Off-line comprehensive 2-dimensional hydrophilic interaction x reversed phase liquid chromatography analysis of procyanidins

Extraction, identification, and starch-digestion inhibition of phenolics from Euryale ferox seed coat

BACKGROUND

Euryale ferox is an important cash crop and valuable tonic in traditional medicine. The seeds of E. ferox are rich in starch, which is hard to digest, and the digestion speed is significantly slower than that of rice starch. The goal of this study was to evaluate the effects of E. ferox seed-coat phenolics (EFCPs) on the digestion of E. ferox seed starch.

RESULTS

EFCPs were extracted and identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. We optimized the extraction parameters, and the final extraction yield was about 1.49%. We identified seven phenolics from the E. ferox seed-coat extracts: gallic acid, digalloylhexoside, catechin, procyanidin B2, epicatechin, ellagic acid, and epicatechin gallate. Quantitative analysis results showed that the E. ferox seed phenolics mainly distributed in the seed coat and the gallic acid, digalloylhexoside, and epicatechin gallate were three main phenolic compounds. The phenolics displayed strong inhibitory activities on α-glucosidase and α-amylase with an IC₅₀ of 3.25 μg mL^-1 and 1.36 mg mL^-1 respectively. Furthermore, these phenolics could interact with starch by hydrogen bonds, which might make its starch more difficult to digest.

CONCLUSION

Our investigation suggests that the EFCPs can strongly inhibit the digestion of E. ferox seed starch by inhibiting the α-amylase and α-glucosidase activities and interacting with starch by hydrogen bonds; therefore, E. ferox seeds have a promising application prospect in foods for hypoglycemia. © 2023 Society of Chemical Industry.

Coupling Hydrophilic Interaction Chromatography and Reverse-Phase Chromatography for Improved Direct Analysis of Grape Seed Proanthocyanidins

Acid-catalyzed depolymerization is recognized as the most practical method for analyzing subunit composition and the polymerization degree of proanthocyanidins, involving purification by removing free flavan-3-ols, as well as acid-catalyzed cleavage and the identification of cleavage products. However, after the removal of proanthocyanidins with low molecular weights during purification, the formation of anthocyanidins from the extension subunits accompanying acid-catalyzed cleavage occurred. Thus, grape seed extract other than purified proanthocyanidins was applied to acid-catalyzed depolymerization. Hydrophilic interaction chromatography was developed to quantify free flavan-3-ols in grape seed extract to distinguish them from flavan-3-ols from terminal subunits of proanthocyanidins. Reverse-phase chromatography was used to analyze anthocyanidins and cleavage products at 550 and 280 nm, respectively. It is found that the defects of the recognized method did not influence the results of the subunit composition, but both altered the mean degree of polymerization. The established method was able to directly analyze proanthocyanidins in grape seed extract for higher accuracy and speed than the recognized method.

Analysis of Proanthocyanidins in Plant Materials Using Hydrophilic Interaction HPLC-QTOF-MS

Proanthocyanidins (PACs) have been proven to possess a wide range of biological activities, but complex structures limit their study of structure–function relationships. Therefore, an efficient and general method using hydrophilic interaction high-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight tandem mass spectrometry (HILIC-QTOF-MS) was established to analyze PACs from different plant materials. This method was successfully applied to characterize PACs from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves (BLPs), sorghum testa (STPs) and grape seeds (GSPs). BLPs with the degree of polymerization (DP) from 1 to 8 were separated. BLPs are mainly B-type prodelphinidins and A-type BLPs were first found in this study. STPs and GSPs belonging to procyanidins showed DP from 3 to 11 and 2 to 12, respectively. A-type linkages were found for every DP of STPs and GSPs, which were first found. These results showed that HILIC-QTOF-MS can be successfully applied for analyzing PACs from different plant materials, which is necessary for the prediction of their potential health benefits.

