Bioactive Labeled Standards

ISOTEC® Stable Isotopes: Bioactive Labeled Standards, 2011

Bioactive Standards

Stable isotope labeled analytical standards are playing an ever-increasing role in the research of biological systems. As mass spectrometric methods are developed to analyze specific biological samples, their utility depends on accurate data interpretation. The use of an internal standard enables compensation for matrix effects and ion suppression.1

To facilitate this need, ISOTEC Stable Isotopes offers a wide variety of 13C, 15N and D labeled bioactive compounds suitable for use as mass spectrometric internal standards. This selection of products boasts of high purity and isotope enrichments and contains a significant portion of products labeled with 13C and/or 15N. This labeling pattern benefits from the inability of 13C and 15N to exchange within the mass spectrometer source.2 This diverse collection includes vitamins, steroids and hormones, caffeine and caffeine metabolites, environmental contaminants, as well as a variety of products suitable for many other applications.


Vitamins are responsible for a wide range of essential functions including calcium homeostasis, fatty acid metabolism and blood clotting. Vitamin deficiencies can have wide ranging health consequences and therefore many nutritional studies have been undertaken to study dietary intake and bioavailability,3 identification and concentration within complex samples4 as well as to further elucidate function.4b,4f

Steroids and Hormones

Steroids and hormones make up a complex group of bioactive compounds due to their therapeutic utility, their role in metabolic processes, their intricate reactivity profile and structural similarities. The same properties that raise interest in these biologically relevant molecules, however, are also those that make their study intensely challenging. The use of stable isotope labeled steroids and hormones has alleviated some of the difficulties surrounding identification, differentiation and analysis of these compounds.

The labeled compounds shown below have been useful in a broad range of research topics, with an emphasis being applied to improving methods for identification, quantification and mixture analysis. Some of the interesting and important topics to be researched include environmental contamination due to hormone excretion,5 the quantification of therapeutic agents such as corticosteroids6 and identification of biomarkers for liver and intestinal disorders, dehydration and stress.7

Caffeine and Metabolites

The prevalence of caffeine in foods, drinks and pharmaceuticals as well as the increased consumption of caffeinated products has lead to a heightened interest in caffeine research.8 Although it is one of the most common, naturally occurring, bioactive compounds, there are still unanswered questions surrounding the properties of caffeine and its metabolites. The development of analytical methods capable of analyzing caffeine in complex samples can aid pharmaceutical research as caffeine has been used to probe enzymes responsible for drug metabolism.9 With current caffeine research relying on the ability to quantitatively study caffeine, the below selection of internal standards is necessary for the advancement of this field.

Melamine and Bisphenol A

Of increasing interest, among this diverse set of products, are compounds identified as food contaminants. Two compounds that have recently been placed into this category include melamine10 and bisphenol A (BPA).

In response to several major controversies, absolute identification and quantification of these compounds is essential. Melamine10 has previously been used as a food additive to falsely increase the measured nitrogen and thus the protein content. The use of melamine in foods, however is prohibited and improving the specificity of analytical methods is crucial in the control of its use. BPA contamination is caused by leaching from plastics as opposed to direct addition to foods. BPA is a compound of increasing concern due to a number health risks thought to be directly related to exposure. With guidelines in place regarding acceptable levels of both melamine and BPA within consumable products, methodology designed to increase sensitivity and accuracy has become necessary.10,11


Please visit this webpage for a listing of related Bioactive Compounds.




