Galloylquinic Acid Research Articles

HYDROXYCINNAMIC ACID DERIVATIVES AND FLAVONOL PROFILES OF MAQUI (Aristotelia chilensis) FRUITS

ABSTRACT Maqui ( Aristotelia chilensis ) is an edible berry native to Southern Chile. The anthocyanin profiles and concentrations of this fruit have been widely studied. The high concentration of anthocyanins confers a deep colour to the skin and pulp of maqui berries, and the biological activity of this fruit has been attributed to these compounds. However, other compounds such as flavonols and hydroxycinnamic acid derivatives in this fruit have not been studied to date.The objective was to determine the hydroxycinnamic acid derivatives and flavonol profiles in maqui berries in order expand the knowledge base for this fruit.Two extraction methodologies (solid phase extraction using a mixed mode cation exchange cartridge and selective precipitation), followed by HPLC-DAD-ESI-MS/MS were applied to the extraction and identification of the main hydroxycinnamic acids and flavonols in the berries. Quantification was accomplished by using the first extraction procedure. Low levels of hydroxycinnamic acid derivatives were detected in maqui berries, where 5-galloylquinic acid was the only quantifiable derivative. However, diverse and high levels of flavonols were detected in the fruit, the most relevant of which are myricetin-galactoside, quercetin-rutinoside, and quercetin-3-galactoside. Nineteen other flavonols were identified, with total concentrations between 1.05 and 1.18 µmol/g fresh weight.The diversity of flavonols makes the profiles and concentrations of these compounds significant, whereas hydroxycinnamic acids in maqui are not significant. The comparatively high levels of flavonols combined with the high concentration of anthocyanins contribute to the consideration of this native fruit from Chile as a “superfruit”.

Multi-response optimization of phenolic antioxidants from white tea (Camellia sinensis L. Kuntze) and their identification by LC–DAD–Q-TOF–MS/MS

The aim of this study was to model the extraction of phenolic antioxidants and identify the principal individual phenolic compounds of white tea by LC-DAD-MS/MS. A Box-Behnken design was applied to evaluate the effects of time, temperature and ethanol concentration in the extraction of phenolics and in vitro antioxidant activity. All mathematical models proposed by multiple regression analysis were significant (P < 0.001) and could explain up to more than 85% of the variance (R2adj > 0.80). A simultaneous optimization was performed using DPPH, ABTS, FRAP, (−)-epigallocatechin gallate, and (−)-epicatechin gallate to maximize the phenolic extraction and suggested optimum conditions of 10 min, 66 °C and 30% ethanol solution, with absolute error lower than 7%. The suggested optimum conditions were confirmed by external validation. The principal individual compounds identified by mass spectrometry were gallic acid, 5-galloylquinic acid, caffeine, theobromine, gallocatechin, epigallocatechin, epicatechin, epigallocatechin gallate, and epicatechin gallate.

Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions.

Lepidopteran larvae encounter a variety of phenolic compounds while consuming their host plants. Some phenolics may oxidize under alkaline conditions prevailing in the larval guts, and the oxidation products may cause oxidative stress to the larvae. In this study, we aimed to find new ways to predict how phenolic compounds may be modified in the guts of herbivorous larvae. To do so, we studied the ease of oxidation of phenolic compounds from 12 tropical tree species. The leaf extracts were incubated in vitro in alkaline conditions, and the loss of total phenolics during incubation was used to estimate the oxidizability of extracts. The phenolic profiles of the leaf extracts before and after incubation were compared, revealing that some phenolic compounds were depleted during incubation. The leaves of the 12 tree species were each fed to 12 species of lepidopteran larvae that naturally feed on these trees. The phenolic profiles of larval frass were compared to those of in vitro incubated leaf extracts. These comparisons showed that the phenolic profiles of alkali-treated samples and frass samples were similar in many cases. This suggested that certain phenolics, such as ellagitannins, proanthocyanidins, and galloylquinic acid derivatives were modified by the alkaline pH of the larval gut. In other cases, the chromatographic profiles of frass and in vitro incubated leaf extracts were not similar, and new modifications of phenolics were detected in the frass. We conclude that the actual fates of phenolics in vivo are often more complicated than can be predicted by a simple in vitro method.

