The scope and limitations of the solid-supported synthesis of a bicyclic diketopiperazine, an internal, putative peptide beta-turn mimetic, are presented. The 4CC multicomponent Ugi reaction of alpha-N-Boc-diaminopropionic acid resin ester (an amine input), optically active alpha-bromoacid, aldehyde, and isocyanide is the key step in the proposed synthetic protocol. Application of cyclitive cleavage as the final step led to desired products in high purity.
[structure: see text]The solid-supported synthesis of a bicyclic diketopiperazine, a potential peptide beta-turn mimetic, is described. The Ugi reaction between the resin ester of alpha-N-Boc-diaminopropionic acid (an amine input), alpha-bromo acid, aldehyde, and isocyanide is the key step in the proposed protocol.
BackgroundFood allergy affects up to 8% of children in the U.S. There is minimal research to date on food allergy policies that are currently in place in schools and the opinions of parents of children with food allergy on the effectiveness of or need for these policies.MethodsAn electronic survey was disseminated to parents of children with food allergy. Frequencies were calculated to describe respondent characteristics and responses. Chi-square tests were performed to examine associations between school and child characteristics and outcomes.ResultsOf the 289 parent respondents, 27.4% were unsure or felt school was unsafe for their child with food allergy. While the majority felt that the polices in their child’s school were helpful, most also believed that implementation of additional polices was necessary, including availability of stock epinephrine (94.2%), lunch menus with allergen information (86%), ingredient labels on food items (81%), and direct food allergy education for students (86%). There were significant differences in school food allergy policy depending on the age of the student body, private versus public school, and geographic location.ConclusionsWhile most schools reportedly have one or more food allergy policies in place, many parents have concerns over the safety of their child at school and feel that additional policies are necessary to improve the safety of the school environment for children with food allergy. The availability of stock epinephrine, improved allergen labeling of food and menus and increased food allergy education may be key policy areas on which to focus.
The conformational properties of bradykinin in five molar excess sodium dodecyl sulfate (SDS) micelles have been examined by two‐dimensional nuclear magnetic resonance (NMR) techniques at 500 MHz. Detailed structural information for bradykinin in SDS was obtained from quantitative 2‐D nuclear Over‐hauser enhancement (n.O.e.) analyses, distance geometry, and restrained molecular mechanics and dynamics calculations. The conformation of bradykinin in SDS micelles, as determined by these methods, is characterized by a β‐turn‐like structure at residues 6–9. A detailed comparison of the structures derived from distance geometry and restrained molecular mechanics and dynamics is also presented.
The complete assignment of resonances in the proton nmr spectrum of the 1-34 amino acid fragment of human parathyroid hormone [hPTH(1-34)], determined using a combination of one- and two-dimensional nmr techniques at 500 MHz, is described. In particular, homonuclear Hartmann-Hahn experiments, recorded in H2O and D2O, are used to resolve ambiguities in the connectivities between the highly overlapped resonances in the aliphatic region of the spectrum. One-dimensional multiple quantum filtering experiments are used to identify serine and phenylalanine spin systems. Analyses of the through-bond and through-space connectivities in the alpha H-NH fingerprint regions of the correlated spectroscopy (COSY) and nuclear Overhauser effect spectroscopy (NOESY) spectra lead to the assignment of resonances to specific amino acid residues in the polypeptide. Examination of the observed NOE cross peaks indicates that hPTH(1-34) has no detectable secondary structural elements in aqueous solution.
With one-third of school nurses reporting an allergic reaction in the past year, schools use many strategies to minimize allergen exposures and increase anaphylaxis preparedness. Most school nurses favor these policies and acknowledge barriers to implementation.
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