1
Intelligent Bucketing for Metabonomics—Part 2 Brent Lefebvre, Ryan Sasaki, and Sergey Golotvin Advanced Chemistry Development, Inc., Toronto, Ontario M5H 3V9 Andrew Nicholls GlaxoSmithKline, Ware, UK INTRODUCTION Auto processing using ACD/Labs’ phasing and baseline correction is now the standard approach for Metabonomics studies of urine. These tools have been proven time and time again to offer the most accurate results and produce the best statistical models for these types of data sets. Now a new procedure for Metabonomics studies, called “Intelligent Bucketing”, is being introduced to further enhance the benefits this product provides to the metabolic profiling industry. In the first poster of this series, “Intelligent Bucketing for Metabonomics-Part 1” 1 , it was shown that Intelligent Bucketing was designed to make smart bucket divisions in complex spectra such as those seen in Metabonomics. In Part 2 of this series, we will attempt to show how the result of placing these integral regions in smarter locations leads to better statistical modeling. Figure 1 - TCA cycle intermediates. Notice the shifting of these components. This is typical in urine spectra and the peak movement is not always controllable by pH adjustment. Divalent cation concentration and temperature will also affect these shifts. METHODS The data used here are from two previous studies. The first set is from a published study 2 of acclimation to a normal environment for germ- free rats, and is used to show the effect on the variance explained within a model and the interpretation of the variable loadings. The second set of data, used to show the model quality for the PCA, is from a study on drug- induced kidney effects. Both data sets were automatically processed with ACD/1D NMR Processor, with an average time of 5s from raw data to fully processed, phased, and base-lined spectrum. These spectra were then loaded into the interface in “add mode”, as they appear in Figure 1, Intelligent Bucketing was performed and the data were exported into a text file for statistical analysis. DISCUSSION When smarter bucket divisions are made, such as those that are optimized to ensure single peaks do not span two bins or buckets, data can be better modeled with fewer principal components. Normally a PC analysis will take into account a peak that spans two buckets by putting both of those buckets in the same principal component. However, there are two problems with this approach. First, the rest of the peaks in the bucket could be from something else that may have been producing an independent variable. This contribution will now be lost in the statistical model. Second, if the peak changes location between spectra, however slight, the contribution of this peak between the buckets will vary and this will decrease the accuracy of the analysis and potentially confuse the interpretation of the results. Intelligent Bucketing avoids these two common problems. It is shown below how this routine then leads the analyst to more accurate models which understand the underlying biochemistry. RESULTS In the first test of how the Intelligent Bucketing performed against Classical Bucketing, a comparison of the % variance explained in successive principal components (PCs) was made. Ideally, any model obtained should be able to describe the variation in the original data in as few PCs as possible. In Figure 2, we can see that the Intelligent Bucketing yielded a 16% increase in the variation explained (R 2 ) in PC1. Figure 2 - The quality of the prediction model for R 2 and Q 2 in Classical and Intelligent Bucketing. The increased variation explained in the first few components results in the need for a smaller number of components to model the data. The increase in Q 2 indicates a higher predictive ability for comparable components. In Figure 3, the loadings plots clearly show the benefit of Intelligent Bucketing. On this type of plot, the ideal situation is when all of the integral regions from a specific metabolite are clustered very close together. If they are not, then it shows that other underlying metabolites are contributing to the region and complicating the interpretation of the model. Here we can see the intelligent buckets produce more accurate clustering with improved precision for the regions specific to the metabolites. Figure 3 - In these loadings plots, some of the integral regions are assigned to the metabolites located in them. It is clear that Intelligent Bucketing (B) produces more precise regions for each metabolite, allowing for a clearer distinction of the metabolic components responsible for an observed effect. Figure 4 - The trajectory of the time course produced with the intelligent buckets ( A) follows a smoother course and backtracks less. This is what would be expected from a gradual change in metabolism following environmental exposure. -0.70 -0.60 -0.50 -0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 -0.90 -0.80 -0.70 -0.60 -0.50 -0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 t[2] t[1] Ellipse: Hotelling T2 (0.95) An 1 Day 21 An 4 24-48h An 4 Day 9 An 4 Day 17 An 7 6-24h An 7 Day 6 An 7 Day 12 An 7 Day 17 An 7 Day 9 An 7 24-48h An 7 Day 4 An 4 Day 21 An 7 0-6h An 4 Day 15 An 4 Day 12 An 4 Day 4 An 4 Day 6 An 4 6-24h An 4 0-6h An 1 Day 17 An 1 Day 15 An 1 Day 12 An 1 Day 9 An 1 Day 6 An 1 Day 4 An 1 6-24h An 1 24-48h An 1 0-6h An 7 Day 21 SIMCA-P+ 10.5 - 02/09/2004 11:12:13 -0.60 -0.50 -0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40 0.50 0.60 -1.00 -0.90 -0.80 -0.70 -0.60 -0.50 -0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 t[2] t[1] Ellipse: Hotelling T2 (0.95) An 1 Day 21 An 4 24-48h An 4 Day 9 An 4 Day 17 An 7 6-24h An 7 Day 6 An 7 Day 12 An 7 Day 17 An 7 Day 9 An 7 24-48h An 7 Day 4 An 4 Day 21 An 7 0-6h An 4 Day 15 An 4 Day 12 An 4 Day 4 An 4 Day 6 An 4 6-24h An 4 0-6h An 1 Day 17 An 1 Day 15 An 1 Day 12 An 1 Day 9 An 1 Day 6 An 1 Day 4 An 1 6-24h An 1 24-48h An 1 0-6h An 7 Day 21 SIMCA-P+ 10.5 - 02/09/2004 