help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vakkuri, O.
Right arrow Articles by Leppaluoto, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vakkuri, O.
Right arrow Articles by Leppaluoto, J.

Endocrinology, Vol 120, 2453-2459, Copyright © 1987 by Endocrine Society

ARTICLES

A cyclic isomer of 2-hydroxymelatonin: a novel metabolite of melatonin

O Vakkuri, J Tervo, R Luttinen, H Ruotsalainen, E Rahkamaa and J Leppaluoto

A previously unknown melatonin metabolite was isolated by chloroform extraction and reverse phase HPLC from human and rat urine after administration of synthetic melatonin and characterized by mass spectroscopy and proton magnetic resonance spectroscopy to 1-acetyl- 1,2,3,3a,8,8a-hexahydro-8a-hydroxy-5-methoxypyrrolo[2,3-b ]indole, a cyclic isomer of 2-hydroxymelatonin. This isolation was based on the fact that our melatonin antibody (a-MT-K1) cross-reacted against this novel metabolite at a level of 0.1% (melatonin 100%). In our HPLC program for indoles the cyclic 2-hydroxymelatonin eluted at 25 min, separately from synthetic indoles, between 6-hydroxymelatonin (19 min) and melatonin (35 min). In [3H] melatonin studies it was found to be present (at 25 min in our HPLC), accounting for 5% of the urinary metabolites of melatonin in the rat. Since beta-glucuronidase- arylsulfatase treatment of rat urine did not liberate the cyclic 2- hydroxymelatonin this would appear to be excreted into urine as the free form.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1987 by The Endocrine Society