Characterization of binary and ternary mixtures of green, white and black tea extracts by electrospray ionization mass spectrometry and modeling of their in vitro antibacterial activity

In this study we modeled the in vitro antibacterial activity of the extracts of green, white and black tea mixtures using the response surface methodology. Camellia sinensis var sinensis tea mixtures were prepared according to a 3-component simplex-centroid design containing ten formulations. The antibacterial activity was used to assess the inhibition ability of the tea mixtures against a range of seven Gram positive, Gram negative, vegetative cells and sporeforming bacteria. A formulation of tea mixtures was then optimized by the desirability function aiming to maximize the inhibition of different strains and/or serotypes of Salmonella. The best tea formulation was chemically characterized by electrospray ionization mass spectrometry (ESI–MS). The linear effects of white and black teas were statistically significant (p < 0.05) as well as the interaction between green and white and green and black on the inhibition of S. Thyphimurium. Although the optimized tea mixture was effective against all Salmonella strains, the inhibition was substantially greater for specific serotypes, with differences observed even among strains of the same serotype (p < 0.05). A total of 11 phenolic constituents such as gallic acid, quinic acid, (+)-catechin/(−)-epicatechin, (−)-gallocatechin/(−)-epigalocatechin, coumaroylquinic acid, galloylquinic acid, and caffeoylquinic acid were tentatively identified using ESI–MS.

Seasonal variation in the levels of the main phenolics in Copaifera langsdorffii leaves

The main phenolics found in Copaifera langsdorffii leaves (Fabaceae, Caesalpinioideae) are galloylquinic acids (GQAs) and flavonoids (Fs). To verify their variation according to seasons and climatic factors, for further standardization of plant raw material, leaf samples of 10 different populations of C. langsdorffii cultivated under the same conditions in Cajuru, SP, Brazil were collected monthly in 2012. Then, they were analyzed by HPLC-UV, using analytical method previously validated to quantify nine GQAs and two Fs. Climatic data for radiation rate (R), temperature (T), humidity (H), and pluviometric precipitation (P) were provided by the National Institute of Meteorology, Brazil. Multivariate analysis was performed to correlate climatic and chemical variables. RDA was carried out using the software CANOCO 4.5 (DCA gradient< 0.5, Monte Carlo analysis p < 0.05), and grouped C. langsdorffii populations by month and not by origin. The results of CDA followed by Jackknifed test (Percentage of correct classification = 100%), confirmed the clustering proposal for four distinct groups: I, May-Jul (negative correlation with R, T, and chemical variables – low levels of phenolics); II, Aug-Sep (negative correlation with P and H); III, Jan (positive correlation with R, T, and chemical variables, especially Fs); IV, Feb-Apr, and Oct-Dec (positive correlation with T, P, H, and chemical variables, especially in February – high levels of phenolics). On one hand, all 10 populations gave similar qualitative and quantitative chemical composition in a particular month, when cultivated under the same conditions; on the other hand, the seasonal variations played an important role on quantitative content of the analyzed phenolics. Therefore, a standardized extract may be produced independently of the chosen cultivated population.

Copaifera langsdorffii supercritical fluid extraction: Chemical and functional characterization by LC/MS and in vitro assays

Copaifera langsdorffii is a native Brazilian plant containing important amounts of polyphenols and diterpenes with biological activity. To obtain extracts enriched in these two types of compounds, supercritical fluid extraction (SFE) conditions have been optimized by using a response surface methodology (RSM) and considering as factors: extraction pressure and temperature and percentage of co-solvent (ethanol). The response variables selected were the concentration of the two most representative compounds in C. langsdorffii, kaurenoic acid (diterpenic acid) and quercitrin (glycosylated flavonol), total flavonoids content, and antioxidant activity (measured by DPPH and TEAC assays). According to the statistical analysis of the experimental design, extraction temperature and ethanol percentage were the main factors influencing the selectivity towards the extraction of the target compounds. Two optimized extracts were obtained: (1) containing high amount of total flavonoids, high concentration of quercitrin and low EC50 for the DPPH assay, named HQE—High Quercitrin Extract (100bar, 70°C and 50% of ethanol, in the region of gas-expanded liquids, GXLs) and (2) containing high value of kaurenoic acid extract, named HKAE-High Kaurenoic Acid Extract, (390bar, 70°C and pure CO2). Chemical characterization by LC/MS of HQE showed the presence of galloylquinic acids and flavonoids while, on the other hand, HKAE presented only nonpolar compounds such as kaurenoic acid. Moreover, a solid–liquid extraction (SLE) with methanol was carried out as a benchmark protocol for comparative purposes. SFE presented approximately 10-fold higher content of total flavonoids than the extracts obtained by SLE.

