Phytochemical profile, antioxidant and cytotoxic potential of Parkinsonia aculeata L. growing in Saudi Arabia

Abstract

Parkinsonia aculeata L. growing in Saudi Arabia was investigated for its phytochemical profile, antioxidant, and cytotoxic properties. UPLC-ESI-MS/MS was employed as a powerful technique for the characterization of secondary metabolites from a hydroalcoholic extract, dichloromethane, and ethyl acetate fractions of P. aculeata L. aerial parts. Sixty-nine compounds (flavonoids, anthocyanins, phenolics and fatty acids) were detected and characterized; flavonoids were the abundant components in the analyzed samples. The dichloromethane fraction was rich in phenolics as vanillic acid hexoside, flavonols as 3,7-dimthylquercetin, and flavones as 3′-hydroxymelanettin. However, the ethyl acetate fraction was rich in flavonoid- C -glycosides as luteolin-8- C -β-D-glucoside (orientin) and apigenin-8- C -glucoside (vitexin), flavonoid- O , C -diglycosides such as luteolin 7- O -[6′'-dihydrogalloyl]-glucosyl-8- C -pentosyl-(1 → 2)-glucoside and 2′'- O -rhamnosyl isoorientin. These compounds were identified for the first time in dichloromethane and ethyl acetate fractions of Saudi P. aculeata L. Additionally, all the samples were assessed for antioxidant activity using DPPH radical scavenging method and for cytotoxic activity through MTT assay. Accordingly, the most active fraction was the ethyl acetate which showed the highest antioxidant activity (SC 50 = 57.4 ± 1.2 μg/mL) compared with the positive control, ascorbic acid (SC 50 = 12.4 ± 0.5 μg/mL) and moderate cytotoxicity against HepG-2 (hepatocellular carcinoma) and MCF-7 (breast carcinoma) cell lines with IC 50 = 56.9 ± 3.1 and 95.8 ± 3.8 μg/mL, respectively compared with cisplatin (IC 50 = 3.67 ± 0.22 and 5.71 ± 0.57 μg/mL, respectively for both cell lines). The antioxidant and cytotoxic activities may be attributed to the presence of high percentage of phenolic compounds and hydroxylated flavonoids detected in ethyl acetate fraction using UPLS-ESI-MS/MS.

UPLC-ESI-MS/MS Profile of The Ethyl Acetate Fraction of Aerial Parts of Bougainvillea 'Scarlett O'Hara' Cultivated in Egypt

“…Compound (18) was tentatively identified as β-aryl ether dilignol hexoside known as fraxiresinol hexoside [23]. One fatty acid, lanopalmitic acid (31) was identified as previously reported [18]. N-Feruloyl tyramine (30) and its isomer (33) were recognized by comparing its MS/MS fragmentation pattern with the reported data [40].…”

“…Further, MS analysis of the m/z 403 ion produced identical product ions as syringyl (8-O-4') guaiacyl dilignol as it yields fragments suggested syringyl and guaiacyl units connected by a structure of resinol bonding. Compound (18) was tentatively identified as β-aryl ether dilignol hexoside known as fraxiresinol hexoside [23]. One fatty acid, lanopalmitic acid (31) was identified as previously reported [18].…”

“…Most of the phenolic acid derivatives are glycosides, their first stage of fragmentation is the cleavage of the glycosidic bond to produce the m/z of the phenolic acid and the respective neutral mass loss of sugar molecules, and then neutral mass losses of methyl, hydroxyl or carboxylic groups helped to identify the specific phenolic acid. Coumaric acid (2) [18], p-hydroxybenzoic hexoside (3) [19], caffeic acid derivative (4) and ferulic acid derivative (38) [20], trihydroxyursolic acid derivative (7) [24], methoxycinnamic acid hexoside (8) and methoxy benzoic acid hexoside (29) [19], caffeic acid hexoside (9) [25], sinapic acid-3-O-glucoside (25) and its isomer (36) [38], ethyl gallate (28) and its isomer (34) [39], protocatechualdehyde…”

“…Other compounds were also characterized in Bougainvillea 'Scarlett O'Hara', like sucrose (1), fraxiresinol hexoside (18), lanopalmitic acid (31), Nferuloyl tyramine (30) and its isomer (33). Moreover, compound (1) was suggested to be sucrose (MS 1 at m/z 341 [M-H] − , MS 2 at m/z 179 [M-H-glc.]…”

“…− , 161, 131) according to [48]. Compound (18) showed a deprotonated molecular ion at m/z 565 and intense fragment at m/z 403, attributed to the loss of hexoside moiety. Further, MS analysis of the m/z 403 ion produced identical product ions as syringyl (8-O-4') guaiacyl dilignol as it yields fragments suggested syringyl and guaiacyl units connected by a structure of resinol bonding.…”