Table 1.

Identification of phenolic compounds, [M-H]^-, by UHPLC/DAD/TOF analysis of stalks of cardoon (Cynara cardunculus var. altilis DC cv. Pieno Inerme Lucchese; PIL and Cynara cardunculus var. altilis DC cv. Plain Blanc Inerme; PBI) cultivated in the field. The symbol (+) indicates the presence of that phenolic compound in the sample. MW: molecular weight.

No	Name	Formula [M-H]-	Exp. MW [M-H]-	Calculated MW [M-H]-	∆, ppm	Score	Unbl. PIL	Bl. PIL	Boil. PIL	Unbl. PBI	Bl. PBI	Boil. PBI	Refs
1	Quinic acid I	C7H12O6	191.0575	191.0561	−7.15	87.28	+	+	+	+	+		[17]
2	Unknown	C13H17O12	365.0737	365.0725	−3.15	73.66						+	-
3	Poly-galacturonic acid methyl ester	C20H27O18	555.1198	555.1203	0.96	83.66		+					[18]
4	Poly-galacturonic acid	C27H37O24	745.1655	745.1680	3.44	74.5						+	[18]
5	Dihydroxybenzene	C6H6O2	109.0291	109.295	3.47	86.14	+						[4]
6	Quinic acid II	C7H11O6	191.0574	191.0561	−6.52	88.32	+				+	+	[17]
7	Caffeic acid I *	C9H8O4	179.0361	179.0350	−6.09	87.24			+		+	+	[4,17]
8	Chlorogenic acid *	C16H18O9	353.0907	353.0878	−8.34	78.95			+		+		[4]
9	Unknown	C8H8O2	135.0463	135.0452	−8.61	85.41							-
10	Unknown	C8H7O2	135.458	135.452	−4.56	93.19			+				-
11	Caffeic acid II	C9H8O4	179.0373	179.0350	−12.9	70.1			+				[4,17]
12	Caffeoyl-di(dihydro)caffeoylquinic acid methyl ester	C35H35O15	695.1865	695.1888	3.22	85.2			+				[19]
13	Caffeoyl-Hexoside	C15H17O9	341.0876	341.0878	0.71	86.67			+		+		[4]
14	Chlorogenic acid hexoside	C22H27O14	515.1441	515.1465	4.71	81.76			+				[20,21]
15	Monocaffeoylquinic acid I	C16H18O9	353.0899	353.0878	−6.04	81.99			+			+	[20]
16	Monocaffeoylquinic acid dimer I	C16H18O9	707.1885	707.1829	−7.92	70.32			+	+	+	+	[20]
17	Quinic acid III	C7H12O6	191.0541	191.0561	−10.31	65.63		+	+			+	[17]
18	Caffeic acid III	C9H8O4	179.0362	179.0350	−6.95	85.63			+			+	[17,20]
19	Unknown	C18H25O11	417.1445	417.1402	−10.31	56.95				+			-
20	Monocaffeoylquinic acid I	C16H18O9	353.0895	353.0878	−4.68	81.04				+			[4]
21	Quinic acid IV	C7H12O6	191.0578	191.0561	−8.99	80.7			+	+	+		[4,17]
22	Monocaffeoylquinic acid dimer I	C16H18O9	707.1885	707.1829	−7.92	70.32			+			+	[20]
23	Unknown	C19H30O8	385.1883	385.1868.	−3.82	84.23				+			-
24	Shikimic acid *	C7H10O5	173.0467	173.0455	−6.74	87.81			+			+	-
25	p-Coumaroylquinic acid	C22H31O11	471.1911	471.1872	−8.39	70.15	+		+	+		+	[19]
26	Cynaroside	C21H19O11	447.1034	447.0992	−9.51	81.23		+				+	[4,17,21]
27	Monocaffeoylquinic acid III	C16H18O9	353.0895	353.0878	−4.68	81.04			+			+	[20]
