Prolactin Response in Border-Leicester X Merino Ewes to Administration of Melatonin, Melatonin Analogues, a Melatonin Metabolite and 6-Methoxybenzoxazolinone

Kennaway, David J.; Royles, P.; Dunstan, E. A.; Hugel, HM

doi:10.1071/bi9860427

Cited by 10 publications

(3 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Effects on the reproductive system were also described for both AFMK and AMK, but they remained weaker than those of melatonin [161]. However, contrary to melatonin, no substantial effects of AFMK on prolactin release were observed in ewes [162].…”

Section: Biological and Pharmacological Actionsmentioning

confidence: 99%

Kynuramines, metabolites of melatonin and other indoles: the resurrection of an almost forgotten class of biogenic amines

Hardeland

Tan

Reíter

2009

Journal of Pineal Research

441

475

View full text Add to dashboard Cite

: Kynuramines represent their own class of biogenic amines. They are formed either by decarboxylation of kynurenines or pyrrole ring cleavage of indoleamines. N2‐formylated compounds formed in this last reaction can be deformylated either enzymatically by arylamine formamidases or hemoperoxidases, or photochemically. The earlier literature mainly focussed on cardiovascular effects of kynuramine, 5‐hydroxykynuramine and their N1,N1‐dimethylated analogs, including indirect effects via release of catecholamines or acetylcholine and interference with serotonin receptors. After the discovery of N1‐acetyl‐N2‐formyl‐5‐methoxykynuramine (AFMK) and N1‐acetyl‐5‐methoxykynuramine (AMK) as major brain metabolites of melatonin, these compounds became of particular interest. They were shown to be produced enzymatically, pseudoenzymatically, by various free radical‐mediated and via photochemical processes. In recent years, AFMK and AMK were shown to scavenge reactive oxygen and nitrogen species, thereby forming several newly discovered 3‐indolinone, cinnolinone and quinazoline compounds, and to protect tissues from damage by reactive intermediates in various models. AMK is of special interest due to its properties as a potent cyclooxygenase inhibitor, NO scavenger forming a stable nitrosation product, inhibitor and/or downregulator of neuronal and inducible NO synthases, and a mitochondrial metabolism modulator. AMK easily interacts with aromates, forms adducts with tyrosyl and tryptophanyl residues, and may modify proteins.

show abstract

Section: Biological and Pharmacological Actionsmentioning

confidence: 99%

Kynuramines, metabolites of melatonin and other indoles: the resurrection of an almost forgotten class of biogenic amines

Hardeland

Tan

Reíter

2009

Journal of Pineal Research

441

475

View full text Add to dashboard Cite

show abstract

“…In our assay system all three analogues were very potent blockers of puberty. We have previously shown these compounds shared with melatonin potent prolactin-lowering activity in sheep (Kennaway et al 1986). Other groups have also shown that 6-chloro-and 6-fluoro-melatonin derivatives possess full biological potency in various assay systems (Flaugh et al 1979;Martin et al 1980;Vaughn et al 1984).…”

Section: Discussionmentioning

confidence: 99%

“…Other compounds examined were intended to test the hypothesis that melatonin is a prohormone and that the brain metabolites of melatonin, N-acetyl-N 2 -formyl-5-methoxy kynurenamine (aFoMK) and N-acetyl-5-methoxy kynurenamine (aMK) (Hirata et al 1974), may mediate many of the effects ascribed to melatonin itself. In a previous communication we described the use of the prolactin-inhibiting activity of melatonin in sheep as our bioassay (Kennaway et al 1986). In the work discussed in this report we D. 1.…”

Section: Introductionmentioning

confidence: 99%

Structure-Activity Studies of Melatonin Analogues in Prepubertal Male Rats

Kennaway¹,

Hügel²,

Clarke³

et al. 1988

Aust. Jnl. Of Bio. Sci.

Self Cite

View full text Add to dashboard Cite

Comparison has been made between the activity of the pineal hormone melatonin, and several analogues and metabolites in inhibiting sexual development in a protein-restricted prepubertal rat model. Eleven melatonin analogues or metabolites were tested with the aim of evaluating the model as a test of the hypothesis that melatonin acts as a prohormone and that the ring schism metabolites (kynurenamines) mediate many of the effects attributable to melatonin. Although the hypothesis could not be confirmed, modification of the melatonin structure by lengthening the acylamide side chain or by replacing the 5 methoxy function with fluorine resulted in loss of biological potency. Modification of the melatonin structure to block the two known points of metabolism resulted in no significant alteration in biological activity. Thus 6-chloromelatonin (blocking 6-hydroxylation) and 2,3-dihydromelatonin (blocking oxidative cleavage of the C2-C3 bond) and 6-chloro-2,3-dihydromelatonin remained biologically active. The metabolic products of brain indolearnine-2,3-dioxygenase, N-acetyl-N 2 -formyl-5-methoxy kynurenamine (aFoMK) and N-acetyl-5-methoxy kynurenamine (aMK), paradoxically were also biologically active.

show abstract

A Convenient and efficient method for the preparation of 6‐Acyl‐2(3H)‐benzoxazolones

Aichaoui

Lesieur

Hénichart

1992

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

Benzoxazolinone derivatives have been found to exhibit various pharmacological properties and 6‐acyl‐2(3H)‐benzoxazolones are considered as key starting materials for the preparation of these compounds. Reported here are the optimal conditions for a regioselective acylation at the 6‐position of the benzoxazolinone ring. A general method leading to the expected products in excellent yields consists in using a mixture of aluminum chloride‐dimethylformamide as catalyst and acid anhydrides or chlorides as acylating agents.

show abstract

Prolactin Response in Border-Leicester X Merino Ewes to Administration of Melatonin, Melatonin Analogues, a Melatonin Metabolite and 6-Methoxybenzoxazolinone

Cited by 10 publications

References 23 publications

Kynuramines, metabolites of melatonin and other indoles: the resurrection of an almost forgotten class of biogenic amines

Kynuramines, metabolites of melatonin and other indoles: the resurrection of an almost forgotten class of biogenic amines

Structure-Activity Studies of Melatonin Analogues in Prepubertal Male Rats

A Convenient and efficient method for the preparation of 6‐Acyl‐2(3H)‐benzoxazolones

Contact Info

Product

Resources

About