Blood pigment

The synthesis of porphyrins from monopyrrolic, dipyrrolic, tripyrrolic and tctrapyrrolic precursors requires, even for an experienced porphyrin chemist, a substantial amount of time and effort to accomplish. As an alternative to these total synthetic routes, nature provides a source of prefabricated porphyrins. Among the several porphyrins which can be isolated from natural material,s the red blood pigment heme, protoporphyrin dimethyl ester81 b and hemato-porphyrin, both derived from heme, are the only compounds which can be obtained in sufficient amounts. Heme is available in almost unlimited amounts from slaughter-house waste. From 1 L of blood ca. 1 g of heme can be isolated.81 b Currently, heme is offered commercially by chemical retailers at a relatively low price so that is cheaper to buy hemin than to perform a self-isolation in the laboratory. 

The modification of porphyrins leading to isobacteriochlorins by C —C-bond formation is important to obtain a wide range of structurally different isobacteriochlorins which can then be further transformed. Protoporphyrin, deutoroporphyrin and hematoporphyrin (readily accessible from red blood pigment) are interesting and useful starting materials in the synthesis of isobacteriochlorins. 

Muscles Blood pigment Bone Hair Organic phosphates... 

In the blood pigment, haemoglobin, the coloured component which is separated as haemin in the manner described above is combined with a complicated protein component known as globin. According to Hans Fischer, haemin has the composition C31H3204N4FeCl. This compound in the form of the so-called Teichmann crystals serves for the microscopic detection of blood. 

Lest hemoglobin be regarded as indispensable to vertebrate life, let me draw attention to the existence of three species of large antarctic fish devoid of erythrocytes or blood pigment (41). The amount of dissolved oxygen their very cold colorless blood can carry is only one-eighth of... 

Copper is usually present in food at levels of 1 to 2 pg per g, the higher levels are found in animal livers. The highest levels of copper are present in shellfish, this is because copper is a component of their blood pigment, haemocyanin. 

Urinary aikaiinization In the treatment of certain drug intoxications (eg, salicylates, lithium) and in hemolytic reactions requiring aikaiinization of the urine to diminish nephrotoxicity of blood pigments. 

Smith, P.K. (1940) Change in blood pigments associated with the prolonged administration of large doses of acetanilide and related compounds. Journal of Pharmacology and Experimental Therapeutics, 70, 171-178. 

There are many organic dyestuffs but only one class, that of the metal chelates, has been found to be active in electrocatalysis. The first compounds described were the phthalocyanines 1-4), which are similar in structure to the heme in the blood pigment, hemoglobin in both, the metal atom is surrounded by four nitrogen ligands. 

Recently, a reducing blood pigment named tunichrome B-l (10) was isolated from the tunicate Ascidia nigra L. and characterized.351 It has a structure derived from three (3,4,5-trihydroxy)phenylalanine units and the trihydroxyphenyl group is suitable for reducing the metal. 

The bile pigments are metabolic products having chains of four pyrrole rings. Their precursors are the porphyrins, which comprise the blood pigments, the chlorophylls and vitamin B12 and consist of four pyrrole units joined in a macro ring. The phthalocyanines are important synthetic pigments (see Scheme 1). 

Haemin (blood pigment) Monastral blue (phthalocyanine pigment)... 

FISCHER, HANS (1881-1945). A German biochemist who studied under Emil Fischer. He was awarded the Nobel prize in chemistry in 1930 lor his synthesis of the blood pigment hcmin. He also did important fundamental research on chlorophyll, and porphyrins, and carotene. 

Pyrrole occurs in bone oil and imparts a bright red colour to pine wood moistened with mineral acid this characteristic behaviour led to its discovery and is used as a qualitative test for pyrrole derivatives. The bile pigments are metabolic products having chains of four pyrrole rings. Their precursors are porphyrins, which include the blood pigments (haem), the chlorophylls, and vitamin B12, and consist of four pyrrole units joined in a macro ring (Section 2.3.1.2). The trisubstituted pyrrole 6 (porphobilinogen) is the biosynthetic precursor of haem and chlorophyll. 

The most common structures of this type are the 2,5-exo derivatives 51 of which common examples are maleimide 53, phthalimide 54, maleic anhydride 55, and phthalic anhydride 56. The structural unit 51 occurs widely and more complex examples are the blood pigment haem 57 and the synthetic phthalocyanine dyes, e.g., 58. 

The problem of isolating pure blood pigments from timicates is very difficult owing to the extreme air-sensitivity and reactivity of the native compounds. Several steps and techniques proved to be necessary to produce a few milligrams of purified material. Structure elucidation following isolation of the purified pigment is also a complex procedure. The main steps leading to structure determination are as follows. 

The resulting purified material is more stable than the impure samples and could be characterized by a variety of spectroscopic and chemical conversion techniques. In addition, an assay of crude blood-cell extract for the presence of tunichrome was developed (162). Tunichrome blood pigments consist of a number of closely related polyphe-nolic compounds with a central triglycyl unit (Fig. 5). A tunichrome (designated An-1) isolated from the species A. nigra, for example, of... 

Fig. 5. The structures of tunichromes (blood pigments) from A. nigra consist of a number of closely related compounds (a) designated TC An-i (i = 1, 2,. . . ) those obtained from M. manhattensis (b) are designated TC Mm-i.

Vanadium has long been recognized as a biologically active metal which has an important metabolic role in various marine organisms 53). A vanadium concentration 5 x 105 times that found in natural sea water has been reported in the blood of the ascidian Phallusia mamillata 57). Vanadium is concentrated in form of the blood pigment hemovanadium58). Moreover, vanadium enrichment factors of 4500 in scallops, 2500 in mussels, and 1500 in oysters were observed 59). 

Bevis DCA. Blood pigments in haemolytic disease of the newborn. J Obstet Gynaecol Br Emp 1956 63 68-75. 

Bromcresol green (BCG) is also firmly boimd to albumin. The difference spectrum of buffered BCG with and without added albumin shows a narrow peak at 615 nm (B3). Under suitable conditions BCG offers the most sensitive means of determining albumin by a dye-binding method. In addition, measurements at the red end of the visible spectrum suffer minimum interference by bilirubin and the blood pigments (B3, E.19). 

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