Evaluation of total antioxidant potential of Pistacia lentiscus var. chia leaves extracts using UHPLC–HRMS

In this study, Pistacia lentiscus var. chia leaves were dehydrated by freeze drying and the initial, final moisture content and the drying kinetics were examined. Soxhlet Extraction (SE), Microwave Assisted (MAE) and Ultrasound Assisted Extraction (UAE) were employed to recover extracts with high antioxidant activity, total phenolic and flavonoid content from fresh and dried leaves. Fresh leaves showed higher yield and antioxidant potential, with MAE extracts exhibiting the greatest extraction yield (48.11±0.56% d.b.), followed by UAE (39.39±1.13% d.b.) and SE (31.99±1.55% d.b.). UAE extracts exhibited the highest antioxidant activity (IC50=37.13±2.7μg/mL), while SE extracts showed the highest total phenolic content (314.88±0.01mg GAE/g dry extract). UAE extracts of dried leaves exhibited total flavonoid content (106.5±0.02mg QE/g dry extract). Moreover, UHPLC-ESI–HMRS was performed to the extract with the highest antioxidant activity and confirmed the presence of isomers of galloyl quinic acid, quercetin and kaempferol glucosides, luteolin and neorehmannioside.

Development of an analytical method by HPLC for quantification of galloylquinic compounds from Copaifera langsdorffii leaves

Copaifera langsdorffii Desf. (Fabaceae, Caesalpinioideae), popularly known as “copaiba”, is a large tree widely distributed in Brazil and used in folk medicine. Its leaves are composed mainly by phenolic compounds, such as galloylquinic acid derivatives (GQA) and flavonoids. The water soluble fraction of the crude hydroalcoholic extract was submitted to Sephadex LH-20 using a gradient of methanol-water (1:9 to 9:1) and purified by preparative RP-HPLC. Sixteen GQA were isolated and used as chromatographic standards. HPLC-PDA analyses were carried out on a Synergi Polar-RP (100 × 3.0 mm, 2.5 µm) column. The mobile phase was made up of formic acid-water (0.1:99.9, solvent A), and isopropanol-methanol-acetonitrile (0.5:4:6, solvent B). The elution gradient was A:B (90:10 to 85:15) in 8.0 minutes, followed by A:B (85:15 to 64:36) up to 30.0 minutes using a flow rate of 0.7 mL/min. The HPLC-PDA developed method was suitable to quantify nine GQA and two flavonoids, quercitrin and afzelin.

Tara tannins as phenolic precursors of thermosetting epoxy resins

Tara pods powder was used as a phenolic source in the synthesis of thermosetting epoxy polymer. The tannase-assisted hydrolysis of galloylquinic acids contained in tara powder allowed the determination of the tannins hydroxyl value (13.7mmol/g powder). Then, galloylquinic acids were reacted with epichlorohydrin and an aqueous solution of sodium hydroxide in the presence of benzyltriethylammonium chloride as phase transfer catalyst (PTC). The 1D and 2D NMR analyses of glycidylated products revealed the galloylquinic esters hydrolysis and the dimerisation of the glycidylated gallic moities. The glycidylated derivatives of tara tannins (GETT) were cured in epoxy polymer with isophorone diamine (IPD). The glass transition temperature (Tg=129°C) and the thermal resistance (Td30=294°C) of the resulting network were determined. Preliminary results showed that this new epoxy polymer based on GETT displayed interesting properties which are close to those of the epoxy polymer formulated with commercial diglycidyl ether of bisphenol A (DGEBA).

Leishmanicidal Galloylquinic Acids are Noncompetitive Inhibitors of Arginase

Leishmanicidal galloylquinic acids were isolated from the ethyl acetate extract of Byrsonima coccolobifolia. These phenols and gallic acid showed to be a new class of potent noncompetitive inhibitors of arginase ARG (Ki ranging from 0.10 to 0.68 µmol L -1 ) from Leishmania amazonensis. Quinic acid did not exhibit significant inhibition of ARG, indicating that galloyl moiety has important features that allows the enzyme-inhibitor interactions. The significant inhibitory activity of gallic acid on ARG can be a clue to understand the immune response previously observed on L. donovani, since ARG activity is associated with the decrease of the levels of NO in Leishmania infection.

