scholarly journals Isolation of two N-monosubstituted protoporphyrins, bearing either the whole drug or a methyl group on the pyrrole nitrogen atom, from liver of mice given griseofulvin

1991 ◽  
Vol 274 (3) ◽  
pp. 843-848 ◽  
Author(s):  
A E Holley ◽  
Y Frater ◽  
A H Gibbs ◽  
F De Matteis ◽  
J H Lamb ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Protoporphyrin Ix ◽  
Secondary Product ◽  
Structural Isomers ◽  
Green Pigment ◽  
Methyl Group ◽  
Group 4 ◽  
Pyrrole Nitrogen

1. A hepatic green pigment with inhibitory properties towards the enzyme ferrochelatase has been isolated from the liver of mice treated with griseofulvin and identified as N-methylprotoporphyrin. 2. All four structural isomers of N-methylprotoporphyrin have been demonstrated to be present, NA, where ring A of protoporphyrin IX is N-methylated, being the predominant isomer. 3. In addition to N-methylprotoporphyrin, a second green pigment, present in far greater amounts, was also isolated from the liver of griseofulvin-treated mice. This second green pigment is also an N-monosubstituted protoporphyrin, but in this case the substituent on the pyrrole nitrogen atom appears to be intact griseofulvin rather than a methyl group. 4. The fragmentation of this adduct in tandem m.s. studies suggests that griseofulvin is bound to the pyrrole nitrogen through one of its carbon atoms and further suggests that N-methylprotoporphyrin may arise as a secondary product from the major griseofulvin pigment.

Dirhodium-Catalyzed Chemo- and Site-Selective C–H Amidation of N,N-Dialkylanilines

Synlett ◽  
2020 ◽  
Author(s):  
Yoshihiro Ueda ◽  
Gong Chen ◽  
Kenta Arai ◽  
Kazuhiro Morisaki ◽  
Takeo Kawabata
Keyword(s):  
Nitrogen Atom ◽  
Aromatic Ring ◽  
Methyl Group ◽  
Site Selective

AbstractA method for dirhodium-catalyzed C(sp3)–H amidation of N,N-dimethylanilines was developed. Chemoselective C(sp3)–H amidation of N-methyl group proceeded exclusively in the presence of C(sp2)–H bonds of the electron-rich aromatic ring. Site-selective C(sp3)–H amidation proceeded exclusively at the N-methyl group of N-methyl-N-alkylaniline derivatives with secondary, tertiary, and benzylic C(sp3)–H bonds α to a nitrogen atom.

scholarly journals Synthesis and spectral characterization of novel 1,5-benzodiazepine oxime derivatives

2019 ◽  
Vol 84 (4) ◽  
pp. 343-353
Author(s):  
Lina Rekovic ◽  
Lidija Kosychova ◽  
Irina Bratkovskaja ◽  
Regina Vidziunaite
Keyword(s):  
Nitrogen Atom ◽  
Fluorescence Spectroscopy ◽  
Organic Solvent ◽  
Elemental Analysis ◽  
13C Nmr ◽  
1H And 13C Nmr ◽  
Methyl Group ◽  
Oxime Derivatives ◽  
New Compounds

Three new 1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one oximes were synthesized and characterized by the methods of 1H- and 13C-NMR, IR and elemental analysis. Along with previously described compounds bearing one additional methyl group on the 5th nitrogen atom, the new compounds were characterized in bulk by UV?Vis and fluorescence spectroscopy in various solvents. The influence of the nature of the organic solvent on the spectra of the title compounds was investigated and is discussed.

Biliverdin IX α, Intermediate and End Product of Tetrapyrolle Biosynthesis

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1057-1063 ◽  
Author(s):  
Hans-Peter Köst ◽  
Eva Benedikt
Keyword(s):  
Aminolevulinic Acid ◽  
Chromic Acid ◽  
Protoporphyrin Ix ◽  
Chloroform Extract ◽  
Cyanidium Caldarium ◽  
Green Pigment ◽  
Acid Degradation ◽  
Turdus Merula ◽  
Egg Shells ◽  
Biliverdin Ix

Abstract Dark-grown cells of the unicellular rhodophyte Cyanidium caldarium were incubated with 17 mmol/l 5-aminolevulinic acid in the dark. The excreted pigments were extracted with chloroform and butanol. The presence of biliverdin IX α in the chloroform-extract (besides phycocyanobilin and other pigments) was demonstrated using TLC, HPLC and chromic acid degradation. A pathway leading to phycocyanobilin is discussed. A green pigment from egg shells of Turdus merula (black bird) was also identified as biliverdin IX α with small amounts of protoporphyrin IX, using the same methods as above.

