Table 3.

Tentative assignment of chemical constituents of 90% MeOH extract of C. rotundus by LC-ESI -MS

Comp. No	tR (min)	MW	[M-H]−	m/z fragments	Tentative assignment
1	12.28	192	191	173	Quinic acid
2	15.09	330	329	315, 203, 116	Unknown
3	16.96	388	387	211, 197	Trimethyl-gallic acid-glucuronide
4	17.76	330	329	314, 135	Trihydroxy-octadecanoic acid
5	18.96	354	353	191 (100%), 179 (63%), 135	3-O- caffeoylquinic acid
6	21.63	594	593	285, 175, 151	Luteolin-7-O-rutinoside
7	23.10	354	353	191 (100%), 179 (13%), 135	4-O- caffeoylquinic acid
8	23.77	354	353	191 (100%), 179, 161	5-O- caffeoylquinic acid
9	31.91	564	563	473, 443, 383, 353	Apigenin-6-C-hexoside-8-C-pentoside
10	32.71	448	447	357, 327, 297	Luteolin-8-C-glucoside (Orientin)
11	33.78	564	563	503, 473, 443	Isoschaftoside
12	36.58	374	373	343, 328, 300	Skullcapflavone II
13	37.12	594	593	447, 285, 175	Luteolin-7-O-rutinoside
14	37.65	344	343	328, 285, 269, 313	5,6-dihydroxy-3’,4’,7-trimethyl-flavone
15	38.85	462	461	285	Luteolin-7-O-glucoronoid
16	40.19	374	373	358, 343, 328, 313, 269	Quercetagetin-tetramethyl ester
17	41.26	638	637	491, 329, 313	Tricin-O-rutinoside
18	41.66	654	653	491, 329, 313	Tricin-O-dihexosides
19	42.06	374	373	358, 343, 328, 313, 269	Quercetagetin-tetramethyl ester isomer
20	43.26	638	637	505, 329, 314	Tricin-O-ferulyl-pentoside
21	45.26	834	833	637, 359, 301, 269	Unknown
22	50.60	286	285	199, 175, 151, 133	Luteolin
23	51.40	374	373	358, 343, 328	Quercetagetin-tetramethyl ester isomer
24	54.48	620	619	577, 431, 269, 175	Apigenin-7-O-Acetyl-rutinoside
25	56.35	820	819	741, 619, 577, 269, 175	Apigenin derivatives
26	59.42	344	343	313, 298, 270	5,6-dihydroxy-3’,4’,7-trimethoxy flavone isomer

t_R retention time, M.W molecular weight, [M-H] deprotonated molecular ion