Saccharin critical

At other times, the public criticizes government attempts to go beyond the simple provision of information. The National Highway Traffic Safety Administration tried to recall certain General Motors trucks whose gas tanks explode more easily in side-impact collisions, rather than just informing consumers of the facts. The political controversy was so great that the agency retreated (Bennet 1994). The slow approval of AIDS drugs and the ban on saccharin have also provoked opposition. 

The role of substitution in determining the course of saccharinic acid formation has been critically examined recently by Kenner and coworkers. They conclude that an 0-glycosyl or 0-alkyl anion is more readily extruded from the sugar enediol anion of the Isbell mechanism than is a hydroxyl ion. In addition, substitution at certain positions in the sugar molecule may inhibit competing side-reactions. For example, a substituent at C4 of the hexose molecule inhibits cleavage (by reverse aldolization) into two three-carbon fragments and the resultant formation of lactic acid, a result that had been demonstrated earlier by the experiments of Evans and his associates. A combination of the two above effects, then, preferentially... 

The metabolism of a food chemical is often a critical determinant in evaluating toxic hazard to humans. Also, the methods for assessing metabolism in humans is usually dictated by the toxic potency of the chemical and its mechanism-of-action. These concepts can be illustrated by comparing the potency, metabolism and mechanism-of-action of two carcinogenic food chemicals, aflatoxin and saccharin. 

Fig. 12. The Co37pe53 pole tip nanostructures with 50 nm critical dimensions produced with two different pulse currents (A) puise = 18mAcm , E —1.24 V, (B) jp = 25mAcm , E —1.35V. Potentials are quoted vs SCE, the saccharin coverage in A is 95% and in B 30% during the pulse current stage. Duty cycle 20%. Reprinted from Ref. 4 with permission. Copyright (2006) IEEE.

---