Consumers have become increasingly aware of potential health benefits from diets rich in fruits and vegetables. While potato has not yet surfaced as a headline-grabber in this respect, there is increasing evidence that some genotypes may possess health attributes that warrant attention. Plant breeders rely on germplasm biodiversity to advance their programs and are also acutely aware of current marketing trends that relate to health attributes. Investigations of antioxidant properties for over 90 genotypes were conducted to characterize antioxidant profiles for the Colorado potato breeding program and to identify those especially rich in antioxidants. The objective was to summarize data based on total phenolics (TP), Trolox equivalent antioxidant capacity (TEAC) and vitamin C, as well as to provide LC/MS characterization of major phenolic compounds and glycoalkaloids for pigmented genotypes. Preliminary data from breast cancer cell culture inhibition studies were examined for relationships to in vitro chemical assays. Genotypes with red or purple skin and flesh consistently had the highest gallic acid equivalent TP, TEAC, and chlorogenic acid content. Baked tubers had lower TP levels, TEAC and vitamin C compared to uncooked, microwave cooked and boiled tubers. Environmental effects contributed year to year variation in TP and TEAC radical scavenging capacity. TP content increased after 6 to 7 months in refrigerated storage at 5±1°C in several highly pigmented, but not in white or yellow fleshed cultivars and selections. Major phenolic compounds, anthocyanins, and glycoalkaloid content were further investigated with LC/MS in six cultivars. The pigmented cultivars 'Purple Majesty' and 'Mountain Rose' contained considerably higher levels of chlorogenic acid isomers than the non-pigmented genotypes. In the nonpigmented genotypes, chlorogenic acid and glycolalkaloid content were highest in 'Rio Grande Russet'. Chlorogenic acid has been demonstrated to exhibit several desirable anticarcinogenic properties in recent biochemical investigations, as have several of the phenolic based anthocyanin pigments found in many colorful fruits and vegetables. Thus, comprehensive compositional profiles using LC/MS are of interest in characterizing germplasm for breeding purposes. Preliminary tests with phosphate buffered saline (PBS) extracts of baked tubers from six cultivars revealed that 'Rio Grande Russet' was most effective in inhibiting growth of breast cancer cultures MCF-7 and MDA-MB-468. 'Purple Majesty' inhibited to some extent, 'Mountain Rose' and 'Yukon Gold' had no inhibitory effect. A subsequent study with 21 genotypes where the initial extract was made with 80% acetone followed by drying and extraction in aqueous PBS differed from direct PBS extraction. Five genotypes including 'Russet Nugget' inhibited at 0.187% to 0.375% w/v of the cell culture Am. solution. However, IC 50 inhibition data was not strongly related to the in vitro chemical data for these cultivars.Resumen Los consumidores se han dado cuenta del potenc...

Background Lung cancer is a major health burden causing 160,000 and 1.6 million deaths annually in the United State and worldwide, respectively. Methods Seeking to identify stable and reproducible biomarkers in non-invasively collected biofluids, we assessed whether previously identified metabolite urinary lung cancer biomarkers, creatine riboside (CR), N-acetylneuraminic acid (NANA), cortisol sulfate and indeterminate metabolite 561+ were elevated in the urines of subjects prior to lung cancer diagnosis in a well-characterized prospective Southern Community Cohort Study (SCCS). Urine was examined from 178 patients and 351 non-diseased controls, confirming that one of four metabolites was associated with lung cancer risk in the overall case-control set, whereas two metabolites were associated with lung cancer risk in European-Americans. Results Odds ratio of lung cancer associated with elevated CR levels, and adjusted for smoking and other potential confounders, was 2.0 (95%CI 1.2–3.4;P=0.01). In European-Americans, both CR and NANA were significantly associated with lung cancer risk (OR=5.3 (95%CI 1.6–17.6; P=0.006 and OR=3.5 (95%CI 1.5, 8.4;P=0.004), respectively). However, race itself did not significantly modify the associations. Receiver Operating Characteristic (ROC) analysis showed that adding CR and NANA to a model containing previously established lung cancer risk factors led to a significantly improved classifier (P=0.01). Increasing urinary levels of CR and NANA displayed a positive association with increasing tumor size, strengthening a previously established link to altered tumor metabolism. Conclusion and Impact These replicated results provide evidence that identified urinary metabolite biomarkers have a potential utility as non-invasive, clinical screening tools for early diagnosis of lung cancer.

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Analysis of biochemical systems requires reliable and self-consistent databases of thermodynamic properties for biochemical reactions. Here a database of thermodynamic properties for the reactions of glycolysis and the tricarboxylic acid cycle is developed from measured equilibrium data. Species-level free energies of formation are estimated based on comparing thermodynamic model predictions for reaction-level equilibrium constants to previously reported data obtained under different experimental conditions. Matching model predictions to the data involves applying state corrections for ionic strength, pH, and metal ion binding for each input experimental biochemical measurement. By archiving all of the raw data, documenting all model assumptions and calculations, and making the computer package and data available, this work provides a framework for extension and refinement by adding to the underlying raw experimental data in the database and/or refining the underlying model assumptions. Thus the resulting database is a refinement of preexisting databases of thermodynamics in terms of reliability, self-consistency, transparency, and extensibility.