Thomas Wilson

Potential sources of high value chemicals from leaves, stems and flowers of Miscanthus sinensis ‘Goliath’ and Miscanthus sacchariflorus

Society demands chemicals from sustainable sources. Identification of commercially important chemicals in crops increases value in biorefineries and reduces reliance on petrochemicals. Miscanthus sinensis and Miscanthus sacchariflorus are high-yielding distinct plants, which are sources of high-value chemicals and bioethanol through fermentation. Cinnamates in leaves, stems and flowers were analysed by LC-ESI-MS(n). Free phenols were extracted and separated chromatographically. More than twenty hydroxycinnamates were identified by UV and LC-ESI-MS(n). Several cinnamate hexosides were detected in the M. sinensis flower and in M. sacchariflorus (leaf and stem). Hydroxybenzoic acids and their hexosides were observed in leaf and stem of M. sacchariflorus. Higher concentrations of 3-feruloylquinic acid were observed in M. sacchariflorus stem, suggesting a role in cell-wall biosynthesis. This technique can be used to screen plants in a mapping family to identify genotypes/species with high concentrations of phenols. Plants with low concentrations of antimicrobial phenols may be good feedstocks for fermentation.

How the Surface Structure Determines the Properties of CuH

CuH is a material that appears in a wide diversity of circumstances ranging from catalysis to electrochemistry to organic synthesis. There are both aqueous and nonaqueous synthetic routes to CuH, each of which apparently leads to a different product. We developed synthetic methodologies that enable multigram quantities of CuH to be produced by both routes and characterized each product by a combination of spectroscopic, diffraction and computational methods. The results show that, while all methods for the synthesis of CuH result in the same bulk product, the synthetic path taken engenders differing surface properties. The different behaviors of CuH obtained by aqueous and nonaqueous routes can be ascribed to a combination of very different particle size and dissimilar surface termination, namely, bonded hydroxyls for the aqueous routes and a coordinated donor for the nonaqueous routes. This work provides a particularly clear example of how the nature of an adsorbed layer on a nanoparticle surface determines the properties.

Structure and spectroscopy of CuH prepared via borohydride reduction

We show by a combination of diffraction and spectroscopic methods that CuH produced by borohydride reduction of a CuII salt consists of a core of CuH with the Wurtzite structure and a shell of water. We also demonstrate that the shell is exchangeable for ethanol.

Ultra high performance liquid chromatography–high resolution mass spectrometry plasma lipidomics can distinguish between canine breeds despite uncontrolled environmental variability and non-standardized diets

Introduction and objectivesThe purpose of this study was to use high accurate mass metabolomic profiling to investigate differences within a phenotypically diverse canine population, with breed-related morphological, physiological and behavioural differences. Previously, using a broad metabolite fingerprinting approach, lipids appear to dominate inter- and intra- breed discrimination. The purpose here was to use Ultra High Performance Liquid Chromatography–High Resolution Mass Spectrometry (UHPLC–HRMS) to identify in more detail, inter-breed signatures in plasma lipidomic profiles of home-based, client-owned dogs maintained on different diets and fed according to their owners’ feeding regimens.MethodsNine dog breeds were recruited in this study (Beagle, Chihuahua, Cocker Spaniel, Dachshund, Golden Retriever, Greyhound, German Shepherd, Labrador Retriever and Maltese: 7–12 dogs per breed). Metabolite profiling on a MTBE lipid extract of fasted plasma was performed using UHPLC-HRMS.ResultsMultivariate modelling and classification indicated that the main source of lipidome variance was between the three breeds Chihuahua, Dachshund and Greyhound and the other six breeds, however some intra-breed variance was evident in Labrador Retrievers. Metabolites associated with dietary intake impacted on breed-associated variance and following filtering of these signals out of the data-set unique inter-breed lipidome differences for Chihuahua, Golden Retriever and Greyhound were identified.ConclusionBy using a phenotypically diverse home-based canine population, we were able to show that high accurate mass lipidomics can enable identification of metabolites in the first pass plasma profile, capturing distinct metabolomic variability associated with genetic differences, despite environmental and dietary variability.

Triacylglycerol composition of British bluebell ( Hyacinthoides non-scripta ) seed oil

Bluebell seeds were collected from the same location for five different growth periods (2006–2010). The composition of fatty acids in the triacylglycerols present in bluebell seeds was determined using 1H- and 13C NMR and GC-MS of fatty acid methyl esters with good agreement between the different methods of analysis for the proportion of individual fatty acids. The seed oil comprised 80% ω-9 monounsaturated (C18:1, C20:1, C22:1), 10% ω-6,9 biunsaturated (C18:2) and 10% saturated fatty acids (C16:0, C18:0, C20:0, C22:0). The oil contained 25% of fatty acids with 20 or 22 carbon chain length. Gondoic acid (C20:1) was present at 20% and there was a consistency in the composition of the seed oil for the different harvest years. Based on the composition of bluebell seed oil, possible future uses are suggested and the combination of bio refining bluebell seeds in tandem with conservation efforts is proposed.

Polyphenols from Allanblackia floribunda seeds: Identification, quantification and antioxidant activity

Oil rich seeds of Allanblackia floribunda, a tree from tropical Africa, have traditionally been used in food preparation. Furthermore, the therapeutic properties of various parts of this tree have long been exploited in traditional medicine. As both food and pharmaceutical industries show growing interest in tropical tree crops, this study aimed to investigate whether A. floribunda seeds could also be used as a source of potentially bioactive compounds. The polyphenol profile revealed six predominant compounds which were identified by HPLC-PDA-ESI/MSn as the biflavonoids morelloflavone, Gb-2a and volkensiflavone and their respective glucosides. A range of less abundant flavones, flavonols and flavan-3-ols was also detected. All six major compounds showed antioxidant activity, with the activity of morelloflavone, its glucoside and Gb-2a-glucoside comparable with that of ascorbic acid. The main compounds accounted for approximately 10% of dry weight, making the seeds used for oil production a rich source of biflavonoids as a by-product.

Surface characterization of titanium implant healing abutments before and after placement

BACKGROUND Implant healing abutments (IHA) have a vital role in soft tissue healing after implant placement. Although there is thorough investigation on the implant surface, little is known about the effects potentially damaging oral conditions impose on healing abutments. PURPOSE To characterize the surface of titanium healing abutments before and after clinical placement to understand the effects of the oral environment and time on the device surface. MATERIALS AND METHODS Ten regular Straumann IHA were subjected to characterization pre and postplacement to elucidate the effects of the oral environment on device surfaces. Changes in surface crystallinity, morphology, and elemental composition were monitored with Raman spectroscopy, scanning electron microscopy, optical microscopy, and x-ray photoelectron spectroscopy, respectively. In addition, corrosion rate and polarization resistance were obtained to assess electrochemical device stability after placement. RESULTS Control analysis indicated the titanium oxide of IHAs was thicker than natural commercially pure titanium and had the structure of crystalline anatase. After removal, the abutments possessed large amounts of biological debris, visible scratches, and discoloration sparsely on the surface. Spectroscopic analysis revealed the titanium oxide on the surface of IHAs was structurally unchanged, with crystalline titanium dioxide still present on the surface. Electrochemical results revealed that implanted healing abutments possessed a significantly higher corrosion rate than controls (change in corrosion rate = 2.34 ± 0.58 nm/year). CONCLUSIONS Healing abutments were stable in the oral environment due to the chemical stability of the oxide, and were likely subjected to abrasions from unintentional loading and oral hygiene techniques.