Porphyrin

Porphyrin

Porphyrins are a group of organic compounds, many naturally occurring. One of the best-known porphyrins is heme, the pigment in red blood cells; heme is a cofactor of the protein hemoglobin. Porphyrins are heterocyclic macrocycles composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH-). Porphyrins are aromatic. That is, they obey Hückel's rule for aromaticity, possessing 4n+2 π electrons (n=4 for the shortest cyclic path) delocalized over the macrocycle. Thus porphyrin macrocycles are highly conjugated systems. As a consequence, they typically have very intense absorption bands in the visible region and may be deeply colored; the name porphyrin comes from a Greek word for purple. The macrocycle has 26 pi electrons in total. The parent porphyrin is porphine, and substituted porphines are called porphyrins. The specific porphyrin in heme B (see Figure) is called protoporphyrin IX and has 4 methyl, two vinyl, and two propionic acid substituents at the indicated positions.

Read more about PorphyrinComplexes of Porphyrins and Related Molecules, Applications

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Porphyrin - Applications - Organic Geochemistry
... on the Earth, had its origins in the isolation of porphyrins from petroleum ... "fingerprinted" by analysis of trace amounts of nickel and vanadyl porphyrins ... Chlorophyll is a magnesium porphyrin, and heme is an iron porphyrin, but neither porphyrin is present in petroleum ...
Erythropoietic Protoporphyria - Presentation
... Since porphyria is not that common, most doctors don't even think to do blood porphyrin levels when symptoms present ... compared to the possibility of a pending burst appendix, especially since porphyrin levels cannot be generally be received back immediately due to lab protocols ... This is because porphyrins are poisonous to the body and produce nerve damage ...
Blood Substitutes - Current Therapeutics - Hyperbranched Polymer-protected Porphyrins
... The "plastic" blood consists of an iron-containing porphyrin which is permanently bonded to a hyperbranched polymer (HBP or dendrimer) "shell" which ... This is similar to hemoglobin in blood, which consists of an iron containing porphyrin reversibly bonded to a protein "shell" ... accompanying research showed that the protected porphyrin was far less susceptible to oxidation than a free porphyrin, while still able to bind oxygen reversibly ...
Porphin - Complex With Metal in The Center
... This is often the case with biological porphyrin compounds, especially with an iron atom in the center ... compounds are called free porphin or free porphyrins ... A porphyrin with an iron atom of the type found in myoglobin, hemoglobin, or certain cytochromes is called heme ...
Chlorophyll - Chemical Structure
... the same metabolic pathway as other porphyrin pigments such as heme ... C17-C18 bond Single (chlorin) Single (chlorin) Double (porphyrin) Double (porphyrin) Single (chlorin) Single (chlorin) Occurrence Universal Mostly plants Various algae Various algae Cyanobacteria ...