11:12:45 -0.30 -0.20 -0.10 0.00 0.10 0.20 -0.20 -0.10 0.00 0.10 0.20 0.30 p[2] p[1] [-1.19 .. -1.17] [-1.17 .. -1.14] [-1.14 .. -1.12] [-1.12 .. -1.10] [-1.10 .. -1.08] [-1.08 .. -1.07] [-1.07 .. -1.05] [-1.05 .. -1.03] [-1.03 .. -1.01] [-1.01 .. -0.98] [-0.98 .. -0.97] [-0.97 .. -0.95] [-0.95 .. -0.93] [-0.93 .. -0.92] [-0.92 .. -0.89] [-0.89 .. -0.87] [-0.87 .. -0.84] [-0.84 .. -0.81] [-0.81 .. -0.80] [-0.80 .. -0.77] [-0.77 .. -0.75] [-0.75 .. -0.72] [-0.72 .. -0.69] [-0.69 .. -0.68] [-0.68 .. -0.67] [-0.67 .. -0.66] [-0.66 .. -0.65] [-0.65 .. -0.62] [-0.62 .. -0.61] [-0.61 .. -0.58] [-0.58 .. -0.56] [-0.56 .. -0.54] [-0.54 .. -0.52] [-0.52 .. -0.51] [-0.51 .. -0.49] [-0.49 .. -0.48] [-0.48 .. -0.45] [-0.45 .. -0.43] [-0.43 .. -0.41] [-0.41 .. -0.39] [-0.39 .. -0.37] [-0.37 .. -0.36] [-0.36 .. -0.34] [-0.34 .. -0.33] [-0.33 .. -0.30] [-0.30 .. -0.27] [-0.27 .. -0.26] [-0.26 .. -0.23] [-0.23 .. -0.22] [-0.22 .. -0.21] [-0.21 .. -0.20] [-0.20 .. -0.19] [-0.19 .. -0.17] [-0.17 .. -0.16] [-0.16 .. -0.14] [-0.14 .. -0.13] [-0.13 .. -0.11] [-0.11 .. -0.08] [-0.08 .. -0.07] [-0.07 .. -0.06] [0.02 .. 0.05] [0.05 .. 0.06] [0.06 .. 0.07] [0.07 .. 0.08] [0.08 .. 0.10] [0.10 .. 0.11] [0.11 .. 0.13] [0.13 .. 0.14] [0.14 .. 0.16] [0.16 .. 0.18] [0.18 .. 0.19] [0.19 .. 0.21] [0.21 .. 0.24] [0.24 .. 0.25] [0.25 .. 0.26] [0.26 .. 0.27] [0.27 .. 0.30] [0.30 .. 0.33] [0.33 .. 0.36] [0.36 .. 0.37] [0.37 .. 0.38] [0.38 .. 0.39] [0.39 .. 0.40] [0.40 .. 0.41] [0.41 .. 0.42] [0.42 .. 0.43] [0.43 .. 0.44] [0.44 .. 0.47] [0.47 .. 0.49] [0.49 .. 0.50] [0.50 .. 0.51] [0.51 .. 0.52] [0.52 .. 0.53] [0.53 .. 0.56] [0.56 .. 0.57] [0.57 .. 0.58] [0.58 .. 0.59] [0.59 .. 0.62] [0.62 .. 0.63] [0.63 .. 0.64] [0.64 .. 0.66] [0.66 .. 0.67] [0.67 .. 0.68] [0.68 .. 0.69] [0.69 .. 0.70] [0.70 .. 0.71] [0.71 .. 0.72] [0.72 .. 0.73] [0.73 .. 0.74] [0.74 .. 0.75] [0.75 .. 0.78] [0.78 .. 0.79] [0.79 .. 0.80] [0.80 .. 0.81] [0.81 .. 0.82] [0.82 .. 0.83] [0.83 .. 0.84] [0.84 .. 0.85] [0.85 .. 0.86] [0.86 .. 0.87] [0.87 .. 0.89] [0.89 .. 0.92] [0.92 .. 0.94] [0.94 .. 0.97] [0.97 .. 1.00] [1.00 .. 1.03] [1.03 .. 1.04] [1.04 .. 1.05] [1.05 .. 1.08] [1.08 .. 1.09] [1.09 .. 1.10] [1.10 .. 1.13] [1.13 .. 1.15] [1.15 .. 1.16] [1.16 .. 1.18] [1.18 .. 1.19] [1.19 .. 1.20] [1.20 .. 1.21] [1.21 .. 1.23] [1.23 .. 1.26] [1.26 .. 1.29] [1.29 .. 1.30] [1.30 .. 1.32] [1.32 .. 1.33] [1.33 .. 1.36] [1.36 .. 1.38] [1.38 .. 1.40] [1.40 .. 1.41] [1.41 .. 1.43] [1.43 .. 1.45] [1.45 .. 1.46] [1.46 .. 1.47] [1.47 .. 1.49] [1.49 .. 1.51] [1.51 .. 1.52] [1.52 .. 1.53] [1.53 .. 1.54] [1.54 .. 1.57] [1.57 .. 1.60] [1.60 .. 1.62] [1.62 .. 1.63] [1.63 .. 1.64] [1.64 .. 1.67] [1.67 .. 1.70] [1.70 .. 1.71] [1.71 .. 1.73] [1.73 .. 1.74] [1.74 .. 1.75] [1.75 .. 1.76] [1.76 .. 1.79] [1.79 .. 1.81] [1.81 .. 1.84] [1.84 .. 1.86] [1.86 .. 1.87] [1.87 .. 1.88] [1.88 .. 1.89] [1.89 .. 1.90] [1.90 .. 1.93] [1.93 .. 1.96] [1.96 .. 1.97] [1.97 .. 1.98] [1.98 .. 2.00] [2.00 .. 2.01] [2.01 .. 2.02] [2.02 .. 2.05] [2.05 .. 2.08] [2.08 .. 2.11] [2.11 .. 2.13] [2.13 .. 2.16] [2.16 .. 2.18] [2.18 .. 2.19] [2.19 .. 2.20] [2.20 .. 2.21] [2.21 .. 2.23] [2.23 .. 2.26] [2.26 .. 2.29] [2.29 .. 2.30] [2.30 .. 2.31] [2.31 .. 2.33] [2.33 .. 2.35] [2.35 .. 2.37] [2.37 .. 2.40] [2.40 .. 2.41] [2.41 .. 2.42] [2.42 .. 2.43] [2.43 .. 2.45] [2.45 .. 2.47] [2.47 .. 2.50] [2.50 .. 2.52] [2.52 .. 2.53] [2.53 .. 2.54] [2.54 .. 2.57] [2.57 .. 2.60] [2.60 .. 2.63] [2.63 .. 2.64] [2.64 .. 2.66] [2.66 .. 2.67] [2.67 .. 2.68] [2.68 .. 2.69] [2.69 .. 2.72] [2.72 .. 2.75] [2.75 .. 2.78] [2.78 .. 2.81] [2.81 .. 2.82] [2.82 .. 2.85] [2.85 .. 2.88] [2.88 .. 2.89] [2.89 .. 2.90] [2.90 .. 2.92] [2.92 .. 2.95] [2.95 .. 2.96] [2.96 .. 2.98] [2.98 .. 2.99] [2.99 .. 3.00] [3.00 .. 3.02] [3.02 .. 3.05] [3.05 .. 3.08] [3.08 .. 3.10] [3.10 .. 3.12] [3.12 .. 3.14] [3.14 .. 3.15] [3.15 .. 3.18] [3.18 .. 3.19] [3.19 .. 3.22] [3.22 .. 3.23] [3.23 .. 3.25] [3.25 .. 3.27] [3.27 .. 3.30] [3.30 .. 3.33] [3.33 .. 3.36] [3.36 .. 3.37] [3.37 .. 3.38] [3.38 .. 3.39] [3.39 .. 3.40] [3.40 .. 3.42] [3.42 .. 3.45] [3.45 .. 3.48] [3.48 .. 3.50] [3.50 .. 3.52] [3.52 .. 3.55] [3.55 .. 3.57] [3.57 .. 3.59] [3.59 .. 3.61] [3.61 .. 3.62] [3.62 .. 3.63] [3.63 .. 3.64] [3.64 .. 3.67] [3.67 .. 3.69] [3.69 .. 3.70] [3.70 .. 3.71] [3.71 .. 3.74] [3.74 .. 3.75] [3.75 .. 3.78] [3.78 .. 3.81] [3.81 .. 3.82] [3.82 .. 3.83] [3.83 .. 3.86] [3.86 .. 3.88] [3.88 .. 3.91] [3.91 .. 3.94] [3.94 .. 3.96] [3.96 .. 3.99] [3.99 .. 4.01] [4.01 .. 4.04] [4.04 .. 4.05] [4.05 .. 4.07] [4.07 .. 4.08] [4.08 .. 4.11] [4.11 .. 4.13] [4.13 .. 4.16] [4.16 .. 4.18] [4.18 .. 4.21] [4.21 .. 4.23] [4.23 .. 4.26] [4.26 .. 4.27] [4.27 .. 4.28] [4.28 .. 4.31] [4.31 .. 4.34] [4.34 .. 4.37] [4.37 .. 4.39] [4.39 .. 4.40] [4.40 .. 4.41] [4.41 .. 4.43] [4.43 .. 4.46] [4.46 .. 4.47] [4.47 .. 4.50] [4.50 .. 4.51] [4.51 .. 4.52] [4.52 .. 4.55] [4.55 .. 4.56] [4.90 .. 4.91] [4.91 .. 4.94] [4.94 .. 4.95] [4.95 .. 4.96] [4.96 .. 4.99] [4.99 .. 5.02] [5.02 .. 5.04] [5.04 .. 5.05] [5.05 .. 5.06] [5.06 .. 5.08] [5.08 .. 5.09] [5.09 .. 5.10] [5.10 .. 5.11] [5.11 .. 5.14] [5.14 .. 5.17] [5.17 .. 5.18] [5.18 .. 5.19] [5.19 .. 5.21] [5.21 .. 5.22] [5.22 .. 5.23] [5.23 .. 5.24] [5.24 .. 5.27] [5.27 .. 5.30] [5.30 .. 5.31] [5.31 .. 5.32] [5.32 .. 5.33] [5.33 .. 5.34] [5.34 .. 5.35] [5.35 .. 5.36] [5.36 .. 5.37] [5.37 .. 5.39] [5.39 .. 5.42] [5.42 .. 5.45] [5.45 .. 5.48] [6.10 .. 6.12] [6.12 .. 6.13] [6.13 .. 6.16] [6.16 .. 6.18] [6.18 .. 6.21] [6.21 .. 6.24] [6.24 .. 6.25] [6.25 .. 6.26] [6.26 .. 6.29] [6.29 .. 6.32] [6.32 .. 6.33] [6.33 .. 6.34] [6.34 .. 6.35] [6.35 .. 6.38] [6.38 .. 6.41] [6.41 .. 6.42] [6.42 .. 6.43] [6.43 .. 6.45] [6.45 .. 6.46] [6.46 .. 6.47] [6.47 .. 6.48] [6.48 .. 6.51] [6.51 .. 6.52] [6.52 .. 6.55] [6.55 .. 6.56] [6.56 .. 6.59] [6.59 .. 6.60] [6.60 .. 6.61] [6.61 .. 6.62] [6.62 .. 6.63] [6.63 .. 6.65] [6.65 .. 6.67] [6.67 .. 6.69] [6.69 .. 6.72] [6.72 .. 6.73] [6.73 .. 6.74] [6.74 .. 6.77] [6.77 .. 6.78] [6.78 .. 6.81] [6.81 .. 6.82] [6.82 .. 6.83] [6.83 .. 6.85] [6.85 .. 6.86] [6.86 .. 6.89] [6.89 .. 