LC-MS identification and preparative HPLC isolation of Frankenia pulverulenta phenolics with antioxidant and neuroprotective capacities in PC12 cell line

Figures & data

Table 1. Total phenolic content (TPC) and antioxidant capacities of F. pulverulenta aerial part and roots fractions.

	Extract/fraction	TPC (mg of GAE/g)	DPPH (mg of TE/g)	ABTS (mg of TE/g)	ORAC (mg of TE/g)	MCA (mg of EDTA/g)
Aerial part	Crude extract	286 ± 10^c	378 ± 42^c	216 ± 33^d	495 ± 43^c	44 ± 3^b
	Hexane fraction	71 ± 5^f	88 ± 17^e	165 ± 27^d	196 ± 30^e	25 ± 2^d
	Dichloromethane	115 ± 7^e	77 ± 10^e	220 ± 22^d	617 ± 58^b	21 ± 2^d
	Ethyl acetate	383 ± 10^a	586 ± 31^b	1453 ± 63^a	821 ± 34^a	37 ± 6^c
	Butanol	319 ± 6^b	698 ± 73^a	1110 ± 67^b	496 ± 38^c	44 ± 4^b
	Water	210 ± 9^d	193 ± 51^d	626 ± 35^c	374 ± 51^d	62 ± 3^a
Root	Crude extract	202 ± 13^c	540 ± 50^b	230 ± 45^d	398 ± 33^d	15 ± 1^b
	Hexane fraction	25 ± 3^f	30 ± 10^d	156 ± 10^d	52 ± 17^f	12 ± 1^c
	Dichloromethane	105 ± 8^e	45 ± 10^d	230 ± 25^d	501 ± 50^c	12 ± 1^c
	Ethyl acetate	374 ± 15^a	750 ± 11^a	1319 ± 76^a	1054 ± 54^a	23 ± 2^a
	Butanol	289 ± 7^b	529 ± 116^b	1242 ± 54^b	646 ± 32^b	23 ± 2^a
	Water	182 ± 6^d	204 ± 66^c	754 ± 41^c	311 ± 23^e	15 ± 1^b

^a–eSignificant difference at p < 0.05 by Tukey’s test.

Figure 1. LC-DAD-ESI-MS base peak chromatograms in negative ion mode and UV at 280 nm for the ethyl acetate fraction of aerial parts and roots of F. pulverulenta.

Table 2. Phenolic compounds detected in ethyl acetate fraction by LC-DAD-ESI-MS from aerial parts and roots of F. pulverulenta in negative mode.

Compound No	Rt (min)	λmax(nm)	[M − H]^−	Fragments	Organ	Compound
1	2.3	270-275	169	125	AP, R	Gallic acid
2	3.6	260	577	407-425-451-289	R	Procyanidin dimer 1
3	4	280	289	245-179-205	AP	Catechin
4	4.3	275	577	407-425-451-289	AP	Procyanidin dimer 2
5	4.3	275	551	291-352-415-465-529	R	ND
6	4.5	275	635	483-465	AP, R	Tri-galloyl hexoside
7	4.8	275	591	301-255-359-407-439-465-487-529	AP	Quercetin galloyl glucoside
8	5.1	270	577	407-425-451-289	AP	Procyanidin dimer 3
9	5.1	280	619	245-289-407-425	R	ND
10	5.3	280/370	301	301	R	Quercetin
11	5.3	285/360	477	301-151-179	AP	Quercetin hexoside
12	5.5	290/320	435	168-315-345	R	ND
13	6.3	280/365	551	343-491	R	ND
14	6.7	290/320	685	365-458-488-514-541-617-649-667	R	ND
15	7.1	290/360	423	343-80	AP, R	Flavonoid-sulfated isomer
16	7.2	290/310	423	343-80	AP	Flavonoid-sulfated isomer

Figure 2. Cytotoxic activity (a) and neuroprotective activity on Aβ-induced toxicity in PC12 cell line (b) of aerial part and root EtOAc fraction. The experiment was repeated three times.

Table 3. Antioxidant capacity (ORAC) of purified molecules of the ethyl acetate fraction.

Pure molecule	ORAC (mmol TE/g polyphenols)
Gallic acid	14.176
Catechin	21.917
Procyanidin dimer	4.71
Trigalloyl hexoside	2.99
Quercetin galloyl glucoside	1.2
Flavonoid sulphate	ND
Quercetin	33.558

The results are expressed in mmol Trolox equivalent/g polyphenols.

Figure 3. Cytotoxic activity (a) and neuroprotective activity on Aβ-induced toxicity in PC12 cell line (b) of purified molecules of the ethyl acetate fraction. GA: gallic acid; P dimer: procyanidin dimer; TGH: trigalloyl hexoside; QGG: quercetin galloyl glucoside; FS: flavonoid sulfated.