Quinic Acid Esters Research Articles

Comparative Anti-oxidant Activity of Korean and Canadian High Bush Blueberry Fructus

Blueberries (Ericaceae) are cultivated worldwide, and are used not only as foodstuff but also for relievement of eyestrain. Bluberry species representatively includes highbush blueberry (V. corymbosum L.), lowbush blueberry (V. angustifolium AIT.), rabbiteye blueberry (V. ashei READE), and bilberry blueberry (V. myrtillus L.). All of these species contain large amounts of phenolics and anthocyanins. In this regard, we isolated six compounds from Korea cultivated blueberry and identified as 3-O-caffeoylquinic acid (1), 5-O-caffeoylquinic acid (2), myricetin-3-O-β-D-galactoside (3), quercetin-3-O-ruti- noside (4), ethyl-3-O-caffeoylquinic acid ester (5), ethyl-5-O-caffeoyl quinic acid ester (6) by 1 H-NMR, 13 C-NMR and MS. Anti-oxidative activities of six compounds were verified by anti-oxidant assay such as DPPH, ABTS and Hypoxanthine/xan- thine oxidase system. And then, anti-oxidant activities of Korea blueberry and Canadian were compared with each other. These results support that Korean blueberry has also the possibility to be potential supplementary material as healthy food like Canadian blueberry. Therefore, Korean blueberry can be used as a substitute of Canadian blueberry. Keywords □ high bush blueberry (V. corymbosum L.), 3-O-caffeoylquinic acid, 5-O-caffeoyl quinic acid, myricetin-3-O-β-D- galactoside, quercetin-3-O-rutinoside, ethyl-3-O-caffeoyl quinic acid ester, ethyl-5-O-caffeoylquinic acid ester, anti-oxidant activity

Quinic Acid Esters from Pavetta owariensis var. owariensis (Rubiaceae)

The stem-bark of Pavetta owariensis var. owariensis is used in Guinean traditional medicine as an anthelmintic. Previous biological and chemical investigations reported the in vivo and/or in vitro anthelmintic, antischistosomal, antiviral and antibacterial properties along with the presence of a wide range of proanthocyanidins possessing a doubly-linked structure and ferulic acid esters substances. From the stem-bark, five previously known quinic acid esters have been isolated for the first time. Their structures have been established by means of FAB-mass, 1H and 13CNMR spectroscopy.

In vitro enzymic hydrolysis of chlorogenic acids in coffee.

Coffee is rich in quinic acid esters of phenolic acids (chlorogenic acids) but also contains some free phenolic acids. A proportion of phenolic acids appear in the blood rapidly after coffee consumption due to absorption in the small intestine. We investigated in vitro whether this appearance could potentially be derived from free phenolic acids in instant coffee or from hydrolysis of chlorogenic acids by pancreatic or brush border enzymes. We quantified six free phenolic acids in instant coffees using HPLC-DAD-mass spectrometry. The highest was caffeic acid, but all were present at low levels compared to the chlorogenic acids. Roasting and decaffeination significantly reduced free phenolic acid content. We estimated, using pharmacokinetic modelling with previously published data, that the contribution of these compounds to small intestinal absorption is minimal. Hydrolysis of certain chlorogenic acids was observed with human-differentiated Caco-2 cell monolayers and with porcine pancreatin, which showed maximal rates on 3- and 5-O-caffeoylquinic acids, respectively. The amounts of certain free phenolic acids in coffee could only minimally account for small intestinal absorption based on modelling. The hydrolysis of caffeoylquinic, but not feruloylquinic acids, by enterocyte and pancreatic esterases is potentially a contributing mechanism to small intestinal absorption.

