Ian J. Colquhoun

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1D NMR (1H and 13C) and 2D NMR spectroscopy have been used to determine the structure of feruloylated oligosaccharides obtained by enzymic degradation or mild acid hydrolysis of sugar-beet pulp. Feruloylated oligosaccharides derived from pectic neutral side-chains containing arabinose or galactose residues were identified. In the feruloylated arabinose(More)
1H NMR spectroscopy is one of the techniques whose potential is currently being explored in the emerging field of metabolomics. It is a non-targeted method, producing signals for all proton-containing chemical species. For crude plant materials the spectra are always complex, with many signals overlapping. Hence a most suitable approach for analysing them(More)
The post-genomic technologies are generating vast quantities of data but many nutritional scientists are not trained or equipped to analyse it. In high-resolution NMR spectra of urine, for example, the number and complexity of spectral features mean that computational techniques are required to interrogate and display the data in a manner intelligible to(More)
The ability of phosphite to control Phytophthora cinnamomi Rands in five Western Australian native plant species was examined. Foliar application of phosphite slowed, but did not completely inhibit, colonisation of stems by P. cinnamomi. For example, in Banksia hookeriana Meisn. inoculated 2 weeks after phosphite application, 5 g phosphite/L inhibited the(More)
The recently described rhamnogalacturonase B, which is able to degrade ramified hairy regions of pectin, was found to be a rhamnogalacturonan alpha-L-rhamnopyranosyl-(1-->4)-alpha-D-galactopyranosyluronide lyase. The cleavage site and mechanism differ from that of the previously described rhamnogalacturonase A, which is a hydrolase and can now be termed(More)
A cinnamoyl esterase, ferulic acid esterase A, from Aspergillus niger releases ferulic acid and 5-5- and 8-O-4-dehydrodiferulic acids from plant cell walls. The breakage of one or both ester bonds from dehydrodimer cross-links between plant cell wall polymers is essential for optimal action of carbohydrases on these substrates, but it is not known if(More)
Metabolite profiling has been carried out to assess the compositional changes occurring in potato tubers after genetic modifications have been made to different metabolic pathways. Most major features in the (1)H NMR and HPLC-UV profiles of tuber extracts have been assigned. About 40 GM lines and controls belonging to 4 groups of samples (derived from cv.(More)
Liquid-state NMR spectroscopy was used to follow the compositional changes in mango juice during ripening, whereas MAS and HR-MAS techniques enabled resolved (13)C and (1)H NMR spectra of mango pulps to be recorded. Spectral assignment enabled the identification of several organic acids, amino acids, and other minor components, and the compositional changes(More)
A set of 191 green teas from different countries was collected and analyzed by (1)H NMR. It was proposed to establish if the teas could be discriminated according to the country of origin or with respect to quality. Both principal component analysis (PCA) and cluster analysis were applied to the data. Some separation of Chinese and non-Chinese teas was(More)
Pre-treatment of plants with foliar sprays of 0.2, 0.5 and 2% phosphite restricted colonisation by Phytophthora cinnamomi in inoculated stems of Adenanthos barbiger and Daviesia decurrens, and led to a reduction in the isolation of P. cinnamomi from these stems in comparison with unsprayed plants. In plants treated with 2% phosphite, P. cinnamomi was not(More)