Chemical profile and antioxidant activity of Gynura bicolor DC. ethanolic extract

Figures & data

Figure 1. Total phenolics extraction optimization, effects of extraction solvent (a), sonication time (b), liquid-to-solid ratio, (c) and sonication temperature (d). Different letter in graph means significant difference (ANOVA, p < 0.05).

Table 1. Characterization of phenolic components in G. bicolor extract by HPLC-Q-TOF-MS.

Peak No.	RT (min)	[M–H]^− (m/z)	Fragment ions (m/z) (% base peak)	Proposed structure	Reference
1	1.18	377.0826	341(100), 215(14),179(38), 119(43)	Caffeic acid derivatives	[14]
2	1.52	191.0202	111(100)	Citric acid	[15]
		133.0155	115(100)	Malic acid	[15]
3	2.48	243.0623	122(33), 110(100)	Uridine	[15]
4	2.63	282.0841	150(100), 133(84)	Guanosine	[15]
5	3.54	282.0841	150(100), 133(84)	Guanosine	[15]
6	4.45	164.0724	147(37), 103(100)	Phenylalanine	[15]
7	4.96	315.0714	152(84), 109(90) 108(100)	Protocatechuate-O-glucoside	[16]
8	6.34	203.0829	142(27), 116(100)	Tryptophan	[15]
9	7.75	323.1342	119(100), 113(88), 101(94)	Isobavachalcone	[17]
10	8.01	353.0868	191(100)	5-O-Caffeoylquinic acid	[25,26]
11	8.48	341.0875	179(30), 135(100)	Caffeoyl glucose	[18]
12	9.26	353.1446	295(100), 251(14), 101(15)	Unidentified
13	9.78	337.0919	191(100), 163(11), 119(11)	3-O-p-Coumaroylquinic acid	[25,26]
14	10.68	367.1012	191(100), 193(9), 173(11), 134(30)	3-O-Feruloylquinic acid	[25,26]
15	11.62	337.092	191(100), 163(2), 119(2)	5-O-p-Coumaroylquinic acid	[25,26]
16	12.69	433.2064	387(10), 225(100), 153(26)	Geniposide	[19]
17	12.99	497.3324	451(100), 433(14), 225(8)	Unidentified
18	13.69	515.1173	353(65), 191(100), 179(60), 173(8)	3,5-Di-O-caffeoylquinic acid	[25,26]
19	14.03	609.1436	301(54), 300(100), 271(18), 255(8)	Quercetin-3-rutinoside	[20]
		463.0860	301(35), 300(100), 271(26), 255(15)	Quercetin-3-O-galactoside	[21]
20	14.55	505.0962	301(33), 300(100), 271(27), 255(16)	quercetin-3-acetylhexose;	[22]
21	15.00	447.0915	285(15), 284(100), 255(65), 227(28)	Kaempferol-3-O-glucoside	[23]
22	15.21	515.1176	353(100), 191(35), 179(65), 173(90)	4,5-Di-O-caffeoylquinic acid	[25,26]
23	15.55	447.0916	285(35), 284(100), 255(65), 227(35)	Kaempferol-3-O-caffeoylate	[23]
24	16.07	301.720	233(100), 179(19), 119(68)	Dihydro-phellopterin	[24]
		279.0905	199(100), 153(16)	Unidentified
25	16.56	723.5008	677(100)	Unidentified
26	17.67	836.5855	790(100)	Unidentified
27	18.55	949.6702	903(100)	Unidentified
28	19.08	1062.7530	1016(100)	Unidentified

Table 2. The EC50 values of G. bicolor extract and vitamin C with different antioxidant tests (μg/mL).

	DPPH	ABTS	Reduce power
G. bicolor	44.35 ± 0.41	36.36 ± 0.29	36.92 ± 0.32
Vitamin C	15.51 ± 0.53	5.83 ± 0.37	<3

Figure 2. Base peak chromatogram (a) and absorbance chromatogram recorded at 327 nm (b) of G. bicolor total phenolic extract.

Figure 3. Antioxidant activity of G. bicolor total phenolic extract. (a) DPPH radical-scavenging assay; (b) ABTS radical-scavenging assay; (c) reducing power assay.

Bystrom, L. M.; Lewis, B. A.; Brown, D. L.; Rodriguez, E.; Obendorf, R. L. Characterisation of Phenolics by LC–UV/Vis, LC–MS/MS and Sugars by GC in Melicoccus bijugatus Jacq.‘Montgomery’ Fruits. Food Chemistry 2008, 111, 1017–1024. DOI: 10.1016/j.foodchem.2008.04.058.

 PubMed Web of Science ®Google Scholar

Rodríguez-Pérez, C.; Quirantes-Piné, R.; Fernández-Gutiérrez, A.; Segura-Carretero, A. Comparative Characterization of Phenolic and Other Polar Compounds in Spanish Melon Cultivars by Using High-Performance Liquid Chromatography Coupled to Electrospray Ionization Quadrupole-Time of Flight Mass Spectrometry. Food Research International 2013, 54, 1519–1527. DOI: 10.1016/j.foodres.2013.09.011.