Composition of the non-polar extracts and antimicrobial activity of Chorisia insignis HBK. leaves

ObjectiveTo investigate the chemical constituents of the petroleum ether extract and the ether fraction of the 70% ethanol extract of Chorisia insignis HBK. leaves, as well as screen its antimicrobial activity. MethodsDifferent chromatographic methods were applied to investigate the non-polar extracts and the diffusion assay method was applied to study the antimicrobial activity. ResultsA total of 50 compounds from the unsaponifiable matter and 20 fatty acid methyl esters were identified from the petroleum ether extract by GC/MS analysis. n-Hentriacontane, n-tritriacontane, stigmastanol, 3-methoxy-5, 6-dihydrostigmasterol, 7,8-dihydroergosterol, 4-methylcholesterol, cholestanol, multiflorenol, cholest-5-en-3-one, cholest-6-one, 5,6-dihydroergosterol, stigmasterol, dihydroalbigenin and 11-methyl-Δ5,7,9,15,17,23-triacont-hex-ene were isolated from the petroleum ether extract. Methyl heptacosanoate and quinic acid ester of rhamnose were isolated from the ether fraction of the 70% ethanol extract. Antimicrobial activity of the total alcohol extract and the successive fractions showed that the ether and the ethyl acetate fractions have potent antibacterial activity against Bacillus subtilis and Bacillus cereus. ConclusionsThe ether and the ethyl acetate fractions could be used in pharmaceutical formulations as antibacterial agents against Bacillus subtilis and Bacillus cereus, and further clinical trials should be performed in order to support the above investigations.

Anti-HSV-1 and antioxidant activities of dicaffeoyl and digalloyl esters of quinic acid

Nine caffeic and gallic acids derivatives were synthesized and evaluated for their antioxidant activity using the DPPH radical scavenging activity assay and for their antiherpes activity against HSV-1. All compounds displayed higher antioxidant activities than α-tocopherol. The most active antioxidant was compound 8 (IC50=177μM). Five compounds (7, 10, 11, 12 and 14) were found to possess anti-HSV-1 activity with selectivity indices values ranging from 7.0 to 27.1. The most active was compound 10 (IC50=15.2μM; SI=27.1).

Resistance to the Weevils Cylas puncticollis and Cylas brunneus Conferred by Sweetpotato Root Surface Compounds

Seven resistant varieties of sweetpotato were compared with three susceptible varieties in field trials and laboratory bioassays and showed that resistance was an active process rather than an escape mechanism, as field resistant varieties also had reduced root damage and oviposition compared with susceptible varieties in the laboratory. Liquid chromatography-mass spectrometry (LC-MS) of root surface and epidermal extracts showed significant variation in the concentration of hexadecyl, heptadecyl, octadecyl, and quinic acid esters of caffeic and coumaric acid, with higher concentrations correlated with resistance. All compounds were synthesized to enable their positive identification. Octadecyl coumarate and octadecyl caffeate applied to the surface of susceptible varieties in laboratory bioassays reduced feeding and oviposition, as observed on roots of resistant varieties, and therefore are implicated in weevil resistance. Segregating populations from breeding programs can use these compounds to identify trait loci for resistance and enable the development of resistant varieties.

Comparison of antioxidant, anti-inflammatory, antimicrobial activity and chemical composition of aqueous and hydroethanolic extracts of the herb of Tropaeolum majus L.

The aim of this study was comparison of antioxidant, anti-inflammatory, and antimicrobial activity, as well as chemical composition of extracts of Tropaeolum majus L. herb. Aqueous and hydroethanolic extracts derived from dried and freeze-dried nasturtium herb, prepared both at room temperature and at 90°C, were studied. In the studies there were no significant differences between antioxidant activity of the extracts. All extracts showed scavenging activity against all the examined reactive species in a concentration-dependent manner. The strongest scavenging activity they showed against reactive nitrogen species, NO (SC50 4.54±0.26–10.90±1.39μg/mL) and ONOO− (SC50 2.49±1.50–6.37±1.86μg/mL). Among reactive oxygen species, they showed strong scavenging activity against H2O2 (SC50 14.90±3.91–38.63±9.28μg/mL). Scavenging activity against O2− was weaker, while against HClO the extracts showed very weak activity, practically at the level of statistical error. Against synthetic radical – DPPH scavenging activity of the tested extracts was negligible. The extracts demonstrated stronger antioxidant activity in ex vivo experiment on human neutrophils. The extracts showed no inhibitory activity on hyaluronidase, but at a concentration of 50μg/mL they inhibited the activity of COX1 by approximately 60%. Lack of antimicrobial activity of the extracts seems to be associated with a low content of benzyl isothiocyanate. The aqueous extracts were characterized by the presence of esters of quinic acid with cinnamic acids (chlorogenic acids, p-coumaroylquinic acids) and the presence of flavonoids. Meanwhile the hydroethanolic extracts were mainly rich in the above mentioned acid esters.

