The synthesis of N-(benzyloxycarbonyl)-3-O-[3,4,6-tri-O-acetyl-2-deoxy-2-(2,4-dinitroanilino)-β-d-glucopyranosly]-l-serine methyl ester, and its condensation with activated esters of amino acids

1976 ◽  
Vol 52 (1) ◽  
pp. 246-250 ◽  
Author(s):  
Hari G. Garg ◽  
Roger W. Jeanloz
Keyword(s):  
Amino Acids ◽  
Methyl Ester ◽  
Activated Esters

Repression ofPseudomonas fluorescensextracellular lipase secretion by arginine

1990 ◽  
Vol 57 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Leonides Fernandez ◽  
Carmen San Jose ◽  
Robin C. McKellar
Keyword(s):  
Amino Acids ◽  
Methyl Ester ◽  
Glutamic Acid ◽  
Pseudomonas Fluorescens ◽  
Lipase Production ◽  
Extracellular Lipase ◽  
Metabolic Intermediate ◽  
Proteinase Production

SummaryThe effect of arginine on the production of extracellular lipase byPseudomonas fluorescens32A was studied. Arginine repressed lipase production when N was supplied partially or totally as arginine. Proteinase production was unaffected under the same conditions. Arginine did not repress lipase secretion when cells were pregrown in an arginine-containing medium; however, repression was found with uninduced cells. Several arginine-analogues were tested for the ability to repress lipase secretion and. of these, L-homoarginine and L-canavanine were the most effective. D-Arginine, L-arginine methyl ester, and L-ornithine did not cause repression. With the exception of glutamic acid and methionine, those amino acids that supplied N but not C for growth were found to repress lipase secretion. It is suggested that the accumulation of metabolic intermediate(s) may cause repression of lipase production.

Fluorination of sulfur-containing amino acids: Reaction of xenon difluoride with cysteine derivatives

1990 ◽  
Vol 68 (3) ◽  
pp. 477-479 ◽  
Author(s):  
Xiaoling Huang ◽  
Barry J. Blackburn ◽  
Steve C. F. Au-Yeung ◽  
Alexander F. Janzen
Keyword(s):  
Amino Acids ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methyl Ester ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Xenon Difluoride ◽  
Nitrophenyl Ester ◽  
Sulfur Containing

The reaction of XeF2 with cysteine derivatives RSCH2CH(NHR)COOR, i.e., S-benzyl-N-trifluoroacetyl-L-cysteine methyl ester, S-benzyl-N-carbobenzoxy-L-cysteine p-nitrophenyl ester, and S-methyl-N-trifluoroacetyl-L-cysteine methyl ester is described. The fluorinated products PhCHFSCH2CH(NHR)COOR, PhCH2SCHFCH(NHR)COOR, and FCH2SCH2CH(NHR)COOR were identified by 1H and 19F nuclear magnetic resonance spectroscopy. PhCH2SCHFCH(NHR)COOR loses HF within 24 hours to give Z- and E-PhCH2SCH=C(NHR)COOR. If the reaction with XeF2 is carried out in the presence of moisture the sulfoxide RS(O)CH2CH(NHR)COOR and sulfone RSO2CH2CH(NHR)COOR are produced. Keywords: fluorination, XeF2, amino acids, cysteine.

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