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Biomedical subjects

G Roma

Publications and source records attributed to G Roma.

At least 37 records · Page 2Linked to original sources
PubMed1988

Formation of 2,6-dimethoxy-1,4-benzoquinone, a highly genotoxic compound, from the reaction of sodium nitrite with the sympathomimetic drug dimethophrine in acidic aqueous solution.

Because of the genotoxic effects shown by Dimethophrine (DMP) nitrosation mixtures, the interaction between DMP hydrochloride and sodium nitrite in acidic aqueous solution at 37 degrees was investigated in a wide range of reagent concentrations and molar ratios, reaction times and pH values. Actually, depending on the operating conditions, it was possible to detect variable amounts of 2,6-dimethoxy-1,4-benzoquinone (DMBQ), a highly genotoxic compound, but no N-nitrosoderivative. The highest conversion of DMP into DMBQ was obtained when concentrated acidic solutions of DMP and NaNO2 (molar ratio 1:1.9) reacted at pH 3.0-4.0 (50-60% after 1 hour, depending on the pH conditions). When DMP hydrochloride and NaNO2 (molar ratio 1:0.95) were allowed to react at pH 3.5 in a more diluted solution, to mimic gastric conditions, the conversion of DMP into DMBQ after 20 min was about 3%. The breakdown of DMP can be prevented by adding suitable amounts of ascorbic acid to the reagents.

Benzoquinones↗
PubMed1988

[Derivatives of pyrimidine 1,2-condensate. IV. Synthesis and pharmacological properties of the N,N-disubstituted 4-amino-2H-pyrido(1,2-a)pyrimidin- 2-ones and 2-amino-4H-pyrido(1,2-a)pyrmidin-4-ones].

The N,N-disubstituted 4-amino-2H-pyrido[1,2-a]pyrimidin-2-ones (III) and isomer 2-amino-4H-pyrido[1,2-a]pyrimidin-4-ones (IV) were obtained from the reaction of 2-aminopyridine with the N,N-disubstituted ethyl malonamate/phosphorus oxychloride reagent (II), in refluxing 1,2-dichloroethane. 2-[(N-Benzyl, N-ethyl)amino]derivative (IV b) was also prepared in excellent yield by treating 2-chloro-4H-pyrido[1,2-a]pyrimidin-4-one (V) with N-ethylbenzylamine. Finally, hydrogenation (Raney Nickel) of 4-[(N-ethyl,N-phenyl)amino]-2H-pyrido[1,2-a]pyrimidin-2-one (III e) afforded 6,7,8,9-tetrahydroderivative (VI) which in turn was treated with potassium borohydride to give 1,6,7,8,9,9a-hexahydroderivative (VII). Several compounds described in the present paper, along with some other compounds (III) and (IV) previously synthesized by us (1,2), were tested for various pharmacological activities. The antiallergic activity (PCA in the rat), even though found in several compounds examined, turned out to be submaximal in any case, in spite of the high dose administered (500 mg/kg p.o. as a rule). The most active compound (the activity being estimated at 0.42 times that of thiaramide hydrochloride) was the 4-aminoderivative (III e). The 2-aminoderivatives (IV) series, was found to have marked antiinflammatory properties (carrageenin oedema in the rat); nevertheless, this activity was related to toxic symptoms with the exception of compound (IV b), almost asymptomatic at the administered dose (200 mg/kg p.o.). Moreover the 2-aminoderivatives (IV) generally showed weak adrenolitic activity in vitro (rat seminal vesicles), which was estimated to be from 100 to 1000 times less than that of phenoxybenzamine.

Aminopyridines↗
PubMed1986

Correlation between subjective labour pain and uterine contractions: a clinical study.

Fifteen primiparous women underwent tocography during the second phase of the first stage of labour in order to evaluate the main characteristics of their uterine contractions (intensity, duration and pattern). At the end of each contraction, for a total of about 8 contractions per woman and an overall total of 125 tocographic curves, each woman was asked to make a subjective evaluation of the pain felt during that contraction using a 10 cm visual analogue scale (VAS). All the tocographic curves corresponding to the contractions studied were elaborated mathematically to determine the peak (intensity), base (duration) and area under the curve (AUC). Lastly, correlations between the mathematical parameters of the curves and corresponding VAS scores were sought. In the population a general positive correlation between the 3 main parameters of tocographic curves and the VAS score was demonstrated; the AUC and the peak tended to be better correlated with VAS than duration. Within-subject comparison showed the existence of a significant correlation with VAS score in 12/15 women as far as peaks are concerned, in 10/15 as far as AUC is concerned and in 0/15 women as regards duration. The findings support the concept that perceived labour pain depends in most of the women on the intensity and pattern of the uterine contractions. The possible clinical and experimental applications of this finding are discussed.

