نتایج جستجو برای: expanded porphyrins
تعداد نتایج: 64232 فیلتر نتایج به سال:
The influence of skin permeation enhancers, such as dimethyl sulphoxide (DMSO) and 1-[2-(decylthio)ethyl]azacyclopentan-2-one (HPE-101), Labrafac CC, Labrafil, Labrasol and Transcutol in a concentration of 10% (wt./wt.) on the formation of porphyrins in normal mouse skin from topical application of creams with methyl 5-aminolevulinate (MAL) was studied. The concentration of porphyrins in the mo...
In addition to the bile pigments, there are present in the urine and stool another series of pyrrole pigments, the porphyrins. Hemoglobin, myoglobin, and other respiratory pigments contain as their prosthetic group a porphyrin of Type III configuration. The porphyrin excreted in urine and feces by normal individuals, and in most pathological states, is coproporphyrin Type I. This substance cann...
A reversed-phase gradient elution system is described for the simultaneous separation of the type I and type III isomers of 8-, 7-, 6-, 5- and 4-carboxylated porphyrins and isocoproporphyrins. The method, adaptable for isocratic and stepwise separation of individual groups of isomers, is also suitable for preparative isolation of pure porphyrins. The analyses of porphyrin isomers in the urine a...
5-Substituted dipyrromethanes are important precursors for the synthesis of meso-substituted porphyrins,1 expanded porphyrins, and porphyrin analogues.2 Several one-flask methods have been reported for the synthesis of 5-substituted dipyrromethanes by the condensation of an aldehyde and pyrrole using various combinations of acids and solvents.3-14 We previously reported a one-flask synthesis of...
Measurement of porphyrins and porphyrin precursors has clinical significance beyond the detection or confirmation of lead poisoning. The porphyric diseases of man are characterized by the presence of a specific clinical syndrome and demonstration of abnormal porphyrin excretion or accumulation in the tissues. In addition, porphyrins accumulate in other disorders that are unrelated to lead poiso...
Hepta-, hexa-, and pentacarboxylic porphyrins have been detected in porphyric as well as normal urine samples. From the former they have been isolated and converted into pure methyl esters (1). For a better understanding of the chemistry of these porphyrins, pure uroporphyrin I and uroporphyrin III were separately subjected to decarboxylation under controlled conditions. The decarboxylation pro...
Thirty patients suffering from chronic kidney disease were examined for urinary, fecal and total plasma porphyrins. Twenty patients had nitrogen retention whereas the remaining ten patients displayed normal values. Urinary coproporphyrin excretion and total plasma porphyrin levels were comparatively less pronounced in patients with nitrogen retention. Such changes in porphyrin metabolism could ...
It is well known that porphyrins can be adsorbed on to precipitates of calcium salts, and adsorption can take place under the most varying conditions. Thus, it has been shown that in certain diseases porphyrins are found to be adsorbed on to urinary sediments of calcium phosphates (Garrod, 1892; Dobriner, 1936; Sveinsson, Rimington, and Barnes, 1949) and on to the bone and tooth tissue in mammals.
136 Application of viscometric methods for studying the interaction of various porphyrins with DNA Vigen G. Barkhudaryan & Gayane V. Ananyan To cite this article: Vigen G. Barkhudaryan & Gayane V. Ananyan (2015) 136 Application of viscometric methods for studying the interaction of various porphyrins with DNA, Journal of Biomolecular Structure and Dynamics, 33:sup1, 88-88, DOI: 10.1080/07391102...
The redox properties of metalloporphyrins have been studied extensively, and particular attention has been paid to the changes in oxidation states of the metaL t-3 In general, the most stable metalloporphyrins are those in which the metal is in the + 2 oxidation state. However, most of the transition metalloporphyrins show a variety of oxidation states. Thus Co(ll) porphyrins can, like the corr...
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