Figure 2 NMR spectrum (δ0.5–6.2 and δ6.2–9.5) of urine at 600 MHz, with a typical 1H spectrum as an external spectrum, showing the assignment of the significant metabolites responsible for distinguishing children with ASD from non-autistic children. The region of δ6.2–9.5 (in the dashed box) was magnified 5 times compared with the corresponding region of δ0.5–6.2 for the purpose of clarity. Ace – acetate; Ach – acetylcholine; Aco – trans-aconitate; Act – acetone; Ad – acetamide; AH – aminohippurate; Ala – alanine; Asc – ascorbate; Bu – butyrate; Cap – caprate; Cho – choline; Ci – citrate; Cn – creatinine; Cr – creatine; DHT – dihydrothymine; DMA – dimethylamine; DMG – N, N-dimethylglycine; EA – ethanolamine; For – formate; Fum – fumarate; GA – guanidoacetate; GABA – Gama-aminobutyrate; Glu – glutamate; Gly – glycine; HIB – 2-hydroxyisobutyrate; Hip – hippurate; HMM – 3-hydroxy-4-methoxymandelate; HP – 3-hydroxypyruvate; IB – isobutyrate; IL – indolelactate; Ino – inosine; KG – α-ketoglutarate; Lac – lactate; Leu – leucine; Lys – lysine; M – malonate; Mal – malate; Met – methionine; MG – methylguanidine; MM – methylmalonate; Mol – methanol; NAA – N-acetylalanine; NMN – N-methylnicotinamide; NP – neopterin; OA – oxaloacetate; PA –picolinate; PAG – phenylacetylglycine; Pan – pantothenate; Py – pyruvate; Set – serotonin; Suc – succinate; Sum – succinimide; Tau – taurine; TMA – trimethylamine; TMAO – trimethylamine N-oxide; Tri – trigonelline; U – unassigned; Val – valine.