Riboflavin diethyl

RIBOFLAVINASE RIBOFLAVIN KINASE RIBOFLAVIN SYNTHASE RIBOFLAVINASE RIBOFLAVIN KINASE RIBOFLAVIN SYNTHASE RIBONUCLEASE (or RNase) PSEUDOROTATION DIETHYL PYROCARBONATE RIBONUCLEASE F RIBONUCLEASE II RIBONUCLEASE III Ribonuclease inactivation,... 

Monosodium Glutamate N,N-Diethyl-3-Methyl-henzamide Niacin Nicotine Nitric Acid Nitric Oxide Nitrogen Dioxide Nitroglycerin Nylon 6 and Nylon 66 Penicillin Polyurethane Potassium Nitrate Pyridoxine Riboflavin Saccharin Silver Nitrate Sodium Cyclamate Theobromine Thiamine Triclocarban Urea... 

N,N -Diethyl-N,N -diphenylurea Michler s ketone Ci7H2oN4Na09P 2H2O Riboflavin-5 -phosphate sodium C17H20N4O6 Riboflavin C17H20O... 

In the s3mthesis of riboflavin and some related flavins, better yields are often available through the use of 5-chloro- or 5,5-dichlorobarbituric acid place of alloxan. In addition to riboflavin, 6-methyl-9-2 i, y-methyl-g- s, 6-ethyl-9-3 , 7-ethyl-9-2 , 6,7-diethyl-9- , 6-ethyl-7-methyl-9-2 .3 , 5,7-di-niethyl-9- , 6,8-dimethyl-9- , 6,7-dichloro-9-29.72 6-chloro-9-3 -, 6-flu-oro-9-3 , 6,7-dibromo-9- , 5,6-dimethyl-9- , 6-chloro-7-methyl-9-2 , 6-meth-yl-7-chloro-9-, 3,6,7-trimethyl-9-(i -D-ribityl)isoalloxazine2 (using 2-methylalloxan), and 6,7-dichloro-9-(i -D-sorbityl)isoalloxazine i have been prepared by this method. 

The availability of the exceptionally successful method for the purification of flavins developed by Pasternack and Brown makes this method the one of choice for the synthesis of several flavins. In addition to riboflavin, [2- C]riboflavin 2 6,7-dimethyl-9-(i -L-lyxityl)isoalloxazine , b-ethyl-y-methyl-9-, 6-methyl-7-ethyl-9-, 6,7-diethyl-9-, and 3,6,7-trimethyl-9-(i -D-ribityl)isoalloxazine ° (using 2-methylbarbituric acid) have been prepared by this method. AT-(i -D-Ribityl)-2-/)-tolylazo-4-ethylaniline , -2-/)-nitrophenylazo-4-chloro-5-methylaniline2 and -2-/>-nitrophenylazo-4-methyl-5-chloroaniline react poorly or not at all with barbituric acid under a variety of conditions. 

Diethyl-9-(i -D-ribityI)isoalloxazine (diethylriboflavm), is a competitive antagonist of riboflavin for growth in the rat with an inhibition index of about 6. When any but very small quantities are administered to the riboflavin-deficient rat, a growth response is obtained . The compound does not, however, serve as a replacement of riboflavin in the nutrition of the animal because it does not permit survival - . It can serve as the sole source of flavin in the nutrition of L. casei for which organism it has 100% of the activity of equivalent amounts of riboflavin up to the concentration of 8.22 lO moles per ml. At higher concentrations its activity levels off at about 90%. It is also able to serve as the sole source of flavin for B. lactis acidi. ... 

The synthesis of riboflavin begins (Scheme 12.115) with the formation of barbituric acid by the condensation of diethyl malonate [(CH3CH202C)2CH2] with urea [(NH2)2C=0] in ethanolic sodium ethoxide. Then, the barbituric acid can either (a) be oxidized directly to the hydrate of alloxan or (b) first be converted to the ben-zylidine adduct and then oxidized to the same compound. Both oxidations are... 

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