6.92] [6.92 .. 6.95] [6.95 .. 6.97] [6.97 .. 6.98] [6.98 .. 7.01] [7.01 .. 7.02] [7.02 .. 7.03] [7.03 .. 7.04] [7.04 .. 7.07] [7.07 .. 7.10] [7.10 .. 7.11] [7.11 .. 7.13] [7.13 .. 7.14] [7.14 .. 7.15] [7.15 .. 7.17] [7.17 .. 7.18] [7.18 .. 7.21] [7.21 .. 7.23] [7.23 .. 7.26] [7.26 .. 7.29] [7.29 .. 7.31] [7.31 .. 7.32] [7.32 .. 7.33] [7.33 .. 7.34] [7.34 .. 7.36] [7.36 .. 7.39] [7.39 .. 7.40] [7.40 .. 7.43] [7.43 .. 7.45] [7.45 .. 7.47] [7.47 .. 7.48] [7.48 .. 7.50] [7.50 .. 7.52] [7.52 .. 7.53] [7.53 .. 7.56] [7.56 .. 7.59] [7.59 .. 7.60] [7.60 .. 7.61] [7.61 .. 7.62] [7.62 .. 7.64] [7.64 .. 7.65] [7.65 .. 7.68] [7.68 .. 7.71] [7.71 .. 7.74] [7.74 .. 7.76] [7.76 .. 7.78] [7.78 .. 7.79] [7.79 .. 7.80] [7.80 .. 7.81] [7.81 .. 7.82] [7.82 .. 7.85] [7.85 .. 7.87] [7.87 .. 7.88] [7.88 .. 7.90] [7.90 .. 7.91] [7.91 .. 7.92] [7.92 .. 7.93] [7.93 .. 7.94] [7.94 .. 7.95] [7.95 .. 7.96] [7.96 .. 7.99] [7.99 .. 8.02] [8.02 .. 8.04] [8.04 .. 8.07] [8.07 .. 8.10] [8.10 .. 8.13] [8.13 .. 8.14] [8.14 .. 8.15] [8.15 .. 8.16] [8.16 .. 8.17] [8.17 .. 8.20] [8.20 .. 8.23] [8.23 .. 8.24] [8.24 .. 8.26] [8.26 .. 8.29] [8.29 .. 8.31] [8.31 .. 8.34] [8.34 .. 8.35] [8.35 .. 8.38] [8.38 .. 8.40] [8.40 .. 8.41] [8.41 .. 8.42] [8.42 .. 8.43] [8.43 .. 8.44] [8.44 .. 8.45] [8.45 .. 8.48] [8.48 .. 8.51] [8.51 .. 8.53] [8.53 .. 8.56] [8.56 .. 8.59] [8.59 .. 8.62] [8.62 .. 8.64] [8.64 .. 8.67] [8.67 .. 8.69] [8.69 .. 8.70] [8.70 .. 8.71] [8.71 .. 8.73] [8.73 .. 8.76] [8.76 .. 8.78] [8.78 .. 8.79] [8.79 .. 8.80] [8.80 .. 8.81] [8.81 .. 8.82] [8.82 .. 8.85] [8.85 .. 8.87] [8.87 .. 8.88] [8.88 .. 8.91] [8.91 .. 8.92] [8.92 .. 8.93] [8.93 .. 8.94] [8.94 .. 8.97] [8.97 .. 9.00] [9.00 .. 9.02] [9.02 .. 9.05] [9.05 .. 9.06] [9.06 .. 9.07] [9.07 .. 9.08] [9.08 .. 9.09] [9.09 .. 9.10] [9.10 .. 9.13] [9.13 .. 9.16] [9.16 .. 9.17] [9.17 .. 9.19] [9.19 .. 9.21] [9.21 .. 9.22] [9.22 .. 9.23] [9.23 .. 9.24] [9.24 .. 9.25] [9.25 .. 9.28] [9.28 .. 9.31] [9.31 .. 9.34] [9.34 .. 9.35] [9.35 .. 9.37] [9.37 .. 9.39] [9.39 .. 9.40] [9.40 .. 9.41] [9.41 .. 9.42] [9.42 .. 9.43] [9.43 .. 9.46] [9.46 .. 9.48] [9.48 .. 9.51] [9.51 .. 9.54] [9.54 .. 9.57] [9.57 .. 9.59] [9.59 .. 9.60] [9.60 .. 9.62] [9.62 .. 9.64] [9.64 .. 9.66] [9.66 .. 9.67] [9.67 .. 9.70] [9.70 .. 9.72] [9.72 .. 9.74] [9.74 .. 9.77] [9.77 .. 9.78] [9.78 .. 9.79] [9.79 .. 9.80] [9.80 .. 9.82] [9.82 .. 9.84] [9.84 .. 9.87] [9.87 .. 9.88] [9.88 .. 9.89] [9.89 .. 9.91] [9.91 .. 9.93] [9.93 .. 9.94] SIMCA-P+ 10.5 - 02/09/2004 11:09:04 2-oxoglutarate Citrate Succinate Citrate and 2- oxoglutarate -0.20 -0.10 0.00 0.10 0.20 -0.20 -0.10 0.00 0.10 0.20 p[2] p[1] [-1.19 .. -1.17] [-1.17 .. -1.15] [-1.15 .. -1.13] [-1.13 .. -1.11] [-1.11 .. -1.09] [-1.09 .. -1.07] [-1.07 .. -1.05] [-1.05 .. -1.03] [-1.03 .. -1.01] [-1.01 .. -0.99] [-0.99 .. -0.97] [-0.97 .. -0.95] [-0.95 .. -0.93] [-0.93 .. -0.91] [-0.91 .. -0.89] [-0.89 .. -0.87] [-0.87 .. -0.85] [-0.85 .. -0.83] [-0.83 .. -0.81] [-0.81 .. -0.79] [-0.79 .. -0.77] [-0.77 .. -0.75] [-0.75 .. -0.73] [-0.73 .. -0.71] [-0.71 .. -0.69] [-0.69 .. -0.67] [-0.67 .. -0.65] [-0.65 .. -0.63] [-0.63 .. -0.61] [-0.61 .. -0.59] [-0.59 .. -0.57] [-0.57 .. -0.55] [-0.55 .. -0.53] [-0.53 .. -0.51] [-0.51 .. -0.49] [-0.49 .. -0.47] [-0.47 .. -0.45] [-0.45 .. -0.43] [-0.43 .. -0.41] [-0.41 .. -0.39] [-0.39 .. -0.37] [-0.37 .. -0.35] [-0.35 .. -0.33] [-0.33 .. -0.31] [-0.31 .. -0.29] [-0.29 .. -0.27] [-0.27 .. -0.25] [-0.25 .. -0.23] [-0.23 .. -0.21] [-0.21 .. -0.19] [-0.19 .. -0.17] [-0.17 .. -0.15] [-0.15 .. -0.13] [-0.13 .. -0.11] [-0.11 .. -0.09] [-0.09 .. -0.07] [-0.07 .. -0.05] [-0.05 .. -0.03] [0.02 .. 0.04] [0.04 .. 0.06] [0.06 .. 0.08] [0.08 .. 0.10] [0.10 .. 0.12] [0.12 .. 0.14] [0.14 .. 0.16] [0.16 .. 0.18] [0.18 .. 0.20] [0.20 .. 0.22] [0.22 .. 0.24] [0.24 .. 0.26] [0.26 .. 0.28] [0.28 .. 0.30] [0.30 .. 0.32] [0.32 .. 0.34] [0.34 .. 0.36] [0.36 .. 0.38] [0.38 .. 0.40] [0.40 .. 0.42] [0.42 .. 0.44] [0.44 .. 0.46] [0.46 .. 0.48] [0.48 .. 0.50] [0.50 .. 0.52] [0.52 .. 0.54] [0.54 .. 0.56] [0.56 .. 0.58] [0.58 .. 0.60] [0.60 .. 0.62] [0.62 .. 0.64] [0.64 .. 0.66] [0.66 .. 0.68] [0.68 .. 0.70] [0.70 .. 0.72] [0.72 .. 0.74] [0.74 .. 0.76] [0.76 .. 0.78] [0.78 .. 0.80] [0.80 .. 0.82] [0.82 .. 0.84] [0.84 .. 0.86] [0.86 .. 0.88] [0.88 .. 0.90] [0.90 .. 0.92] [0.92 .. 0.94] [0.94 .. 0.96] [0.96 .. 0.98] [0.98 .. 1.00] [1.00 .. 1.02] [1.02 .. 1.04] [1.04 .. 1.06] [1.06 .. 1.08] [1.08 .. 1.10] [1.10 .. 1.12] [1.12 .. 1.14] [1.14 .. 1.16] [1.16 .. 1.18] [1.18 .. 1.20] [1.20 .. 1.22] [1.22 .. 1.24] [1.24 .. 1.26] [1.26 .. 1.28] [1.28 .. 1.30] [1.30 .. 1.32] [1.32 .. 1.34] [1.34 .. 1.36] [1.36 .. 1.38] [1.38 .. 1.40] [1.40 .. 1.42] [1.42 .. 1.44] [1.44 .. 1.46] [1.46 .. 1.48] [1.48 .. 1.50] [1.50 .. 1.52] [1.52 .. 1.54] [1.54 .. 1.56] [1.56 .. 1.58] [1.58 .. 1.60] [1.60 .. 1.62] [1.62 .. 1.64] [1.64 .. 1.66] [1.66 .. 1.68] [1.68 .. 1.70] [1.70 .. 1.72] [1.72 .. 1.74] [1.74 .. 1.76] [1.76 .. 1.78] [1.78 .. 1.80] [1.80 .. 1.82] [1.82 .. 1.84] [1.84 .. 1.86] [1.86 .. 1.88] [1.88 .. 1.90] [1.90 .. 1.92] [1.92 .. 1.94] [1.94 .. 1.96] [1.96 .. 1.98] [1.98 .. 2.00] [2.00 .. 2.02] [2.02 .. 2.04] [2.04 .. 2.06] [2.06 .. 2.08] [2.08 .. 2.10] [2.10 .. 2.12] [2.12 .. 2.14] [2.14 .. 2.16] [2.16 .. 2.18] [2.18 .. 2.20] [2.20 .. 2.22] [2.22 .. 2.24] [2.24 .. 2.26] [2.26 .. 2.28] [2.28 .. 2.30] [2.30 .. 2.32] [2.32 .. 2.34] [2.34 .. 2.36] [2.36 .. 2.38] [2.38 .. 2.40] [2.40 .. 2.42] [2.42 .. 2.44] [2.44 .. 2.46] [2.46 .. 2.48] [2.48 .. 2.50] [2.50 .. 2.52] [2.52 .. 2.54] [2.54 .. 2 [2.56 .. 2.58] [2.58 .. 2.60] [2.60 .. 2.62] [2.62 .. 2.64] [2.64 .. 2.66] [2.66 .. 2.68] [2.68 .. 2.70] [2.70 .. 2.72] [2.72 .. 2.74] [2.74 .. 2.76] [2.76 .. 2.78] [2.78 .. 2.80] [2.80 .. 2.82] [2.82 .. 2.84] [2.84 .. 2.86] [2.86 .. 2.88] [2.88 .. 2.90] [2.90 .. 2.92] [2.92 .. 2.94] [2.94 .. 2.96] [2.96 .. 2.98] [2.98 .. 3.00] [3.00 .. 3.02] [3.02 .. 3.04] [3.04 .. 3.06] [3.06 .. 3.08] [3.08 .. 3.10] [3.10 .. 3.12] [3.12 .. 3.14] [3.14 .. 3.16] [3.16 .. 3.18] [3.18 .. 3.20] [3.20 .. 3.22] [3.22 .. 3.24] [3.24 .. 3.26] [3.26 .. 