The biosynthesis of hydroxycinnamoyl quinate esters and their role in the storage of cocaine in Erythroxylum coca

Complexation of alkaloids is an important strategy plants utilize to facilitate storage in vacuoles and avoid autotoxicity. Previous studies have implicated hydroxycinnamoyl quinate esters in the complexation of purine alkaloids in Coffea arabica. The goal of this study was to determine if Erythroxylum coca uses similar complexation agents to store abundant tropane alkaloids, such as cocaine and cinnamoyl cocaine. Metabolite analysis of various E. coca organs established a close correlation between levels of coca alkaloids and those of two hydroxycinnamoyl esters of quinic acid, chlorogenic acid and 4-coumaroyl quinate. The BAHD acyltransferase catalyzing the final step in hydroxycinnamoyl quinate biosynthesis was isolated and characterized, and its gene expression found to correlate with tropane alkaloid accumulation. A physical interaction between chlorogenic acid and cocaine was observed and quantified in vitro using UV and NMR spectroscopic methods yielding similar values to those reported for a caffeine chlorogenate complex in C. arabica. These results suggest that storage of cocaine and other coca alkaloids in large quantities in E. coca involves hydroxycinnamoyl quinate esters as complexation partners.

Analysis of Camellia sinensis green and black teas via ultra high performance liquid chromatography assisted by liquid–liquid partition and two-dimensional liquid chromatography (size exclusion × reversed phase)

Green and black teas ( Camellia sinensis) contain compounds ranging from simple phenolics to complex glycosides, many of which have well-recognized health benefits. Here, we describe two methodologies aiming to achieve a comprehensive analysis of hydro-alcoholic extracts of C. sinensis. In the first step, the extracts were partitioned in water, n-butanol, ethyl acetate and chloroform to separate the compounds according to their polarity, yielding less complex samples to be analyzed by ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC–MS). Additionally, a comprehensive two dimensional liquid chromatography (2D-LC) technique, employing size exclusion chromatography (SEC) × reversed phase (BEH-C18) was developed. The following compounds were identified on the basis of retention time, UV-spectra and MS fragmentation patterns: catechins, theaflavins and their gallate derivatives; kaempferol, quercetin and myricetin mono-, di-, tri- and tetraglycosides; esters of quinic acid and gallic or hydroxycinnamic acids; purine alkaloids, such as caffeine and theobromine and many lipids. Additionally, there were many novel compounds that were previously undescribed, such as saponin isomers and gallic acid esters of four glycosides of myricetin, quercetin and kaempferol.

Synthesis and biological evaluation of quinic acid derivatives as anti-inflammatory agents

Quinic acid (QA) esters found in hot water extracts of Uncaria tomentosa (a.k.a. cat’s claw) exert anti-inflammatory activity through mechanisms involving inhibition of the pro-inflammatory transcription factor nuclear factor kappa B (NF-κB). Herein, we describe the synthesis and biological testing of novel QA derivatives. Inhibition of NF-κB was assessed using A549 (Type II alveolar epithelial-like) cells that stably express a secreted alkaline phosphatase (SEAP) reporter driven by an NF-κB response element. A549-NF-κB cells were stimulated with TNF-α (10 ng/mL) in the presence or absence of QA derivative for 18 hours followed by measurement of SEAP activity. Amide substitution at the carboxylic acid position yielded potent inhibitors of NF-κB. A variety of modifications to the amide substitution were tolerated with the N-propyl amide derivative being the most potent. Further examination of the SAR demonstrated that acetylation of the hydroxyl groups reduced NF-κB inhibitory activity. QA amide derivatives lacked anti-oxidant activity and were found to be neither anti-proliferative nor cytotoxic at concentrations up to 100 μM. In conclusion, we have discovered a novel series of non-toxic QA amides that potently inhibit NF-κB, despite their lack of anti-oxidant activity. Mechanistic studies and pre-clinical efficacy studies in various inflammatory animal models are on-going.