Adult↗
PubMed1986

[Derivatives of 1,2-condensed pyrimidines. II. Synthesis and pharmacological study of N,N-disubstituted 5-amino-7H-thiazol [3,2-a]pyrimdine-7-ones].

Reaction of 2-aminothiazole with the N,N-dialkyl or (N-alkyl, N-phenyl) ethoxycarbonylacetamide/POCl3 reactant (I), in refluxing 1,2-dichloroethane, yielded the corresponding N,N-disubstituted 5-amino-7H-thiazolo[3,2-a]pyrimidin-7-ones (VII) along with lower quantities of isomeric N,N-disubstituted 7-amino-5H-thiazolo[3,2-a]pyrimidin-5-ones (VIII). Structures attributed to isomeric compounds (VII) and (VIII) were supported both by spectroscopic and chemical evidences. Some compounds (VII) were submitted to pharmacological investigation and results are described: only (N-alkyl, N-phenyl)derivatives (VII f,g) showed a significant, even if mild, activity as peripheral analgesics.

Animals↗
PubMed1986

[3-Dialkylamino-substituted 2H-1,4-benzoxazines].

N,N,N',N'-Tetrasubstituted 2-(2-aminophenoxy)malonamides (IX) in the presence of phosphorus oxychloride led to the formation of N,N-dialkyl-3-(dialkylamino)-2H-1,4-benzoxazine-2-carboxamides (XII). In the same way 2-(2-amino-3-pyridyloxy)-N,N,N',N'-tetraethylmalonamide (X) yielded 3-(diethylamino)-N,N-diethyl-2H-pyrido[3,2-b] [1,4]oxazine-2-carboxamide (XIII). Also N,N-dialkyl-2-(2-aminophenoxy)acetamides (XIV) by the action of phosphorus oxychloride afforded 3-(dialkylamino)-2H-1,4-benzoxazines (XV). Some compounds when submitted to pharmacological screening showed a weak depressant activity in the Irwin test.

Analgesics↗
PubMed1985

[Chemistry and pharmacology of pyran derivatives. 16. Derivatives of 2-(dialkylamino)-7-methoxychromone with antiallergic activity].

Since 2-(diethylamino)-7-methoxychromone (III a) showed remarkable activity in the rat PCA test, some modifications to its structure were made. For instance new substituents such as chlorine or nitro group were introduced into the molecule and the diethylamino group modified. Thus, 2-(ethylamino)-7-methoxychromone (IX) was prepared by treating 3-methoxyphenol with N-ethylethoxycarbonylacetamide in the presence of phosphorus oxychloride. In this case a small amount of 4-chloro-7-methoxycoumarin was also isolated from the reaction mixture. Moreover compounds (XIV), (XV), (XVII) structurally related to sodium cromoglycate were prepared. The pharmacological screening of some compounds showed a useful antiallergic activity.

Animals↗
PubMed1984

Double-blind placebo-controlled trial of baclofen, alone and in combination, in patients undergoing voluntary abortion.

This study evaluated the analgesic efficacy of baclofen in relation to specific pain stimuli in 83 women (27 nulliparas and 56 multiparas) undergoing voluntary abortion (clamping of the cervix and dilatation and curettage). The patient population was divided into five treatment groups as follows: group 1, placebo; group 2, baclofen, 0.3 mg/kg, administered intravenously (IV); group 3, baclofen, 0.6 mg/kg IV; group 4, baclofen, 0.3 mg/kg IV, and fentanyl, 1.5 mg IV; and group 5, baclofen, 0.3 mg/kg IV, and diazepam, 5 mg given orally and 5 mg IV. In each case the surgical intervention was started using analgesia only. When the first sensation of pain was recorded, a paracervical anesthetic block was performed to provide pain relief for completion of the operation. The results showed that baclofen had significantly better analgesic properties than did placebo, with no important side effects. Its analgesic action seemed to be dose-dependent, since better results were obtained with the higher dose. The analgesic effect was slightly potentiated when baclofen was combined with fentanyl, but not when it was combined with diazepam. Factors independent of the pain stimuli and drugs used--the most important being parity--influenced the results.

