Comparison of the Antioxidant Activities and Phenolic Content of Five Lonicera Flowers by HPLC-DAD/MS-DPPH and Chemometrics

Table 2

ESI-MS² results of antioxidants in Lonicera.

No.	tR/min	[M–H]– (m/z)	Exptl. exact mass	Fragment ions (m/z)	Error (ppm)	Molecular formula	Identification
1	4.281	[M-H]-	353.0877	191.0559, 179.0343	0.53	C16H18O9	3-O-Caffeoylquinic acid
2	15.983	[M-H]-	353.0875	191.0557	−2.57	C16H18O9	5-O-Caffeoylquinic acid
3	19.586	[M-H]-	335.0773	179.0346, 161.0242, 135.0446, 317.0667	0.82	C16H18O9	4-O-Caffeoylshikimic acid
4	19.754	[M-H]-	353.0877	173.0453, 179.0345, 191.0558	0.45	C16H18O9	cis−4-O-Caffeoylquinic acid
5	19.987	[M-H]-	367.1026	161.0244, 135.0452	2.37	C17H20O9	Methyl-4-O-caffeoylquinate
6	21.271	[M-H]-	404.3684	371.0243, 179.0455	−2.15	C17H24O11	Secoxyloganin
7	21.623	[M-H]-	335.0775	179.0344, 135.0451	1.85	C16H16O8	3-O-Caffeoylshikimic acid
8	23.290	[M-H]-	367.1026	179.0345, 135.0452, 191.0559, 161.0243	0.64	C17H20O9	Methyl-5-O-caffeoylquinate
9	27.345	[M-H]-	381.1084	161.0243, 135.0452	−2.35	C18H22O9	Ethyl-4-O-caffeoylquinate
10	30.296	[M-H]-	381.1081	179.0343, 135.0454, 191.0558, 161.0245	−2.17	C18H22O9	Ethyl-5-O-caffeoylquinate
11	33.269	[M-H]-	515.1193	353.0876, 173.0453, 179.03445, 191.0559	−0.82	C25H23O12	3,4-di-O-Caffeoylquinic acid
12	35.504	[M-H]-	515.1196	353.0876, 191.0558, 179.0345	0.69	C25H23O12	3,5-di-O-Caffeoylquinic acid
13	37.875	[M-H]-	515.1195	353.0874, 173.0452, 179.0345, 191.0559	−3.12	C25H23O12	4,5-di-O-Caffeoylquinic acid
14	42.663	[M-H]-	515.1197	353.0876, 173.0453, 191.0562, 179.0347	−2.53	C25H23O12	1,4-di-O-Caffeoylquinic acid
15	43.397	[M-H]-	677.1592	515.1193, 353.0876	−0.49	C34H30O15	3,4,5-tri-O-Caffeoylquinic acid