Conversion of phenolic constituents in aqueous Hamamelis virginiana leaf extracts during fermentation

INTRODUCTION

Hamamelis virginiana, known for its high level of tannins and other phenolics is widely used for treatment of dermatological disorders. Although reports on hydroalcoholic and aqueous extracts from Hamamelis leaf and bark exist, knowledge on fermented leaf preparations and the underlying conversion processes are still scant.

OBJECTIVE

Aqueous Hamamelis leaf extracts were monitored during fermentation and maturation in order to obtain an insight into the bioconversion of tannins and other phenolics.

METHODOLOGY

Aliquots taken during the production period were investigated by HPLC-DAD-MS/MS as well as GC-MS after derivatisation into the corresponding trimethylsilyl compounds.

RESULTS

In Hamamelis leaf extracts, the main constituents exhibited changes during the observational period of 6 months. By successive depside bond cleavage, the gallotannins were completely transformed into gallic acid after 1 month. Although not completely, kaempferol and quercetin glycosides were also converted during 6 months to yield their corresponding aglycones. Following C-ring fission, phloroglucinol was formed from the A-ring of both flavonols. The B-ring afforded 3-hydroxybenzoic acid from quercetin and 3,4-dihydroxybenzoic acid as well as 2-(4-hydroxyphenyl)-ethanol from kaempferol. Interestingly, hydroxycinnamic acids remained almost stable in the same time range.

CONCLUSION

The present study broadens the knowledge on conversion processes in aqueous fermented extracts containing tannins, flavonol glycosides and hydroxycinnamic acids. In particular, the analogy between the microbial metabolism of phenolics from fermented Hamamelis extracts, fermented sourdough by heterofermentative lactic acid bacteria or conversion of phenolics by the human microbial flora is indicated.

Polyphenol composition of plum selections in relation to total antioxidant capacity

Dietary polyphenols are associated with protection against chronic diseases such as cardiovascular disease. Pharmacological studies show a range of bioactivities and efficacy attributable to specific polyphenols. While many fruits are rich in polyphenols, wide cultivar variation of polyphenol composition is common. Our objective was to determine the composition of major bioactive polyphenols in 29 prevarietal selections of Western Australian plums, and Black Amber as an evaluation in developing breeding tools to develop fruit that may have enhanced health-promoting capacities. Total phenolics were quantified colorimetrically; selected polyphenols were quantified by HPLC; and the total antioxidant capacity (TAC) was measured by the antioxidant inhibition of oxygen radicals (AIOR) assay. Total phenolic concentration was significantly correlated with TAC (R = 0.95, P < 0.01). Neo-chlorogenic acid and quercetin glycosides were found to be the predominant polyphenols (mean 29.9 mg·kg(-1) and 50.7 mg·kg(-1), respectively). No significant correlations were found between the composition of predominant polyphenols in plums and the TAC. We argue that the value of in vitro TAC assays to breeding programs may be limited, and future research should focus on the heritability of known bioactive polyphenols.

Cissus quadrangularis ethanol extract upregulates superoxide dismutase, glutathione peroxidase and endothelial nitric oxide synthase expression in hydrogen peroxide-injured human ECV304 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Cissus quadrangularis has been widely used in traditional medicine for the treatment of hemorrhoid. However, the detailed mechanism of antioxidant defense of C. quadrangularis in endothelial cells under oxidative stress remains unclear.

AIM OF THE STUDY

The present study aims to elucidate the protective role of ethanol extract of C. quadrangularis (CQE) including its constituents, quercetin and resveratrol, on hydrogen peroxide (H(2)O(2))-injured human umbilical vein endothelial ECV304 cells.

MATERIALS AND METHODS

Viability, genotoxicity and protein expression of ECV304 cells were analyzed by MTT, alkaline comet and Western blot, respectively. Production of intracellular reactive oxygen species (ROS) was determined using dichlorofluorescein fluorescence dye.

RESULTS

After exposing cells to CQE containing quercetin and resveratrol, DNA damage was not observed. CQE including quercetin and resveratrol significantly attenuated ROS in H(2)O(2)-injured ECV304 cells in a concentration-dependent manner. The protein expression of superoxide dismutase (Cu/Zn-SOD, Mn-SOD), glutathione peroxidase (GPx) and endothelial nitric oxide synthase (eNOS) increased in the cells treated with CQE, quercetin or resveratrol prior to H(2)O(2) exposure, as compared with control.

