摘要:
A method for the crystallization of tryptophan, comprising storing a tryptophan solution at a pH of 8 to 13 and at a temperature of room temperature to 100° C. for 0.5 hour to 1 week and then, followed by crystallization.
摘要:
A method for producing guanosine by aerobic culture of a microorganism of the genus Bacillus which requires adenine for growth and is resistant to at least one of methionine, methionine-analogues and azaserine.
摘要:
Tyrosine-requiring mutant strains of Brevibacterium lactofermentum and Brevibacterium flavum which are capable of vigorous growth on culture media containing enough of a tryptophan analog to suppress growth of the parent strain and also capable of vigorous growth on media containing enough phenylalanine analog to suppress growth of the parent strain, produce more phenylalanine by aerobic fermentation of generally conventional aqueous media than the best phenylalanine-producing related microorganisms available heretofore.
摘要:
DL-Alanine is optically resolved by making an aqueous solution of DL-alanine and of maleic acid supersaturated with respect to mono-alanine maleate, and seeding the supersaturated solution with crystals of an optically active enantiomorph of mono-alanine maleate. The grown crystals are recovered and decomposed to separate the optically active alanine moiety from the maleic acid moiety which may be recycled.
摘要:
An N -acyl derivative of a basic amino acid is obtained in high yield by holding the salt of the amino acid with the carboxylic acid intended to furnish the acyl group at 100* to 250*C.
摘要:
Polysaccharides soluble in water are obtained by contacting water-insoluble, naturally occurring polysaccharides with strong, hot, aqueous solutions of urea, thiourea, guanidine, and their Nlower-alkyl derivatives. No change in primary chemical structure nor shortening of polymer chains occurs under mild processing conditions. Polysaccharides may be separated from other constituents of natural raw materials in soluble form by this method.
摘要:
Phosphoric acid esters of fatty acid mono- or di-glyceride are prepared by reacting a fatty acid mono- or di-glyceride with phosphorylating amounts of polyphosphoric acids.
摘要:
The hydrochloride and hydrobromide of aspartic anhydride are obtained in high yields when the known reaction between one mole of aspartic acid and suitable halide dehydrating agents, such as phosphorus chlorides, is carried out in the presence of at least one mole of a lower alkanoic acid which provides at least a portion of the liquid reaction medium. The yield is further improved by adding the anhydride of the alkanoic acid to the reaction mixture.
摘要:
Amino acids having masked amino groups react with amino acids having masked carboxyl groups to form peptide derivatives in good yields if the reaction medium contains an isonitrile. Isonitriles also are effective in causing condensation of amino acids having masked amino groups with compounds having active hydroxyl groups to the corresponding amino acid esters. The yields of the firstmentioned reaction are enhanced if the reaction mixture additionally contains one of the compounds having active hydroxyl groups. Both the peptide derivatives and the amino acid esters of the compounds having active hydroxyl groups are useful for peptide synthesis. The term ''''amino acid'''' herein embraces also oligopeptides having free amino and carboxyl groups unless specifically stated otherwise.
摘要:
WHEREIN R is the nucleoside moiety of the starting material, and R1, R2, R3 are as above. Some of the compounds are known therapeutic agents, and those which are new have corresponding physiological properties.
WHEREIN R1, R2, R3 are hydrogen or lower alkyl having up to four carbon atoms, and salts of such phosphoryl ethanolamines in the presence of S-triazine derivatives, particularly cyanuric chloride, as condensation agents to form nucleoside-5''diphosphate ethanolamines of the formula
Purine and pyrimidine-5''-monophosphates, AICAR, N-succinylAICAR, and their salts react with phosphoryl ethanolamines of the formula