Defensive strategies in Geranium sylvaticum, Part 2: Roles of water-soluble tannins, flavonoids and phenolic acids against natural enemies

Geranium sylvaticum is a common herbaceous plant in Fennoscandia, which has a unique phenolic composition. Ellagitannins, proanthocyanidins, galloylglucoses, gallotannins, galloyl quinic acids and flavonoids possess variable distribution in its different organs. These phenolic compounds are thought to have an important role in plant-herbivore interactions. The aim of this study was to quantify these different water-soluble phenolic compounds and measure the biological activity of the eight organs of G. sylvaticum. Compounds were characterized and quantified using HPLC-DAD/MS, in addition, total proanthocyanidins were determined by BuOH-HCl assay and total phenolics by the Folin-Ciocalteau method. Two in vitro biological activity measurements were used: the prooxidant activity was measured by the browning assay and antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Organ extracts were fractionated using column chromatography on Sephadex LH-20 and the activities of fractions was similarly measured to evaluate which polyphenol groups contributed the most to the biological activity of each organ. The data on the activity of fractions were examined by multivariate data analysis. The water-soluble extracts of leaves and pistils, which contained over 30% of the dry weight as ellagitannins, showed the highest pro-oxidant activity among the organ extracts. Fraction analysis revealed that flavonoids and galloyl quinic acids also exhibited high pro-oxidant activity. In contrast, the most antioxidant active organ extracts were those of the main roots and hairy roots that contained high amounts of proanthocyanidins in addition to ellagitannins. Analysis of the fractions showed that especially ellagitannins and galloyl quinic acids have high antioxidant activity. We conclude that G. sylvaticum allocates a significant amount of tannins in those plant parts that are important to the fitness of the plant and susceptible to natural enemies, i.e. pistil and leaf tannins protect against insect herbivores and root tannins against soil pathogens.

Copaifera langsdorffii aqueous extract and its galloylquinic acid display gastroprotective activity

Copaifera langsdorffii aqueous extract and its galloylquinic acid display gastroprotective activity

Defensive strategies in Geranium sylvaticum. Part 1: Organ-specific distribution of water-soluble tannins, flavonoids and phenolic acids

A combination of high-resolution mass spectrometry and modern HPLC column technology, assisted by diode array detection, was used for accurate characterization of water-soluble polyphenolic compounds in the pistils, stamens, petals, sepals, stems, leaves, roots and seeds of Geranium sylvaticum. The organs contained a large variety of polyphenols, five types of tannins (ellagitannins, proanthocyanidins, gallotannins, galloyl glucoses and galloyl quinic acids) as well as flavonoids and simple phenolic acids. In all, 59 compounds were identified. Geraniin and other ellagitannins dominated in all the green photosynthetic organs. The other organs seem to produce distinctive polyphenol groups: pistils accumulated gallotannins; petals acetylglucose derivatives of galloylglucoses; stamens kaempferol glycosides, and seeds and roots accumulated proanthocyanidins. The intra-plant distribution of the different polyphenol groups may reflect the different functions and importance of various types of tannins as the defensive chemicals against herbivory.

A comparison on the metabolic profiling of the Mexican anxiolytic and sedative plant Galphimia glauca four years later

Ethnopharmacological relevanceGalphimia glauca has a long traditional use, and continues to be used in Mexico as a natural tranquilizer for the treatment of Central Nervous System disorders as well as for other illnesses. Aim of the studyIn 2005 the initial use of metabolic profiling to populations of Galphimia glauca resulted in two of the six collected populations being producers for galphimines, the markers for sedative and anxiolytic activities. The aim of this investigation was to confirm the previously established metabolic profile, as well as the previous in vivo results on mice. Additionally in this study we wanted to investigate potential anti-inflammatory properties. Materials and methodsFour years later, we collected samples in the five localities designated for the first-stage investigation in 2005, and in two new locations. Metabolic profiling was carried out by means of 1H NMR spectroscopy and multivariate data analysis applied to crude extracts from wild plant specimens. HPLC analysis was performed to confirm and quantify the presence of galphimines. Two neuropharmacological in vivo assays on mice were employed to study anxiolytic (elevated plus maze test) and sedative (sodium pentobarbital-induced hypnosis model) activities in the extracts. Anti-inflammatory activity was determined by using the tetradecanoylphorbol acetate-induced mouse ear inflammation model (TPA). Results and conclusionsThe results for the 2009 collected species were similar to the 2005 collection, confirming the metabolic profiles and that galphimines are consistent good markers for CNS activity. Galloylquinic acid levels varied between the years without, as of yet, known effects. In vivo anti-inflammatory activity was similar for all plants and thus not linked with galphimines, requiring further studies to identify the active compound(s). Areas of collection affect neuropharmacological activities but not anti-inflammatory action.