Abortion, Induced↗
PubMed1983

[1,5-benzodiazepines. V. Synthesis of pyrazolo (3,4-b)(1,5)benzodiazepines and 5H-pyrimido(4,5-b)(1,5)benzodiazepines].

The reaction of 4-(dialkylamino)-1,3-dihydro-2H-1,5-benzodiazepin-2-ones (I a-c) with N,N-dimethylformamide in the presence of phosphorus pentachloride at room temperature gave rise to the formation of 4-(dialkylamino)-3-[(dimethylamino)methylene]-1,3-dihydro-2H-1,5-benzodiazepin- 2-ones (IX a-c) which were useful starting materials to achieve the synthesis of tricyclic 1,5-benzodiazepine derivatives. Actually (IX a), selected for the smallest steric hindrance of the 4-dialkylamino substituent, by reaction with hydrazines afforded pyrazolo[3,4-b][1,5]benzodiazepine derivatives whereas reaction with guanidine or amidines gave 5H-pyrimido-[4,5-b][1,5]benzodiazepine derivatives. The structure of isomeric N-methyl-pyrazoles (X c) and (XI a) and of N-phenylpyrazole (X b) were elucidated by comparison with compounds prepared by unequivocal chemical methods. Pharmacological evaluation of some of the products showed only generic CNS depressant activity.

Animals↗
PubMed1982

[Chemical and pharmacological research on pyran derivatives. XV. Phenyl-substituted 2-(dialkylamino)chromones].

Some 2-(dialkylamino)chromones phenyl substituted in position 6 or 7 or 8 were synthesized by reaction of N,N-dialkylethoxycarbonylacetamides with 4- or 3- or 2-biphenylol, respectively, in the presence of phosphorus oxychloride. The pharmacological activity of these compounds was then evaluated and compared with that shown by naphthopyran derivatives of structures (I), (II), and (III). With this same purpose also 6- and 8-benzyl derivatives of 2-(dialkylamino)chromones were prepared by using in the reaction 4- or 2-benzylphenol. Pharmacological screening showed that 6-phenyl substituted 2-(dialkylamino)chromones maintained the antireserpine and antimetrazole acti-activities which were possessed by the 1H-naphtho[2,1-b]pyran derivatives (I) and the 4H-naphtho[2,3-b]pyran derivatives (II), whereas 7-phenyl substituted compounds were devoid of any activity. 8-Phenyl substituted 2-(dialkylamino)chromones maintained to some extent the antiamphetamine activity which was clearly shown by the 4H-naphtho[1,2-]pyran derivatives (III). Furthermore, the compounds bearing the benzyl substituent both in the 6 or 8 position showed only antimetrazole activity.

Animals↗
PubMed1979

[Chemical and pharmacological research on pyran derivatives. XIII. Derivatives of 2H-pyrano/3,2-c/quinoline].

Treatment of N-alkylanilines or diphenylamine with N,N-dialkylethoxycarbonylacetamides in the presence of phosphorus oxychloride afforded 6-alkyl(phenyl)-4-dialkylaminopyrano [3,2-c] quinoline-2,5-(6H)-diones, two molecules of amide being involved in the reaction. In some instances 6-alkyl(phenyl)-4-alkylaminopyrano [3,2-c] quinoline-2,5(6H)-diones were obtained through a partial dealkylation of the amino group. Pharmacological evaluation of some compounds showed no activity on the CNS.

Animals↗
PubMed1979

Psychopharmacological study with K 8409, a 1H-naphtho[2,1-b]pyran 3-dialkylamino substituted derivative.

A 1H-naphtho[2,1-b]pyran derivative (K 8409) has undergone pharmacological investigation for psychotropic activity. The results show potential antidepressant action quantitatively similar to that of imipramine and amitriptyline, but due rather to MAO inhibition than to imipramine-like activity; interestingly enough, anti-MAO activity was particularly selective for the serotonin-converting enzyme, both centrally and peripherally. The outcome of the other tests suggests that the incidence of untoward effects is likely to be limited.

Animals↗
PubMed1979

[Chemical and pharmacological research on pyran derivatives. XIV. 3-alkylaminoaphtho/2,1-b/pyran-1-ones and derivatives].