 Web of Science ®Google Scholar

Guo, M.; Zhang, L.; Liu, H.; Qin, L.; Zhang, Z.; Bai, X.; Gao, X. A Metabolomic Strategy to Screen the Prototype Components and Metabolites of Qingkailing Injection in Rat Urine by High-Performance Liquid Chromatography with Tandem Mass Spectrometry. Journal of Separation Science 2014, 37, 2844–2850. DOI: 10.1002/jssc.v37.20.

 PubMed Web of Science ®Google Scholar

Kim, D. W.; Curtis-Long, M. J.; Yuk, H. J.; Wang, Y.; Song, Y. H.; Jeong, S. H.; Park, K. H. Quantitative Analysis of Phenolic Metabolites from Different Parts of Angelica Keiskei by HPLC-ESI MS/MS and Their Xanthine Oxidase Inhibition. Food Chemistry 2014, 153, 20–27. DOI: 10.1016/j.foodchem.2013.12.026.

 PubMed Web of Science ®Google Scholar

Gouveia, S.; Castilho, P. C. Antioxidant Potential of Artemisia Argentea L’Hér Alcoholic Extract and Its Relation with the Phenolic Composition. Food Research International 2011, 44, 1620–1631. DOI: 10.1016/j.foodres.2011.04.040.

 Web of Science ®Google Scholar

Weisz, G. M.; Kammerer, D. R.; Carle, R. Identification and Quantification of Phenolic Compounds from Sunflower (Helianthus Annuus L.) Kernels and Shells by HPLC-DAD/ESI-MSn. Food Chemistry 2009, 115, 758–765. DOI: 10.1016/j.foodchem.2008.12.074.

 Web of Science ®Google Scholar

Liu, Z.; Chen, Z.; Guo, H.; He, D.; Zhao, H.; Wang, Z.; Zhang, W.; Liao, L.; Zhang, C.; Ni, L. The Modulatory Effect of Infusions of Green Tea, Oolong Tea, and Black Tea on Gut Microbiota in High-Fat-Induced Obese Mice. Food & Function 2016, 7, 4869–4879. DOI: 10.1039/C6FO01439A.

 PubMed Web of Science ®Google Scholar

Ma, S.; Chen, L.; Luo, G.; Ren, K.; Wu, J.; Wang, Y. Off-Line Comprehensive Two-Dimensional High-Performance Liquid Chromatography System with Size Exclusion Column and Reverse Phase Column for Separation of Complex Traditional Chinese Medicine Qingkailing Injection. Journal of Chromatography 2006, 1127, 207–213. DOI: 10.1016/j.chroma.2006.06.021.

 PubMed Web of Science ®Google Scholar

Mullen, W.; Yokota, T.; Lean, M. E.; Crozier, A. Analysis of Ellagitannins and Conjugates of Ellagic Acid and Quercetin in Raspberry Fruits by LC–MSn. Phytochemistry 2003, 64, 617–624. DOI: 10.1016/S0031-9422(03)00281-4.

 PubMed Web of Science ®Google Scholar

Schieber, A.; Keller, P.; Streker, P.; Klaiber, I.; Carle, R. Detection of Isorhamnetin Glycosides in Extracts of Apples (Malus domestica cv.“Brettacher”) by HPLC-PDA and HPLC-APCI-MS/MS. Phytochemical 2002, 13, 87–94. DOI: 10.1002/pca.630.

 PubMed Web of Science ®Google Scholar

Geng, P.; Zhang, R.; Aisa, H. A.; He, J.; Qu, K.; Zhu, H.; Abliz, Z. Fast Profiling of the Integral Metabolism of Flavonols in the Active Fraction of Gossypium herbaceam L. Using Liquid Chromatography/Multi-Stage Tandem Mass Spectrometry. Rapid Communications in Mass Spectrometry 2007, 21, 1877–1888.

 PubMed Web of Science ®Google Scholar

Downey, M. O.; Rochfort, S. Simultaneous Separation by Reversed-Phase High-Performance Liquid Chromatography and Mass Spectral Identification of Anthocyanins and Flavonols in Shiraz Grape Skin. Journal of Chromatography 2008, 1201, 43–47. DOI: 10.1016/j.chroma.2008.06.002.

 PubMed Web of Science ®Google Scholar

Park, A. Y.; Park, S. Y.; Lee, J.; Jung, M.; Kim, J.; Kang, S. S.; Youm, J. R.; Han, S. B. Simultaneous Determination of Five Coumarins in Angelicae dahuricae Radix by HPLC/UV and LC-ESI-MS/MS. Biomedical Chromatography 2009, 23, 1034–1043. DOI: 10.1002/bmc.1219.

 PubMed Web of Science ®Google Scholar