Serum Metabolomics Analysis of Asthma in Different Inflammatory Phenotypes: A Cross-Sectional Study in Northeast China

Table 2

Identification results of all metabolite compounds in the serum of all subjects.

NO	tR/min	Mass/Da		VIP	Formula	Compound	KEGG ID	MS^E	Error/ppm	Pathway
S1	0.61	280.0917	+	2.51	C8H20NO6P	Glycerophosphocholine	C00670	80.9704, 104.1085, 166.0630, 256.1188	1	Ether lipid & Glycerophospholipid
S2^∗	0.70	203.0524	+	2.82	C6H12O6	Monosaccharides	C00137	85.0292, 103.0079, 135.0020, 145.0090, 150.9735, 180.9964, 203.0503	1	Galactose, Inositol phosphate metabolism, Starch and sucrose & Glycolysis or Gluconeogenesis
S3	5.91	860.5206	+	2.08	C46H80NO10P	PS(18:0/22:5)	C02737	88.0626, 267.2686, 325.6945, 751.4440, 821.5210	1	Glycerophospholipid
S4	5.99	585.37	+	1.74	C33H54O7	Cholesterol glucuronide	C03033	85.0627, 177.1049, 261.1591, 545.3312	10	Starch and sucrose
S5	6.89	842.6057	+	1.99	C44H86NO10P	PS(18:0/20:0)	C02737	86.0997, 249.1219, 313.1090, 462.2505, 803.7540	3	Glycerophospholipid
S6	11.06	828.5487	+	1.19	C42H79NO13	Lactosylceramide (d18:1/12:0)	C01290	85.0646, 209.1875, 626.0863, 788.5036	3	Sphingolipid
S7	12.90	318.301	+	7.38	C18H39NO3	Phytosphingosine	C12144	71.0698, 141.1184, 300.2883, 318.3008	2	Sphingolipid
S8	15.19	302.3055	+	1.97	C18H39NO2	Sphinganine	C00836	69.0691, 137.0778, 187.1063, 284.2958, 302.3056	0	Sphingolipid
S9	16.65	544.3407	+	3.05	C26H52NO7P	LysoPC(18:1)	C04230	86.0990, 104.1086, 184.0737, 240.0987, 339.2748, 522.3394	2	Glycerophospholipid
S10	18.13	303.2326	+	1.7	C20H30O2	Retinyl ester	C02075	105.0726, 124.9997, 177.1134, 191.1274	2	Retinol
S11	18.81	572.3703	+	1.2	C28H56NO7P	PC(18:1/2:0)	C04598	86.1000, 153.1025, 184.0749, 235.1490, 479.3224	1	Ether lipid
S12	19.18	506.3594	+	1.07	C26H52NO6P	LysoPC(p-18:1)	C04230	86.0996, 125.0010, 166.0626, 184.0737, 240.1007, 249.1681, 309.3069, 506.3631	2	Glycerophospholipid
S13	20.06	508.3861	-	3.2	C26H56NO6P	LysoPC(o-18:0)	C04317	152.9793, 168.2547, 240.0734, 283.4419, 421.3464, 508.3806	3	Ether lipid
S14	22.81	305.2452	+	1.19	C20H32O2	Arachidonic acid	C00219	67.0587, 81.0723, 103.0763, 133.0868, 149.0226, 177.1091, 185.0739, 191.1209, 235.1497	0	Arachidonic acid
S15^∗	25.80	287.2364	+	1.54	C20H30O	Retinols	C00473	79.0569, 105.0711, 121.1011, 133.0850, 149.0295, 185.0760	2	Retinol
S16	26.79	686.4818	+	2.62	C37H68NO8P	PE(18:3/14:0)	C00350	183.2750, 261.1780, 476.3340, 686.4854	9	Glycerophospholipid
S17	27.99	782.5671	+	3.39	C42H82NO8P	PC(16:0/18:1)	C00157	86.0991, 184.0737, 283.0508, 313.2929, 701.5731	0	Arachidonic acid, Glycerophospholipid & Linoleic acid
S18	28.41	780.5483	+	3.08	C44H78NO8P	PC(20:4/16:1)	C00157	86.0996, 184.0748, 285.2657, 345.0710, 597.4855, 762.5735	4	Arachidonic acid, Glycerophospholipid & Linoleic acid

(+): positive mode of electrospray ionization; ESI^- (-): negative mode of electrospray ionization. ^∗Identified with reference standards. mass spectrum ion mass fragments in MS/MS. The characteristic fragments are highlighted as bold font. The unit of m/z is Th (Thomson).