Analysis of Phenolic Acids of Jerusalem Artichoke (Helianthus tuberosus L.) Responding to Salt-Stress by Liquid Chromatography/Tandem Mass Spectrometry

Table 1

Identification of phenolic compounds in H. tuberosus leaves by HPLC-MS/MS.

Peaks number	𝑡𝑅 (min)	UV 𝜆max (nm)	MW	MS^−	MS/MS	Identification
1	3.58	246.0, 263.0	360	359.4	297.3, 281.6, 230.9, 135.2	Unknown
2	4.36	214.3, 323.4	354	353.4	191.1, 179.1, 161.1, 135.1, 85.1	Caffeoylquinic acid (isomer of chlorogenic acid)
3	5.78	214.4, 327.0	354	353.4	191.1, 127.0, 85.0	3-o-Caffeoylquinic acid (3-CQA)
4	6.07	237.9, 324.4	354	353.4	191.2, 127, 93.1, 85.0	Caffeoylquinic acid
5	8.57	323.0	180	179.1	136.0, 107.9	Caffeic acid (CA)
6	9.19	239.1, 311.5	338	337.3	191.1, 173.0, 93.0	p-Coumaroyl-quinic acid
7	10.12	241.4, 325.8	368	367.3	191.0, 173.1, 134.0, 93.0	Feruloylquinic acid
8	18.09	243.8, 327.0	516	515.5	354.3, 191.1, 173.1, 179.1, 135.0	Dicaffeoylquinic acid (3,4-DiCQA)
9	19.03	242.6, 327.0	516	515.5	354.1, 191.2	Dicaffeoylquinic acid (3,5-DiCQA)
10	20.04	327	342	341.3	179.1, 161.1	Caffeoyl glucopyranose
11	20.43	243, 329.4	516	515.5	354.1, 191.1, 179.1, 173.1, 135.1	Dicaffeoylquinic acid (1,5-DiCQA)
12	22.97	253.3, 349.7	478	477.4	315.3, 300.1, 270.9, 180.2	Isorhamnetin glucoside
13	26.57	327.0	516	515.5	191.1, 179.1, 173.1, 135.0	Dicaffeoylquinic acid (4,5-DiCQA)
14	30.20	263.9, 341.3	462	461.4	315.2, 284.8, 161.0, 132.7, 85.1	Kaempferol glucuronide
15	30.58	263.0, 333.0	448	447.4	285.4, 190.8, 153.1, 96.9	Kaempferol-3-o-glucoside