3.28] [3.28 .. 3.30] [3.30 .. 3.32] [3.32 .. 3.34] [3.34 .. 3.36] [3.36 .. 3.38] [3.38 .. 3.40] [3.40 .. 3.42] [3.42 .. 3.44] [3.44 .. 3.46] [3.46 .. 3.48] [3.48 .. 3.50] [3.50 .. 3.52] [3.52 .. 3.54] [3.54 .. 3.56] [3.56 .. 3.58] [3.58 .. 3.60] [3.60 .. 3.62] [3.62 .. 3.64] [3.64 .. 3.66] [3.66 .. 3.68] [3.68 .. 3.70] [3.70 .. 3.72] [3.72 .. 3.74] [3.74 .. 3.76] [3.76 .. 3.78] [3.78 .. 3.80] [3.80 .. 3.82] [3.82 .. 3.84] [3.84 .. 3.86] [3.86 .. 3.88] [3.88 .. 3.90] [3.90 .. 3.92] [3.92 .. 3.94] [3.94 .. 3.96] [3.96 .. 3.98] [3.98 .. 4.00] [4.00 .. 4.02] [4.02 .. 4.04] [4.04 .. 4.06] [4.06 .. 4.08] [4.08 .. 4.10] [4.10 .. 4.12] [4.12 .. 4.14] [4.14 .. 4.16] [4.16 .. 4.18] [4.18 .. 4.20] [4.20 .. 4.22] [4.22 .. 4.24] [4.24 .. 4.26] [4.26 .. 4.28] [4.28 .. 4.30] [4.30 .. 4.32] [4.32 .. 4.34] [4.34 .. 4.36] [4.36 .. 4.38] [4.38 .. 4.40] [4.40 .. 4.42] [4.42 .. 4.44] [4.44 .. 4.46] [4.46 .. 4.48] [4.48 .. 4.50] [4.50 .. 4.52] [4.52 .. 4.54] [4.54 .. 4.56] [4.56 .. 4.58] [4.90 .. 4.92] [4.92 .. 4.94] [4.94 .. 4.96] [4.96 .. 4.98] [4.98 .. 5.00] [5.00 .. 5.02] [5.02 .. 5.04] [5.04 .. 5.06] [5.06 .. 5.08] [5.08 .. 5.10] [5.10 .. 5.12] [5.12 .. 5.14] [5.14 .. 5.16] [5.16 .. 5.18] [5.18 .. 5.20] [5.20 .. 5.22] [5.22 .. 5.24] [5.24 .. 5.26] [5.26 .. 5.28] [5.28 .. 5.30] [5.30 .. 5.32] [5.32 .. 5.34] [5.34 .. 5.36] [5.36 .. 5.38] [5.38 .. 5.40] [5.40 .. 5.42] [5.42 .. 5.44] [5.44 .. 5.46] [5.46 .. 5.48] [6.10 .. 6.12] [6.12 .. 6.14] [6.14 .. 6.16] [6.16 .. 6.18] [6.18 .. 6.20] [6.20 .. 6.22] [6.22 .. 6.24] [6.24 .. 6.26] [6.26 .. 6.28] [6.28 .. 6.30] [6.30 .. 6.32] [6.32 .. 6.34] [6.34 .. 6.36] [6.36 .. 6.38] [6.38 .. 6.40] [6.40 .. 6.42] [6.42 .. 6.44] [6.44 .. 6.46] [6.46 .. 6.48] [6.48 .. 6.50] [6.50 .. 6.52] [6.52 .. 6.54] [6.54 .. 6.56] [6.56 .. 6.58] [6.58 .. 6.60] [6.60 .. 6.62] [6.62 .. 6.64] [6.64 .. 6.66] [6.66 .. 6.68] [6.68 .. 6.70] [6.70 .. 6.72] [6.72 .. 6.74] [6.74 .. 6.76] [6.76 .. 6.78] [6.78 .. 6.80] [6.80 .. 6.82] [6.82 .. 6.84] [6.84 .. 6.86] [6.86 .. 6.88] [6.88 .. 6.90] [6.90 .. 6.92] [6.92 .. 6.94] [6.94 .. 6.96] [6.96 .. 6.98] [6.98 .. 7.00] [7.00 .. 7.02] [7.02 .. 7.04] [7.04 .. 7.06] [7.06 .. 7.08] [7.08 .. 7.10] [7.10 .. 7.12] [7.12 .. 7.14] [7.14 .. 7.16] [7.16 .. 7.18] [7.18 .. 7.20] [7.20 .. 7.22] [7.22 .. 7.24] [7.24 .. 7.26] [7.26 .. 7.28] [7.28 .. 7.30] [7.30 .. 7.32] [7.32 .. 7.34] [7.34 .. 7.36] [7.36 .. 7.38] [7.38 .. 7.40] [7.40 .. 7.42] [7.42 .. 7.44] [7.44 .. 7.46] [7.46 .. 7.48] [7.48 .. 7.50] [7.50 .. 7.52] [7.52 .. 7.54] [7.54 .. 7.56] [7.56 .. 7.58] [7.58 .. 7.60] [7.60 .. 7.62] [7.62 .. 7.64] [7.64 .. 7.66] [7.66 .. 7.68] [7.68 .. 7.70] [7.70 .. 7.72] [7.72 .. 7.74] [7.74 .. 7.76] [7.76 .. 7.78] [7.78 .. 7.80] [7.80 .. 7.82] [7.82 .. 7.84] [7.84 .. 7.86] [7.86 .. 7.88] [7.88 .. 7.90] [7.90 .. 7.92] [7.92 .. 7.94] [7.94 .. 7.96] [7.96 .. 7.98] [7.98 .. 8.00] [8.00 .. 8.02] [8.02 .. 8.04] [8.04 .. 8.06] [8.06 .. 8.08] [8.08 .. 8.10] [8.10 .. 8.12] [8.12 .. 8.14] [8.14 .. 8.16] [8.16 .. 8.18] [8.18 .. 8.20] [8.20 .. 8.22] [8.22 .. 8.24] [8.24 .. 8.26] [8.26 .. 8.28] [8.28 .. 8.30] [8.30 .. 8.32] [8.32 .. 8.34] [8.34 .. 8.36] [8.36 .. 8.38] [8.38 .. 8.40] [8.40 .. 8.42] [8.42 .. 8.44] [8.44 .. 8.46] [8.46 .. 8.48] [8.48 .. 8.50] [8.50 .. 8.52] [8.52 .. 8.54] [8.54 .. 8.56] [8.56 .. 8.58] [8.58 .. 8.60] [8.60 .. 8.62] [8.62 .. 8.64] [8.64 .. 8.66] [8.66 .. 8.68] [8.68 .. 8.70] [8.70 .. 8.72] [8.72 .. 8.74] [8.74 .. 8.76] [8.76 .. 8.78] [8.78 .. 8.80] [8.80 .. 8.82] [8.82 .. 8.84] [8.84 .. 8.86] [8.86 .. 8.88] [8.88 .. 8.90] [8.90 .. 8.92] [8.92 .. 8.94] [8.94 .. 8.96] [8.96 .. 8.98] [8.98 .. 9.00] [9.00 .. 9.02] [9.02 .. 9.04] [9.04 .. 9.06] [9.06 .. 9.08] [9.08 .. 9.10] [9.10 .. 9.12] [9.12 .. 9.14] [9.14 .. 9.16] [9.16 .. 9.18] [9.18 .. 9.20] [9.20 .. 9.22] [9.22 .. 9.24] [9.24 .. 9.26] [9.26 .. 9.28] [9.28 .. 9.30] [9.30 .. 9.32] [9.32 .. 9.34] [9.34 .. 9.36] [9.36 .. 9.38] [9.38 .. 9.40] [9.40 .. 9.42] [9.42 .. 9.44] [9.44 .. 9.46] [9.46 .. 9.48] [9.48 .. 9.50] [9.50 .. 9.52] [9.52 .. 9.54] [9.54 .. 9.56] [9.56 .. 9.58] [9.58 .. 9.60] [9.60 .. 9.62] [9.62 .. 9.64] [9.64 .. 9.66] [9.66 .. 9.68] [9.68 .. 9.70] [9.70 .. 9.72] [9.72 .. 9.74] [9.74 .. 9.76] [9.76 .. 9.78] [9.78 .. 9.80] [9.80 .. 9.82] [9.82 .. 9.84] [9.84 .. 9.86] [9.86 .. 9.88] [9.88 .. 9.90] [9.90 .. 9.92] [9.92 .. 9.94] [9.94 .. 9.96] [9.96 .. 9.98] Citrate 2-oxoglutarate and succinate A major benefit of Intelligent Bucketing can also be seen in Figure 5. Here the predictive quality (Q 2 ) of the PCA components is shown for each of the bucketing methods. Most notably, the Q 2 value is negative for Principal Components 2, 3, and 5, with Classical Bucketing indicting that anything other than a 1 component model would have no predictive value. In the PCA models produced with the intelligent buckets, the Q 2 are positive, indicting some predictive quality. The generally low values for Q 2 are due to the low number of samples in the data set. Figure 5 - In these plots, the quality of the PCA models is shown. This Q 2 value for the data from the intelligent buckets, is much improved over that from the classical buckets. CONCLUSION Intelligent Bucketing has been shown to allow for improvements to the accuracy of the modeling of NMR data by removing an inherent failing of Classical Bucketing. This failing arises from the inherent sensitivity of NMR to the molecular environment; most notably, the sensitivity to pH subtleties, changes in temperature, and the presence of ion interactions. REFERENCES 1. Intelligent Bucketing for Metabonomics—Part 1, http://www.acdlabs.com/download/publ/2004/enc04/intelbucket.pdf 2. Nicholls A.W., Mortishire-Smith, R.J. and Nicholson, J.K. (2003) NMR spectroscopic and metabonomic studies of urinary variation in acclimatising germ free rats. Chemical Research in Toxicology, 16(11):1395-1404. 90 Adelaide St. W., Suite 600 Toronto, Canada M5H 3V9 Tel: (416) 368-3435 Fax: (416) 368-5596 Toll Free: 1-800-304-3988 Email: [email protected] www.acdlabs.com A B A B ItelliBuck2004DEC 12/9/04 9:59 AM Page 1

