Characterization of antioxidant phenolics in Syringa vulgaris L. flowers and fruits by HPLC‐DAD‐ESI‐MS

Abstract

In this study the polyphenolic composition of lilac flowers and fruits was determined for the first time. For the identification of compounds, accurate molecular masses and formulas, acquired by LC and ESI-TOF-MS and fragmentation pattern given by LC-ESI/MS/MS analyses, were used. Our chromatographic system in conjunction with tandem MS was found to be valuable in the rapid separation and determination of the multiple constituents in methanolic extracts of lilac flowers and fruits. Altogether 34 phenolics, comprising 18 secoiridoids, seven phenylpropanoids, four flavonoids and five low-molecular-weight phenols, were identified. As marker compounds two secoiridoids (oleuropein and nuzhenide), two phenylpropanoids (acteoside and echinacoside) and rutin were quantified by validated methods. As a result of quantitative analysis, it was confirmed that flowers contain significant amounts of phenylpropanoids (acteoside, 2.48%; echinacoside, 0.75%) and oleuropein (0.95%), while in fruits secoiridoid oleuropein (1.09%) and nuzhenide (0.42%) are the major secondary metabolites. The radical scavenging activities of the extracts and the constituents were investigated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] assays. Both extracts show remarkable antioxidant activities. Our results clearly show that lilac flowers and fruits are inexpensive, readily available natural sources of phenolic compounds with pharmacological and cosmetic applications. Copyright © 2015 John Wiley & Sons, Ltd.

Application of UHPLC-ESI-Q-TOF-MS to Identify Multiple Constituents in Processed Products of the Herbal Medicine Ligustri Lucidi Fructus

“…Two isomers of nuezhenide (compounds 22 and 29 ) were found in the 80% methanol extract of processed-LLF and they exhibited an identical fragmentation profile ( m / z 523, 453, 299 and 223). Compound 29 was then tentatively identified as isonuezhenide based on the later retention time than nuezhenide [ 26 ], while it was difficult to ascertain the structure of compound 22 due to the absence of available references. Compound 19 showed a strong signal at m / z 315 in its MS 2 spectrum, indicating a hydroxytyrosol glucoside moiety in its structure [ 26 ].…”

“…Compound 29 was then tentatively identified as isonuezhenide based on the later retention time than nuezhenide [ 26 ], while it was difficult to ascertain the structure of compound 22 due to the absence of available references. Compound 19 showed a strong signal at m / z 315 in its MS 2 spectrum, indicating a hydroxytyrosol glucoside moiety in its structure [ 26 ]. Combined with other fragments ( m / z 539, 469, and 437), compound 19 can be tentatively identified as neonuezhenide which owns an extra hydroxyl group than nuezhenide.…”

Determination of Polyphenols Using Liquid Chromatography–Tandem Mass Spectrometry Technique (LC–MS/MS): A Review

“…To overcome this problem, in recent years, the use of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been increasing in order to characterize the polyphenol-rich extracts. In addition, LC-MS/MS was able to achieve noise reduction and sensitivity improvements by exploiting multiple reaction monitoring (MRM) scan mode [1,28,29,[33][34][35][36][37][38]. Besides, in the last years, high-resolution LC-MS and LC-MS/MS approaches coupled with multivariate statistics have been widely used to realize the so-called "metabolomic profiling" of plant foods for human nutrition.…”

Effects of Phytochemically Characterized Extracts From Syringa vulgaris and Isolated Secoiridoids on Mediators of Inflammation in a Human Neutrophil Model

“…Scientific data supporting the traditional use of S. vulgaris are connected with its antioxidant, anti-inflammatory, anti-nociceptive and antipyretic properties (Bálinet, 1971 ; Tóth et al, 2015 , 2016 ; Dudek et al, 2017 ). Moreover, information about the single compounds responsible for each of these activities is scarce.…”