摘要:
To produce optically active .alpha.-arylalkylamine from optically impure .alpha.-arylalkylamine.Optically impure .alpha.-arylalkylamine is mixed with optically active N-acyl-aspartic acid or glutamic acid in a solvent and the resulting two types of diastereomer salts are optically resolved utilizing difference in solubility.
摘要:
A process for optical resolution of a racemic substituted benzylamine is provided that involves reacting the racemic substituted benzylamine in a solvent with an optically active N-acyl-phenylalanine, -aspartic acid, or -glutamic acid, and separating the diastereomers formed by making use of the difference in the mutual solubilities of the two diastereomer salts which are generated therein.
摘要:
The present invention provides crystals of L-phenylalanine monomethyl sulfate which have low solubility compared to L-tyrosine and D-phenylalanine. The L-phenylalanine monomethylsulfate crystals are obtained by subjecting a solution containing monomethyl sulfuric acid and phenylalanine to crystallization.Further, the present invention also provides a process for recovering L-phenylalanine from a water layer by neutralizing the esterified reaction, extracting an ester of L-phenylalanine therefrom with an organic solvent, and recovering remaining L-phenylalanine in the water layer as L-phenylalanine monomethylsulfate. L-phenylalanine monomethyl sulfate is obtained by esterifying L-phenylalanine and methanol in the presence of sulfuric acid, neutralizing the esterified solution with a base in the presence of water, extracting the produced L-phenylalanine methyl ester from the neutralized solution with an organic solvent, and then crystallized the resultant water layer under acidic condition.
摘要:
The present invention provides crystals of L-phenylalanine monomethyl sulfate which have low solubility compared to L-tyrosine and D-phenylalanine. The L-phenylalanine monomethylsulfate crystals are obtained by subjecting a solution containing monomethyl sulfuric acid and phenylalanine to crystallization.Further, the present invention also provides a process for recovering L-phenylalanine from a water layer by neutralizing the esterified reaction, extracting an ester of L-phenylalanine therefrom with an organic solvent, and recovering remaining L-phenylalanine in the water layer as L-phenylalanine monomethylsulfate. L-phenylalanine monomethyl sulfate is obtained by esterifying L-phenylalanine and methanol in the presence of sulfuric acid, neutralizing the esterified solution with a base in the presence of water, extracting the produced L-phenylalanine methyl ester from the neutralized solution with an organic solvent, and then crystallized the resultant water layer under acidic condition.
摘要:
The present specification discloses a ruminant feed additive composition which contains as an active ingredient a phosphoric acid-amino acid-polyvalent metal composite salt (final composite salt) which is insoluble in neutral or alkaline water and is soluble in acidic water and which can be obtained by treating a composite salt composed of a basic amino acid, magnesium and phosphoric acid with a salt of a divalent or trivalent (polyvalent) metal other than magnesium, or by treating the above-mentioned composite salt with the polyvalent metal salt and a condensed phosphoric acid component (alone) or the condensed phosphoric acid component and a phosphoric acid component (in combination), this composition taking the form of a powder or granules. The above-mentioned final composite salt can exhibit the excellent stability to neutral or slightly acidic water, namely, the low solubility therein in comparison with the intermediate composite salt, and it can have both the excellent insolubility of the basic amino acid in a rumen of a ruminant and the excellent elution thereof in an abomasum and lower digestive organs.
摘要:
The present invention provides a method of preparing L-aspartyl-D-.alpha.-aminoalkane carboxylic acid-(S)-N-.alpha.-alkylbenzylamide which is less expensive and more efficient than previous methods using N-protected-L-aspartic anhydride.
摘要:
The invention relates to a process for producing N-protected-.alpha.L-aspartyl-L-phenylalanine methyl ester, which comprises esterifying L-phenylalanine with methanol in the presence of a strong acid catalyst, adding, to the resulting solution, an aqueous alkaline solution to neutralize the acid catalyst and a water-immiscible organic solvent to extract the free L-phenylalanine methyl ester thus formed, collecting the organic layer, and reacting the L-phenylalanine methyl ester dissolved in said collected organic layer with N-protected-L-aspartic anhydride.
摘要:
L-amino acid amides are converted to the corresponding D-amino acid amides. An amide formed from an L-amino acid and an optically active (S)-.alpha.-alkylbenzylamine is subjected to dehydration condensation with an aryl aldehyde to form a Schiff's base, which is racemized at the amino acid moiety in the presence of a base to yield an N-allylidene-D-amino acid-(S)-amide. The less-soluble diastereomer N-allylidene-D-amino acid-(S)-amide is crystallized from the reaction mixture and recovered by means of solid/liquid separation. The N-allylidene form is readily hydrolyzed into the amino acid-(S)-amide and the starting aldehyde.
摘要:
Spherical aggregate crystals of a phosphoric acid/lysine/magnesium composite salt represented by formula (1):R.sub.a Mg.sub.b H.sub.c PO.sub.4.(H.sub.2 O).sub.n (1)whereR is a lysine cation;a is 0.15 to 1.0;b is 1.0 to 1.42;c is 0 to 0.3;n is 0 to 10; anda+(2.times.b)+c=3.
摘要翻译:由式(1)表示的磷酸/赖氨酸/镁复合盐的球形聚集晶体:RaMgbHcPO4。(H2O)n(1)其中R是赖氨酸阳离子; a为0.15〜1.0; b为1.0〜1.42; c为0〜0.3; n为0〜10; 和+(2xb)+ c = 3。
摘要:
An economical process for producing .alpha.-L-aspartyldipeptide amide derivatives useful as sweeteners, by using amino protecting groups which can be removed by hydrolysis under acidic conditions, resulting in conversion of a .beta.-carboxyl acid ester to a carboxylic acid.