Oleic acid-13C is intended for use as an internal standard for the quantification of oleic acid by GC- or LC-MS. Oleic acid is a monounsaturated fatty acid and a major component of membrane phospholipids that has been found in human plasma, cell membranes, and adipose tissue.1,2 It contributes approximately 17% of the total fatty acids esterified to phosphatidylcholine, the major phospholipid class in porcine platelets.1 Oleic acid inhibits collagen-stimulated platelet aggregation by approximately 90% when used at a concentration of 10 μg ml. It also inhibits fMLF-induced neutrophil aggregation and degranulation by 55 and 68%, respectively, when used at a concentration of 5 μM, similar to arachidonic acid .3 Oleic acid (60 μM) induces release of intracellular calcium in human platelets.4
5-Fluorouracil-13C,15N2 is intended for use as an internal standard for the quantification of 5-flurouracil by GC- or LC-MS. 5-Fluorouracil is a pyrimidine analog that irreversibly inhibits thymidylate synthase, blocking the synthesis of thymidine which is required for DNA synthesis. Intracellular metabolites of 5-fluorouracil exert cytotoxic effects by either inhibiting thymidylate synthetase, or through incorporation into RNA and DNA, ultimately initiating apoptosis.
1,2,3-Trioctanoyl-rac-glycerol-13C3 is intended for use as an internal standard for the quantification of 1,2,3-trioctanoyl-rac-glycerol by GC- or LC-MS. 1,2,3-Trioctanoyl-rac-glycerol is a triacylglycerol that contains octanoic acid at the sn-1, sn-2, and sn-3 positions. Dietary administration of 1,2,3-trioctanoyl-rac-glycerol increases hippocampal levels of the glycolytic metabolites glucose 6-phosphate, fructose 6-phosphate, and β-hydroxybutyrate and the seizure threshold in the 6 Hz psychomotor seizure test in mice.1 Formulations containing 1,2,3-trioctanoyl-rac-glycerol have been used in cosmetic products as thickening and skin-conditioning agents.