Table 1: Characterization of compounds from acidified methanolic extracts of rice during grain development by LC-ESI-QTOF-MS/MS in positive mode.
| No. | tR(min) | [M + H] + m/z | MS/MSm/z | Formula | Error (ppm) | Tentative identification | Variety and Stage found | |
| 2 | 3.01 | 134.0445 | a | C4 H7 N O4 | 2.12 | D-Aspartic acid | W: S1-S5 | |
| 6 | 3.06 | 166.0522 | a | C5H11NO3S | 6.3 | DL-Methionine sulfoxide | W: S4 | |
| 9 | 3.29 | 319.1504 | a | C16H24O5 | 3.74 | Graphinone | W: S4 | |
| 16 | 4.82 | 234.1341 | 157.05,113.02,85.02 | C10H19NO5 | -2.14 | Hydroxypropionylcarnitine | W: S3 | |
| 46 | 10.95 | 274.0693 | a | C12H13NO5 | -2.58 | N-feruloyl glycine | W: S4 | |
| 54 | 12.45 | 313.1197 | 105.04,78.04 | C14H20N2O4S | 6.24 | Methionyl-Tyrosine | W: S2 | |
| 5 | 3.06 | 439.1451 | a | C17H26O13 | -1.1 | Phlomiol | R: S2 | |
| 8 | 3.27 | 116.0708 | 70.07 | C5H9NO2 | -1.68 | Proline | R: S1 | |
| 47 | 11.01 | 409.094[M + NH4]+ | a | C11H21NO10S2 | 1.25 | Glucoconringin | R: S2 | |
| 25 | 7.37 | 247.1304 | 84.04 | C10H18N2O5 | -6.28 | Lgamma-glutamyl-L-valine | B: S1 | |
| 26 | 7.62 | 306.1569 | 229.07,197.04, 169.05,73.03 | C13H23NO7 | -7.12 | (2R,3S)-5-Ethoxy-2-{[(2-methoxyethoxy)acetyl]amino}-3-methyl-5-oxopentanoic acid | B: S1 | |
| 27 | 7.66 | 190.1086 | 158.08,130.09,98.06 | C8H15NO4 | -6.39 | Australine | B: S2-S3 | |
| 28 | 7.84 | 227.1403[M + Na]+ | 130.09,70.06 | C14H20O | 1.48 | 13-tetradecen-2,4-diyn-1-ol | B: S1 | |
| 29 | 7.97 | 196.0981 | 179.07,136.07,91.05 | C10H13NO3 | -6.53 | Damascenine | B: S1-S5 | |
| 35 | 8.85 | 449.1173 | 287.06 | C21H21O11 | -21.07 | Cyanidin 3-O-glucoside* | B: S3-S5 | |
| 42 | 9.96 | 287.057 | a | C15H11O6 | -6.92 | Cyanidin* | B: S4-S5 | |
| 37 | 9.37 | 463.1269 | 301.07,258.05 | C22H23O11 | -7.34 | Peonidin glucoside* | B: S3-S5 | |
| 44 | 10.3 | 222.0769 | 162.05,144.04,89.044 | C11H11NO4 | -3.67 | 6-Hydroxyindolelactate | B: S5 | |
| 49 | 11.32 | 183.0637[M + Na]+ | a | C7H12O4 | 0.22 | 3,3-Dimethyl-glutaric acid | B: S1 | |
| 56 | 12.72 | 252.0885 | a | C12H13NO5 | -7.37 | 2-[(3- Carboxypropyl)carbamoyl]benzoic acid | B: S1 | |
| 57 | 13.12 | 271.1171[M + CH3OH + H] + | 239.08,129.03 | C12H14O5 | 1.9 | Trans-2,3,4-trimethoxycinnamate | B: S1,S2 | |
