Sotolon, degradation formation

Apart from sotolon, the other compounds in Fig. 5 can be explained as the products of a Maillard reaction, and their carbon skeletons simply originate from the active Amadori intermediate in other words, they still preserve the straight carbon chain structure of monosaccharides. In spite of being a simple Cg lactone, sotolon has a branched carbon skeleton, which implies another formation process in the Maillard reaction. Sulser e al.(6) reported that ethyl sotolon (ll) was prepared from threonine with sulfuric acid, and that 2-oxobutyric acid, a degradation product of threonine, was a better starting material to obtain II. This final reaction is a Claisen type of condensation, which would proceed more smoothly under alkaline conditions. As we(lO) obtained II from 2-oxobutyric acid (see figure 6) with a high yield in the presence of potassium carbonate in ethanol, a mixed condensation of 2-oxobutyric and 2-oxo-propanoic (pyruvic) acids was attempted under the same conditions, and a mixture of sotolon (22% yield) and II were obtained however, the... 

In the sample based on MIL and methylglyoxal, the ratio of Strccker aldehyde to sotolone was about 1 2 at pH 5 (Table VT). Consequently, the Slrecker degradation of HIL is a competitive reaction to the formation of sotolone. In contrast. only traces of Strecker aldehyde were detected In the sample containing the laciom-ADF, i.e about 50 times less than in the reaction with HIL 1 he formation orsololoiir from ADF is the favoured reaction, most likely due to the blocked carboxyl pmnp... 

B. cinerea metabolizes aromatic terpenes including linalool, geraniol, and nerol in the formation less volatile compounds such as p-pinene, a-terpineol, and other oxides (Nigam, 2000). In addition, the mold produces esterases that degrade the esters, compounds that give many white wines their fruity character, and can also synthesize sotolon ( honey-like ) and l-octeno-3-ol (Nigam, 2000). 

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