Brent Lefebvre, Ryan Sasaki, Intelligent Bucketing for · 2011-02-09 · When smarter bucket divisions are made, such as those that are optimized to ensure single peaks do not span

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Page 1: Brent Lefebvre, Ryan Sasaki, Intelligent Bucketing for · 2011-02-09 · When smarter bucket divisions are made, such as those that are optimized to ensure single peaks do not span

Intelligent Bucketing for Metabonomics—Part 2

Brent Lefebvre, Ryan Sasaki, and Sergey Golotvin

Advanced Chemistry Development, Inc.,Toronto, Ontario M5H 3V9

Andrew NichollsGlaxoSmithKline,

Ware, UK

INTRODUCTION

Auto processing using ACD/Labs’ phasing andbaseline correction is now the standard approachfor Metabonomics studies of urine. These toolshave been proven time and time again to offerthe most accurate results and produce the beststatistical models for these types of data sets.Now a new procedure for Metabonomics studies,called “Intelligent Bucketing”, is being introducedto further enhance the benefits this productprovides to the metabolic profiling industry.

In the first poster of this series, “IntelligentBucketing for Metabonomics-Part 1”1, it wasshown that Intelligent Bucketing was designed tomake smart bucket divisions in complex spectrasuch as those seen in Metabonomics. In Part 2 ofthis series, we will attempt to show how the resultof placing these integral regions in smarterlocations leads to better statistical modeling.

Figure 1 - TCA cycle intermediates. Notice theshifting of these components. This is typical inurine spectra and the peak movement is notalways controllable by pH adjustment. Divalentcation concentration and temperature will alsoaffect these shifts.

METHODS

The data used here are from two previous studies.The first set is from a published study2 ofacclimation to a normal environment for germ-free rats, and is used to show the effect on thevariance explained within a model and theinterpretation of the variable loadings. Thesecond set of data, used to show the modelquality for the PCA, is from a study on drug-induced kidney effects.

Both data sets were automatically processed withACD/1D NMR Processor, with an average time of5s from raw data to fully processed, phased, andbase-lined spectrum. These spectra were thenloaded into the interface in “add mode”, as theyappear in Figure 1, Intelligent Bucketing wasperformed and the data were exported into a textfile for statistical analysis.

DISCUSSION

When smarter bucket divisions are made, such asthose that are optimized to ensure single peaksdo not span two bins or buckets, data can bebetter modeled with fewer principal components.Normally a PC analysis will take into account apeak that spans two buckets by putting both ofthose buckets in the same principal component.

However, there are two problems with thisapproach. First, the rest of the peaks in thebucket could be from something else that mayhave been producing an independent variable.This contribution will now be lost in the statisticalmodel.

Second, if the peak changes location betweenspectra, however slight, the contribution of thispeak between the buckets will vary and this willdecrease the accuracy of the analysis andpotentially confuse the interpretation of theresults. Intelligent Bucketing avoids these twocommon problems. It is shown below how thisroutine then leads the analyst to more accuratemodels which understand the underlyingbiochemistry.

RESULTS

In the first test of how the Intelligent Bucketingperformed against Classical Bucketing, acomparison of the % variance explained insuccessive principal components (PCs) was made.Ideally, any model obtained should be able todescribe the variation in the original data in asfew PCs as possible. In Figure 2, we can see thatthe Intelligent Bucketing yielded a 16% increasein the variation explained (R2) in PC1.

Figure 2 - The quality of the prediction model forR2 and Q2 in Classical and Intelligent Bucketing.The increased variation explained in the first fewcomponents results in the need for a smallernumber of components to model the data. Theincrease in Q2 indicates a higher predictive abilityfor comparable components.

In Figure 3, the loadings plots clearly show thebenefit of Intelligent Bucketing. On this type ofplot, the ideal situation is when all of the integralregions from a specific metabolite are clusteredvery close together. If they are not, then it showsthat other underlying metabolites are contributingto the region and complicating the interpretationof the model. Here we can see the intelligentbuckets produce more accurate clustering withimproved precision for the regions specific to themetabolites.

Figure 3 - In these loadings plots, some of theintegral regions are assigned to the metaboliteslocated in them. It is clear that IntelligentBucketing (B) produces more precise regions foreach metabolite, allowing for a clearer distinctionof the metabolic components responsible for anobserved effect.

Figure 4 - The trajectory of the time courseproduced with the intelligent buckets (A) follows asmoother course and backtracks less. This iswhat would be expected from a gradual changein metabolism following environmental exposure.

- 0 .7 0

- 0 .6 0

- 0 .5 0

- 0 .4 0

- 0 .3 0

- 0 .2 0

- 0 .1 0

0 .0 0

0 .1 0

0 .2 0

0 .3 0

0 .4 0

0 .5 0

0 .6 0

0 .7 0

-0 .9 0 - 0 .8 0 - 0 .7 0 - 0 .6 0 - 0 .5 0 - 0 .4 0 - 0 .3 0 -0 .2 0 - 0 .1 0 0 .0 0 0 .1 0 0 .2 0 0 .3 0 0 .4 0 0 .5 0 0 .6 0 0 .7 0 0 .8 0 0 .9 0

t[2]

t[1]

Ellipse: Hotelling T2 (0.95)

An 1 Day 21

An 4 24-48h

An 4 Day 9

An 4 Day 17

An 7 6-24h

An 7 Day 6 An 7 Day 12

An 7 Day 17

An 7 Day 9

An 7 24-48h An 7 Day 4

An 4 Day 21

An 7 0-6h

An 4 Day 15

An 4 Day 12

An 4 Day 4

An 4 Day 6

An 4 6-24h

An 4 0-6h

An 1 Day 17

An 1 Day 15

An 1 Day 12

An 1 Day 9 An 1 Day 6

An 1 Day 4

An 1 6-24h An 1 24-48h

An 1 0-6h

An 7 Day 21

SIMCA-P+ 10.5 - 02/09/2004 11:12:13

- 0 .6 0

- 0 .5 0

- 0 .4 0

- 0 .3 0

- 0 .2 0

- 0 .1 0

0 .0 0

0 .1 0

0 .2 0

0 .3 0

0 .4 0

0 .5 0

0 .6 0

- 1 .0 0 - 0 .9 0 - 0 .8 0 - 0 .7 0 - 0 .6 0 - 0 .5 0 - 0 .4 0 - 0 .3 0 - 0 .2 0 - 0 .1 0 0 .0 0 0 .1 0 0 .2 0 0 .3 0 0 .4 0 0 .5 0 0 .6 0 0 .7 0 0 .8 0 0 .9 0 1 .0 0

t[2]

t[1]

Ellipse: Hotelling T2 (0.95)

An 1 Day 21

An 4 24-48h

An 4 Day 9

An 4 Day 17

An 7 6-24h

An 7 Day 6

An 7 Day 12

An 7 Day 17

An 7 Day 9

An 7 24-48h An 7 Day 4

An 4 Day 21

An 7 0-6h

An 4 Day 15

An 4 Day 12

An 4 Day 4

An 4 Day 6

An 4 6-24h

An 4 0-6h

An 1 Day 17

An 1 Day 15

An 1 Day 12

An 1 Day 9

An 1 Day 6

An 1 Day 4

An 1 6-24h An 1 24-48h

An 1 0-6h

An 7 Day 21

SIMCA-P+ 10.5 - 02/09/2004 11:12:45

- 0 .3 0

- 0 .2 0

- 0 .1 0

0 .0 0

0 .1 0

0 .2 0

- 0 .2 0 - 0 .1 0 0 .0 0 0 .1 0 0 .2 0 0 .3 0

p[2]

p[1]

[-1.19 .. -1.17][-1.17 .. -1.14][-1.14 .. -1.12][-1.12 .. -1.10][-1.10 .. -1.08][-1.08 .. -1.07][-1.07 .. -1.05][-1.05 .. -1.03][-1.03 .. -1.01][-1.01 .. -0.98][-0.98 .. -0.97][-0.97 .. -0.95][-0.95 .. -0.93][-0.93 .. -0.92][-0.92 .. -0.89][-0.89 .. -0.87][-0.87 .. -0.84][-0.84 .. -0.81][-0.81 .. -0.80][-0.80 .. -0.77][-0.77 .. -0.75][-0.75 .. -0.72][-0.72 .. -0.69][-0.69 .. -0.68][-0.68 .. -0.67][-0.67 .. -0.66][-0.66 .. -0.65][-0.65 .. -0.62][-0.62 .. -0.61][-0.61 .. -0.58][-0.58 .. -0.56][-0.56 .. -0.54][-0.54 .. -0.52][-0.52 .. -0.51][-0.51 .. -0.49][-0.49 .. -0.48][-0.48 .. -0.45][-0.45 .. -0.43][-0.43 .. -0.41][-0.41 .. -0.39][-0.39 .. -0.37][-0.37 .. -0.36][-0.36 .. -0.34][-0.34 .. -0.33][-0.33 .. -0.30][-0.30 .. -0.27][-0.27 .. -0.26][-0.26 .. -0.23][-0.23 .. -0.22][-0.22 .. -0.21][-0.21 .. -0.20][-0.20 .. -0.19][-0.19 .. -0.17][-0.17 .. -0.16][-0.16 .. -0.14][-0.14 .. -0.13][-0.13 .. -0.11][-0.11 .. -0.08][-0.08 .. -0.07][-0.07 .. -0.06][0.02 .. 0.05][0.05 .. 0.06][0.06 .. 0.07][0.07 .. 0.08][0.08 .. 0.10][0.10 .. 0.11][0.11 .. 0.13][0.13 .. 0.14][0.14 .. 0.16][0.16 .. 0.18][0.18 .. 0.19][0.19 .. 0.21][0.21 .. 0.24][0.24 .. 0.25][0.25 .. 0.26][0.26 .. 0.27][0.27 .. 0.30][0.30 .. 0.33][0.33 .. 0.36][0.36 .. 0.37][0.37 .. 0.38][0.38 .. 0.39][0.39 .. 0.40][0.40 .. 0.41][0.41 .. 0.42][0.42 .. 0.43][0.43 .. 0.44][0.44 .. 0.47][0.47 .. 0.49][0.49 .. 0.50][0.50 .. 0.51][0.51 .. 0.52][0.52 .. 0.53][0.53 .. 0.56][0.56 .. 0.57][0.57 .. 0.58][0.58 .. 0.59][0.59 .. 0.62][0.62 .. 0.63][0.63 .. 0.64][0.64 .. 0.66][0.66 .. 0.67][0.67 .. 0.68][0.68 .. 0.69][0.69 .. 0.70][0.70 .. 0.71][0.71 .. 0.72][0.72 .. 0.73][0.73 .. 0.74][0.74 .. 0.75]