| 7 | 3.18 | 236.149 | 104.11 | C10H21N5 | 1.06 | 2,5-Anhydro-1-deoxy-1-{[(2R)-1-hydroxy-2-butanyl]amino}-D-glucitol | W: S1,S2,S4; B: S3,S4 | |
| 19 | 5.45 | 182.081 | 91.05 | C9H11NO3 | 0.94 | N-Hydroxy-L-phenylalanine | W: S1-S3;B: S1-S5 | |
| 24 | 7.35 | 216.1244 | 157.05,113.03,85.03 | C10H17N4 | -6.32 | Diethyl[(dimethylamino)methylene] malonate | W: S1;B: S1 | |
| 10 | 3.35 | 148.0604 | 102.05 | C5H9NO4 | 0.23 | Glutamate | W: S1-S5;R: S2 | |
| 14 | 3.54 | 176.0916 | 117.05,85.03 | C7H13NO4 | 0.74 | N-Carboxyethyl-g-aminobutyric acid | W: S3,S5;R: S1-S3 | |
| 18 | 5.33 | 305.0845[M + Na]+ | C10 H18 O9 | -0.64 | Xylobiose | W: S1-S4;R: S3 | ||
| 33 | 8.8 | 265.1601 | 177.05,145.03, 117.03,89.04 | C19H20O | -5.33 | (E)-3-(4-isopropylphenyl)-1-(p-tolyl)pro-2-en-1-one | W: S1-S5;R: S2 | |
| 51 | 11.43 | 495.2429[2M + H]+ | a | C9H17N35 | 4 | Gamma-glutamyl-Threonine | W: S1,S4;R: S1 | |
| 40 | 9.96 | 325.0913 | a | C15H16O8 | 1.52 | (3,4-Diacetoxyphenyl)methylene diacetate | R: S3,S5;B: S2 | |
| 43 | 10.07 | 419.1186 | 345.08,243.05,86.09 | C17H22O12 | -0.47 | 1-(3,4-Diacetoxy-5-oxotetrahydro-2-furanyl)-1,2,3-propanetriyl triacetate | R: S5;B: S2 | |
| 1 | 2.94 | 266.1605 | 104.11,60.08 | C11H23NO6 | -2.58 | 5-Aminopentyl-a-D-mannopyranoside | W: S1-S4;R: S1,S4;B: S1-S5 | |
| 3 | 3.1 | 365.1054[M + Na]+ | a | C12H22O11 | 0.09 | Sucrose | W: S3-S5;R: S1-S5; B: S1,S2,S5 | |
| 4 | 3.03 | 527.1588[M + Na]+ | a | C18 H32 O16 | -1.03 | 6-alpha-Maltosylglucose | W: S3-S5; R: S1; B: S5 | |
| 11 | 3.41 | 136.0622 | 119.03,65.01 | C5H5N5 | -3.15 | Adenine | W: S1-S5;R: S1-S3;B: S1-S5 | |
| 12 | 3.47 | 333.1665 | 128.08 | C17H26O5 | 2.24 | Methyl 8-[2-(2-formyl-vinyl)-3-hydroxy-5-oxo-cyclopentyl]-octanoate | W: S1-S4; R: S4;B: S1-S3,S5 | |
| 13 | 3.5 | 152.0568 | 135.03.110.03 | C5 H5 N5O | -0.75 | 8-Hydroxyadenine | W: S1; R-S1;B: S2-S3 | |
| 15 | 3.76 | 162.0761 | 102.05,84.04,56.05 | C6H11NO4 | -0.1 | N-Methylglutamic acid | W: S1-S5;R: S1-S5;B: S1- S5 | |
| 17 | 4.96 | 379.123 | 217.07 | C15H22O11 | 1.29 | 1-C-(Acetoxymethyl)-2,3,4-tri-O-acetylhexopyranose | W: S1-S5;R: S1-S5;B: S1-S5 | |
| 20 | 5.64 | 176.0927 | 130.2 | C7H13NO4 | -5.52 | Diethyl aminomalonate | W: S1-S5;R: S1-S5;B: S1-S5 | |
| 21 | 6.19 | 160.1082 | 101.05,59.05 | C6H13N3O2 | -0.92 | delta-Guanidinovaleric acid | W: S3-S4;R: S3-S5;B: S1,S4-S5 | |
