Investigations in the Biosynthesis of the Pigments of Life: Calculations on the Formation of Uroporphyrinogen III from Hydroxymethylbilan and Description of a New Mechanism for the D-Ring Inversion
✍ Scribed by Prof. Dr. Lutz F. Tietze; Dr. Holger Geissler
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 338 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0044-8249
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✦ Synopsis
MI
M4
Scheme 1 were treated with equal amounts of acetic acid under identical reaction conditions (20 "C, 2 h). The yields of the cyclic tetrapyrroles were determined by HPLC with 5,5,10,10,15,15,20,20-octamethylporphyrinogen as internal
The reaction of 2 gave no identifiable products; 3 provided an 82% yield of the corresponding cyclic tetrapyrrole 7.[13] Reaction of 4 and 5 led in each case to a mixture of 8 and the three possible isomeric tetrapyrroles in approximately 20 % yield. The calculations and experimental results show unequivocally the importance of substitution at C3 and C4 in the pyrrole ring in the formation of cyclic tetrapyrroles.