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9-O-carbamoyl

The conformational preferences of 9-O-carbamoyl cinchona free bases reflect in general those of the native cinchona alkaloids. 6 -Neopentoxy-9-0-tert-butylcarba-moylcinchonidine exists as a mixture of two major anti-closed and anti-open conformers in a 65 35 ratio, whereas upon protonation anti-open conformation has been observed exclusively [62]. [Pg.436]

This enzyme [EC 3.1.3.9] catalyzes the hydrolysis of o-glucose 6-phosphate to yield o-glucose and orthophosphate. Some glucose phosphatases also catalyze transphosphorylation reactions from carbamoyl phosphate, hexose phosphates, pyrophosphate, phosphoenolpyru-vate and nucleoside di- and triphosphates, using D-glu-cose, D-mannose, 3-methyl-D-glucose, or 2-deoxy-D-glu-cose as phosphoryl acceptors. See Isotope Exchange (Reactions Away from Equilibrium)... [Pg.313]

Figure 9. Enzymatic degradation of different dextran derivatives by dextranase. (A) 5% ox.red.Dextran, ( ) 3% succinoylated dextran, (O) 4.5% carbamoylated dextran. Figure 9. Enzymatic degradation of different dextran derivatives by dextranase. (A) 5% ox.red.Dextran, ( ) 3% succinoylated dextran, (O) 4.5% carbamoylated dextran.
Figure 12.3 Reaction profile of D-methionine production from D,L-methylthioethylhydantoin (d.l-MTEH) using (a) a double system with D-hydantoinase and D-carbamoylase enzymes and (b) a triple system with hydantoin racemase enzyme as third enzyme. Symbols , D-methionine O, N-carbamoyl d-methionine , D,L-methylthioethylhydantoin , sum of all three [9]. Figure 12.3 Reaction profile of D-methionine production from D,L-methylthioethylhydantoin (d.l-MTEH) using (a) a double system with D-hydantoinase and D-carbamoylase enzymes and (b) a triple system with hydantoin racemase enzyme as third enzyme. Symbols , D-methionine O, N-carbamoyl d-methionine , D,L-methylthioethylhydantoin , sum of all three [9].
Active research on the development of further cinchonan-based anion exchangers is in progress. In this context we have recently shown that also O -modified CSPs (with other than methoxy substituents at Ri. see Fig. 9.32) 90], carbamoylated C -dimeric CSPs 1390], and CX -hydrazide CSPs [391] as well as C -urea and Cy-amide-modified cinchonan-derived CSPs possess a high potential for enantiomeric separations of acidic SAs. [Pg.425]

The enzyme, Af-carbamoyl o-amino acid amidohydrolase can be incorporated with hydantoinase to produce o-amino acids in one step from the corresponding racemic hydantoins. Because many of the five-substituted hydantoins undergo spontaneous racemization under the enzymatic reaction conditions (pH > 8), complete conversion from racemic hydantoin to the o-amino acid can be achieved. The starting hydantoins are prepared by the Bucherer-Bergs reaction (Scheme 9.34), the simple condensation of potassium cyanide and ammonium carbonate with the... [Pg.173]

Toluenesulphonamido)phenyl] ethyl 2,3,4-tri-(9-benzyl-Q -D-gluco-pyranoside has been condensed with 2,3,4-tri-0-benzyl-6-0-(7V-phenyl-carbamoyl)-l-0-tosyl-D-glucopyranose to yield 2,4-(4-toluene-sulphonamido)-phenyl ethyl 2,3,4,2, 3 4 -hexa-0-benzyl-6 -<9-(7V-phenylcarbamoyl)-a-isomalto-side. The disaccharide was decarbanilated in ethanol with sodium ethoxide. The sequence of coupling with the 1-O-tosyl-D-glucose derivative followed by decarbanilation was repeated to form the tri- and tetra-saccharide derivatives. [Pg.575]

Novobiocin (7-[0 -carbamoyl-5-0 -dimethyl-P-L-Zj so-6-desoxyhexahydropyranosyloxy]-4-hydroxy-3[4-hydroxy-3- 3-methylbut-2-enyl -benzylamino]-8-methylcoumarin) [303-81-1] M 612.6, two forms m 152-156 and m 172-174 , 174-178 , at 330nm (acidic EtOH), 305nm (alkaline EtOH), [a] -63 (c 1, EtOH), pKi 4.03 (4.2), pK2 9.16. Ciystallise novobiocin from EtOH and store it in the dark. It has also been recrystallised from McoCO/H O. [Hoeksema et al. JAm Chem Soc 77 6710 1955, Kaczka et al. JAm Chem Soc 11 9404 iP55.]... [Pg.890]


See other pages where 9-O-carbamoyl is mentioned: [Pg.444]    [Pg.445]    [Pg.445]    [Pg.453]    [Pg.444]    [Pg.445]    [Pg.445]    [Pg.453]    [Pg.47]    [Pg.159]    [Pg.606]    [Pg.835]    [Pg.134]    [Pg.733]    [Pg.269]    [Pg.301]    [Pg.783]    [Pg.927]    [Pg.115]    [Pg.138]    [Pg.455]    [Pg.155]    [Pg.18]    [Pg.125]    [Pg.168]    [Pg.55]    [Pg.80]    [Pg.116]    [Pg.358]    [Pg.332]    [Pg.59]   
See also in sourсe #XX -- [ Pg.453 , Pg.454 ]




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