1.Influence of storage on volatile profiles in roasted almonds (Prunus dulcis).
Lee J1, Xiao L, Zhang G, Ebeler SE, Mitchell AE. J Agric Food Chem. 2014 Nov 19;62(46):11236-45. doi: 10.1021/jf503817g. Epub 2014 Nov 11.
Hexanal, peroxide value, and lipid hydroperoxides are common indicators of lipid oxidation in food products. However, these markers are not always reliable as levels are dynamic and often can be detected only after significant oxidation has occurred. Changes in the volatile composition of light- and dark-roast almonds were evaluated during storage over 24 weeks at 25 or 35 °C using headspace solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS). Several volatile changes were identified in association with early oxidation events in roasted almonds. Hexenal decreased significantly during the first 6 weeks of storage and did not increase above initial levels until 20-24 weeks of storage depending upon the degree of roast. In contrast, levels of 1-heptanol and 1-octanol increased at 16-20 weeks, depending upon the degree of roast, and no initial losses were observed. Seventeen new compounds, absent in raw and freshly roasted almonds but detectable after 6 weeks of storage, were identified.
2.Brushed block copolymer micelles with pH-sensitive pendant groups for controlled drug delivery.
Lee HJ1, Bae Y. Pharm Res. 2013 Aug;30(8):2077-86. doi: 10.1007/s11095-013-1060-1. Epub 2013 May 2.
PURPOSE: To investigate the effects of small aliphatic pendent groups conjugated through an acid-sensitive linker to the core of brushed block copolymer micelles on particle properties.
3.A contact sex pheromone component of the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae).
Silk PJ1, Ryall K, Barry Lyons D, Sweeney J, Wu J. Naturwissenschaften. 2009 May;96(5):601-8. doi: 10.1007/s00114-009-0513-1. Epub 2009 Feb 24.
Analyses of the elytral hydrocarbons from male and female emerald ash borer, Agrilus planipennis Fairmaire, that were freshly emerged vs. sexually mature (>10 days old) revealed a female-specific compound, 9-methyl-pentacosane (9-Me-C(25)), only present in sexually mature females. This material was synthesized by the Wittig reaction of 2-decanone with (n-hexadecyl)-triphenylphosphonium bromide followed by catalytic reduction to yield racemic 9-Me C(25), which matched the natural compound by gas chromatography/mass spectrometry (retention time and EI mass spectrum). In field bioassays with freeze-killed sexually mature A. planipennis females, feral males spent significantly more time in contact and attempting copulation with unwashed females than with females that had been washed in n-hexane to remove the cuticular lipids. Hexane-washed females to which 9-Me-C(25) had been reapplied elicited similar contact time and percentage of time attempting copulation as unwashed females, indicating that 9-methyl-pentacosane is a contact sex pheromone component of A.
4.Exhaustive extraction of peptides by electromembrane extraction.
Huang C1, Gjelstad A2, Pedersen-Bjergaard S3. Anal Chim Acta. 2015 Jan 1;853:328-34. doi: 10.1016/j.aca.2014.10.017. Epub 2014 Oct 16.
This fundamental work illustrates for the first time the possibility of exhaustive extraction of peptides using electromembrane extraction (EME) under low system-current conditions (<50 μA). Bradykinin acetate, angiotensin II antipeptide, angiotensin II acetate, neurotensin, angiotensin I trifluoroacetate, and leu-enkephalin were extracted from 600 μL of 25 mM phosphate buffer (pH 3.5), through a supported liquid membrane (SLM) containing di-(2-ethylhexyl)-phosphate (DEHP) dissolved in an organic solvent, and into 600 μL of an acidified aqueous acceptor solution using a thin flat membrane-based EME device. Mass transfer of peptides across the SLM was enhanced by complex formation with the negatively charged DEHP. The composition of the SLM and the extraction voltage were important factors influencing recoveries and current with the EME system. 1-nonanol diluted with 2-decanone (1:1 v/v) containing 15% (v/v) DEHP was selected as a suitable SLM for exhaustive extraction of peptides under low system-current conditions.