Simultaneous Extraction and Depolymerization of Condensed Tannins from Chinese Bayberry Leaves for Improved Bioavailability and Antioxidant Activity

Biorefineries of polyphenols from plant leaves maximize their commercial value for developing biomedicines and nutrients. However, condensed tannins (CTs) constitute extensive polyphenols from plant leaves, which hinders the maximization due to extremely low bioavailability. Therefore, a simple, and sustainable one-step method was established to simultaneously extract polyphenols and depolymerize CTs with only endogenous flavan-3-ols from Chinese bayberry leaves via acid catalysis, which markedly improved the bioavailability of total polyphenols. Afterward, purification of polyphenols from depolymerized extract was studied with specific polymeric resins. Silica C18 showed the highest absorption efficiency of total polyphenols, while Amberlite XAD-7 and XAD-2 presented high selectivity toward polyphenols with high and low molecular weight, respectively. Combined depolymerization of CTs and purification with Amberlite XAD-2 showed the highest bioavailability and cellular free-radical scavenging activity of total polyphenols, which proved to be an ideal methodology for improving the bioavailability and activity of polyphenols from plant leaves.

Reversed phase versus hydrophilic interaction liquid chromatography as first dimension of comprehensive two-dimensional liquid chromatography systems for the elucidation of the polyphenolic content of food and natural products

Comprehensive two-dimensional liquid chromatography is a well-established method for the unraveling of very complex real-world samples. With regard to food and natural products such a technique turned out to be a very promising approach due to its high resolving power and improved identification capability, especially in combination with mass spectrometry. In this context, polyphenols comprise a particular complex class of bioactive compounds, due to their nature and content in commonly consumed foodstuffs, making their analysis challenging. The present contribution shows an overview of the two commonly employed approaches used for polyphenol analysis, viz. RP-LC × RP-LC and HILIC × RP-LC. Furthermore, the latest implementations as well as limitations and future perspectives are critically reported.

Assembly of Oil-Based Microcapsules Coated with Proanthocyanidins as a Novel Carrier for Hydrophobic Active Compounds

Proanthocyanidins are sustainable materials with amphiphilic characteristic, network-forming capacity, and health benefits, which give them possibility as encapsulating biomaterials. We found that proanthocyanidins from Chinese bayberry leaves and grape seeds (BLPs and GSPs) were able to encapsulate oil to form spherical microcapsules of controlled size and architecture. Microcapsules encapsulated with BLPs and GSPs (BMs and GMs) exhibited different physical stability when subjected to environmental stresses. BMs showed higher physical stability to environmental stresses than GMs. The proanthocyanidin shell could protect β-carotene from chemical degradation. Subsequently, varied gastrointestinal behaviors of the microcapsules were observed in simulated digestion. GMs with low stability reduced the lipid digestion and β-carotene bioaccessibility. BMs with high stability retarded lipid digestion but did not change the amount of hydrolyzed lipids and β-carotene bioaccessibility. Our study demonstrates that BLPs rather than GSPs can be used alone as encapsulating material for protection and targeted delivery of lipophilic bioactive compounds.

Phenolic profile, in vitro antimicrobial activity and antioxidant capacity of Vaccinium meridionale swartz pomace

Berries of Vaccinium meridionale Swartz contain a variety of phytochemicals, which are believed to account for their bioactive properties. The potential of Vaccinium meridionale Swartz pomace as a source of bioactive compounds was investigated. The dietary fiber (DF) content was assessed by the AOAC method, phenolic compounds were characterized and quantified via HPLC-PDA and UPLC-QTOF-MS. The in vitro antibacterial activity was tested against Gram-positive and Gram-negative bacteria. The antioxidant properties were assessed by the ORAC and the ABTS assays. The DF content was 52.4 ± 3.7%, phenolic compounds comprised anthocyanins (ACNs) (747.6 ± 167.5 mg cyanidin-3-glucoside/100 g FW), hydroxycinammic acids (HCAs) (229.2 ± 68.4 mg chlorogenic acid equivalents/100 g FW), flavonols (335.0 ± 139.5 rutin equivalents/100 g FW), and procyanidins (PACs) (140.9 ± 33.3 mg cocoa procyanidin equivalents/100 g FW). Staphylococcus aureus was more sensitive than E. coli. The ORAC value was 250.0 ± 32.0 μmol TE/g fresh weight (FW). Results suggest that the residue from V. meridionale S. can be utilized to obtain valuable nutraceuticals for the development of functional foods.

