Vanillin-mandelic acid
Structural formula | |||||||||||||||||||
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Simplified structural formula without stereochemistry | |||||||||||||||||||
General | |||||||||||||||||||
Surname | Vanillin-mandelic acid | ||||||||||||||||||
other names |
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Molecular formula | C 9 H 10 O 5 | ||||||||||||||||||
Brief description |
white to beige powder |
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properties | |||||||||||||||||||
Molar mass | 198.17 g · mol -1 | ||||||||||||||||||
Physical state |
firmly |
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Melting point |
131–134 ° C (decomposition) |
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solubility |
soluble in water |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Vanillin-mandelic acid (VMS, 3-methoxy-4-hydroxy mandelic acid ) is a breakdown product of adrenaline and noradrenaline - both of which are formed as hormones in the adrenal medulla and also act as neurotransmitters - and is formed from these via intermediate stages through the action of the enzyme monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). VMS is excreted in the urine as an inactive metabolite.
A measurement of VMS in the urine allows conclusions to be drawn about its concentration in the plasma and, moreover, approximately to the amounts of adrenaline and noradrenaline previously formed in the body, the specificity being high at 95–100%, while the sensitivity depends on the respective question.
A strong increase in VMS in the collected urine (> 7 mg / 24 h) indicates a pheochromocytoma or a tumor of the sympathetic nervous system. VMS can also be used as a tumor marker for a neuroblastoma , then more in monitoring the course than in screening the disease.
Vanillin-mandelic acid can be detected in the urine by HPLC (liquid chromatography). The reliable qualitative and quantitative determination in urine samples is achieved through the use of lipophilic gel chromatography on Sephadex LH 20 and subsequent gas chromatography of the trimethylsilyl derivatives. The advantage of this procedure is that in addition to vanillin-mandelic acid, other diagnostically important substances, such as B. homovanillic acid can be quantified.
literature
- Manfred J. Müller: Nutritional Medicine Practice: Methods - Prevention - Treatment . Springer Medizin Verlag, 2007, ISBN 978-3-540-38230-0 , p. 114 ( limited preview in Google Book search).
Individual evidence
- ↑ a b c Data sheet vanillin-mandelic acid from Acros, accessed on February 19, 2010.
- ↑ a b Data sheet DL-4-Hydroxy-3-methoxymandelic acid from Sigma-Aldrich , accessed on April 25, 2011 ( PDF ).
- ↑ BM Eriksson, BA Persson, M. Wikström: Determination of urinary vanillylmandelic acid by direct injection and coupled-column chromatography with electrochemical detection. In: Journal of Chromatography B . 527 (1), 1990, pp. 11-19. doi: 10.1016 / S0378-4347 (00) 82078-2 . PMID 2365768 .
- ↑ H.-U. Melchert, H. Hoffmeister: Gas Chromatographic Determination of Hydroxyindole Acetic Acid, Vanillinmandelic Acid and Homovanillic Acid, Das Medical Laboratorium Volume 29, Issue 9, pp. 199-206, Hirzel Verlag, Stuttgart 1976, ZB-ID 205609-4, ISSN 0025-8466 [1]
- ↑ HU Melchert, H. Hoffmeister: Determination of the urinary metabolites hydroxyindole-acetic acid, vanillyl mandelic acid and homovanillic acid by means of lipophilic gel chromatography and gas chromatography. In: J Clin Chem Clin Biochem. 15 (2), Feb 1977, pp. 81-87. PMID 845547 .