- New and efficient process for the preperation of cabergoline and its intermediates
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This invention relates to a new and efficient process for the production of dopamine agonists such as Cabergoline and the intermediates thereof.
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Page/Page column 9
(2008/12/08)
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- Serotonergic ergoline derivatives
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Novel classes of 13- and 14-tertbutyl-ergoline derivatives were prepared, and characterised in vitro for their affinity for adrenergic, dopaminergic and serotonergic binding sites. This study particularly examines the importance of the presence and the position of the tert-butyl group in conferring either significant 5-HT(1A) or 5-HT2 affinity and selectivity respectively.
- Mantegani, Sergio,Brambilla, Enzo,Caccia, Carla,Damiani, Gabriele,Fornaretto, Maria Gioia,McArthur, Robert A.,Varasi, Mario
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p. 1117 - 1122
(2007/10/03)
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- Naturally occurring clavines: Antagonism/partial agonism at 5-HT(2A) receptors and antagonism at α1-adrenoceptors in blood vessels
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The interaction of eight typical representatives of naturally occurring clavines (agroclavine, costaclavine, dihydrolysergol-I, elymoclavine, festuclavine, lysergene, lysergol, and pyroclavine) with 5-HT(2A) receptors and α1-adrenoceptors was studied in rat tail artery and aorta, respectively. Clavines antagonized 5-HT-induced contractions with calculated pK(B) values (pK(p) values for partial agonists) of 4.84 - 7.81 and (R)-phenylephrine-induced contractions with calculated pK(B) values of 5.34 - 7.09. Specificity of clavines at 5-HT(2A) receptors relative to α1-adrenoceptors was rather low. Low affinity for costaclavine at both 5-HT(2A) receptors (pK(p) = 4.84 ± 0.06) and α1-adrenoceptors (pK(B) = 5.34 ± 0.05) indicates that the trans-junction of ring C and D of the ergoline pharmacophore is crucial for the binding of ergolines to these sites. Lysergol, lysergene, and costaclavine produced non-parallel displacements of the 5-HT concentration-response curve in the rat tail artery and caused small contractions by themselves. Lysergol contracted the rat tail artery with a pEC50 of 6.36 ± 0.04 and an intrinsic activity of 0.18 ± 0.03 with respect to 5-HT. Lysergol-induced contractile responses were surmountably antagonized by ketanserin (10 nM) with a pK(B) of 9.1 which is consistent with an interaction of lysergol with 5-HT(2A) receptors. The pK(p) for the lysergol-5-HT(2A) receptor complex calculated from concentration-response curves to lysergol was 6.88 ± 0.07 and did not match the pK(p) of 7.66 ± 0.02 calculated from antagonism by lysergol of the contractile response to 5-HT. This suggests that lysergol and 5-HT possibly bind in two slightly different orientations at the 5-HT2(A) receptor. It is concluded that partial agonism and pure antagonism at 5-HT2(A) receptors on the one side and antagonism at α1-adrenoceptors on the other side may contribute to the noxious effects of naturally occurring clavines.
- Pertz
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p. 387 - 392
(2007/10/03)
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- Synthesis and structure-activity relationships of new (5R,8R,10R)-ergoline derivatives with antihypertensive or dopaminergic activity
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A series of new (5R,8R,10R)-ergoline derivatives was synthesized, and their antihypertensive and dopaminergic activities were tested in conscious spontaneously hypertensive rats and in rats with unilateral 6- hydroxydopamine-induced lesions of the substantia nigra. (5R,8R,10R)-6- Alkyl-8-ergolinemethanols, prepared from the corresponding ergolinecarboxylates, were converted to the tosylates, which were treated with various five-membered heterocycles containing nitrogen atoms to afford the new ergolines. (5R,8R,10R)-8-(1,2,4-Triazol-1-ylmethyl)-6-methylergoline (4s, maleate: BAM-1110) exhibited potent dopaminergic activity, about 18- fold greater than that of bromocriptine mesylate. (5R,8R,10R)-8-(1,2,4- Triazol-1-ylmethyl)-6-propylergoline (8b, fumarate: BAM-1602) showed extremely potent dopaminergic activity, being about 220 and 1.15 times more active than bromocriptine mesylate and pergolide mesylate, respectively. Several compounds exhibited potent antihypertensive activity. Structure- activity relationships for antihypertensive and dopaminergic activities are discussed.
- Ohno,Adachi,Koumori,Mizukoshi,Nagasaka,Ichihara,Kato -
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p. 1463 - 1473
(2007/10/02)
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- Diastereospecific formation of 6-N-oxide ergolines: A 1H NMR study of the configuration at nitrogen
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The 6-N-oxides derivatives of a series of analogous ergoline/ene derivatives were prepared and their stereochemistry at nitrogen determined by 1H NMR analysis. The factors governing the outcome of the oxidation are discussed.
- Ballabio,Sbraletta,Mantegani,Brambilla
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p. 4555 - 4566
(2007/10/02)
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