نتایج جستجو برای: porphyrins

تعداد نتایج: 3593  

2001
A C Deacon G H Elder

The porphyrias are uncommon disorders of haem biosynthesis and their eVective management requires prompt and accurate diagnosis. This article describes methods for the determination of urinary porphobilinogen, urinary and faecal total porphyrins, and total porphyrins in erythrocytes and plasma that are suitable for use in non-specialist laboratories. The selection and interpretation of these me...

Journal: :Clinical chemistry 1984
K M Ivanetich C Movsowitz M R Moore

Magnetic circular dichroism is a suitable technique for semiquantitative determination of total porphyrins in urine and feces, being rapid, reliable, and involving little sample preparation. The sensitivity of the assay suffices to distinguish normal from above-normal concentrations of total porphyrins in urine and feces. Results for urine compare well with those obtained by thin-layer chromato...

Journal: :The Ulster Medical Journal 1979
M B Poh-Fitzpatrick

The porphyrias are a group of disorders of heme metabolism that result from partial defects in the several enzymes that control heme biosynthesis. Accumulation of porphyrins or porphyrin precursors in several different patterns results from these defects and biochemically characterizes each specific syndrome. Patterns of cutaneous photosensitivity and associated systemic symptoms among the seve...

Journal: :Clinical chemistry 1974
C Sobel C Cano R E Thiers

Coproporphyrin and uroporphyrin are separated from urineand from each other by absorption onto, and Selective elution from, an anion-exchange resin. The two compounds are #{233}eparated by using solvents differing in both polarity and pH. The porphyrins are then quantitated with an Aminco-Bowman Spectrophotofluorometer equipped with an ellipsoidal mirror and a red-sensitive photomultiplier tube...

Journal: :The Biochemical journal 1987
F Li C K Lim T J Peters

A reversed-phase h.p.l.c. system is described for the separation of all five naturally occurring pentacarboxylic porphyrinogen isomers. The compounds are detected electrochemically with high sensitivity. The peaks are positively identified by h.p.l.c. analysis of the pentacarboxylic porphyrinogens from reduction of pentacarboxylic porphyrins prepared by partial decarboxylation of hexa- and hept...

Journal: :Chemistry 2009
Chellaiah Arunkumar Yong-Min Lee Jung Yoon Lee Shunichi Fukuzumi Wonwoo Nam

High-valent manganese(IV or V)-oxo porphyrins are considered as reactive intermediates in the oxidation of organic substrates by manganese porphyrin catalysts. We have generated Mn(V)- and Mn(IV)-oxo porphyrins in basic aqueous solution and investigated their reactivities in C-H bond activation of hydrocarbons. We now report that Mn(V)- and Mn(IV)-oxo porphyrins are capable of activating C-H bo...

Journal: :Beilstein Journal of Organic Chemistry 2021

The use of halogens in the crystal engineering supramolecular porphyrin assemblies has been a topic strong interest over past decades. With this mind we have characterized series direct meso-halogenated porphyrins using single X-ray crystallography. This is accompanied by detailed conformational analysis all deposited CSD. In study used Hirshfeld fingerprint plots together with normal-coordinat...

Journal: :Industrial Crops and Products 2021

Furan-2,5-diylbis(phenylmethanol) is a key intermediate to access sub(oxa)porphyrins. Previously, this was accessible from fossil-derived furan using highly dangerous lithium reagents. Presently, we have produced cashew apple bagasse (CAB), via the formation of 5-hydroxymethylfurfural (HMF). CAB non-food biomass containing cellulose and hemicellulose. From CAB, obtained HMF in yield 310 mg/g CA...

Journal: :Langmuir : the ACS journal of surfaces and colloids 2008
Jonathan Rochford Elena Galoppini

A series of six Zn(II) tetraphenylporphyrins (ZnTPP), with a phenyl (P) or oligophenyleneethynylene (OPE = (PE) n ) rigid-rod bridge varying in length (9-30 A) and terminated with an isophthalic acid (Ipa) anchoring unit, were prepared as model dyes for the study of sensitization processes on metal oxide semiconductor nanoparticle surfaces (MO(n) = TiO(2), ZnO, and insulating ZrO(2)). The dyes ...

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