[0.75 .. 0.78][0.78 .. 0.79][0.79 .. 0.80][0.80 .. 0.81][0.81 .. 0.82][0.82 .. 0.83][0.83 .. 0.84][0.84 .. 0.85][0.85 .. 0.86][0.86 .. 0.87]

[0.87 .. 0.89]

[0.89 .. 0.92][0.92 .. 0.94]

[0.94 .. 0.97]

[0.97 .. 1.00][1.00 .. 1.03][1.03 .. 1.04][1.04 .. 1.05][1.05 .. 1.08]

[1.08 .. 1.09][1.09 .. 1.10]

[1.10 .. 1.13][1.13 .. 1.15][1.15 .. 1.16][1.16 .. 1.18][1.18 .. 1.19][1.19 .. 1.20][1.20 .. 1.21][1.21 .. 1.23][1.23 .. 1.26]

[1.26 .. 1.29][1.29 .. 1.30]

[1.30 .. 1.32][1.32 .. 1.33]

[1.33 .. 1.36]

[1.36 .. 1.38][1.38 .. 1.40][1.40 .. 1.41]

[1.41 .. 1.43][1.43 .. 1.45][1.45 .. 1.46][1.46 .. 1.47]

[1.47 .. 1.49][1.49 .. 1.51][1.51 .. 1.52][1.52 .. 1.53][1.53 .. 1.54]

[1.54 .. 1.57][1.57 .. 1.60][1.60 .. 1.62]

[1.62 .. 1.63][1.63 .. 1.64][1.64 .. 1.67][1.67 .. 1.70]

[1.70 .. 1.71]

[1.71 .. 1.73]

[1.73 .. 1.74]

[1.74 .. 1.75]

[1.75 .. 1.76]

[1.76 .. 1.79]

[1.79 .. 1.81]

[1.81 .. 1.84][1.84 .. 1.86]

[1.86 .. 1.87][1.87 .. 1.88]

[1.88 .. 1.89][1.89 .. 1.90]

[1.90 .. 1.93][1.93 .. 1.96]

[1.96 .. 1.97][1.97 .. 1.98]

[1.98 .. 2.00][2.00 .. 2.01][2.01 .. 2.02]

[2.02 .. 2.05]

[2.05 .. 2.08][2.08 .. 2.11][2.11 .. 2.13]

[2.13 .. 2.16][2.16 .. 2.18][2.18 .. 2.19][2.19 .. 2.20]

[2.20 .. 2.21][2.21 .. 2.23]

[2.23 .. 2.26][2.26 .. 2.29]

[2.29 .. 2.30][2.30 .. 2.31]

[2.31 .. 2.33]

[2.33 .. 2.35]

[2.35 .. 2.37][2.37 .. 2.40]

[2.40 .. 2.41]

[2.41 .. 2.42]

[2.42 .. 2.43]

[2.43 .. 2.45]

[2.45 .. 2.47]

[2.47 .. 2.50]

[2.50 .. 2.52][2.52 .. 2.53]

[2.53 .. 2.54][2.54 .. 2.57][2.57 .. 2.60]

[2.60 .. 2.63]

[2.63 .. 2.64][2.64 .. 2.66][2.66 .. 2.67][2.67 .. 2.68][2.68 .. 2.69]

[2.69 .. 2.72]

[2.72 .. 2.75]

[2.75 .. 2.78]

[2.78 .. 2.81]

[2.81 .. 2.82]

[2.82 .. 2.85]

[2.85 .. 2.88]

[2.88 .. 2.89]

[2.89 .. 2.90]

[2.90 .. 2.92]

[2.92 .. 2.95]

[2.95 .. 2.96][2.96 .. 2.98][2.98 .. 2.99][2.99 .. 3.00]

[3.00 .. 3.02]

[3.02 .. 3.05]

[3.05 .. 3.08]

[3.08 .. 3.10][3.10 .. 3.12][3.12 .. 3.14]

[3.14 .. 3.15]

[3.15 .. 3.18]

[3.18 .. 3.19]

[3.19 .. 3.22]

[3.22 .. 3.23]

[3.23 .. 3.25][3.25 .. 3.27]

[3.27 .. 3.30]

[3.30 .. 3.33]

[3.33 .. 3.36]

[3.36 .. 3.37]

[3.37 .. 3.38][3.38 .. 3.39]

[3.39 .. 3.40][3.40 .. 3.42]

[3.42 .. 3.45]

[3.45 .. 3.48]

[3.48 .. 3.50][3.50 .. 3.52][3.52 .. 3.55]

[3.55 .. 3.57]

[3.57 .. 3.59]

[3.59 .. 3.61]

[3.61 .. 3.62][3.62 .. 3.63]

[3.63 .. 3.64]

[3.64 .. 3.67][3.67 .. 3.69]

[3.69 .. 3.70]

[3.70 .. 3.71][3.71 .. 3.74]

[3.74 .. 3.75]

[3.75 .. 3.78][3.78 .. 3.81]

[3.81 .. 3.82][3.82 .. 3.83][3.83 .. 3.86]

[3.86 .. 3.88]

[3.88 .. 3.91]

[3.91 .. 3.94]

[3.94 .. 3.96]

[3.96 .. 3.99]

[3.99 .. 4.01]

[4.01 .. 4.04]

[4.04 .. 4.05][4.05 .. 4.07][4.07 .. 4.08]

[4.08 .. 4.11]

[4.11 .. 4.13][4.13 .. 4.16]

[4.16 .. 4.18][4.18 .. 4.21][4.21 .. 4.23]

[4.23 .. 4.26][4.26 .. 4.27][4.27 .. 4.28]

[4.28 .. 4.31][4.31 .. 4.34]

[4.34 .. 4.37][4.37 .. 4.39]

[4.39 .. 4.40][4.40 .. 4.41][4.41 .. 4.43]

[4.43 .. 4.46][4.46 .. 4.47]

[4.47 .. 4.50]

[4.50 .. 4.51][4.51 .. 4.52][4.52 .. 4.55][4.55 .. 4.56]

[4.90 .. 4.91][4.91 .. 4.94]

[4.94 .. 4.95][4.95 .. 4.96][4.96 .. 4.99]

[4.99 .. 5.02][5.02 .. 5.04]

[5.04 .. 5.05][5.05 .. 5.06][5.06 .. 5.08][5.08 .. 5.09][5.09 .. 5.10]

[5.10 .. 5.11]

[5.11 .. 5.14]

[5.14 .. 5.17]

[5.17 .. 5.18][5.18 .. 5.19][5.19 .. 5.21][5.21 .. 5.22][5.22 .. 5.23][5.23 .. 5.24][5.24 .. 5.27] [5.27 .. 5.30]

[5.30 .. 5.31][5.31 .. 5.32][5.32 .. 5.33][5.33 .. 5.34][5.34 .. 5.35][5.35 .. 5.36][5.36 .. 5.37]

[5.37 .. 5.39]

[5.39 .. 5.42]

[5.42 .. 5.45]

[5.45 .. 5.48][6.10 .. 6.12][6.12 .. 6.13][6.13 .. 6.16][6.16 .. 6.18][6.18 .. 6.21][6.21 .. 6.24][6.24 .. 6.25][6.25 .. 6.26]

[6.26 .. 6.29][6.29 .. 6.32]

[6.32 .. 6.33][6.33 .. 6.34][6.34 .. 6.35][6.35 .. 6.38][6.38 .. 6.41][6.41 .. 6.42][6.42 .. 6.43][6.43 .. 6.45][6.45 .. 6.46][6.46 .. 6.47][6.47 .. 6.48][6.48 .. 6.51][6.51 .. 6.52]

[6.52 .. 6.55]

[6.55 .. 6.56][6.56 .. 6.59]

[6.59 .. 6.60][6.60 .. 6.61][6.61 .. 6.62][6.62 .. 6.63]

[6.63 .. 6.65][6.65 .. 6.67][6.67 .. 6.69][6.69 .. 6.72][6.72 .. 6.73][6.73 .. 6.74]

[6.74 .. 6.77]

[6.77 .. 6.78]

[6.78 .. 6.81]

[6.81 .. 6.82][6.82 .. 6.83][6.83 .. 6.85]

[6.85 .. 6.86][6.86 .. 6.89]

[6.89 .. 6.92][6.92 .. 6.95][6.95 .. 6.97][6.97 .. 6.98][6.98 .. 7.01]

[7.01 .. 7.02][7.02 .. 7.03][7.03 .. 7.04]

[7.04 .. 7.07]

[7.07 .. 7.10][7.10 .. 7.11][7.11 .. 7.13][7.13 .. 7.14][7.14 .. 7.15]

[7.15 .. 7.17][7.17 .. 7.18]

[7.18 .. 7.21]

[7.21 .. 7.23][7.23 .. 7.26]

[7.26 .. 7.29]

[7.29 .. 7.31]

[7.31 .. 7.32][7.32 .. 7.33][7.33 .. 7.34][7.34 .. 7.36]

[7.36 .. 7.39][7.39 .. 7.40]

[7.40 .. 7.43][7.43 .. 7.45]

[7.45 .. 7.47][7.47 .. 7.48][7.48 .. 7.50][7.50 .. 7.52]

[7.52 .. 7.53][7.53 .. 7.56][7.56 .. 7.59][7.59 .. 7.60][7.60 .. 7.61][7.61 .. 7.62]

[7.62 .. 7.64][7.64 .. 7.65][7.65 .. 7.68]

[7.68 .. 7.71]

[7.71 .. 7.74][7.74 .. 7.76][7.76 .. 7.78][7.78 .. 7.79][7.79 .. 7.80][7.80 .. 7.81]

[7.81 .. 7.82]

[7.82 .. 7.85]

[7.85 .. 7.87][7.87 .. 7.88][7.88 .. 7.90]