CONCLUSIONS

The results provide a molecular mechanism of C. quadrangularis, which could be partially related to quercetin and resveratrol, in restoring ROS in endothelial cells through the upregulation of Cu/Zn-SOD, Mn-SOD, GPx and eNOS.

Phenolic constituents of the Chilean herbal tea Fabiana imbricata R. et P

"Pichi" or "pichi romero" (Fabiana imbricata R. et. P., Solanaceae) is a Chilean plant used as a tea in the Andean regions of Chile and Argentina. A very simple and direct method was developed for the qualitative analysis of polyphenols in the tea by high-performance liquid chromatography (HPLC) with diode array detection and electrospray ionization tandem mass spectrometry. The phenolic constituents identified in the teas were chlorogenic acid (3-O-caffeoylquinic acid), p-hydroxyacetophenone, scopoletin and quercetin derivatives. The glycosides were mainly glucosides from p-hydroxyacetophenone and scopoletin while di- and tri-glycosides from quercetin were the main flavonoids. The content of the main phenolic compounds in the teas (g/100 g lyophilized infusion) was 0.8-1.9 % for scopoletin, 0.4-6.2 % for p-hydroxyacetophenone and 2.1-4.3 % for rutin, respectively. The health-promoting properties reported for this herbal tea can be associated with the presence of several phenolics with known antioxidant, diuretic and antiinflammatory activity.

Characterization and quantification of phenolic compounds in four tomato (Lycopersicon esculentum L.) farmers' varieties in northeastern Portugal homegardens

Tomato (Lycopersicon esculentum L.) is one of the most widely consumed fresh and processed vegetables in the world, and contains bioactive key components. Phenolic compounds are one of those components and, according to the present study, farmers' varieties of tomato cultivated in homegardens from the northeastern Portuguese region are a source of phenolic compounds, mainly phenolic acid derivatives. Using HPLC-DAD-ESI/MS, it was concluded that a cis p-coumaric acid derivative was the most abundant compound in yellow (Amarelo) and round (Batateiro) tomato varieties, while 4-O-caffeolyquinic acid was the most abundant in long (Comprido) and heart (Coração) varieties. The most abundant flavonoid was quercetin pentosylrutinoside in the four tomato varieties. Yellow tomato presented the highest levels of phenolic compounds (54.23 μg/g fw), including phenolic acids (43.30 μg/g fw) and flavonoids (10.93 μg/g fw). The phenolic compounds profile obtained for the studied varieties is different from other tomato varieties available in different countries, which is certainly related to genetic features, cultivation conditions, and handling and storage methods associated to each sample.

Complete 1H NMR spectral analysis of ten chemical markers of Ginkgo biloba

The complete and unambiguous (1)H NMR assignments of ten marker constituents of Ginkgo biloba are described. The comprehensive (1)H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO-d(6) were obtained through the examination of 1D (1)H NMR and 2D (1)H,(1)H-COSY data, in combination with (1)H iterative full spin analysis (HiFSA). The computational analysis of discrete spin systems allowed a detailed characterization of all the (1)H NMR signals in terms of chemical shifts (δ(H)) and spin-spin coupling constants (J(HH)), regardless of signal overlap and higher order coupling effects. The capability of the HiFSA-generated (1)H fingerprints to reproduce experimental (1)H NMR spectra at different field strengths was also evaluated. As a result of this analysis, a revised set of (1)H NMR parameters for all ten phytoconstituents was assembled. Furthermore, precise (1)H NMR assignments of the sugar moieties of isoquercetin and rutin are reported for the first time.

[Quality evaluation of Fructus Toosendan]

OBJECTIVE

To evaluate the quality of Fructus Toosendan.

METHODS

HPLC method was used to determine the content of rutin, isoquercitrin and quercetin in Fructus Toosendan from different origins, and the HPLC fingerprints were established correspondingly.