28	Monocaffeoylquinic acid IV	C16H18O9	353.0904	353.0878	−7.42	66.29			+				[20]
29	Monocaffeoylquinic acid V	C16H18O9	353.0899	353.0878	−5.79	72.14			+				[20]
30	Dicaffeoylquinic acid hexoside	C31H34O17	677.1726	677.1723	−0.46	80.3			+				[20]
31	Luteolin-7-O-glucoside *	C21H19O11	447.0943	447.0933	−2.38	78.41			+		+	+	[4,17,21]
32	Dicaffeoylquinic acid I	C25H24O12	515.1223	515.1195	−5.37	79.06		+	+	+	+	+	[4]
33	Dicaffeoylquinic acid III	C18H28O17	515.1225	515.1254	5.54	80.21			+			+	[20]
34	Unknown	C25H26O13	533.1317	533.1301	−2.97	75.99			+				-
35	Myricetin galloylhexoside I	C29H28O16	631.1309	631.1305	−0.77	79.27		+	+				[20]
36	Myricetin galloylhexoside II	C29H28O16	631.1309	631.1305	−0.77	79.27			+				[20]
37	Myricetin galloylhexoside III	C29H28O16	631.1308	631.1305	−0.54	79.09			+				[20]
38	Dicaffeoylquinic acid II	C18H28O17	515.1225	515.1254	5.54	80.21			+	+	+	+	[4]
39	Caffeoylquinic acid II	C18H28O17	515.1225	515.1195	−5.73	79.89			+			+	[20]
40	Quinic acid V	C7H12O6	191.0575	191.0561	−7.15	88.03		+	+		+	+	[17]
41	Monocaffeoylquinic acid II	C16H18O9	353.0904	353.0878	−7.42	66.29				+	+	+	[4]
42	Apigenin glucuronide	C21H17O11	445.0771	445.0776	1.2	79.34				+	+		[9]
43	Caffeoylquinic acid I	C18H28O17	515.1225	515.1195	−5.73	79.89			+	+	+	+	[4]
44	Apigeninacetyl glucoside	C23H22O12	489.1032	489.1038	1.31	77.72					+	+	[9]
45	4-O-Caffeoyl-5-O-[3-methoxy-3-(3,4-dihydroxyphenyl)-propionyl] quinic acid methyl ester I	C27H29O13	561.1613	561.1614	0.07	82.21						+	[22]
46	4-O-Caffeoyl-5-O-[3-methoxy-3-(3,4-dihydroxyphenyl) -propionyl] quinic acid methyl ester II	C27H29O13	561.1613	561.1614	0.05	82.45						+	[22]
47	Dicaffeoylquinic acid IV	C18H28O17	515.1209	515.1195	−2.74	76.53			+				[20]
48	Caffeoyl-dihydrocaffeoyl-sinapoyl quinic acid II	C36H35O16	723.1901	723.1931	4.08	74.8						+	[19]
49	Caffeoyl-dihydrocaffeoyl-sinapoyl quinic acid II	C36H35O16	723.1901	723.1931	4.08	74.8						+	[19]
50	Apigenin *	C15H9O5	269.0459	269.0455	−1.45	87.78					+		[21]
51	Kaempferol *	C15H9O6	285.0417	285.0405	−4.37	88.32	+					+	-
52	Unknown	C35H55O13	683.3629	683.3648	2.79	73.81				+	+		-
53	Trihydroxy-octradecenoic acid	C18H33O5	329.2324	329.2333	2.91	85.72					+		[19]
54	Dihydroxy-octradecenoic acid	C18H31O4	311.2220	311.2228	2.47	74.33					+	+	[21]
55	Unknown	C18H29O4	313.2422	313.2384	−11.88	55.84					+		-
56	Unknown	C29H45O7	564.3321	564.3093	−0.87	74.37			+				-
57	Unknown	C15H22O3	249.1522	249.1496	−10.25	67.16			+				-

* Confirmed by authentic chemical standards.