Development of a Rapid Method for the Determination of Phenolic Antioxidants in Dark Chocolate Using Ultra Performance Liquid Chromatography Coupled to Orbitrap Mass Spectrometry

Development of a new comprehensive method based on one-step liquid-liquid extraction (LLE) combined with ultra-high-performance liquid chromatography-Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-HRMS) for the determination of eight phenolic compounds in dark chocolate is demonstrated. The study focuses on the optimization of sample preparation, chromatographic separation and Orbitrap-HRMS detection parameters to adjust selectivity and sensitivity of the method. The LLE mixture of formic acid-water-acetonitrile (2:58:40, v/v) and hexane at the component ratio of 1:1 (v/v) was applied for sample preparation. The inter-day and intra-day precision expressed from the relative standard deviations (RSDs) ranged between 5.50-14.2% and 5.60-16.2%. The quantification limits of the target analytes were between 0.1 and 1.0 mg/kg. The method was applied for the analysis of twenty-six samples of dark chocolate with various cocoa solid contents (30-77%) collected from the markets in Latvia. The total levels of the phenolic contents ranged between 330 and 2631 mg/kg. The study demonstrates advantages of the Orbitrap-HRMS method for the study of phenolic compounds in dark chocolate.

Comprehensive Three-Dimensional LC × LC × Ion Mobility Spectrometry Separation Combined with High-Resolution MS for the Analysis of Complex Samples

Comprehensive two-dimensional liquid chromatography (LC × LC) and ion mobility spectrometry-mass spectrometry (IMS-MS) are increasingly being used to address challenges associated with the analysis of highly complex samples. In this work, we evaluate the potential of the combination of these techniques in the form of a comprehensive three-dimensional LC × LC × IMS separation system. As application, hydrophilic interaction chromatography (HILIC) × reversed phase LC (RP-LC) × IMS-high-resolution MS (HR-MS) was used to analyze a range of phenolic compounds, including hydrolyzable and condensed tannins, flavonoids, and phenolic acids in several natural products. A protocol for the extraction and visualization of the four-dimensional data obtained using this approach was developed. We show that the combination of HILIC, RP-LC, and IMS offers excellent separation of complex phenolic samples in three dimensions. Benefits associated with the incorporation of IMS include improved MS sensitivity and mass-spectral data quality. IMS also provided separation of trimeric procyanidin isomeric species that could not be differentiated by HILIC × RP-LC or HR-MS. On the traveling wave IMS (TWIMS) system used here, both IMS separation performance and the extent of second dimension (²D) undersampling depend on the upper mass scan limit, which might present a limitation for the analysis of larger molecular ions. The performance of the LC × LC × IMS system was characterized in terms of practical peak capacity and separation power, using established theory and taking undersampling and orthogonality into account. An average increase in separation performance by a factor of 13 was found for the samples analyzed here when IMS was incorporated into the HILIC × RP-LC-MS workflow.

Variability between organs of proanthocyanidins in Geranium sylvaticum analyzed by off-line 2-dimensional HPLC-MS

Proanthocyanidins have been characterized in the different organs of Geranium sylvaticum by using an off-line 2-dimensional chromatographic method. In the first dimension, proanthocyanidins were separated according to their increasing degree of polymerization by hydrophilic interaction liquid chromatography. In the second dimension, reversed-phase liquid chromatography was used to separate the same size isomers based on their hydrophobicity. Ultraviolet detection and high-resolution electrospray ionization time-of-flight mass spectrometry were used for the identification and characterization of proanthocyanidins. The method was proven to be suitable for the analysis of plant organ fractions of G. sylvaticum that contained complex mixtures of phenolic compounds and proanthocyanidins from several classes. Procyanidins, prodelphinidins and mixed proanthocyanidins composed of both (epi)catechin and (epi)gallocatechin units including monomers, oligomers and polymers up to the degree of polymerization of 20 were identified. The type and size of proanthocyanidins varied between eight studied organs of G. sylvaticum. The 2-dimensional analysis revealed that each proanthocyanidin type occur in the equally complex isomeric pattern. The mean degree of polymerization of different proanthocyanidins in the eight plant organs of G. sylvaticum was 5 and it varied only slightly between plant organs.

Liquid chromatography-high resolution mass spectrometry for the analysis of phytochemicals in vegetal-derived food and beverages

The recent years witnessed a change in the perception of nutrition. Diet does not only provide nutrients to meet the metabolic requirements of the body, but it also constitutes an active way for the consumption of compounds beneficial for human health. Fruit and vegetables are an excellent source of such compounds, thus the growing interest in characterizing phytochemical sources, structures and activities. Given the interest for phytochemicals in food, the development of advanced and suitable analytical techniques for their identification is fundamental for the advancement of food research. In this review, the state of the art of phytochemical research in food plants is described, starting from sample preparation, throughout extract clean-up and compound separation techniques, to the final analysis, considering both qualitative and quantitative investigations. In this regard, from an analytical point of view, fruit and vegetable extracts are complex matrices, which greatly benefit from the use of modern hyphenated techniques, in particular from the combination of high performance liquid chromatography separation and high resolution mass spectrometry, powerful tools which are being increasingly used in the recent years. Therefore, selected applications to real samples are presented and discussed, in particular for the analysis of phenols, polyphenols and phenolic acids. Finally, some hot points are discussed, such as waste characterization for high value-compounds recovery and the untargeted metabolomics approach.