3-Alkyl(phenyl)aminoaphtho[2,1-b]pyran-1-ones (III) were prepared from N-alkyl or N-phenylethoxycarbonylacetamides and 2-naphthol in the presence of phosphorus oxychloride, in order to evaluate their pharmacological activity on the CNS in comparison with previously described 3-dialkylaminoaphtho[2,1-b]pyran-1-ones. Compounds (III) gave 2-morpholinomethyl derivatives as well as N-acetyl and N-ethtoxycarbonyl derivatives. The reaction of (III) in which R = alkyl and N,N-dimethylformamide-POCl3 afforded 2-formyl derivatives and in some cases also 8-alkyl-9,10-bisdimethylaminoaphtho[1',2':5,6]pyrano[2,3-b]pyrrol-11(8H)-ones; when R = phenyl, only naphtho[1',2':5,6]pyrano[2,3-b]quinolin-14-one was obtained from the same reaction. Pharmacological evaluation showed that compounds (III) had a weak CNS depressant activity. Some of them also exhibited antagonist effect on reserpine-induced blepharospasm and hypothermia and on metrazole-induced seizures in the mouse. Within the limits of these activities a special behavior was found for the compound 3-ethylaminoaphtho[2,1-b]pyran-1-one [(III b) - K 12479].

Amphetamines↗
PubMed1979

[Chemical and pharmacological research on pyran derivatives. XII. Bis-(beta-chloroethyl)amino-substituted chromones and benzochromones].

By the reaction of phenols or naphthols with N,N-bis-(beta-methoxyethyl)ethoxycarbonylacetamide in the presence of phosphorus oxychloride the preparation of bis-(beta-methoxyethyl)amino substituted chromones or benzochromones was achieved. Treatment of these compounds with hydriodic acid at 95 degrees and then with thionyl chloride gave rise to the formation of the corresponding bis-(beta-chloroethyl)amino derivatives. When beta-naphthols reacted with N-ethoxycarbonylacetylmorpholine 1-oxo-3-morpholino-1H-naphtho[2,1-b]pyrans were obtained. These compounds as well as the corresponding 3-bis-(beta-methoxyethyl)amino derivatives afforded 1-oxo-3-bis-(beta-iodoethyl)amino-1H-naphtho[2,1-b]pyrans by treatment with hydriodic acid at reflux. The latter compounds were also easily transformed into 3-bis-(beta-chloroethyl)amino derivatives by reaction with phosphorus oxychloride in N,N-dimethylformamide. Pharmacological screening of some of the compounds described indicated no tumor-inhibiting activity.

Animals↗
PubMed1979

[1,5-Benzodiazepines. III. Synthesis of 2,4-bisdialkylamino-3H-1,5-benzodiazepines].

Treatment of 2,3-dihydro-2-oxo-4-dialkylamino-1H-1,5-benzodiazepines with phosphorus pentasulfide afforded 2-thio derivatives which in turn gave the corresponding methylmercapto derivatives by reaction with sodium hydride and methyl iodide. By treating these compounds with dialkylamines the formation of 2,4-bisdialkylamino-3H-1,5-benzodiazepines was achieved. Pharmacological screening of some of the products indicated that the introduction of a second dialkylamino substituent into the 1,5-benzodiazepine molecule gave the compounds CNS excitant properties, while the initial monodialkylamino derivatives containing sulfur showed a CNS depressant activity.

Amphetamine↗
PubMed1978

[Chemical and pharmaceutical research on pyran derivatives. X. Synthesis of 1-oxo-2-alkyl-3-dialkylamino-1H-naphtho[2,1b]pyrans].

When reaction of N,N-dialkyl-alpha-ethoxycarbonyl-alpha-alkylacetamides with beta-naphthol in the presence of phosphorus oxychloride was carried out in chlorobenzene at reflux, formation of 1-oxo-2-alkyl-3-dialkyl-amino-1H-naphtho[2,1-b]pyrans was achieved together with some other products whose structure was defined. Moreover, substitution of the 2 position of 1-oxo-3-dialkylamino-1H"naphtho[2,1-b]pyrans with chlorine or cyano group as well as the preparation of 1-thio-3-dialkylamino-1H-naphtho[2,1-b]pyrans was obtained by suitable chemical methods. Pharmacological screening of these compounds showed the lack of psychotropic activity of the corresponding 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans.

Animals↗