Karrer-Tishler process

For many years, riboflavin has been produced from D-ribose (Rib) and 3,4-xyli-dine, via the Karrer-Tishler process (see Fig. 8.27) [135], which pushed the existing fermentative procedures from the market in the late 1960s [137], although the laborious synthesis of Rib [135] was a serious drawback. Later, a fermentative process for Rib [138] was adopted. The Karrer-Tishler process is, from the green standpoint, not one of the worst as the overall yield is 60%, relatively little organic solvents are used and few auxiliary groups are discarded. 

The aerobic microbial production of riboflavin in various microbes dates back to the 1930s [141] but was discontinued in the late 1960s because the chemical process described above was more profitable. Fermentation soon (Merck, 1974) made a comeback, however, and subsequently has steadily eroded the position of the Karrer-Tishler process. Around 1990, production levels of 15-20 g I. 1 had been achieved [136], up from 2 g I. 1 in 1940 [141], causing the product to crys-... 

Fig. 8.27 The Karrer-Tishler industrial process for riboflavin. Abbreviation Rib, D-ribose.

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See also in sourсe #XX -- [ ]

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