Large-scale qualitative and quantitative characterization of components in Shenfu injection by integrating hydrophilic interaction chromatography, reversed phase liquid chromatography, and tandem mass spectrometry

It is of great importance to clarify in depth the chemical composition, including qualitative and quantitative aspects, of traditional Chinese medicine (TCM) injection that contains a great number of hydrophilic and hydrophobic ingredients to guarantee its safe medication in clinic. Column-switching hydrophilic interaction liquid chromatography-reversed phase liquid chromatography coupled with tandem mass spectrometry (HILIC-RPLC-MS/MS) has been revealed to be advantageous at simultaneous measurement of compounds covering a broad polarity range. Previous studies have profiled the hydrophobic components, mainly aconite alkaloids and ginsenosides, in Shenfu Injection (SFI); however, the hydrophilic substances haven't been taken into account. In the present study, we aim to holistically characterize the hydrophilic constituents and to simultaneously quantitate both hydrophilic and hydrophobic components in SFI. A strategy integrating predefined multiple reaction monitoring, step-wise multiple ion monitoring, and enhanced product ion scans was proposed to universally screen the hydrophilic substances using a hybrid triple quadrupole-linear ion trap mass spectrometer. Structural identification was carried out by comparing with authentic compounds, analyzing MS(2) spectra, and referring to accessible databases (e.g., MassBank, METLIN and HMDB). A total of 157 hydrophilic compounds were detected from SFI, and 154 ones were identified as amino acids, nucleosides, organic acid, carbohydrates, etc. A column-switching HILIC-RPLC-MS/MS system was developed and validated for simultaneously quantitative analysis of 40 primary hydrophilic and hydrophobic ingredients in SFI, including eleven amino acids, nine nucleosides, nine aconite alkaloids, and eleven ginsenosides. Taken together, the findings obtained could provide meaningful information for comprehensively understanding the chemical composition and offer a reliable approach for the quality control of SFI.

Methods to determine effects of cranberry proanthocyanidins on extraintestinal infections: Relevance for urinary tract health

Urinary tract infections (UTI) are one of the most frequent extraintestinal infections caused by Escherichia coli (ExPEC). Cranberry juice has been used for decades to alleviate symptoms and prevent recurrent UTI. The putative compounds in cranberries are proanthocyanidins (PAC), specifically PAC with "A-type" bonds. Since PAC are not absorbed, their health benefits in UTI may occur through interactions at the mucosal surface in the gastrointestinal tract. Recent research showed that higher agglutination of ExPEC and reduced bacterial invasion are correlated with higher number of "A-type" bonds and higher degree of polymerization of PAC. An understanding of PAC structure-activity relationship is becoming feasible due to advancements, not only in obtaining purified PAC fractions that allow accurate estimation, but also in high-resolution MS methodologies, specifically, MALDI-TOF MS. A recent MALDI-TOF MS deconvolution method allows quantification of the ratios of "A-type" to "B-type" bonds enabling characteristic fingerprints. Moreover, the generation of fluorescently labeled PAC allows visualization of the interaction between ExPEC and PAC with microscopy. These tools can be used to establish structure-activity relationships between PAC and UTI and give insight on the mechanism of action of these compounds in the gut without being absorbed.

