The nutrient composition and dietary importance of some vegetable foods eaten by the !Kung bushmen

No Abstrac

An experimental and computational approach to understanding the reactions of acyl nitroso compounds in [4+2]-cycloadditions

Catalytic aerobic oxidation of phenyl hydroxycarbamate 1 and 1-hydroxy-3-phenylurea 2 using CuCl2 and 2-ethyl-2-oxazoline in methanol gave acyl nitroso species in situ, which were trapped in nitroso-Diels–Alder (NDA) reactions with various dienes to afford the corresponding cycloadducts in high yields (90–98%). Competing ene products were also present for dienes containing both alkene π-bonds and allylic σ-bonds, and the ene yields are higher with 1 than with 2. The use of the chiral hydroxamic acid, (R)-1-hydroxy-3-(1-phenylethylurea) 3 (same conditions) gave NDA cycloadducts in high yields (97–99%) with no ene product from 2,3-dimethyl-1,3-butadiene. NDA cycloadducts were not obtained from other hydroxamic acid analogues [RCONHOH (R = PhCH2 4; Ph(CH2)2 5; Ph(CH2)3 6; Ph(CH2)4 7; Ph 8; 2-pyridyl 9; 3-pyridyl 10] with various dienes using copper-oxidation but rather were obtained using sodium periodate, resulting in variable NDA yields (13–51%) from hydroxamic acids 1–10 with cyclohexa-1,3-diene and 2,3-dimethyl-1,3-butadiene (several cycloadducts characterized by X-ray crystallography). The NDA and nitroso-ene reaction pathways of nitroso intermediates with dienes were mapped by DFT computations (B3LYP/6-31G*), which showed that the acyl nitroso species are super-reactive and that activation energies in the NDA processes are lower than the isomerization barriers between some cis- and trans-butadienes

Structure-functional relationship of cellular retinoic acid binding proteins I and II interacting with natural and synthetic ligands

A detailed understanding of the interactions between small-molecule ligands and their proposed binding targets is of the utmost importance for modern drug-development programs. Cellular retinoic acid-binding proteins I and II (CRABPI and CRABPII) facilitate a number of vital retinoid signalling pathways in mammalian cells and offer a gateway to manipulation of signalling that could potentially reduce phenotypes in serious diseases, including cancer and neurodegeneration. Although structurally very similar, the two proteins possess distinctly different biological functions, with their signalling influence being exerted through both genomic and nongenomic pathways. In this article, crystal structures are presented of the L29C mutant of Homo sapiens CRABPI in complex with naturally occurring fatty acids (1.64 A˚ resolution) and with the synthetic retinoid DC645 (2.41 A˚ resolution), and of CRABPII in complex with the ligands DC479 (1.80 A˚ resolution) and DC645 (1.71 A˚ resolution). DC645 and DC479 are two potential drug compounds identified in a recent synthetic retinoid development program. In particular, DC645 has recently been shown to have disease-modifying capabilities in neurodegenerative disease models by activating both genomic and nongenomic signalling pathways. These co-crystal structures demonstrate a canonical binding behaviour akin to that exhibited with all-trans-retinoic acid and help to explain how the compounds are able to exert an influence on part of the retinoid signalling cascade

A selective transformation of enals into chiral γ-amino alcohols

A one-pot synthesis of chiral amino alcohols from α,β-unsaturated aldehydes is reported which circumvents competitive 1,2- versus 1,4-boryl addition, by means of using a sterically hindered amine-derived imine. In addition to the complete chemoselectivity, modification of the Cu(I) catalyst with readily available chiral diphosphines, such as (R)-DM-BINAP, gave the 1,4-boryl addition products with high levels of asymmetric induction

Direct Amidation of Amino Acid Derivatives Catalyzed by Arylboronic Acids: Applications in Dipeptide Synthesis

The direct amidation of amino acid derivatives catalyzed by arylboronic acids has been examined. The reaction was generally slow relative to simple amine-carboxylic acid combinations though proceeded at 65–68 °C generally avoiding racemization. 3,4,5-Trifluorophenylboronic and o-nitrophenylboronic acids were found to be the best catalysts, though for slower dipeptide formations, high catalyst loadings were required and an interesting synergistic catalytic effect between two arylboronic acids was discovered

Approaches to Styrenyl Building Blocks for the Synthesis of Polyene Xanthomonadin and its Analogues

A number of aryl building blocks for the synthesis of two xanthomonadin natural product pigments, as well as a related analogue, were accessed using a divergent hydroboration/bromoboration approach from a key alkynyl intermediate. A new approach towards substitution patterns around the ring was adopted following the isolation of an unexpected regioisomer from the bromination reaction. Potential coupling reactions onto these building blocks were explored, with a successful Sonogashira coupling performed on the key alkynyl intermediate, and with the key debrominated styrenyl boronate ester intermediate functionalised both by preliminary Suzuki–Miyaura coupling and by iododeboronation/Heck–Mizoroki coupling. Coupling reactions with brominated styrenyl intermediates proved much more challenging due to the instability of the intermediates to cross‐coupling, but some studies have shown promise

Enhancing resilience and self-efficacy in the parents of children with disabilities and complex health needs

Aim: The principal aim of this study was to develop, pilot and evaluate an intervention intended to support the development of resilience and self-efficacy in parents of children with disabilities or complex health needs. Background: Previous research has found that families often experience physical, social and emotional stress in the context of living with and caring for their disabled child. The literature indicates that a key factor in determining how well the parents of these children cope with their situation may be how resilient and self-efficacious they are. Methods: A total of 16 parents of children with complex needs and disabilities were engaged in a series of guided conversations delivered during six contact visits with nurse co-researchers (community children’s nurses who had received an intensive three-day preparation programme). The conversations, which were supported with additional material that was designed specifically for use in the study, were based around four key themes: emotional coping, practical coping, support networks and ‘you and your child’. The impact of the intervention was evaluated using both qualitative and quantitative measures. Findings: When interviewed, parents reported increased self-belief and self-confidence and indicated that they felt better supported and stronger as a result of the intervention. This was consistent with the quantitative evaluation which identified significant improvements on scores for active coping and self-blame on the brief COPE inventory scale and for empathy and understanding and self-acceptance on the TOPSE scale. Scores on the self-report distress thermometer demonstrated a significant reduction in self-reported distress scores at the end of the intervention period

Decision theory in the study of national action: problems and a proposal

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66743/2/10.1177_002200276500900202.pd

Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change