Table 2. Potential biomarkers and their identification results.

m/z	Adduct	VIP (Trendb)	Column	P value	Identified results	Related pathway
89.0226/2.59	[M − H]	1.29 (↑)	HILIC	0.032	Lactic acid c	Glycolysis
181.0635/3.64	[M − H]	1.80 (↑)	HILIC	0.030	Hydroxyphenyllactic acid	Tyrosine metabolism
214.1450/1.66	[M − H]	1.35 (↑)	HILIC	0.022	N-nonanoylglycine	Fatty acids oxidation
141.0138/4.53	[M − H]	1.82 (↑)	HILIC	0.024	5-hydroxymethyluracil	Oxidative stress
116.9278/14.81	[M − H]	1.98 (↑)	RP	0.003	Succinic acid c	TCA cycle
131.0701/2.07	[M − H]	1.45 (↑)	RP	0.030	Ornithine c	Urea cycle
258.1698/2.43	[M − H]	1.17 (↑)	RP	0.015	Hexanoylcarnitine	Energy metabolism
321.2885/8.67	[M + H]	1.35 (↑)	RP	<0.0001	Propionylcholine	-
142.0973/2.34	[M − H2O − H]	1.49 (↓)	RP	0.039	Carnitine c	Beta oxidation of long chain fatty acids
142.0028/2.34	[M − H]	2.42 (↓)	RP	0.045	4-hydroxy-L-glutamic acid	Arginine and proline metabolism
415.2137/4.20 a	[2M + H]	4.42 (↓)	RP/HILIC	<0.0001	Acetylphenylalanine	Phenylalanine metabolism
302.3048/4.87 a	[M + H]	3.95 (↓)	RP/HILIC	0.001	Sphinganine	Sphingolipid metabolism
318.2967/3.72 a	[M + H]	4.02 (↓)	RP/HILIC	<0.0001	Phytosphingosine	Sphingolipid metabolism
180.0359/15.16	[M + H]	2.39 (↓)	RP	<0.0001	S-carboxymethyl-L-cysteine	-

^aRetention time of RPLC.

^bChange trend compared with controls. (↑): up-regulated. (↓): down-regulated.

^cvalidated with standard sample.