pyrazine 19 upon thermolysis of 2,4-diphenyl-2-oxazolin-5-one (4b, Scheme 7).

9,10-Dehydroanthracene. A derivative of 1,4-dehydrobenzene

Abstract: Die UV-Bestrahlung des Diketens (I) in einer 3-Methylpentan-Matrix bei 77 K ergibt ein biradikalisches Intermediarprodukt (II), das beim Erwarmen Anthracen bildet.

The chemistry of fungi. Part LXVIII. The absolute configuration of (+)-sclerotiorin and of the azaphilones

Abstract: X-Ray crystallographic examination of N-methylsclerotioramine, derived from (+)-sclerotiorin, has defined the absolute stereochemistry of the derivative and hence that of (+)-sclerotiorin and of the other members of the azaphilone group of fungal metabolites.

1,2,4-Triazole-containing compounds and their use as pesticides

Abstract: Plant fungicidal compounds of formula: ##STR1## WHEREIN R 1 is hydrogen, or nitro, R 3 is alkyl, furyl, thienyl or phenyl, R 4 is hydrogen, halogen, nitro, phenyl, alkoxy or alkyl, n is 1, 2 or 3, and Z is C ═ O or a derivative thereof; and their salts.