نتایج جستجو برای: porphyrins

تعداد نتایج: 3593  

Journal: :Journal of nanoscience and nanotechnology 2011
Priscilla P Luz Thatyane M Nobre Osvaldo A Serra Maria E D Zaniquelli

Porphyrins are currently used in photodynamic therapy as photosensitizers. In this paper we studied the interaction of two charged porphyrins, 5, 10, 15, 20-mesotetrakis(N-metyl-4-pyridyl) porphyrin, (TMPyP/chloride salt) cationic, and 5, 10, 15, 20-meso-tetrakis(sulfonatophenyl) porphyrin, (TPPS4/sodium salt) anionic, nanoassembled in phospholipid Langmuir monolayers and Langmuir-Blodgett film...

Journal: :Clinical chemistry 1989
I S Rose G P Young D J St John M C Deacon D Blake R W Henderson

Stools from asymptomatic volunteers on diets containing red meat, whole blood, or high fiber were analyzed for their content of hemes and dicarboxylic (heme-derived) porphyrins by the "HemoQuant" assay, the "Hemoccult" test, and "high-performance" liquid chromatography (HPLC). In 49 subjects, ingestion of red meat increased HemoQuant-determined combined fecal heme plus dicarboxylic porphyrins b...

2012
Yumiao Zhang Jonathan F. Lovell

Long before humans roamed the planet, porphyrins in blood were serving not only as indispensable oxygen carriers, but also as the bright red contrast agent that unmistakably indicates injury sites. They have proven valuable as whole body imaging modalities have emerged, with endogenous hemoglobin porphyrins being used for new approaches such as functional magnetic resonance imaging and photoaco...

2001
Chang-Hee Lee Jonathan S. Lindsey

The reaction at room temperature of an aldehyde with excess pyrrole in the absence of solvent affords the meso-substituted dipyrromethane. The reaction is catalyzed with trifluoroacetic acid or with BF9,0(Et)2. The dipyrromethaue is purified by crystallixation or by flash chromatography on silica with eluants containing 1% triethylamine. The reaction is compatible with aliphatic or aromatic ald...

2013
CECIL JAMES WATSON

Evidence for a dualism of the porphyrins in nature has been repeatedly presented by Hans Fischer (1, 2, 3). This means that both plant and animal organisms are capable of the formation of porphyrins of two isomeric series, those corresponding to aetioporphyrin III, including hemoglobin and chlorophyll, and those of the aetioporphyrin I type, the function of whose representatives is as yet very ...

Journal: :Molecules 2016
Juan C Barona-Castaño Christian C Carmona-Vargas Timothy J Brocksom Kleber T de Oliveira

Catalysis is a topic of continuous interest since it was discovered in chemistry centuries ago. Aiming at the advance of reactions for efficient processes, a number of approaches have been developed over the last 180 years, and more recently, porphyrins occupy an important role in this field. Porphyrins and metalloporphyrins are fascinating compounds which are involved in a number of synthetic ...

Journal: :research in pharmaceutical sciences 0

porphyrins are a ubiquitous large class of naturally occurring macrocyclic compounds with many significant biological representatives comprising heme and chlorophyll. some novel adaptable methods for the synthesis of free-based porphyrins as promising sensitizers for the use in photo-dynamic therapy by the virtue of their known tumor affinity, low dark cytotoxicity, and easy synthesis in good t...

2008
E. Milanesio S. M. Chiacchiera J. J. Silber E. N. Durantini

A convenient procedure for the synthesis of 5-(4-acetamidophenyl)-10,15,20tris(4-substituted phenyl) porphyrins from dipyrrolomethane is reported. meso-(4Substituted phenyl) dipyrrolomethanes were obtained in yields of 72-84%. The amide porphyrins were isolated with appreciable yields of 15-17%. Introduction The design of new material systems involves the synthesis of asymmetric porphyrins. Thu...

Journal: :Zeitschrift fur klinische Chemie und klinische Biochemie 1969
T K With

Bones from porphyric animals are treated first with 40% sodium hydroxide and subsequently with concentrated hydrochloric acid which dissolves the chalky residue from the alkaline digestion under violent foaming. The porphyrins are precipitated from the acid solution at pH ca. 3 together with calcium salts and subsequently washed and dissolved in about 50% acetic acid. The solution is then dilut...

2004
Kathryn E. Splan Charlotte L. Stern Joseph T. Hupp

The synthesis of a pair of electron-deficient porphyrin building blocks and their resulting coordinatively linked supramolecular assemblies are described. The perfluorophenyl substituted porphyrins feature pendant pyridines which, upon reaction with Re(CO)5Cl assemble into discrete dimers and tetramers, as dictated by the geometry of the porphyrin monomer. The resulting supramolecular complexes...

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