- D-Aminolevulinic acid
D-Aminolevulinic acid (dALA or δ-ALA or 5-aminolevulinic acid) is the first compound in the
porphyrin synthesis pathway, the pathway that leads tohemoglobin in mammals.In non-photosynthetic
eukaryotes such as animals, insects, fungi, andprotozoa , as well as the α-proteobacteria group of bacteria, it is produced by theenzyme ALA synthase , fromglycine andsuccinyl CoA . This reaction is known as theShemin pathway .In
plants ,algae ,bacteria (except for the α-proteobacteria group) andarchaea , it is produced fromglutamic acid via glutamyl-tRNA andglutamate-1-semialdehyde . The enzymes involved in this pathway areglutamyl-tRNA synthetase ,glutamyl-tRNA reductase , andglutamate-1-semialdehyde aminotransferase . This pathway is known as the C5 or Beale pathway. [Beale, Samuel I. (1990) Biosynthesis of the tetrapyrrole pigment precursor, d-aminolevulinic acid, from glutamate. Plant Physiology, 93(4), 1273-1279] [Willows R.D. (2004) Chlorophylls In: Encylopaedia of Plant and Crop Science. pp 258-262, Ed: Robert M. Goodman. Marcel Dekker Inc, ISBN 0-8247-4268-0]Clinical significance
It elicits synthesis and accumulation of
fluorescent porphyrin s (protoporphyrin IX) in epithelia and neoplastic tissues, among them malignant gliomas. It is used to visualise tumorous tissue in neurosurgical procedures. Studies have shown that the intraoperative use of this guiding method may reduce the tumour residual volume and prolong progression-free survival in patients suffering from this disease. [ cite journal |author=Stummer W, Pichlmeier U, Meinel T, Wiestler OD, Zanella F, Reulen HJ |title=Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomised controlled multicentre phase III trial |journal=Lancet Oncol. |volume=7 |issue=5 |pages=392–401 |year=2006 |pmid=16648043 |doi=10.1016/S1470-2045(06)70665-9]dALA is also a
photosensitizer forphotodynamic therapy .References
ee also
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Porphyrin
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