RESULTS

There were significant differences among the HPLC fingerprints, and the contents of rutin, isoquercitrin and quercetin were different in Fructus Toosendan from different origins.

CONCLUSION

Quantitative analysis of effective component and integral analysis of HPLC fingerprints can be used for the quality evaluation of Fructus Toosendan.

[Chemical constituents of the roots of Vaccinium bracteatum]

OBJECTIVE

To study the chemical constituents of the roots of Vaccinium bracteatum.

METHODS

The constituents were separated and purified with chromatographic methods (including silica gel, Sephadex LH-20 and RP-18 column chromatography), and their structures were determined by spectroscopic methods (including MS, 1H-NMR and 13C-NMR).

RESULTS

10 compounds were isolated from the roots of Vaccinium bracteatu and were elucidated as chlorogenic acid (1), pinoresinol (2), ferulic acid (3), kaempferol (4), trans-caffeic acid (5), beta-sitosterol (6), quercetin (7), oleanolic acid (8), apigenin (9) and luteolin (10).

CONCLUSION

Compounds 1 -3 are obtained from this plant for the first time.

[Analysis of fingerprint and bioactive components of Bidens biternata by HPLC]

OBJECTIVE

To establish HPLC fingerprint of Bidens biternata from different habitats and determine the contents of hyperoside, isoquercetin, astragalin and bipinnatapolyacetylpside.

METHODS

Analysis was carried on Hypersil ODS C18 column (4.6 mm x 250 mm, 5.0 microm) with acetonitrile and 3% acetic acid as the mobile phase in a gradient elution. The contents of 4 components were determined simultaneously.

RESULTS

The fingerprint of 10 populations were established and the data were analyzed by the similarity evaluation software. There were almost no differences between the similarities of 10 population, but the contents of 4 main compoerls were different among them.

CONCLUSION

This method is stable and reliable which could be applied in quality assessment.

¹H-NMR simultaneous identification of health-relevant compounds in propolis extracts

INTRODUCTION

Propolis is a resinous substance collected by bees from exudates of different plants that is rich in well-known health-relevant phenolic compounds such as flavonoids and phenolic acids. Propolis extracts are very complex matrices difficult to study. Different analytical methods are usable to analyse propolis extracts and to obtain chemical fingerprint but to our knowledge NMR has not previously been used for this purpose.

OBJECTIVE

This study aims to demonstrate that it is possible to use ¹H-NMR for the simultaneous recognition of phenolic compounds in complex matrices, such as propolis extracts, using appropriate tools for spectra pre-treatment and analysis.

METHODOLOGY

In this work 12 typical phenolic propolis compounds (apigenin, chrysin, galangin, kaempferol, quercetin, naringenin, pinocembrin, pinostrobin, caffeic acid, cinnamic acid, p-coumaric acid and ferulic acid) were considered as reference compounds and their presence in samples was verified by HPLC-MS. A simple ¹H-NMR sequence was used to obtain spectra of samples. Spectra were pre-treated by using an appropriate tool for spectra alignment and analysed by using software for the study of spectra originated from complex matrices. Sixty-five propolis samples were used to test the proposed identification procedure.

RESULTS

Ten out of 12 considered compounds were identified as statistically significant in most of the samples.

CONCLUSION

This work suggests that it is possible to efficiently use ¹H-NMR, coupled with appropriate spectral analytical tools, for the simultaneous detection of phenolic compounds in complex matrices.

Characterization of sulfated quercetin and epicatechin metabolites

Different monosulfates of quercetin and epicatechin with metabolic interest were obtained by hemisynthesis and characterized regarding their chromatographic behavior and absorption and mass spectra. Three of these compounds were further isolated, and their structures were elucidated by mass spectrometry and (1)H and (13)C nuclear magnetic resonance using one- and two-dimensional techniques (heteronuclear single-quantum coherence and heteronuclear multiple-bond correlation). The calculation of the proton and carbon shifts caused by sulfation allowed for the assignment of the position of the sulfate group in the flavonoids, so that the compounds were identified as quercetin-3'-O-sulfate, quercetin 4'-O-sulfate, and epicatechin 4'-O-sulfate. It was found that sulfation at position 3' induced a large upfield shift in the carbon bearing the sulfate group and downfield displacements of the adjacent carbons, whereas no significant upfield or downfield shifts were observed with respect to the parent flavonoid when sulfation was produced at position 4'.

