Table 2: Characterization of compounds from acidified methanolic extracts of rice during grain development by LC-ESI-QTOF-MS/MS in negative mode.
No. | tR (min) | [M-H]-m/z | MS/MSm/z | Formula | Error(ppm) | Tentative identification | Rice variety and Stage found |
19 | 8.65 | 359.0743 | a | C18H16O8 | 8.16 | 5,2',3'-Trihydroxy-3,6,7-trimethoxyflavone | W: S2 |
21 | 8.97 | 439.1918[M + Cl]- | 403.22,359.19,329.18, 297.15,186.12,127.05 | C23H32O6 | -5.71 | 1-alpha-O-Methylquassin | W: S4-S5 |
25 | 9.38 | 176.0369 | 134.02 | C6H11NO3S | 10.09 | N-Formylmethionine | W: S4 |
28 | 9.73 | 325.0497[M +Cl]- | 289.07,245.07 | C15H14O6 | -3.92 | Catechin* | R: S2-S3 |
2 | 2.99 | 104.0348 | 74.02 | C3H7NO3 | 4.97 | D-Serine | B: S1-S3 |
3 | 3.01 | 225.0599 | 179.05,161.04 | C6H12O6 | 1.73 | Hexose | B: S1-S3,S5 |
15 | 7.22 | 147.0317 | 129.01,85.02 | C5H8O5 | -12.18 | (S)-2-Hydroxyglutarate | B: S1 |
17 | 8.04 | 164.0733 | a | C9H11NO2 | -9.68 | Phenylalanine | B: S2 |
20 | 8.84 | 465.1006[M + 16] | 285.048,329.08 | C21H21O11 | -19.85 | Cyanidin glucoside* | B: S4-S5 |
8.85 | 447.089[M-H]- | 284.03,256.03 | |||||
24 | 9.36 | 479.1143[M +16]- | 355.06,299.05,284.03, 149.02 | C22 H23O11 | 10.85 | Peonidin glucoside* | B: S4-S5 |
30 | 11.68 | 463.083[M-H]- | 301.03,257.04,109.02 | C21H20O12 | 11.23 | Tricetin-7-glucoside | B: S5 |
5 | 3.16 | 171.0081 | 78.95 | C3H9O6P | -9.95 | Glycerol-3-phosphate | R: S2,S4,S5;B: S1,S3,S5 |
26 | 9.5 | 153.0183 | 109.02 | C7H6O4 | 6.7 | Protocatechuic acid | R: S4-S5;B: S2-S5 |
31 | 12.78 | 167.035 | 108.022 | C8H8O4 | -0.11 | Vanillic acid | R: S2-S5,B: S2-S5 |
32 | 13.37 | 195.0292 | 136.01,108.02 | C9H8O5 | 3.57 | (2E)-3-(2,4,5-Trihydroxyphenyl)acrylic acid | R: S5;B: S2-S5 |
1 | 2.88 | 194.9476 | 176.93,96.96 | Unidentified | W: S1,S3,S5;R: S1,S2,S4; B: S1-S4 | ||
4 | 3.03 | 132.0298 | 88.03 | C4H7NO4 | 3.27 | D-Aspartic acid | W: S1-S5;R: S1-S4; B: S3-S5 |
6 | 3.25 | 377.0864[M + Cl]- | 341,10,179.05,89.05 | C12H22O11 | -2.09 | Sucrose | W: S5;R: S1-S5;B: S1 |
7 | 3.25 | 215.0343[M + Cl]- | 179.05,89.05 | -7.02 | Glucose | W: S5;R: S1-S5;B: S1 | |
8 | 3.42 | 134.049 | 107.03,65.01 | C5H5N5 | -13.19 | Adenine | W: S1,S3,S5;R: S1-S3; B: S1-S4 |
9 | 3.55 | 359.0768 | 305.08,215.83 | C18H16O8 | 1.23 | 5,8,4'-Trihydroxy-3,6,7-trimethoxyflavone | W: S1,S3,S4;R: S1-S5; B: S1-S5 |
10 | 3.7 | 391.1037[M + Cl]- | 355.14,193.08 | C13H24O11 | -6.23 | D-Pinitol hexose isomer | W: S1-S3,S5;R: S1-S5; B: S1-S5 |
11 | 3.75 | 110.9767 | 79.96 | CH4O4S | -8.46 | Monomethyl sulfate | W: S1-S5;R: S5;B: S1-S5 |
12 | 3.98 | 229.0482 | 170.89,78.95 | C13H10O4 | 10.62 | 4-Hydroxyphenyl-4-hydroxybenzoate | W: S1-S5;R: S1-S5; B: S1,S2, S4,S5 |
13 | 4.78 | 391.1027[M+Cl]- | 355.12,193.07,89.02 | C13H24O11 | -3.67 | D-Pinitol hexose isomer | W: S2-S3,S5;R: S3,S5; B: S1-S5 |
14 | 5.18 | 279.0369 | 243.06,200.05,111.02, 110.02 | C14H12O4 | 15.09 | 3,3',4,5'-Tetrahydroxy-trans-stilbene | W: S1-S4; R: S1-S3; B: S1-S5 |
16 | 8.04 | 323.0557 | 164.07 | C18H12O6 | 1.27 | Neobanol | W: S2,S4;R: S3,S5;B: S1-S3 |
18 | 8.05 | 205.0371 | 143.03,111.08,87.00, 67.01 | C7H10O7 | -8.41 | 2-Methylcitric acid | W: S3; R: S3-S5;B: S4 |
22 | 9.13 | 236.0535 | 176.03,162.01,134.02 | C7H15N32S2 | -0.88 | Cysteinyl-N-(2-sulfanylethyl)glycinamide | W: S2-S4,R: S5,B:S4 |
27 | 9.73 | 219.0526 | 169.04,115.03,73.02 | C8H12O7 | -7.18 | 1-Hydroxypentane-1,2,5-tricarboxylate | W: S1-S5;R: S1-S5; B: S1.S2,S4,S5 |
29 | 11.01 | 137.0228 | 93.0343 | C7H6O3 | 11.72 | p-hydroxybenzoic acid | W: S2;R: S1-S5;B: S1,S4-S5 |
W = White Rice, R = Red Rice, B = Black Rice, S = Stage, a = Fragmentation was not achieved