Effects of water availability on free amino acids, sugars, and acrylamide-forming potential in potato

Irrigation is used frequently in potato cultivation to maximize yield, but water availability may also affect the composition of the crop, with implications for processing properties and food safety. Five varieties of potatoes, including drought-tolerant and -sensitive types, which had been grown with and without irrigation, were analyzed to show the effect of water supply on concentrations of free asparagine, other free amino acids, and sugars and on the acrylamide-forming potential of the tubers. Two varieties were also analyzed under more severe drought stress in a glasshouse. Water availability had profound effects on tuber free amino acid and sugar concentrations, and it was concluded that potato farmers should irrigate only if necessary to maintain the health and yield of the crop, because irrigation may increase the acrylamide-forming potential of potatoes. Even mild drought stress caused significant changes in composition, but these differed from those caused by more extreme drought stress. Free proline concentration, for example, increased in the field-grown potatoes of one variety from 7.02 mmol/kg with irrigation to 104.58 mmol/kg without irrigation, whereas free asparagine concentration was not affected significantly in the field but almost doubled from 132.03 to 242.26 mmol/kg in response to more severe drought stress in the glasshouse. Furthermore, the different genotypes were affected in dissimilar fashion by the same treatment, indicating that there is no single, unifying potato tuber drought stress response.

Asymmetric cyclopropanation of conjugated cyanosulfones using a novel cupreine organocatalyst: rapid access to d3-amino acids

An organocatalytic asymmetric synthesis of a novel, highly functionalised cyclopropane system furnished with versatile substituents and containing a quaternary centre is described. The process utilises a new bifunctional catalyst based on the cinchona alkaloid framework and the products made using this catalyst were obtained as single diastereoisomers, with very high enantioselectivities (up to 96% ee). We have also demonstrated that these resulting cyclopropanes are very useful synthetic intermediates to interesting products, such as the difficult to access d3-amino acids.

Sialic acids in biological and therapeutic processes: opportunities and challenges

It is now well documented that carbohydrates play multiple roles in biological processes, and hence are interesting targets for chemical biology and medicinal chemistry programmes. This review focuses on a subset of carbohydrates, specifically sialic acid containing carbohydrates. It highlights their occurrence and diversity, and presents evidence for their roles in a range of biological pathways. It illustrates that they are targets for novel medicinal chemistry strategies for a range of therapeutic areas, including cancer and immunity. Case studies highlight opportunities and challenges in this area, and sialic acid based drugs that have entered clinical practice, and are promising candidates for future disease intervention schemes, are discussed. The review concludes by highlighting perspectives and emerging roles for these targets.

Exploring the association of diary product intake with the fatty acids C15:0 and C17:0 measured from dried blood spots in a multi-population cohort: findings from the Food4Me study

Scope: The use of biomarkers in the objective assessment of dietary intake is a high priority in nutrition research. The aim of this study was to examine pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0) as biomarkers of dairy foods intake. Methods and results: The data used in the present study were obtained as part of the Food4me Study. Estimates of C15:0 and C17:0 from dried blood spots and intakes of dairy from an FFQ were obtained from participants (n=1,180) across 7 countries. Regression analyses were used to explore associations of biomarkers with dairy intake levels and receiver operating characteristic (ROC) analyses were used to evaluate the fatty acids. Significant positive associations were found between C15:0 and total intakes of high-fat dairy products. C15:0 showed good ability to distinguish between low and high consumers of high-fat dairy products. Conclusion: C15:0 can be used as a biomarker of high-fat dairy intake and of specific high-fat dairy products. Both C15:0 and C17:0 performed poorly for total dairy intake highlighting the need for caution when using these in epidemiological studies.