Trifolitoxin (TFX, CHNOS) is a selective, ribosomally-synthesized, post-translationally modified, peptide antibiotic, produced by Rhizobium leguminosarum bv. trifolii T24. TFX specifically inhibits α-proteobacteria, including the plant symbiont Rhizobium spp.
View Article and Find Full Text PDFAgrocinopine C is a small molecule found in crown gall tumours induced by pathogenic Agrobacterium radiobacter carrying the tumour-inducing plasmid pTi Bo542. This phosphodiester opine was isolated (at 0.02 g/100 g fresh wt.
View Article and Find Full Text PDFWe previously described a plasmid of Agrobacterium spp., pAoF64/95, in which the quorum-sensing system that controls conjugative transfer is induced by the opine mannopine. We also showed that the quorum-sensing regulators TraR, TraM, and TraI function similarly to their counterparts in other repABC plasmids.
View Article and Find Full Text PDFAgrocin 108 is a 3'-O-β-D-xylopyranosyl-cytidine-5'-O-phosphodiester of an ascorbate-carbocyclic cyclopentenone analogue, with bacteriocin-like properties. This bacteriocin exhibits orders of magnitude greater than the inhibition zone diameter towards the indicator strain than either ampicillin or streptomycin. It has been isolated from cultures of Rhizobium rhizogenes strain K108.
View Article and Find Full Text PDFAsian noodles prepared from bread wheat flour darken over time due to a combination of polyphenol oxidase (PPO) activity and non-PPO effects. Although the enzymatic mechanism associated with the PPO reaction is well established, the non-PPO component consists of both physical (e.g.
View Article and Find Full Text PDFDarkening in yellow alkaline noodles (YAN) was examined over a 24 h period in noodles made from 4 wheat varieties, including varieties with different levels of polyphenol oxidase (PPO) activity, selected to cover a range of protein levels. Noodles were made in the presence and absence of the PPO inhibitor, tropolone. The darkening was divided into two time periods: 0-4 h and 4-24 h.
View Article and Find Full Text PDFDarkening in yellow alkaline noodles (YAN) was measured over 24 h in a high polyphenol oxidase (PPO) bread wheat ( Triticum aestivum L. cv. Tasman) and a very low PPO durum wheat ( Triticum durum cv.
View Article and Find Full Text PDFPaper electrophoresis has been used over the pH range 1.2 to 10.4 to measure apparent pK(a) values for malvidin-3-O-glucoside of pK(a(1)) 1.
View Article and Find Full Text PDFA new method has been developed for the isolation and rapid identification of anthocyanins from two floricultural crops based on the use of high-voltage paper electrophoresis with bisulphite buffer. Using this method, anthocyanin pigments were successfully purified as their negatively charged bisulphite-addition compounds from crude extracts of plant tissue. In conjunction with liquid chromatography-electrospray mass spectrometry, the method enabled the anthocyanins from the flowers of two Banksia species and the leaves of two Acacia species to be identified.
View Article and Find Full Text PDFRed wine extracts were screened for potential wine pigments derived from anthocyanins, using a combination of nanoelectrospray tandem mass spectrometry techniques. Fourteen aglycons were considered to be of anthocyanidin origin on the basis of their MS/MS spectra. The proposed structures of the aglycons were anthocyanidin C-4 substituted with vinyl linkage between C-4 and the hydroxy group at C-5.
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