ZfN: Search Results

1	Author	Karl Folkers, Cyril Bowers, Pui-FunL. Tang, Minoru Kobota, Xiao Shao-Bo, Wolf Gang Bender, Liu Yin-Zeng	Requires cookie*
	Title	Relative Potencies of Antagonists of the Luteinizing Hormone Releasing Hormone with Lys8 and Arg8 and Substitutions in Positions 3 ,5 ,6 ,7 and 8d-Ala10] — N H 2 and [N -A c—D-2
	Abstract	Antagonists of the luteinizing hormone releasing hormone (L H R H) of increased potency is a goal for control of ovulation. In the design and synthesis of 26 decapeptides, emphasis was given to analogs with Lys8 and Arg8 and with various substitutions in positions 3, 5, 6, 7 and 8. Two antagonists, [N — A c—D-2-Nal]-N H 2 showed 80-85% antiovulatory activity (A O A) at 0.25 (ig in the rat. The latter antagonist showed 60% A O A at 0.125 ^.g. O f four pairs of analogs with Arg8 and Lys8, respectively, two pairs favored Lys8 over Arg8 for potency. One pair showed negligible difference and another pair favored Arg8 over Lys8. There is specificity of substitution for potency. In other antagonists, d -3-Pal3, Tyr5 or Phe5, D-Arg6 and Leu7 or Nie7 or Val7 and Arg8 were variously effective substitutions for increase of potency and reduction of histamine release.
	Reference	Z. Naturforsch. 41c, 1087—1091 (1986); received June 10 1986
	Published	1986
	Keywords	Luteinizing Hormone Releasing Hormone, Ovulation, Peptide, Antagonist, Histamine Release
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	TEI-XML for	default:Reihe_C/41/ZNC-1986-41c-1087.pdf
	Identifier	ZNC-1986-41c-1087
	Volume	41

2	Author	Karl Folkers, Cyril Bowers, Xiao Shao-Bo, Pui-Fun, Louisa Tang, Minoru Kubota, Janusz Stepinski, Teresa Kubiak	Requires cookie*
	Title	Activities of Antagonists of the Luteinizing Hormone Releasing Hormone with Emphasis on Positions 1, 5 and 6 and on Positions 1, 2 and 3
	Abstract	Analogs of the luteinizing hormone releasing hormone (LHRH) which are antagonists for controlling ovulation require potency and negligible release of histamine as a side effect. Forty analogs were designed, synthesized and bioassayed in two groups with emphasis upon positions 1, 5 and 6 and upon positions 1, 2 and 3. N-Ac-D-2-Nal 1 , D-pClPhe 2 , D-3-Pal 3 , Ser 4 , Tyr 5 . D-Lys 6 ,
	Reference	(Z. Naturforsch. 42b, 101—106 [1987]; received July 18 1986)
	Published	1987
	Keywords	Luteinizing Hormone Releasing Hormone, a«f/-Ovulatory Activity, Peptide, Antagonist, Histamine Release
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	TEI-XML for	default:Reihe_B/42/ZNB-1987-42b-0101.pdf
	Identifier	ZNB-1987-42b-0101
	Volume	42

3	Author	Anna Janecka3, StevenK. Oerberb, Tomasz Janecki3, Cyril Bowersc, Karl Folkers3	Requires cookie*
	Title	N5-PyrazinylcarbonyIornithine, an Effective Substituent for Position 5 of Antagonists of LHRH
	Abstract	Com puter modeling was used to find an effective substituent for position 5 in antagonists of the luteinizing hormone-releasing hormone (LHRH). In particular, it was desired to replace ds-3-(4-pyrazinylcarbonylaminocyclohexyl)alanine in position 5 because this sub stituent is laborious to synthesize. Calculations revealed that N5-pyrazinylcarbonylornithine (PzOrn) should be a suitable substitute for cPzACAla, with N6-pyrazinylcarbonyllysine (PzLys) being a second choice. Twelve analogs were synthesized in four series with DNal or DQal in position 1 and ILys or Arg in position 8. Biological assays validated the calculations and show that antagonists with PzOrn are more potent in antiovulatory assay than antag onists with PzLys. The antagonists with PzOrn were comparable in AOA with antagonists with cPzACAla. What is also im portant, antagonists with PzOrn released significantly less histamine than those with cPzACAla.
	Reference	Z. Naturforsch. 50b, 147—150 (1995); received April 27 1994
	Published	1995
	Keywords	LH RH Antagonists, Com puter Modeling, Antiovulatory Activity, Histamine Release, Solid Phase Peptide Synthesis
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	TEI-XML for	default:Reihe_B/50/ZNB-1995-50b-0147.pdf
	Identifier	ZNB-1995-50b-0147
	Volume	50