POLYPHENOLIC COMPOUNDS FROM THE LEAVES OF SCHINUS TEREBINTHIFOLIUS RADDI

Two quinic acid esters, 5-O-caffeoylquinic acid (1) and 5-Ocoumaroylquinic acid (2); three myricetin glycosides, myricetin 3O--L-rhamnopyranosyl(1′′′6′′)-D-galactopyranoside (3), myricetin 3-O--D-glucuronide (4), and myricetin 3-O--Dgalactopyranoside (5); 1,6-digalloyl--D-glucose (6); and (+)catechin (7) were isolated and identified for the first time from the leaves of Schinus terebinthifolius Raddi. Furthermore, investigation of tannic acid content was carried out by HPLC.

5-Caffeoylquinic acid and caffeic acid orally administered suppress P-selectin expression on mouse platelets

Caffeic acid and 5-caffeoylquinic acid are naturally occurring phenolic acid and its quinic acid ester found in plants. In this article, potential effects of 5-caffeoylquinic acid and caffeic acid on P-selectin expression were investigated due to its significant involvement in platelet activation. First, the effects of 5-caffeoylquinic acid and caffeic acid on cyclooxygenase (COX) enzymes were determined due to their profound involvement in regulating P-selectin expression on platelets. At the concentration of 0.05 μM, 5-caffeoylquinic acid and caffeic acid were both able to inhibit COX-I enzyme activity by 60% ( P<.013) and 57% ( P<.017), respectively. At the same concentration, 5-caffeoylquinic acid and caffeic acid were also able to inhibit COX-II enzyme activity by 59% ( P<.012) and 56% ( P<.015), respectively. As expected, 5-caffeoylquinic acid and caffeic acid were correspondingly able to inhibit P-selectin expression on the platelets by 33% ( P<.011) and 35% ( P<.018), at the concentration of 0.05 μM. In animal studies, 5-caffeoylquinic acid and caffeic acid orally administered to mice were detected as intact forms in the plasma. Also, P-selectin expression was respectively reduced by 21% ( P<.016) and 44% ( P<.019) in the plasma samples from mice orally administered 5-caffeoylquinic acid (400 μg per 30 g body weight) and caffeic acid (50 μg per 30 g body weight). These data suggest that both 5-caffeoylquinic acid and caffeic acid orally administered can be absorbed and suppress P-selectin expression on mouse platelets.

Polyphenols Are Intensively Metabolized in the Human Gastrointestinal Tract after Apple Juice Consumption

Polyphenols are secondary plant compounds showing anticarcinogenic effects both in vitro and in animal experiments and may thus reduce the risk of colorectal cancer in man. The identification of polyphenol metabolites formed via their passage through the small intestine of healthy ileostomy subjects after apple juice consumption is presented. Identification and quantification of polyphenols and their metabolites were performed using HPLC-DAD as well as HPLC-ESI-MS/MS. Total procyanidin content (TPA) was measured, and additionally the mean degree of polymerization (DPm) of the procyanidins was determined in the apple juice and ileostomy effluents. As products of polyphenol metabolism, D-(-)-quinic acid and methyl esters of caffeic acid and p-coumaric acid are liberated from the corresponding hydroxycinnamic acid esters. 1-Caffeoylquinic acid and 3-caffeoylquinic acid were determined as products of isomerization. Phloretin 2'-O-glucoside (phloridzin) and phloretin 2'-O-xyloglucoside were metabolized into the corresponding aglycons phloretin and phloretin 2'-O-glucuronide and all were found in the ileostomy effluent. Ninety percent of the consumed procyanidins were recovered in the ileostomy effluent and therefore would reach the colon under physiologic circumstances. The DP m was reduced (DP m of apple juice=5.7) and varied depending on the time point of excretion. The gastrointestinal passage seems to play an important role in the colonic availability of apple polyphenols.