Triterpene hexahydroxydiphenoyl esters and a quinic acid purpurogallin carbonyl ester from the leaves of Castanopsis fissa

Triterpene hexahydroxydiphenoyl (HHDP) esters have only been isolated from Castanopsis species, and the distribution of these esters in nature is of chemotaxonomical interest. In this study, the chemical constituents of the leaves of Castanopsis fissa were examined in detail to identify and isolate potential HHDP esters. Together with 53 known compounds, 3,4-di- O-galloyl-1- O-purpurogallin carbonyl quinic acid ( 1) and 3,24-( S)-HHDP-2α,3β,23,24-tetrahydroxytaraxastan-28,20β-olide ( 2) were isolated and their structures were elucidated by spectroscopic and chemical methods. The polyphenols of the leaves were mainly composed of galloyl quinic acids, triterpenes HHDP esters, ellagitannins and flavonol glycosides. In particular, the isolation yields of 1,3,4-trigalloyl quinic acid and compound 2 were 1.53% and 0.27%, respectively, from the fresh leaves. The presence of lipid soluble HHDP esters of oleanane-type triterpenes as one of the major metabolites is an important chemotaxonomical discovery. Lipase inhibition activities and ORAC values of the major constituents were compared. The triterpene HHDP ester showed moderate lipase inhibition activity and myricitrin gave the largest ORAC value.

HPLC/DAD/ESI-MS analyses and anti-radical activity of hydrolyzable tannins from different vegetal species

In the present work, several tannin extracts from myrtle and pomegranate were analyzed and characterized using HPLC/DAD/ESI-MS methods. Both aqueous and hydroalcoholic myrtle leaf extracts were found to be rich in galloyl-glucosides, galloyl-quinic acids, ellagitannins and flavonoids. In these extracts we observed a predominance of galloyl-glucosides and galloyl-quinic derivatives with respect to ellagic derivatives; 87.14% and 12.86%, respectively, average gallic and ellagic derivatives with respect to total tannins content. In pomegranate extracts, substantial differences were found in polyphenol contents between peel and seed extracts with regard to the relative abundance of gallic and ellagic acid derivatives: 28.81% and 71.19%, respectively, as average total gallic and ellagic derivatives in peel extracts; 61.30% and 38.70%, in seed extracts. The antiradical properties were evaluated and compared to those of two commercial extracts of chestnut bark and grape seeds. The collected data could suggest the use of myrtle and pomegranate extracts as nutraceuticals and functional foods for their important antioxidant properties.

Metabolomics Analysis Reveals the Compositional Differences of Shade Grown Tea (Camellia sinensis L.)

The different cultivation methods affect tea quality by altering the basic metabolite profiles. In this study, the metabolome changes were investigated in green tea and shade cultured green tea (tencha) by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) coupled with a multivariate data set. The principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of green tea clearly showed higher levels of galloylquinic acid, epigallocatechin, epicatechin, succinic acid, and fructose, together with lower levels of gallocatechin, strictinin, apigenin glucosyl arabinoside, quercetin p-coumaroylglucosyl-rhamnosylgalactoside, kaempferol p-coumaroylglucosylrhamnosylgalactoside, malic acid, and pyroglutamic acid than tencha. The effects of some seasonal variations were also observed in the primary metabolite concentrations such as amino acids and organic acids. In addition, green tea showed stronger antioxidant activity than tencha in both April and July. The antioxidant activity of green tea samples were significantly correlated with their total phenol and total flavonoid contents. This present study delineates the possibility to get high umami and less astringent green teas in shade culture. It highlights the metabolomic approaches to find out the effect of cultivation methods on chemical composition in plants and the relationship with antioxidant activity.

Relationship correlation of antioxidant and antiproliferative capacity of Cyperus rotundus products towards K562 erythroleukemia cells