scholarly journals Determination of the structure of an N-substituted protoporphyrin isolated from the livers of griseofulvin-fed mice

1995 ◽  
Vol 307 (2) ◽  
pp. 505-512 ◽  
Author(s):  
R M A Bellingham ◽  
A H Gibbs ◽  
F de Matteis ◽  
L Y Lian ◽  
G C K Roberts
Keyword(s):  
Zinc Complex ◽  
Pyrrole Ring ◽  
Protoporphyrin Ix ◽  
Free Base ◽  
Mechanism Of Formation ◽  
Ring Nitrogen ◽  
Green Pigments ◽  
Anti Fungal ◽  
Pyrrole Nitrogen

Feeding mice with griseofulvin, a widely used anti-fungal agent which induces protoporphyria as a side-effect, leads to the formation in the liver of two green pigments which have been shown to be porphyrin adducts. In this work, the major porphyrin adduct isolated from the livers of griseofulvin-fed mice has been characterized structurally using one- and two-dimensional NMR spectroscopy. The adduct was shown to be an N-alkylated protoporphyrin IX in which the whole of griseofulvin (less a hydrogen atom) is attached to a pyrrole ring nitrogen of the porphyrin. It was shown that the drug-to-porphyrin linkage is an an -O-CH2-Npyrrole = linkage, to either the 4- or 6-position of ring a of griseofulvin. In an attempt to identify which pyrrole nitrogen is involved in this linkage, the 1H spectra of the free base and zinc complex of the adduct were compared with the corresponding spectra of the four regioisomers of N-methylprotoporphyrin. These comparisons indicated that the adduct isolated from the livers of griseofulvin-fed mice is either the NC or the ND regioisomer, although a clear distinction between these two could not be made on the available evidence. The mechanism of formation of the adduct and its relation to griseofulvin-induced protoporphyria are discussed.

Purely Aliphatic Azoxy Compounds with a Methyl Group attached to the Nitrogen Atom

Nature ◽  
1951 ◽  
Vol 167 (4256) ◽  
pp. 863-864 ◽  
Author(s):  
J. G. ASTON ◽  
D. M. JENKINS
Keyword(s):  
Nitrogen Atom ◽  
Methyl Group ◽  
Azoxy Compounds

Kinetics of acid-catalyzed cyclization of substituted hydantoinamides to substituted hydantoins

1987 ◽  
Vol 52 (8) ◽  
pp. 1999-2004 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Gabriela Svobodová ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Hydrochloric Acid ◽  
Dissociation Constants ◽  
Amide Group ◽  
The Other ◽  
Methyl Group ◽  
Acid Catalyzed ◽  
Cyclization Rate ◽  
Kinetics Of

The kinetics of acid-catalyzed cyclization of the hydantoinamides type R3-N(5)H-CO-N(3)R2-CH2-CO-N(1)HR1 (R1, R2, R3 = H and/or CH3) has been studied in 0·5 to 5 mol l-1 hydrochloric acid. The cyclization rate is limited by the rate of the attack of nitrogen atom N(5) on the carbon atom of the protonated amide group. The dissociation constants of the protonated hydantoinamides and rate constants of their cyclizations have been determined. Replacement of hydrogen atom by methyl group at the N(5) nitrogen atom accelerates the cyclization about two times., the same substitution at N(3) accelerates about 50x, whereas at N(1) it results in a 300 fold retardation. With the hydantoinamides having R3 = CH3, the cyclization rate of the protonated hydantoinamide increases with increasing concentration of hydrochloric acid, whereas with the other derivatives this value is independent of the acid concentration.

Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine VI [1]. X-Ray Structure Analysis of Trimethyl[2-(propionyloxy)ethyl]- ammonium-iodide (O-Propionylcholine-iodide)

1986 ◽  
Vol 41 (5-6) ◽  
pp. 641-646 ◽  
Author(s):  
Alfred Gieren ◽  
Michail Kokkinidis
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Formula Unit ◽  
Ammonium Iodide ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Methyl Group ◽  
X Ray ◽  
Acetylcholine Chloride ◽  
Structure Investigations

The title compound (1) crystallizes in the orthorhombic, noncentrosymmetric space group Pna21 with a = 10.241(11), b = 12.903(12), c = 9.312(9) Å and with one formula unit per asymmetric unit. The stereochemically comparable torsion angles of the cation of 1 and of acetylcholine chloride are analogous. In the crystal structure the trimethylammonio methyl group is surrounded by three anions in the first coordination sphere. The geometry of a triangle formed by one of these counterions which occupies a special face of the N+C4 tetrahedron of the (CH3)3N+-CH2-R moiety, the nitrogen atom of the ammonium group and the oxygen atom of the carbonyl group is typical for nicotinic agonists.