Identification of Flavonoids and Hydroxycinnamic Acids in Pak Choi Varieties ( Brassica campestris L. ssp. chinensis var. communis) by HPLC–ESI-MS n and NMR and Their Quantification by HPLC–DAD

Twenty-eight polyphenols (11 flavonoid derivatives and 17 hydroxycinnamic acid derivatives) were detected in different cultivars of the Chinese cabbage pak choi ( Brassica campestris L. ssp. chinensis var. communis) by HPLC-DAD-ESI-MS(n). Kaempferol was found to be the major flavonoid in pak choi, glycosylated and acylated with different compounds. Smaller amounts of isorhamnetin were also detected. A structural determination was carried out by (1)H and (13)C NMR spectroscopy for the main compound, kaempferol-3-O-hydroxyferuloylsophoroside-7-O-glucoside, for the first time. Hydroxycinnamic acid derivatives were identified as different esters of quinic acid, glycosides, and malic acid. The latter ones are described for the first time in cabbages. The content of polyphenols was determined in 11 cultivars of pak choi, with higher concentrations present in the leaf blade than in the leaf stem. Hydroxycinnamic acid esters, particularly malic acid derivatives, are present in both the leaf blade and leaf stem, whereas flavonoid levels were determined only in the leaf blade.

Quinic acid esters from Pluchea indica with collagenase, MMP‐2 and MMP‐9 inhibitory activities

Investigation of collagenase inhibitory natural components afforded two quinic acid esters (1 and 2) and quercetin (3) from the leaves of Pluchea indica (Compositae). Of these, compounds 1 and 2 exhibited collagenase inhibitory activity (IC(50)) at a concentration of less than 10 microm, and 1 showed matrix metalloproteinase (MMP)-2 and -9 inhibitory activity (IC(50)) at 2.5 and 6.4 microm, respectively.

Determination of some polyphenolic compounds in buds of Alnus and Corylus species by HPLC

The presence of 19 polyphenolic compounds was simultaneously assessed through a HPLC method in the buds of three species: Alnus glutinosa, Alnus incana, and Corylus avellana. The pattern of phenol carboxylic acids indicates that compounds like gentisic acid, sinapic acid, and the esters of tartaric acid (cichoric acid, caftaric acid) do not exist in buds, although they have been detected in mature organs. Buds only contain esters of quinic acid. Ferulic acid is a common compound in buds, being observed in all genus investigated. In the case of the flavonoid profile, young tissues of Alnus sp. and Corylus avellana only contain glycosides of quercetin. The preferred sugar for glycosylation is galactose, as the major flavonoid glycoside is in all cases hyperoside. The buds of A. glutinosa display the highest content in phenol carboxylic acids; this situation justifies their main prescription in the treatment of hepatic disorders.

A quinic acid ester from Strychnos lucida

A new quinic acid ester, 4-O-(3,5-dimethoxy-4-hydroxybenzoyl)quinic acid (1) was isolated, together with 22 known compounds, from the barks and woods of Strychnos lucida. The structure of the new compound was determined by spectroscopic (NMR, MS) and chemical means.

Collagenase Inhibitory Quinic Acid Esters from Ipomoea pes-caprae

Two new quinic acid esters (1 and 2) were isolated from the extract of Ipomoea pes-caprae together with six known quinic acid esters (3-8). The structures of compounds 1 and 2 were elucidated by spectroscopic data interpretation. These new compounds exhibited collagenase inhibitory activity and showed almost no cytotoxicity.

Phenolic Compounds fromViburnum cylindricum

Three novel quinic acid esters, i.e., neochlorogenic acid methyl ester (1), cryptochlorogenic acid methyl ester (2), and chlorogenic acid methyl ester (3), were isolated from Viburnum cylindricum. Their structures were determined by spectroscopic analysis.

An active ingredient of Cat's Claw water extracts: Identification and efficacy of quinic acid

Historic medicinal practice has defined Cat's Claw, also known as Una de Gato or Uncaria tomentosa, as an effective treatment for several health disorders including chronic inflammation, gastrointestinal dysfunction such as ulcers, tumors and infections. The efficacy of Cat's Claw was originally believed, as early as the 1960s, to be due to the presence of oxindole alkaloids. However, more recently water-soluble Cat's Claw extracts were shown not to contain significant amounts of alkaloids (<0.05%), and yet still were shown to be very efficacious. Here we characterize the active ingredients of a water-soluble Cat's Claw extract called C-Med-100 as inhibiting cell growth without cell death thus providing enhanced opportunities for DNA repair, and the consequences thereof, such as immune stimulation, anti-inflammation and cancer prevention. The active ingredients were chemically defined as quinic acid esters and could also be shown to be bioactive in vivo as quinic acid.