The demethylation of m-methyl orange and methyl orange in vivo and in vitro

Barrett, J.; Pitt, Patricia A.; Ryan, A. J.; Wright, Stephen E.

doi:10.1016/0006-2952(66)90001-3

Cited by 7 publications

(4 citation statements)

References 9 publications

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“…The cleiiie;hylated product was also formed on incubation of the dimethyl acid with a 9,000 g supernatant of rat liver without added cofactors (Barrett et al, 1966). The results are consistent with a number of recent observations (Barrett et al, 1966) that N-dcmethylation is associated with the reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-linked system of liver microsomes and is observed with both lipid-soluble and water-soluble compounds.…”

Section: Demethylation Of L-dimethylaminonaphthalene-5-sulphonic Acidsupporting

confidence: 87%

“…When incubated with rat liver microsomes, glucose-6-phosphate, glucose-6-phosphatc dehydrogenase and NADP in the conditions described by Barrett et al (1966), the monomethyl derivative was formed from the dimethyl acid, but no aminonaphthalene sulphonic acid was detected on chromatography in the s-butanol -ammonia system. The cleiiie;hylated product was also formed on incubation of the dimethyl acid with a 9,000 g supernatant of rat liver without added cofactors (Barrett et al, 1966).…”

Section: Demethylation Of L-dimethylaminonaphthalene-5-sulphonic Acidmentioning

confidence: 94%

“…after injection, but whereas in the rat the ratio [monomethyl acid]/ [dimethyl acid] at this time was 0-16-0-2, the ratio in the sheep was 0-02 and no free amino acid was detected. Barrett, Pitt, Ryan and Wright (1966) have recently reported a much more extensive demethylation of methyl orange in tlie mouse, where the ratios of dimethylamino-, monomethylamino-and fully deniethylated derivatives in a 24-hr, sample of urine were 1 : 2-8 : 9-1.…”

Section: Urinary Excretion Of Demethylation Products Of 1-dimethylamimentioning

confidence: 99%

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Urinary Excretion of Demethylation Products of 1‐dimethylaminonaphthalene‐ 5‐ Sulphonic Acid

Eckermann

Cooper

1967

Aust J Exp Biol Med

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The l-dimethylaminonaphthalene-5-sulphonyl group has been used extensively for fluorescent labelling of amino acids, peptides, and proteins; it has also been used to modify the pharmacological properties of a number of amines. The intense fluorescence of dimethylaminonaphthalene sulphonyl derivatives permits their detection and analysis on a millimicromolar scale (Neadle and PoUitt, 1965;Laurence, 1957).During a study of the metabolism of dimethylaminonaphthalene sulphonyl growth hormone, control rats were injected with l-dimethylaminonaphthalene-5-sulphonic acid and in 5-15 min. the urine was found to contain traces of l-aniinonaphthalene-5-sulphonic acid, together with much larger quantities of unchanged dimethyl acid and of an unidentified fluorescent acid that had less hydrophobic properties than the dimethyl acid, migrating with a lower R* on chromatography in organic solvents.The unknown metabolite has now been identified as the previously-undescribed 1-methylaminonaphthalene-5-sulphonic acid and this compound has been prepared by an unambiguous synthesis.Demethylation of the dimethyl sulphonic acid has been demonstrated in vitro with a rat-liver microsome fraction in the presence of a glucose-6-phosphate -glucose-6-phosphate dehydrogenase system to maintain a supply of reduced nico'.inamide-adenine dinucleotide phosphate. Purification of l-dimethylaminonaphthalene-5-sulphonic acid and synthesis of l-methylaminonaphthalene-5-sulphonic acid.Commercial l-dimethylaminonaphthalene-5-sulphonic acid (Fluka Co., "purum") contained several fluorescent impurities, including the methylamino derivative, which had R0 -56 in s-butanol-0-lN-NH^OH; 17:8, v/v; mobility 0-33 cm.^V.-ihr.-i on electrophoresis in 0-05M-tris citrate, pH 4-8. The impurities were removed by remethylation with methyl sulphate (Laurence, 1957); the recrystallised dimethyl sulphonic acid ran as a single fluorescent component (R^ 0-76) in s-butanol -ammonia and had a mobility of 0-26 cm.2V.~ihr. -' on electrophoresis in tris citrate.

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Section: Demethylation Of L-dimethylaminonaphthalene-5-sulphonic Acidsupporting

confidence: 87%

Section: Demethylation Of L-dimethylaminonaphthalene-5-sulphonic Acidmentioning

confidence: 94%

Section: Urinary Excretion Of Demethylation Products Of 1-dimethylamimentioning

confidence: 99%

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Urinary Excretion of Demethylation Products of 1‐dimethylaminonaphthalene‐ 5‐ Sulphonic Acid

Eckermann

Cooper

1967

Aust J Exp Biol Med

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“…The work now reported presents the results of experiments designed to discover the relation between the effects of mebanazine on growth hormone and insulin potentiation. A preliminary account of this study has been presented to the British Pharmacological Society (Barrett, 1966). …”

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confidence: 98%

Simulation of the apparent effects of mebanazine on growth hormone by pair-feeding of control animals

Barrett¹

1969

Journal of Pharmacy and Pharmacology

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The degree and duration of insulin hypoglycaemia was potentiated by chronic oral medication with mebanazine in rats. Hypophysectomy alone increased sensitivity to insulin but did not abolish the potentiating effect of mebanazine. Chronic mebanazine treatment (15 mg/kg/day) for 6 weeks markedly reduced weight gain, food and water consumption and pituitary growth hormone content, but the results were not significantly different from those in unmedicated pair-fed controls. Similarly, immature rats treated with mebanazine had a significant reduction in the width of the tibia1 epiphysial cartilage but this was not different from that in pair-fed animals. After 18 h of fasting, acute administration of mebanazine had little effect on food consumption in the 2 h period following dosing but a significant effect over 24 h. In fed rats mebanazine in a single oral dose significantly reduced eating in the following 6 h. Treatment with mebanazine at 2.5 mg/kg for 15 days significantly reduced food intake but did not potentiate insulin hypoglycaemia. From the results it would appear that previous suggestions that mebanazine specifically interferes with growth hormone release are incorrect and the findings emphasize the importance of measuring food intake in experiments of long duration.

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