A Total Oligomers Flavonoids (TOFs) and ethyl acetate extracts of Cyperus rotundus were analyzed, in vitro, for their antioxidant activity using several biochemical assays: the xanthine (X)/xanthine oxidase (XO), the lipid peroxidation induced by H 2O 2 in K562 human chronic myelogenous leukemia cells and the DNA damage in pKS plasmid DNA assay induced by H 2O 2/UV-photolysis and for their apoptotic effect. TOF and ethyl acetate extracts were found to be efficient in inhibiting xanthine oxidase with IC 50 values of 240 and 185 μg/ml and superoxide anion with IC 50 values of 150 and 215 μg/ml, respectively. Also, all the extracts tested were effective in reducing the production of thiobarbituric acid reactive substances (TBARS) and were able to protect against H 2O 2/UV-photolysis induced DNA damage. The highest activity, measured as equivalents of MDA concentration, was observed in the ethyl acetate extract (MDA = 2.04 nM). In addition, the data suggest that only TOF enriched extract exerts growth inhibition on K562 cells through apoptosis induction. Therefore, these extracts were subjected to further separation by chromatographic methods. Thus, three major compounds (catechin, afzelechin and galloyl quinic acid) were isolated from the TOF enriched extract and five major compounds (luteolin, ferulic acid, quercetin, 3-hydroxy, 4-methoxy-benzoic acid and 6,7-dimethoxycoumarin) from ethyl acetate extract. Their structures were determined by spectroscopic data analysis and comparison with the literature. In addition, we evaluate the biological activities of the catechin, ferulic acid and luteolin. This investigation has revealed that the luteolin was the most active in reducing the production of TBARS (MDA = 1.5 nM), inhibiting significantly the proliferation of K562 cells (IC 50 = 25 μg/ml) and protecting against H 2O 2/UV-photolysis induced DNA damage. In conclusion, the study reveals that the ability of C. rotundus to inhibit the enzyme xanthine oxidase (XO), the lipid peroxidation and to exert apoptotic effect, may explain possible mechanisms by which C. rotundus exhibits its health benefits.

Multivariate data analysis using magnetic resonance spectroscopy for the in silico analysis of the Mexican anxiolytic and sedative plant Galphimia glauca

Galphimia glauca is popularly employed in Mexico to treat central nervous system disorders. The anxiolytic and sedative principle of this species consists of a mixture of nor-secofriedelanes, named the galphimine series1. These active constituents were found in plants collected in the vicinity of a restricted region in Central Mexico. A metabolic profiling carried out by means of 1H NMR spectroscopy and multivariate data analysis was applied to crude extracts from wild plant populations, from six different locations, in order to differentiate their chemical profile. Principal component analysis (PCA) of the 1H NMR spectra revealed clear variations among the populations, with two populations out of the six studied manifesting differences, when the principal components PC-1 and PC-2 were analyzed. PC-1 permitted the differentiation of the various sample populations, depending on the presence of galphimines. This information consistently correlated with the corresponding HPLC analysis. PC-2 better defined the separation in terms of differential concentrations of galloylquinic acid derivatives. The neuropharmacological effects of the crude extracts were evaluated by using ICR mice in the elevated plus-maze, as well as the sodium pentobarbital-induced hypnosis models, demostrating anxiolytic and sedative responses on those sample populations which had been differentiated by PC-1. Partial least square regression-discriminant analysis also confirmed a strong correlation between the observed effects and the metabolic profiles of the plants. The overall results of this study confirm the benefits of using metabolic profiling for the in silico analysis of active principles in medicinal plants.

Profiling and Characterization by LC-MSn of the Galloylquinic Acids of Green Tea, Tara Tannin, and Tannic Acid

Green tea, tara tannin, and tannic acid have been profiled for their contents of galloylquinic acids using LC-MS8. These procedures have provided evidence for the first observation of (i) 1-galloylquinic acid (11), 1,3,5-trigalloylquinic acid (22), 4-(digalloyl)quinic acid (28), 5-(digalloyl)quinic acid (29), and either 3-galloyl-5-(digalloyl)quinic acid (32) or 3-(digalloyl)-5-galloylquinic acid (33) from any source; (ii) 4-galloyl-5-(digalloyl)quinic acid (34), 5-galloyl-4-(digalloyl)quinic acid (35), 3-(digalloyl)-4,5-digalloylquinic acid (41), 4-(digalloyl)-3,5-digalloylquinic acid (40), 5-(digalloyl)-3,4-digalloylquinic acid (39), and 1,3,4-trigalloylquinic acid (21) from tara tannin; and (iii) 3-galloylquinic acid (12) and 4-galloylquinic acid (14) from green tea. The first mass spectrometric fragmentation data are reported for galloylquinic acids containing between five and eight gallic acid residues. For each of these mass ranges at least two isomers based on the 1,3,4,5-tetragalloylquinic acid core (25) and at least three based on the 3,4,5-trigalloylquinic acid core (24) were observed. Methanolysis of tara tannin yielded methyl gallate, methyl digallate, and methyl trigallate, demonstrating that some of these galloylquinic acids contained at least one side chain of up to four galloyl residues.