Subathira Sivakumaran

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Gas chromatography-mass spectrometry (GC-MS) is a widely used analytical technique in metabolomics. GC provides the highest resolution of any standard chromatographic separation method, and with modern instrumentation, retention times are very consistent between analyses. Electron impact ionization and fragmentation is generally reproducible between(More)
The proanthocyanidin polymer fractions of the leaves of the forage legume Dorycnium rectum were analysed by acid catalysis with benzyl mercaptan, NMR and ES-MS. The results showed that D. rectum differs from other temperate proanthocyanidin-containing forage legumes in that the range of polymers extends up to very high degrees of polymerisation. Three(More)
The chemical characteristics of the purified procyanidin polymers of the flowers of the forage legume red clover (Trifolium pratense L.) were studied by (13)C NMR, acid-catalyzed degradation with benzyl mercaptan, and electrospray ionization mass spectrometry (ESI-MS). The (13)C NMR showed that the fraction consisted of predominantly procyanidin polymers.(More)
The proanthocyanidin (PA) chemistry of 12 Lotus species of previously unknown PA content was examined in comparison with agricultural cultivars of L. pedunculatus, L. corniculatus, and L. tenuis and a “creeping” selection of L. corniculatus. Herbage harvested in winter 2000 and again in spring had extractable PA concentrations, estimations of which varied(More)
An acetone:water (7:3) extract obtained from the leaves of Rumex obtusifolius was fractionated into procyanidin oligomer and polymer fractions using a linear gradient and a simple step method on Sephadex LH-20. The chemical characteristics of the procyanidin fractions were studied by 13C-NMR spectroscopy, acid-catalysed degradation in the presence of benzyl(More)
OBJECTIVE To evaluate electroencephalographic (EEG) changes during ovariohysterectomy (OVH) in rats anaesthetized with halothane, and modification of the EEG changes by the co-administration of fentanyl, ketamine or thiopental. STUDY DESIGN Prospective, randomized, blinded controlled study. ANIMALS Sixty adult female Sprague-Dawley rats. METHODS(More)
The composition of kiwifruit is important for understanding the nutritional value of kiwifruit for consumption. Our aim was to develop a reference nutritional composition profile for a gold-fleshed kiwifruit Zespri® SunGold Kiwifruit and a green-fleshed kiwifruit Zespri® Sweet Green Kiwifruit. Ten representative single-replicate (10 growers) samples, each(More)
A country-specific food composition databases is useful for assessing nutrient intake reliably in national nutrition surveys, research studies and clinical practice. The New Zealand Food Composition Database (NZFCDB) programme seeks to maintain relevant and up-to-date food records that reflect the composition of foods commonly consumed in New Zealand(More)
Recent studies on the biosynthesis of proanthocyandins have identified key genes and enzymes in the formation of 2,3-cis-flavan-3-ols (epiafzelechin, epicatechin, and epigallocatechin). However, the enzymes that catalyze the polymerization of monomer units remain unknown. Studies of proanthocyanidin synthesis have involved the reference plant, Arabidopsis(More)
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