Detailed polyphenolic profiling of Annurca apple (M. pumila Miller cv Annurca) by a combination of RP-UHPLC and HILIC, both hyphenated to IT-TOF mass spectrometry

Annurca apple, a Southern Italian cultivar, possesses not only a particular taste and flavor, different from other types of apple, but also several healthy properties. With the aim to thoroughly elucidate the polyphenolic profile of this variety, listed as Protected Geographical Indication product, an extensive qualitative profiling of Annurca apple polyphenolic peel extract was carried out, by employing a combination of ultra high performance reversed phase (RP-UHPLC) and hydrophilic liquid chromatography (HILIC) coupled to ion trap-time of flight (IT-TOF) mass spectrometry. A total of 63 compounds were tentatively identified, 25 of which not reported in Annurca apple extract so far. Furthermore, thanks to the different selectivity obtained with the HILIC, in combination with accurate mass measurements, an improved separation and detection of procyanidins, was obtained. Moreover, the obtained profiles were compared with those of a conventional variety, such as Red Delicious (RD), highlighting their differences. This work contributes to increase the knowledge about the polyphenolic fingerprint of this typical apple variety.

Isolation and quantification of oligomeric and polymeric procyanidins in leaves and flowers of Hawthorn (Crataegus spp.)

Proanthocyanidins (PAs) constitute a class of polyphenols with flavan-3-ols as monomeric building blocks. These polyphenols are mostly quantified by colorimetric methods or by chromatographic determination of monomeric flavan-3-ols or low molecular oligomers as lead compounds. No reliable analytical methods are available for unambiguous identification of the homologues series of oligo- and polymeric PAs. For Hawthorn leaf and flower (Crataegi folium cum flore) from Crataegus spp. (Rosaceae) a protocol for preparative isolation of oligomeric and polymeric PAs from an acetone-water extract was developed, yielding procyanidin reference clusters with defined degree of polymerization (DP) from 2 to 10 besides a procyanidin-polymer. Identity and purity of these clusters were proven by HPLC, MS and in part NMR studies. For identification and quantification from Hawthorn an ICH-Q2 validated UHPLC method with fluorimetric detection and less than 10min runtime was developed. The method enabled quantification of procyanidin clusters with DP from 2 to 10 besides the polymer fraction. Batch analysis revealed procyanidin contents of about 20 to 45mg/g from a homologues series of oligomeric PAs and about 50% of polymer fraction. Monitoring of procyanidin distribution during seasonal growth of fresh plants of Crataegus monogyna showed more or less constant contents between 20 and 55mg/g dry weight of oligomeric procyanidins during the growing season in the different plant organs with strong accumulation in the flowers and fruits (55mg/g dry weight). From these data it can be speculated that procyanidins serve as part of the plants defense system in the reproductive organs of the plant.

Proanthocyanidins in wild sea buckthorn (Hippophaë rhamnoides) berries analyzed by reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography with UV and MS detection

A rapid and sensitive method for profiling of proanthocyanidins (PAs) of sea buckthorn (Hippophaë rhamnoides) berries was established based on aqueous, acidified acetone extraction. The extract was purified by Sephadex column chromatography and analyzed using reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography (HILIC). Negative ion electrospray ionization mass spectrometry (ESI-MS) in single ion recording (SIR) and full scan modes combined with UV detection were used to define the combinations and ratios of PA oligomer classes. PAs with degree of polymerization from 2 to 11 were detected by HILIC-ESI-MS. Quantification of dimeric, trimeric, and tetrameric PAs was carried out with ESI-MS-SIR, and their molar proportions were 40, 40, and 20%, respectively. Only B-type PAs were found, and (epi)gallocatechins were the main monomeric units. More than 60 combinations of (epi)catechins and (epi)gallocatechins of proanthocyanidin dimers and trimers were found. A majority of the PAs were shown to be higher polymers based on the HILIC-UV analysis.

Separation and characterization of phlorotannins from brown algae Cystoseira abies-marina by comprehensive two-dimensional liquid chromatography

Phlorotannins are an important class of polyphenolic compounds only found in brown algae. The chemical analysis of these bioactive polyphenols is rather difficult due to the great chemical variability and complexity of the natural composition of these components in algae, forming large phloroglucinol polymers. In the present work, a new approach based on the use of comprehensive 2D LC (LC × LC) is shown to analyze this complex family of compounds. The developed LC × LC methodology is based on the coupling of a hydrophilic-interaction LC (HILIC)-based separation in the first dimension and an RP-based separation in the second dimension. The employment of this online coupling together with DAD and MS/MS allowed the separation and identification of more than 50 compounds in a Cystoseira abies-marina brown alga extract. Phlorotannins containing from 5 to 17 phloroglucinol units were identified in this sample by HILIC × RP-DAD-MS/MS. Besides, using the 2,4-dimethoxybenzaldehyde assay, it was possible to determine that the total amount of phlorotannins present in the extract was 40.2 mg phloroglucinol equivalents per gram of extract. To our knowledge, this work is the first demonstration of the usefulness of HILIC × RP-DAD-MS/MS for the determination of phlorotannins.