Visible Light Photocatalytic Degradation of Methylene Blue over N-Doped TiO2

2014 ◽  
Vol 609-610 ◽  
pp. 141-146 ◽  
Author(s):  
Yu Long Hu ◽  
Li Qing Zhou ◽  
Hong Fang Liu ◽  
Xing Peng Guo
Keyword(s):  
Methylene Blue ◽  
Nitrogen Atom ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Functional Group ◽  
Degradation Process ◽  
Degradation Pathway ◽  
Methyl Group ◽  
Intermediate Products ◽  
Visible Light Photocatalytic

The visible light photocatalytic degradation of methylene blue (MB) over N-doped TiO2 (N-TiO2) was investigated. The intermediate products of MB in the photocatalytic degradation process were analyzed by HPLC-MS technique. The results show that the cleavages of CS+=C and CN=C functional group in the central aromatic ring and the cleavage of N-C bond between the methyl group and nitrogen atom all can occur in the visible light photocatalytic degradation process over N-TiO2, but MB is difficult to be mineralized completely to the inorganic products. A detailed degradation pathway of MB has been proposed on the basis of a careful identification of intermediate products.

scholarly journals Transient kinetics of the reaction catalysed by magnesium protoporphyrin IX methyltransferase

2004 ◽  
Vol 382 (3) ◽  
pp. 1009-1013 ◽  
Author(s):  
Mark SHEPHERD ◽  
C. Neil HUNTER
Keyword(s):  
Catalytic Mechanism ◽  
Protoporphyrin Ix ◽  
Tryptophan Fluorescence ◽  
Lag Phase ◽  
Transient Kinetics ◽  
Methyl Group ◽  
Synechocystis Pcc6803 ◽  
Propionate Group ◽  
Tryptophan Fluorescence Quenching ◽  
Flow Techniques

Magnesium protoporphyrin IX methyltransferase (ChlM), an enzyme in the chlorophyll biosynthetic pathway, catalyses the transfer of a methyl group to magnesium protoporphyrin IX (MgP) to form magnesium protoporphyrin IX monomethyl ester (MgPME). S-Adenosyl-L-methionine is the other substrate, from which a methyl group is transferred to the propionate group on ring C of the porphyrin macrocycle. Stopped-flow techniques were used to characterize the binding of porphyrin substrate to ChlM from Synechocystis PCC6803 by monitoring tryptophan fluorescence quenching on a millisecond timescale. We concluded that a rapid binding step is preceded by a slower isomerization of the enzyme. Quenched-flow techniques have been employed to characterize subsequent partial reactions in the catalytic mechanism. A lag phase has been identified that has been attributed to the formation of an intermediate. Our results provide a greater understanding of this catalytic process which controls the relative concentrations of MgP and MgPME, both of which are implicated in signalling between the plastid and nucleus in plants.

scholarly journals N-alkylation of the haem moiety of cytochrome P-450 caused by substituted dihydropyridines. Preferential attack of different pyrrole nitrogen atoms after induction of various cytochrome P-450 isoenzymes

1983 ◽  
Vol 211 (2) ◽  
pp. 455-461 ◽  
Author(s):  
F De Matteis ◽  
A H Gibbs ◽  
C Hollands
Keyword(s):  
Isomeric Composition ◽  
Structural Isomers ◽  
Ethyl Group ◽  
Cytochrome P 450 ◽  
Pyrrole Nitrogen

1. 3,5-Diethoxycarbonyl-4-ethyl-1,4-dihydro-2,6-dimethylpyridine (4-ethyl-DDC) gives rise to N-ethylprotoporphyrin in the liver of rats by donating its 4-ethyl group to one of the pyrrole nitrogen atoms of haem. Four structural isomers are obtained, depending on which pyrrole nitrogen is alkylated. 2. When rats are pretreated with an inducer of cytochrome P-450, the production of N-ethylprotoporphyrin caused by 4-ethyl-DDC is greater, both in the whole animal and in hepatocytes incubated with the drug in vitro. 3. Pre-incubation of hepatocytes with 2-allyl-2-isopropylacetamide decreases the yield of N-ethylprotoporphyrin due to 4-ethyl-DDC, an effect largely reversed by adding exogenous haem. 4. The isomeric composition of N-ethylprotoporphyrin produced in vivo and in vitro depends on the cytochrome P-450 isoenzyme that predominates at the time of treatment, suggesting a role for the apo-cytochrome in directing alkylation on to one of the pyrrole nitrogens.

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