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...

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...

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...

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 ...

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 ...

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...

Development of artificial systems, capable of delivering electrons to metal-based catalysts for the reductive activation of dioxygen, has been proven very difficult for decades, constituting a major scientific lock for the elaboration of environmentally friendly oxidation processes. Here we demonstrate that the incorporation of a flavin mononucleotide (FMN) in a water-soluble polymer, bearing a...

We apply density functional theory (DFT) and the DFT+U technique to study the adsorption of transition metal porphine molecules on atomistically flat Au(111) surfaces. DFT calculations using the Perdew-Burke-Ernzerhof exchange correlation functional correctly predict the palladium porphine (PdP) low-spin ground state. PdP is found to adsorb preferentially on gold in a flat geometry, not in an e...

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...

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...