Table 6 Putatively identified compounds from Lactuca sativa leaf extract by UHPLC-ESI-Orbitrap-MS/MS analysis, including polyphenol content in lettuce leaves and the impact of biostimulant treatments.

1

Caffeic acid

C₉H₈O₄

Phenolic acids

66.74 ± 9.19 ^b

39.93 ± 0.46 ^c

101.33 ± 0.16 ^a

46.29 ± 2.74 ^{b, c}

2

Chlorogenic acid

C₁₆H₁₈O₉

Phenolic acids

626.38 ± 59.59 ^b

205.33 ± 33.64 ^d

909.79 ± 12.22 ^a

354.78 ± 13.46 ^c

3

Coumaroylquinic acid

C₁₆H₁₈O₈

Phenolic acids

69.24 ± 6.28 ^{a, b}

45.14 ± 5.36 ^c

80.22 ± 1.23 ^a

56.83 ± 3.46 ^{b, c}

4

Feruloylquinic acid

C₁₇H₂₀O₉

Phenolic acids

12.53 ± 0.16 ^a

12.18 ± 0.08 ^a

12.51 ± 0.35 ^a

12.19 ± 0.16 ^a

5

Quercetin hexoside

C₂₁H₂₀O₁₂

Flavonoids

4.55 ± 0.61 ^a

2.15 ± 0.09 ^b

3.55 ± 0.37 ^{a, b}

3.02 ± 0.36 ^{a, b}

6

Luteolin 7-O-glucoside

C₂₁H₂₀O₁₁

Flavonoids

1.33 ± 0.12 ^a

1.01 ± 0.09 ^b

1.15 ± 0.01 ^{a, b}

1.08 ± 0.03 ^{a, b}

7

Quercetin glucuronide

C₂₁H₁₈O₁₃

Flavonoids

11.30 ± 1.84^a

4.42 ± 0.01 ^b

5.41 ± 0.24 ^b

5.43 ± 0.54 ^b

8

Luteolin glucoronide

C₂₁H₁₈O₁₂

Flavonoids

10.76 ± 1.68 ^a

6.94 ± 0.33 ^b

7.49 ± 0.42 ^{a, b}

7.49 ± 0.43 ^{a, b}

9

Quercetin O-malonylglucoside

C₂₄H₂₂O₁₅

Flavonoids

22.71 ± 3.43 ^a

9.31 ± 0.43 ^b

21.99 ± 1.32 ^a

12.02 ± 1.54 ^b

10

Dicaffeoylquinic acid (DCQA)

C₂₅H₂₄O₁₂

Phenolic acids

40.39 ± 4.52 ^{a, b}

18.72 ± 1.63 ^c

53.57 ± 4.83 ^a

26.57 ± 0.22 ^{b, c}

11

Dicaffeoyltartaric acid (DCTA)

C₂₂H₁₈O₁₂

Phenolic acids

714.36 ± 68.7 ^b

243.78 ± 26.02 ^c

921.68 ± 12.84 ^a

575.64 ± 18.99 ^b

12

Luteolin O-malonylglucoside

C₂₄H₂₂O₁₄

Flavonoids

1.05 ± 0.06 ^a

0.84 ± 0.01 ^a

1.00 ± 0.09 ^a

0.92 ± 0.13 ^a

IS

QUE-d3 (IS)

C₁₅H₇D₃O₇