| 22 | 6.25 | 132.1019 | 86.09 | C6H13NO2 | 0.04 | L-Norleucine | W: S1-S5;R: S3-S4;B:S1-S5 | |
| 23 | 7.27 | 212.1296 | 145.05,127.04,85.03 | C11H17N3 | -1.79 | Isoprenaline | W: S4; R: S3-S5; B:S1 | |
| 30 | 8.07 | 166.0872 | 120.08,77.04 | C9H11N2 | -5.72 | Phenylalanine | W: S1-S5;R: S1-S4;B: S1-S5 | |
| 31 | 8.43 | 144.0663 | 84.04 | C6H9NO3 | -5.42 | N-Acrylylglycine methyl ester | W: S1-S5;R: S1-S4;B: S1-S5 | |
| 32 | 8.58 | 146.1181 | 86.09 | C7H15NO2 | -3.73 | (S)-3-Amino-5-methylhexanoic acid | W: S1-S5;R: S2-S4;B: S1-S5 | |
| 34 | 9.12 | 260.0737[M+ Na]+ | a | C8 H15NO7 | 1.43 | Glycolyl-D-mannosamine | W: S1-S4;R: S1-S5;B: S4-S5 | |
| 36 | 9.224 | 180.1158 | 120.08,103.05,77.04 | C10H13N2 | -4.97 | (R)-3-Amino-4-phenylbutyric acid | W: S2,S3,S5;R: S3;B: S1-S5 | |
| 38 | 9.56 | 185.0425[M+ Na]+ | 84.96 | C6H10O5 | -2.46 | (S)-2-(Hydroxymethyl)glutarate | W: S1-S5;R: S1-S5;B: S1-S5 | |
| 39 | 9.75 | 243.0493[M+ Na]+ | 130.08,70.06 | C8H12O7 | -7.31 | 1-Hydroxypentane-1,2,5-tricarboxylate | W: S1-S5;R: S1-S5;B: S1-S5 | |
| 41 | 9.96 | 280.1058 | 220.08,188.06, 136.06,119.03 | C10H17N8 | -11.13 | N,N-Bis[2-carboxymethoxy)ethyl]glycine | W: S1-S3,S5;R: S1;B: S1-S3 | |
| 45 | 10.67 | 240.0856 | C11H13N5 | 4.39 | N-carbobenzoxy serine | W: S1-S5;R: S1-S5;B: S2-S5 | ||
| 48 | 11.41 | 301.0893[M+ Na] + | 241.06,145.03, 81.03.269.06 | C11H18O8 | 0.29 | Tuleposide A | W: S1-S5;R: S2-S5;B: S2-S5 | |
| 50 | 11.43 | 259.1158 | 181.92,155.03 | Unidentified | W: S1,S4;R: S1;B: S3,S5 | |||
| 52 | 11.56 | 261.0976 | 197.04,115.03 | C12 H12 N4 O3 | 3.51 | Furafylline | W: S1,S2,S4;R: S5;B: S5 | |
| 53 | 12.12 | 257.0651[M + Na]+ | 183.02 | C11H12O7 | 1.87 | Methyl3,5-dihydroxy-4-(2-methoxy-2-oxoethoxy)benzoate | W: S3;R: S2,S3,S5;B: S3-S5 | |
| 55 | 12.7 | 141.0544 | 109.03,81.03,53.04 | C7H8O3 | 1.56 | 4-Hydroxymethylcatechol | W:S1,S2,S4;R:S5;B:S1,S3 | |
| 58 | 13.43 | 273.1326 | 241.10,167.06,109.03 | C11H18N3O5 | -0.65 | N-Acetyl-L-alanyl-N-[(1S)-1-carboxylatoethyl]-L-alaninamide | W: S1-S5; R: S1; B: S2-S5 | |
| 59 | 14.23 | 273.1322 | 241.1 | C11H18N3O5 | -1.02 | N-Acetyl-L-alanyl-N-[(1S)-1-carboxylatoethyl]-L-alaninamide | W: S1-S4;R: S1,S2,S5;B: S2-S5 | |
W = White Rice, R = Red Rice, B = Black Rice, S = Stage, a = Fragmentation was not achieved