  1. a) Annesley, T.M.; Clin. Chem. 2003, 49, 1041-1044. b) Woolf, I.F. E.J.; Matuszewski, B.K.; J. Pharm. Biomed. Anal. 1998, 18, 347-357.
  2. Wang, S.; Cyronak, M.; Yang, E.; J. Pharm. Biomed. Anal. 2007, 43, 701-707.
  3. a) Goldschmidt, R.J.; Wolf, W.R.; Anal. Bioanal. Chem. 2010, 397, 471-481. b) Chen, P.; Ozcan, M.; Wolf, W.R.; Anal. Bioanal. Chem. 2007, 389, 343-347. c) Bruno, R.S.; Leonard, S.W.; Park, S. Zhao, Y.; Traber, M.G.; Am. J. Clin. Nutr. 2006, 83, 299-304. d) Leonard, S.W.; Good, C.K.; Gugger, E.T.; Traber, M.G.; Am. J. Clin. Nutr. 2004, 79, 86-92.
  4. a) Trenerry, V.C.; Plozza, T.; Caridi, D.; Murphy, S.; Food Chem. 2011, 125, 1314-1319. b) Tai, S. S.-C.; Bedner, M.; Phinney, K.W.; Anal. Chem. 2010, 82, 1942-1948. c) Huang, M.; LaLuzerne, P.; Winters, D.; Sullivan, D.; J. AOAC Int. 2009, 92, 1327-1335. d) Blum, M.; Dolnikowski, G.; Seyoum, E.; Harris, S.S.; Booth, S.L.; Peterson, J.; Saltzman, E.; Dawson-Hughes, B.; Endocr. 2008, 33, 3390-3394. e) Nelson, B C.; Sharpless, K.E.; Sander, L.C.; J. Agric. Food Chem. 2006, 54, 8710-8716. f ) Rychlik, M.; Anal. Chim. Acta, 2003, 495, 133-141.
  5. a) Duong, C.N.; Ra, J.S.; Schlenk, D.; Kim, S.D.; Choi, H.K.; Kim, S.D.; Arch. Environ, Contam. Toxicol. 2010, 59, 147-156. b) Rice, S.L.; Hale, R.C.; Anal. Chem. 2009, 81, 6716-6724.
  6. Ionita, I.A.; Fast, D.M.; Akhlaghi, F.; J. Chrom. B, 2009, 877, 765-772.
  7. a) Taylor, P.J.; van Rosendal, S.P.; Coombes, J.S.; Gordon, R.D.; Stowasser, M.; J. Chrom. B. 2010, 878, 1195-1198. b) Taylor, P.J.; Cooper, D.P.; Gordon, R.D.; Stowasser, M.; Clin. Chem. 2009, 55, 1155-1162. c) Soldin, O.P.; Sharma, H.; Husted, L.; Soldin, S.J.; Clin. Biochem. 2009, 42, 823-827. d) Guo, T.; Taylor, R.L.; Singh, R.J.; Soldin, S.J.; Clin. Chim. Acta, 2006, 372, 76-82. e) Burkard, I.; von Eckardstein, A.; Rentsch, K.M.; J. Chrom. B, 2005, 826, 147-159.
  8. a) Ptolemy, A.S.; Tzioumis, E.; Thomke, A.; Rifai, S.; Kellogg, M.; J. Chrom. B 2010, 878, 409-416. b) Morlock, G.; Ueda, Y.; J. Chrom. A, 2007, 1143, 243-251. c) Köfeler, H.C.; Gross, M.L.; J. Am. Soc. Mass Spectrom. 2005, 16, 406-408.
  9. Caubet, M.-S.; Comte, B.; Brazier, J.-L.; J. Pharm. Biomed. Anal. 2004, 34, 379-389.
  10. a)Wu, Y.-T.; Huang, C.-M.; Lin, C.-C.; Ho, W.-A.; Lin, L.-C.; Chiu, T.-F.; Tarng, D.-C.; Lin, C.-H.; Tsai, T.-H.; J. Chrom. A 2009, 1216, 7595-7601. b) Tyan, Y.-C.; Yang, M.-H.; Jong, S.-B.; Wang, C.-K.; Shiea, J.; Anal. Bioanal. Chem. 2009, 395, 729-735.
  11. a) Deorge, D.R.; Twaddle, N.C.; Vanlandingham. M.; Fisher, J.W.; Toxicol. Appl. Pharmacol. 2010, 247, 158-165. b)Kawaguchi, M.; Hayatsu, Y.; Nakata, H.; Ishii, Y.; Ito, R.; Saito, K.; Nakazawa, H.; Anal. Chim. Acta 2005, 539, 83-89.


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Stable Isotopes Technical Service
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