[7.90 .. 7.91][7.91 .. 7.92][7.92 .. 7.93][7.93 .. 7.94][7.94 .. 7.95][7.95 .. 7.96]

[7.96 .. 7.99]

[7.99 .. 8.02]

[8.02 .. 8.04][8.04 .. 8.07][8.07 .. 8.10]

[8.10 .. 8.13][8.13 .. 8.14][8.14 .. 8.15][8.15 .. 8.16][8.16 .. 8.17][8.17 .. 8.20]

[8.20 .. 8.23]

[8.23 .. 8.24][8.24 .. 8.26][8.26 .. 8.29][8.29 .. 8.31][8.31 .. 8.34][8.34 .. 8.35][8.35 .. 8.38][8.38 .. 8.40][8.40 .. 8.41][8.41 .. 8.42][8.42 .. 8.43][8.43 .. 8.44][8.44 .. 8.45]

[8.45 .. 8.48]

[8.48 .. 8.51][8.51 .. 8.53][8.53 .. 8.56][8.56 .. 8.59][8.59 .. 8.62][8.62 .. 8.64][8.64 .. 8.67][8.67 .. 8.69][8.69 .. 8.70][8.70 .. 8.71][8.71 .. 8.73][8.73 .. 8.76][8.76 .. 8.78][8.78 .. 8.79][8.79 .. 8.80][8.80 .. 8.81]

[8.81 .. 8.82][8.82 .. 8.85][8.85 .. 8.87]

[8.87 .. 8.88][8.88 .. 8.91]

[8.91 .. 8.92]

[8.92 .. 8.93][8.93 .. 8.94]

[8.94 .. 8.97][8.97 .. 9.00][9.00 .. 9.02][9.02 .. 9.05][9.05 .. 9.06][9.06 .. 9.07][9.07 .. 9.08][9.08 .. 9.09][9.09 .. 9.10][9.10 .. 9.13][9.13 .. 9.16][9.16 .. 9.17][9.17 .. 9.19][9.19 .. 9.21][9.21 .. 9.22][9.22 .. 9.23][9.23 .. 9.24][9.24 .. 9.25][9.25 .. 9.28]

[9.28 .. 9.31]

[9.31 .. 9.34][9.34 .. 9.35][9.35 .. 9.37][9.37 .. 9.39][9.39 .. 9.40][9.40 .. 9.41][9.41 .. 9.42][9.42 .. 9.43][9.43 .. 9.46][9.46 .. 9.48][9.48 .. 9.51][9.51 .. 9.54][9.54 .. 9.57][9.57 .. 9.59][9.59 .. 9.60][9.60 .. 9.62][9.62 .. 9.64][9.64 .. 9.66][9.66 .. 9.67][9.67 .. 9.70][9.70 .. 9.72][9.72 .. 9.74][9.74 .. 9.77][9.77 .. 9.78][9.78 .. 9.79][9.79 .. 9.80][9.80 .. 9.82][9.82 .. 9.84][9.84 .. 9.87][9.87 .. 9.88][9.88 .. 9.89][9.89 .. 9.91][9.91 .. 9.93][9.93 .. 9.94]

SIMCA-P+ 10.5 - 02/09/2004 11:09:04

2-oxoglutarate

Citrate

Succinate

Citrate and 2-oxoglutarate

- 0 .2 0

- 0 .1 0

0 .0 0

0 .1 0

0 .2 0

-0 .2 0 -0 .1 0 0 .0 0 0 .1 0 0 .2 0

p[2]

p[1]

[-1.19 .. -1.17][-1.17 .. -1.15][-1.15 .. -1.13][-1.13 .. -1.11][-1.11 .. -1.09][-1.09 .. -1.07][-1.07 .. -1.05][-1.05 .. -1.03][-1.03 .. -1.01][-1.01 .. -0.99][-0.99 .. -0.97][-0.97 .. -0.95][-0.95 .. -0.93][-0.93 .. -0.91][-0.91 .. -0.89][-0.89 .. -0.87][-0.87 .. -0.85][-0.85 .. -0.83][-0.83 .. -0.81][-0.81 .. -0.79][-0.79 .. -0.77][-0.77 .. -0.75][-0.75 .. -0.73][-0.73 .. -0.71][-0.71 .. -0.69][-0.69 .. -0.67][-0.67 .. -0.65][-0.65 .. -0.63][-0.63 .. -0.61][-0.61 .. -0.59][-0.59 .. -0.57][-0.57 .. -0.55][-0.55 .. -0.53][-0.53 .. -0.51][-0.51 .. -0.49][-0.49 .. -0.47][-0.47 .. -0.45][-0.45 .. -0.43][-0.43 .. -0.41][-0.41 .. -0.39][-0.39 .. -0.37][-0.37 .. -0.35][-0.35 .. -0.33][-0.33 .. -0.31][-0.31 .. -0.29][-0.29 .. -0.27][-0.27 .. -0.25][-0.25 .. -0.23][-0.23 .. -0.21][-0.21 .. -0.19][-0.19 .. -0.17][-0.17 .. -0.15][-0.15 .. -0.13][-0.13 .. -0.11][-0.11 .. -0.09][-0.09 .. -0.07][-0.07 .. -0.05][-0.05 .. -0.03][0.02 .. 0.04][0.04 .. 0.06][0.06 .. 0.08][0.08 .. 0.10][0.10 .. 0.12][0.12 .. 0.14][0.14 .. 0.16][0.16 .. 0.18][0.18 .. 0.20][0.20 .. 0.22][0.22 .. 0.24][0.24 .. 0.26][0.26 .. 0.28][0.28 .. 0.30][0.30 .. 0.32][0.32 .. 0.34][0.34 .. 0.36][0.36 .. 0.38][0.38 .. 0.40][0.40 .. 0.42][0.42 .. 0.44][0.44 .. 0.46][0.46 .. 0.48][0.48 .. 0.50][0.50 .. 0.52][0.52 .. 0.54][0.54 .. 0.56][0.56 .. 0.58][0.58 .. 0.60][0.60 .. 0.62][0.62 .. 0.64][0.64 .. 0.66][0.66 .. 0.68][0.68 .. 0.70][0.70 .. 0.72][0.72 .. 0.74][0.74 .. 0.76][0.76 .. 0.78][0.78 .. 0.80][0.80 .. 0.82][0.82 .. 0.84][0.84 .. 0.86]

[0.86 .. 0.88]

[0.88 .. 0.90][0.90 .. 0.92]

[0.92 .. 0.94][0.94 .. 0.96]

[0.96 .. 0.98][0.98 .. 1.00]

[1.00 .. 1.02][1.02 .. 1.04][1.04 .. 1.06]

[1.06 .. 1.08]

[1.08 .. 1.10][1.10 .. 1.12][1.12 .. 1.14][1.14 .. 1.16]

[1.16 .. 1.18][1.18 .. 1.20][1.20 .. 1.22][1.22 .. 1.24][1.24 .. 1.26]

[1.26 .. 1.28][1.28 .. 1.30]

[1.30 .. 1.32][1.32 .. 1.34][1.34 .. 1.36]

[1.36 .. 1.38][1.38 .. 1.40][1.40 .. 1.42][1.42 .. 1.44][1.44 .. 1.46][1.46 .. 1.48][1.48 .. 1.50][1.50 .. 1.52]

[1.52 .. 1.54][1.54 .. 1.56]

[1.56 .. 1.58][1.58 .. 1.60][1.60 .. 1.62][1.62 .. 1.64]

[1.64 .. 1.66][1.66 .. 1.68][1.68 .. 1.70]

[1.70 .. 1.72]

[1.72 .. 1.74]

[1.74 .. 1.76][1.76 .. 1.78]

[1.78 .. 1.80]

[1.80 .. 1.82]

[1.82 .. 1.84][1.84 .. 1.86][1.86 .. 1.88]

[1.88 .. 1.90]

[1.90 .. 1.92]

[1.92 .. 1.94]

[1.94 .. 1.96]

[1.96 .. 1.98]

[1.98 .. 2.00][2.00 .. 2.02]

[2.02 .. 2.04]

[2.04 .. 2.06]

[2.06 .. 2.08]

[2.08 .. 2.10][2.10 .. 2.12][2.12 .. 2.14][2.14 .. 2.16]

[2.16 .. 2.18][2.18 .. 2.20]

[2.20 .. 2.22][2.22 .. 2.24]

[2.24 .. 2.26]

[2.26 .. 2.28][2.28 .. 2.30][2.30 .. 2.32]

[2.32 .. 2.34]

[2.34 .. 2.36]

[2.36 .. 2.38]

[2.38 .. 2.40]

[2.40 .. 2.42]

[2.42 .. 2.44]

[2.44 .. 2.46]

[2.46 .. 2.48]

[2.48 .. 2.50]

[2.50 .. 2.52]

[2.52 .. 2.54]

[2.54 .. 2.56]

[2.56 .. 2.58]

[2.58 .. 2.60]

[2.60 .. 2.62]

[2.62 .. 2.64]

[2.64 .. 2.66]

[2.66 .. 2.68]

[2.68 .. 2.70]

[2.70 .. 2.72]

[2.72 .. 2.74]

[2.74 .. 2.76]

[2.76 .. 2.78][2.78 .. 2.80]

[2.80 .. 2.82]

[2.82 .. 2.84][2.84 .. 2.86]

[2.86 .. 2.88]

[2.88 .. 2.90]

[2.90 .. 2.92][2.92 .. 2.94]

[2.94 .. 2.96][2.96 .. 2.98]

[2.98 .. 3.00]

[3.00 .. 3.02]

[3.02 .. 3.04]

[3.04 .. 3.06]

[3.06 .. 3.08]

[3.08 .. 3.10][3.10 .. 3.12][3.12 .. 3.14]

[3.14 .. 3.16][3.16 .. 3.18]

[3.18 .. 3.20][3.20 .. 3.22]

[3.22 .. 3.24]

[3.24 .. 3.26]

[3.26 .. 3.28]

[3.28 .. 3.30]

[3.30 .. 3.32]

[3.32 .. 3.34]