Hydrophilic interaction chromatographic analysis of anthocyanins

Hydrophilic interaction chromatography (HILIC) provides an alternative separation mode for the analysis of phenolic compounds, in which aqueous-organic mobile phases with polar stationary phases are used. This paper reports the evaluation of HILIC for the analysis of the natural pigments anthocyanins, which are of importance because of their chromophoric properties and a range of health benefits associated with their consumption. Several HILIC stationary phases (silica, diol, amine, cyanopropyl and amide) and mobile phase combinations were evaluated, with the latter proving particularly important due to the distinctive chromatographic behaviour of anthocyanins. Diode array detection was used for selective detection of anthocyanins, while high resolution quadrupole-time-of-flight mass spectrometry (Q-TOF-MS) was used for compound identification. The potential of HILIC separation is demonstrated for a range of anthocyanins varying in glycosylation and acylation patterns found in blueberries, grape skins, black beans, red cabbage and red radish. HILIC is shown to be a complementary separation method to reversed phase liquid chromatography (RP-LC) due to the alternative retention mechanism.

On-line comprehensive two dimensional separations of charged compounds using reversed-phase high performance liquid chromatography and hydrophilic interaction chromatography. Part II: application to the separation of peptides

In this second paper of a two-part series, on-line RPLC×HILIC is compared to on-line RPLC×RPLC through the separation of peptides. Our choices regarding the conditions are discussed. Injection effects and overloading effects are evaluated in both configurations. It is shown that whereas large volumes can be injected in the second dimension in RPLC×RPLC under HT-UHPLC conditions (>20% of the column dead volume), even small injection volumes (8% of the column the dead volume) have a detrimental effect on peak shapes in RPLC×HILIC. Advantages and limits of the two 2D-systems are compared through the 2D-separation of a tryptic digest of three proteins. A ten-fold gain in analysis time along with a significant gain in peak capacity are obtained with both systems compared to the most efficient one-dimensional separation of peptides recently published.

Profiling of phenolic compounds from different apple varieties using comprehensive two-dimensional liquid chromatography

An innovative analytical approach based on the use of comprehensive two-dimensional liquid chromatography (LC×LC) is applied to obtain the profiling of phenolic compounds in different apple varieties. The method combines the use of hydrophilic interaction liquid chromatography in the first dimension and a reversed phase separation in the second dimension, as well as the use of diode array and mass spectrometry detection. Using this methodology is possible to obtain in less than 50 min the complete profiling of phenolic compounds in a complex food matrix such as apple. In fact, different flavan-3-ols including procyanidin oligomers with degree of polymerization up to 8, as well as several dihydrochalcones, flavonols and a phenolic acid are separated and tentatively identified in these samples in a single run. Besides, the total phenols and total procyanidins amounts were determined using two in vitro assays. Reinette apples presented the highest content on total phenols (6.46 mg galic acid equiv./g dry matter) whereas Granny Smith apples were the richest on total procyanidins (0.73 mg epicatechin equiv./g dry matter). This work shows the great potential of LC×LC for phenolic compounds profiling in complex food samples.

Serial coupling of reversed-phase and zwitterionic hydrophilic interaction LC/MS for the analysis of polar and nonpolar phenols in wine

In the present study, an easy and efficient method based on the serial coupling of analytical reversed-phase and zwitterionic hydrophilic interaction liquid chromatography was developed for the simultaneous separation of polar and nonpolar phenols occurring in wine. The zwitterionic hydrophilic column was connected in series to the reversed-phase one via a T-piece, with which the ACN content in eluent of the second dimension was increased, in order to cope the solvent strength incompatibility between the two columns. The final mobile phase at low-flow rate (≤0.5 mL/min), high-ACN content (90%), and low-salt concentration was directed to an ESI-TOF-MS , for high accurate mass detections. The developed method was applied for the identification of target phenols in several wines. Retention time and peak width intra- and interday repeatability studies proved the reliability of the method for the simultaneous analysis of all the polar and nonpolar analytes in wine. The serial reversed-phase/zwitterionic hydrophilic interaction liquid chromatography coupling offered the possibility to enlarge the number of identified compounds and it represents a valid approach for nontarget analysis of complex samples by a single injection.