54090-85-6Relevant academic research and scientific papers
Non-enzymic tetramisation of ethyl 3-(4-ethoxycarbonylmethyl-1H-pyrrol-3-yl)propionate with formaldehyde follows a similar course to the non-enzymic tetramisation of porphobilinogen
Cheung, Kwai-Ming,Shoolingin-Jordan, Peter M.
, p. 5973 - 5976 (2007/10/03)
The octaethyl esters of uroporphyrins were formed directly from ethyl 3-(4-ethoxy-carbonylmethyl-1H-pyrrol-3-yl)propionate and formalin in a yield of ca. 30% with the isomers I, II, III and IV being formed in the ratio 1:1:4:2. Under anaerobic conditions, the colourless uroporphyrinogen esters were formed in a similar ratio. These observations parallel the non-enzymic formation of uroporphyrinogens from the naturally occurring tetrapyrrole precursor, porphobilinogen, highlighting the similarity in both tetramisation and isomerisation reactions.
Molar absorption coefficients of porphyrin esters in chloroform determined by copper titration
With,Pedersen
, p. 425 - 429 (2007/10/09)
Chromatographically pure porphyrin esters free from metalloporphyrins were titrated with Cu2+ to determine the molar amount of porphyrin present. The end point of the titration was defined by a t.l.c. method detecting traces of metal free porphyrin ester in admixture to its copper complex. From spectrometic measurement at the Soret maximum and the molar amounts found by the titration, ε(M) was calculated for proto-, copro-, penta-, hexa- and hepta- carboxylic and uro porphyrin permethyl esters. The values for uroporphyrin showed perfect agreement with those of previous workers, whereas those for coproporphyrin were about 5% lower and those for protoporphyrin more than 20% lower. The implications of the findings are discussed. Determinations of ε(M) of some higher esters (ethyl to pentyl) and some partial methyl esters with one carboxyl group free are also presented.
