A rapid and simple method for the simultaneous determination of twelve sweeteners and nine preservatives in various foods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sweeteners and preservatives were extracted from solid samples with 80% and 50% methanol and from liquid samples with 80% methanol, followed by Oasis WAX cartridge cleanup. The LC separation was ...

It has been known for many years that p-aminobenzoic acid at high concentration is inhibitory to a variety of organisms, including rickettsiae (I), bacteria (2, 3), fungi (4), protozoa (5), and plants (6). The site of inhibition by p-aminobenzoic acid in most of these organisms has not been established. However, Davis (3) has shown that the bacteriostatic activity of p-aminobenzoic acid toward ...

In a previous report, the synthesis of p-hydroxybenzoic acid and salicylic acid from alkali phenoxides and carbon dioxide in aprotic-polar solvents was reported. In the present study, the effects of reaction conditions on the yields and the rule of orientation under atmospheric pressure were examined in a typical aprotic-polar solvent, N,N-dimethylfomamide. Stabilities of the alkali salts of p-...

Glycosylated p-hydroxybenzoic acid methyl esters and structurally related phenolphthiocerol glycolipids are important virulence factors of Mycobacterium tuberculosis. Although both types of molecules are thought to be derived from p-hydroxybenzoic acid, the origin of this putative biosynthetic precursor in mycobacteria remained to be established. We describe the characterization of a transposon...