Principal component analysis for the comparison of metabolic profiles from human rectal cancer biopsies and colorectal xenografts using high-resolution magic angle spinning 1 H magnetic resonance spectroscopy

Table 1 Chemical shift assignment.

Assigned number	Metabolite		Multiplicity	ppm
1	Fatty acids	CH₃	t	0.89
		(CH₂)_n	m	1.31
		CH₂CH₃	m	1.35
		CH₂CH₂CO	m	1.59
		CH=CHCH₂CH₂	m	2.03
		-CH₂-CH₂-CO-	m	2.26
2	Isoleucine	δCH3	t	0.95
		γCH₃	d	1.02
		γCH	m	1.46
		βCH	m	1.99
3	Leucine	δ'CH3	d	0.95
		δCH3	d	0.97
		βCH	m	1.71
		αCH	t	3.75
4	Valine	γCH₃	d	0.99
		γ'CH₃	d	1.04
		βCH	m	2.29
		αCH	d	3.62
5	Betahydroxybutyrate	CH₃	d	1.18
6	Lactate	CH₃	d	1.33
		CH	q	4.13
7	Alanine	βCH₃	d	1.48
		αCH	q	3.79
8	Lysine	γCH₂	m	1.48
		δCH₂	m	1.73
		βCH₂	m	1.92
		εCH₂	t	3.02
		αCH₂	t	3.79
9	Acetate	CH₃	s	1.94
10	Glutamate	βCH2	c	2.11
		γCH₂	t	2.34
		αCH	t	3.77
11	Glutamine	βCH2	c	2.14
		γCH2	c	2.45
		αCH	t	3.79
12	Succinate	(α,βCH₂)	s	2.41
13	Aspartate	βCH	dd	2.71
		β'CH	dd	2.83
		αCH	dd	3.91
14	Tyrosine	βCH	dd	2.87
		β'CH	dd	2.96
		αCH	dd	4.02
15	Creatine	CH₃	s	3.04
		CH₂	s	3.94
16	Choline	N(CH₃)₃	s	3.22
17	Phosphoethanolamine	NCH₂	dd	3.23
		OCH₂	dd	3.99
18	Phosphocholine	N(CH₃)₃	s	3.23
		NCH₂	dd	3.62
		OCH₂	dd	4.18
19	Glycerophosphocholine	N(CH₃)₃	s	3.24
20	Taurine	N-CH₂	t	3.24
		S-CH₂	t	3.42
21	β-Glucose	C2H	t	3.26
		C5H	dd	3.42
		C6H	d	3.85
		C1H	d	4.64
22	scyllo-Inositol	(All Hs)	s	3.35
23	myo-Inositol	C5H	t	3.27
		C1H, C3H	dd	3.52
		C4H, C6H	t	3.62
		C2H	t	4.07
24	Glycine	αCH2	s	3.56
25	Amino acid residues	αCH	q	3.77
26	Triglycerides, glyceryl	1/2 CH₂OCOR	m	4.09
		1/2 CH₂OCOR	m	4.31
27	Ascorbic acid	C4H	d	4.53

Tentative ¹H chemical shift assignment of HR MAS MR spectra obtained from human rectal cancer tissue and xenografts. Chemical shift referencing is relative to TSP. Peak multiplicity is given as s: singlet, d:doublet, dd: double doublet, t: triplet, q: quartet, m: multiplet or c: complex. Assigned numbers correspond to the numbering in Fig. 1 and Fig 2.