Untersuchungen in der Phenylalanin‐Reihe V. Hydrierung des Tyrosins

Waser, E.; Brauchli, E.

doi:10.1002/hlca.19240070190

Cited by 37 publications

(3 citation statements)

References 4 publications

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“…Direct proof that the molecule contains a preformed six-carbon ring is lacking. Hydrogenation of phenylalanine, tyrosine and 3,4-dihydroxyphenylalanine with platinum oxide as catalyst yields hexahydrophenylalanine, which shows RTy3 280 300 1-8 in butan-l-ol-acetic acid-water (see Waser & Brauchli, 1926). No significant amount of a com-bacilysin, including the formation from it of tyrosine in hot 6N-hydrochloric acid, would be understandable if a cyclohexanone grouping carrying an epoxide were present in the molecule.…”

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confidence: 99%

Observations on the structure of bacilysin

Rogers

Lomakina

Abraham

1965

Biochemical Journal

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1. Elementary analysis and other properties of a highly purified preparation of bacilysin indicated that a possible molecular formula for the substance is C(12)H(18)N(2)O(5). The results of electrometric titration were consistent with the hypothesis that the substance was a peptide containing one free alpha-amino group and one free carboxyl group. 2. Hydrolysis of bacilysin with 6n-hydrochloric acid at 105 degrees yielded l-alanine and l-tyrosine, but the ultraviolet spectrum of the substance showed that no tyrosine residue was present in the molecule and a nuclear-magnetic-resonance spectrum indicated that olefinic and aromatic protons were absent. The dinitrophenyl (DNP) derivative of bacilysin yielded DNP-alanine on acid hydrolysis. 3. Bacilysin was hydrolysed by leucine aminopeptidase (EC 3.4.1.1) and by Pronase to give alanine and an uncharacterized amino acid. Its infrared spectrum was consistent with the presence of a peptide grouping in the molecule. 4. The optical rotatory dispersion of bacilysin and its reaction with thiosemicarbazide indicated that the substance contained an aldehyde or ketone group. Its behaviour on catalytic reduction and its reaction with sodium thiosulphate and with certain thiols suggested that an epoxide group was present. 5. A possible type of structure for bacilysin is considered in the light of its known properties.

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mentioning

confidence: 99%

Observations on the structure of bacilysin

Rogers

Lomakina

Abraham

1965

Biochemical Journal

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“…(0.08-11.9) 2') (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32) [25] 35 [26] [Phe5] -LH-RH 42 …”

Section: Lh-rhmentioning

confidence: 99%

“…Cyclohexylalanine hydrochloride (Cha . HC1) [42] was carbobenzoxylated by the general procedure of Bergmann & Zervas [43] …”

Section: Pglzl-his-?'rp-ser-phe-gly-leu-a~g-pro-gly-sh Boc-ser(bz1)mentioning

confidence: 99%

Synthesis of Some Structural Analogues of LH‐RH Modified in Position 5, their in vivo and in vitro Gonadotropin‐releasing Activity and Immunoreactivity

Künzi

Gillessen

Trzeciak

et al. 1974

Helvetica Chimica Acta

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Four analogues of LH-RH modified in position 5 have been synthesized using either classical procedures or the solid phase method. The gonadotropin-releasing activities were dctcrmined by radioimmunological measurements of LH and FSH in vivo and in vitro and the immunoreactivities by a specific LH-RH radioimmunoassay (RIA). The following relative potencics and irnmunorcnctivities were found :Part of this work was prcscnted at the I X Acta Endocrinologica Congress, Oslo, 17th-21th June, 1973 [1]. 2132 HELVETICA CHIMICA ACTA -Vol. 57, Fax. 7 (1974) -Nr. 232 structural changes could yield substances competing with endogenous LH-KH at the pituitary binding sites, acting thus as inhibitors of the release of either LH or FSH or both. Structure-activity studies in the field of oxytocin [4], lysine-vasopressin [ 5 ] , bradykinin [6] and angiotensin [7] suggest that chemically reactive groups are involved in the interaction of a hormone with its receptor sites. Since modification of tyrosine in oxytocin had led to a partial inhibitor, we were interested in studying the effects of LH-RH analogues similarly altered. We therefore syn-[Gly5]-LH-RH was prepared by solid phase synthesis according to the general procedure of Merrifield [8] [9] using dicyclohexylcarbodiimide (DCC) as coupling agent and the t-butoxycarbonyl (Boc) group as amino protecting group for all amino acids except pyroglutamic acid. The latter was introduced in the form of its pentachlorophenylester. The side chain functional group of serine was protected by the benzyl group, that of histidine by the dinitrophenyl group and that of arginine by the nitro group. The protected decapeptide was cleaved from the resin by transesterification [lo]. Subsequent treatment with liquid H F [ll], followed by ainmonolysis and purification, yielded pure [Gly5]-LH-RH. The synthesis of [Phe5]-LH-RH was carried out by condensation of the central tetrapeptide Boc-Ser(Bz1)-Phe-Gly-Leu-OH with the C-terminal tripeptide H-L4rg(N0,)-Pro-Gly-NH, [12-151 by means of DCC. The resulting heptapeptide was treated with trifluoroacetic acid and coupled to the N-terminal tripeptide pGlu-His-Trp-OH [16] by means of DCC. The central tetrapeptide was prepared by stepwise elongation of H-Gly-Leu-OMe [17] with Boc-Phe-OH [18] and then with Boc-Ser(Bz1)-OH [19] using the DCC method.[Tyr(Me)5l1-LH-RH was prepared according to the same procedure using Boc-Tyr(Me)-OH instead of Boc-Phe-OH. The protecting groups of both resulting decapeptidarnides were removed by liquid HF.The synthesis of [Cha5]-LH-RH was carried out by coupling the N-terminal tripeptide pGlu-His-Trp-OH to the central tripeptide H-Ser(But)-Cha-Gly-OEt by means of DCC. The resulting hexapeptidester was transformed into its hydrazide and coupled via azide to the C-terminal tetrapeptide H-Leu-Arg(Tos)-Pro-Gly-NH, [ZO] [all. To obtain the central tripeptide, 2-Cha-OH was coupled with H-Gly-OEt to the corresponding dipeptide, which, after hydrogenation, was elongated with 2-Ser(But)-OH to the fully protected tripeptidester. Hydrog...

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Gränacher Synthesis

2010

Comprehensive Organic Name Reactions and Reagents

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The preparation of thionic acid by the treatment of Aldol condensation product from an aldehyde and rhodanine with a base (e.g., NaOH) is known as the Gränacher synthesis or Gränacher reaction. The prepared thionic acid in this reaction has been found to convert into a variety of derivatives under different conditions. This reaction has general application in the preparation of α‐keto acids, nitriles, α‐amino acids, etc.

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Untersuchungen in der Phenylalanin‐Reihe V. Hydrierung des Tyrosins

Cited by 37 publications

References 4 publications

Observations on the structure of bacilysin

Observations on the structure of bacilysin

Synthesis of Some Structural Analogues of LH‐RH Modified in Position 5, their in vivo and in vitro Gonadotropin‐releasing Activity and Immunoreactivity

Gränacher Synthesis

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