selective multiple quantum coherence lactate

DQ filtered spectroscopic imaging has been demonstrated on tissue samples and rat brain ( He et al., 1995, 1996). Multiple‐quantum editing techniques have, for example, been used for the selective detection of lactate in tumours in the presence of lipid signals ( Sotak et al., 1988 Trimble et al., 1990 Lei and Peeling, 1999). If there is interest in only one specific assimilate, a method selectively to detect only that compound would be preferable.īoth water suppression and a partial selection of specific metabolites can be achieved by multiple‐quantum (usually zero‐ and double‐quantum) filtering using phase cycling ( Hore et al., 1982) or pulse field gradients ( Wokaun and Ernst, 1977 Bax et al., 1980 van Dijk et al., 1992) for coherence pathway selection. Additionally, plant tissue contains a large variety of different 1H‐containing metabolites ( Fan et al., 1986), creating complex spectra, partly due to the large amount of signal overlap. The water signal needs to be suppressed to enable detection of other 1H‐containing compounds, which generally have a concentration that is smaller than that of water, by a factor of 1000. Water usually has a significantly broader linewidth in plant tissues as compared to animal tissues, because of the prominent presence of magnetic susceptibility gradients.

Metabolite detection using 1H NMR spectroscopy in plants is difficult to accomplish because of the dominating presence of water and a large overlap in metabolite signals. MR data available from living plants range from anatomical and physiological parameters, like water distribution ( Kuchenbrod et al., 1995 Meininger et al., 1997 b) and flow velocities ( Van As and Schaafsma, 1984 Köckenberger et al., 1997 Edzes et al., 1998 Kuchenbrod et al., 1998 Scheenen et al., 1998 Rokitta et al., 1999), to the monitoring of metabolites ( Ziegler et al., 1996 Meininger et al., 1997 a Verscht et al., 1998). New developments in these techniques, mainly used in clinical and pharmacological research, have prepared the ground for successful applications on plants ( Walter et al., 1992 Ratcliffe, 1994 McFall and Van As, 1996 Chudek and Hunter, 1997). In vivo NMR spectroscopic imaging methods allow non‐invasive metabolic studies in living organisms. CHESS, chemical shift selective, COSY, correlated spectroscopy, CPI, correlation peak imaging, CSI, chemical shift imaging, DQ, double‐quantum, NMR, nuclear magnetic resonance, SLOOP, spectral localization with optimal pointspread function Introduction

Selective multiple quantum coherence lactate