[3.34 .. 3.36]

[3.36 .. 3.38]

[3.38 .. 3.40]

[3.40 .. 3.42]

[3.42 .. 3.44][3.44 .. 3.46]

[3.46 .. 3.48][3.48 .. 3.50]

[3.50 .. 3.52] [3.52 .. 3.54][3.54 .. 3.56]

[3.56 .. 3.58]

[3.58 .. 3.60]

[3.60 .. 3.62]

[3.62 .. 3.64]

[3.64 .. 3.66][3.66 .. 3.68][3.68 .. 3.70]

[3.70 .. 3.72]

[3.72 .. 3.74][3.74 .. 3.76]

[3.76 .. 3.78][3.78 .. 3.80]

[3.80 .. 3.82]

[3.82 .. 3.84][3.84 .. 3.86][3.86 .. 3.88]

[3.88 .. 3.90][3.90 .. 3.92]

[3.92 .. 3.94]

[3.94 .. 3.96]

[3.96 .. 3.98]

[3.98 .. 4.00]

[4.00 .. 4.02]

[4.02 .. 4.04][4.04 .. 4.06]

[4.06 .. 4.08]

[4.08 .. 4.10]

[4.10 .. 4.12]

[4.12 .. 4.14][4.14 .. 4.16]

[4.16 .. 4.18][4.18 .. 4.20][4.20 .. 4.22][4.22 .. 4.24]

[4.24 .. 4.26][4.26 .. 4.28]

[4.28 .. 4.30][4.30 .. 4.32]

[4.32 .. 4.34][4.34 .. 4.36][4.36 .. 4.38][4.38 .. 4.40]

[4.40 .. 4.42]

[4.42 .. 4.44]

[4.44 .. 4.46]

[4.46 .. 4.48]

[4.48 .. 4.50]

[4.50 .. 4.52][4.52 .. 4.54][4.54 .. 4.56][4.56 .. 4.58]

[4.90 .. 4.92][4.92 .. 4.94][4.94 .. 4.96][4.96 .. 4.98][4.98 .. 5.00]

[5.00 .. 5.02]

[5.02 .. 5.04][5.04 .. 5.06][5.06 .. 5.08][5.08 .. 5.10]

[5.10 .. 5.12]

[5.12 .. 5.14]

[5.14 .. 5.16][5.16 .. 5.18][5.18 .. 5.20][5.20 .. 5.22][5.22 .. 5.24][5.24 .. 5.26] [5.26 .. 5.28]

[5.28 .. 5.30][5.30 .. 5.32][5.32 .. 5.34][5.34 .. 5.36]

[5.36 .. 5.38][5.38 .. 5.40]

[5.40 .. 5.42]

[5.42 .. 5.44]

[5.44 .. 5.46][5.46 .. 5.48][6.10 .. 6.12][6.12 .. 6.14][6.14 .. 6.16][6.16 .. 6.18][6.18 .. 6.20][6.20 .. 6.22][6.22 .. 6.24]

[6.24 .. 6.26]

[6.26 .. 6.28][6.28 .. 6.30]

[6.30 .. 6.32][6.32 .. 6.34][6.34 .. 6.36][6.36 .. 6.38][6.38 .. 6.40][6.40 .. 6.42][6.42 .. 6.44][6.44 .. 6.46][6.46 .. 6.48][6.48 .. 6.50][6.50 .. 6.52]

[6.52 .. 6.54]

[6.54 .. 6.56][6.56 .. 6.58][6.58 .. 6.60][6.60 .. 6.62]

[6.62 .. 6.64]

[6.64 .. 6.66][6.66 .. 6.68][6.68 .. 6.70][6.70 .. 6.72][6.72 .. 6.74]

[6.74 .. 6.76][6.76 .. 6.78][6.78 .. 6.80]

[6.80 .. 6.82]

[6.82 .. 6.84]

[6.84 .. 6.86]

[6.86 .. 6.88]

[6.88 .. 6.90][6.90 .. 6.92]

[6.92 .. 6.94][6.94 .. 6.96]

[6.96 .. 6.98][6.98 .. 7.00][7.00 .. 7.02][7.02 .. 7.04]

[7.04 .. 7.06]

[7.06 .. 7.08][7.08 .. 7.10][7.10 .. 7.12][7.12 .. 7.14]

[7.14 .. 7.16][7.16 .. 7.18]

[7.18 .. 7.20][7.20 .. 7.22]

[7.22 .. 7.24][7.24 .. 7.26][7.26 .. 7.28][7.28 .. 7.30]

[7.30 .. 7.32][7.32 .. 7.34]

[7.34 .. 7.36]

[7.36 .. 7.38] [7.38 .. 7.40]

[7.40 .. 7.42][7.42 .. 7.44]

[7.44 .. 7.46]

[7.46 .. 7.48][7.48 .. 7.50][7.50 .. 7.52][7.52 .. 7.54]

[7.54 .. 7.56]

[7.56 .. 7.58]

[7.58 .. 7.60][7.60 .. 7.62]

[7.62 .. 7.64][7.64 .. 7.66]

[7.66 .. 7.68]

[7.68 .. 7.70][7.70 .. 7.72]

[7.72 .. 7.74][7.74 .. 7.76][7.76 .. 7.78][7.78 .. 7.80][7.80 .. 7.82]

[7.82 .. 7.84][7.84 .. 7.86]

[7.86 .. 7.88][7.88 .. 7.90][7.90 .. 7.92]

[7.92 .. 7.94][7.94 .. 7.96][7.96 .. 7.98][7.98 .. 8.00][8.00 .. 8.02]

[8.02 .. 8.04][8.04 .. 8.06]

[8.06 .. 8.08]

[8.08 .. 8.10]

[8.10 .. 8.12][8.12 .. 8.14][8.14 .. 8.16][8.16 .. 8.18]

[8.18 .. 8.20][8.20 .. 8.22]

[8.22 .. 8.24][8.24 .. 8.26][8.26 .. 8.28][8.28 .. 8.30][8.30 .. 8.32]

[8.32 .. 8.34][8.34 .. 8.36][8.36 .. 8.38][8.38 .. 8.40][8.40 .. 8.42]

[8.42 .. 8.44][8.44 .. 8.46]

[8.46 .. 8.48]

[8.48 .. 8.50][8.50 .. 8.52]

[8.52 .. 8.54][8.54 .. 8.56][8.56 .. 8.58][8.58 .. 8.60][8.60 .. 8.62][8.62 .. 8.64][8.64 .. 8.66][8.66 .. 8.68][8.68 .. 8.70][8.70 .. 8.72][8.72 .. 8.74][8.74 .. 8.76][8.76 .. 8.78][8.78 .. 8.80]

[8.80 .. 8.82][8.82 .. 8.84]

[8.84 .. 8.86]

[8.86 .. 8.88][8.88 .. 8.90]

[8.90 .. 8.92]

[8.92 .. 8.94][8.94 .. 8.96]

[8.96 .. 8.98]

[8.98 .. 9.00][9.00 .. 9.02][9.02 .. 9.04][9.04 .. 9.06][9.06 .. 9.08][9.08 .. 9.10]

[9.10 .. 9.12]

[9.12 .. 9.14]

[9.14 .. 9.16][9.16 .. 9.18][9.18 .. 9.20][9.20 .. 9.22][9.22 .. 9.24]

[9.24 .. 9.26]

[9.26 .. 9.28]

[9.28 .. 9.30]

[9.30 .. 9.32][9.32 .. 9.34][9.34 .. 9.36][9.36 .. 9.38][9.38 .. 9.40][9.40 .. 9.42][9.42 .. 9.44][9.44 .. 9.46][9.46 .. 9.48][9.48 .. 9.50][9.50 .. 9.52][9.52 .. 9.54][9.54 .. 9.56][9.56 .. 9.58][9.58 .. 9.60][9.60 .. 9.62][9.62 .. 9.64][9.64 .. 9.66][9.66 .. 9.68][9.68 .. 9.70][9.70 .. 9.72][9.72 .. 9.74][9.74 .. 9.76][9.76 .. 9.78][9.78 .. 9.80][9.80 .. 9.82][9.82 .. 9.84][9.84 .. 9.86][9.86 .. 9.88][9.88 .. 9.90][9.90 .. 9.92][9.92 .. 9.94][9.94 .. 9.96][9.96 .. 9.98]

SIMCA-P+ 10.5 - 02/09/2004 11:09:27

Citrate

2-oxoglutarateand succinate

A major benefit of Intelligent Bucketing can alsobe seen in Figure 5. Here the predictive quality(Q2) of the PCA components is shown for each ofthe bucketing methods. Most notably, the Q2

value is negative for Principal Components 2, 3,and 5, with Classical Bucketing indicting thatanything other than a 1 component model wouldhave no predictive value. In the PCA modelsproduced with the intelligent buckets, the Q2 arepositive, indicting some predictive quality. Thegenerally low values for Q2 are due to the lownumber of samples in the data set.

Figure 5 - In these plots, the quality of the PCAmodels is shown. This Q2 value for the data fromthe intelligent buckets, is much improved overthat from the classical buckets.

CONCLUSION

Intelligent Bucketing has been shown to allow forimprovements to the accuracy of the modeling ofNMR data by removing an inherent failing ofClassical Bucketing. This failing arises from theinherent sensitivity of NMR to the molecularenvironment; most notably, the sensitivity to pHsubtleties, changes in temperature, and thepresence of ion interactions.

REFERENCES

1. Intelligent Bucketing for Metabonomics—Part 1,http://www.acdlabs.com/download/publ/2004/enc04/intelbucket.pdf

2. Nicholls A.W., Mortishire-Smith, R.J. andNicholson, J.K. (2003) NMR spectroscopic andmetabonomic studies of urinary variation inacclimatising germ free rats. Chemical Researchin Toxicology, 16(11):1395-1404.

90 Adelaide St. W., Suite 600 Toronto, Canada M5H 3V9Tel: (416) 368-3435 Fax: (416) 368-5596Toll Free: 1-800-304-3988Email: [email protected]

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