[Effects of different processing on active components in fructus polygoni orientalis by HPLC analysis]

OBJECTIVE

To study the effects of different processing on taxifolin and quercetin in Fructus Polygoni Orientalis.

METHODS

The analysis was performed on a Agilent column (4. 6 mm x 150 mm, 5 microm) eluted with a gradient elution of methanol-water containing 0. 1% phosphoric acid. The flow rate was 1 mL/min, the detection wave length was 270 nm and the column temperature was set at 25 degrees C. The content changes of taxifolin and quercetin processed by different methods was compared.

RESULTS

The contents of active ingredients in Fructus Polygoni Orientalis that processed by the method of therm-high pressure (the pressure was 14Pa) was obvious higher than those of other methods.

CONCLUSION

Active ingredients of Fructus Polygoni Orientalis may be promoted by therm-high pressure processed. There is significant difference for the major components by different processing methods. The method of therm-high pressure to processing is used for the first time in the Fruit Polygoni Orientalis. The method appears to be simple, easy and can be used as quantitative determination method for quality control of the Fructus Polygoni Orientalis.

Effect of rosehip (Rosa canina L.) phytochemicals on stable free radicals and human cancer cells

BACKGROUND

The commercial development of plants as sources of antioxidants that can be used to enhance the properties of foods, for nutritional purposes and preservation as well as for prevention of oxidation-related diseases, is currently of major interest. Rosehip (Rosa canina L.) is a rich source of vitamin C and polyphenols.

RESULTS

Phytochemicals in rosehip tea were separated into three fractions: Fr1 (vitamin C, 39.17 mg kg(-1)), Fr2 (flavonoids, 451.05 µg kg(-1)) and Fr3 (phenolic acids, 504.69 µg kg(-1)). Quercetin and ellagic acid were the most abundant polyphenolic compounds. Rosehip fractions, primarily rosehip flavonoids (EC(50) = 49 mg L(-1)), showed high antioxidant activity towards 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH(•)). Cell growth effects of rosehip fractions were assessed in HeLa, MCF7 and HT-29 cell lines, with the lowest IC(50) values being determined for rosehip flavonoids, (80.63, 248.03 and 363.95 mg L(-1) respectively). However, the vitamin C fraction did not inhibit the growth of tested tumour cells.

CONCLUSION

The results of this study confirm that vitamin C and flavonoids are responsible for the antioxidant activity of rosehip tea, while only polyphenols contribute to its antiproliferative activity.

Effects of industrial tomato paste processing on ascorbic acid, flavonoids and carotenoids and their stability over one-year storage

BACKGROUND

The effects of industrial tomato paste processing and long-term (12 months) ambient storage on the content and stability of quercetin, kaempferol, ascorbic acid (AA), dehydroascorbic acid (DHAA), β-carotene and lycopene were evaluated in a commercially produced tomato paste.

RESULTS

The initial thermal treatment (hot break; 93 °C for 5 min) resulted in significant reductions in quercetin (54%), kaempferol (61%), AA (63%) and β-carotene (30%), whereas subsequent processing steps (e.g. evaporation and sterilization) did not result in marked changes in these compounds. Lycopene was stable during hot break but decreased by 20% through evaporation and sterilization. The ratio of DHAA:vitamin C increased during hot break to 23%, whereas the ratio of DHAA:vitamin C remained relatively low in subsequent processing steps, indicating that AA was not oxidized. AA decreased with prolonged storage, with only 13% remaining at 12 months. The carotenoids and quercetin remained stable through 12 months of ambient storage.

CONCLUSIONS

Tomato pomace contained significant amounts of carotenoids and flavonoids, indicating that it may be an underutilized processing byproduct.

Protective effect of fruits of Morinda citrifolia L. on scopolamine induced memory impairment in mice: a behavioral, biochemical and cerebral blood flow study

ETHNOPHARMACOLOGICAL RELEVANCE

Noni (Morinda citrifolia L.) is widely used for different illnesses including CNS disorders. Recently Noni has been reported to prevent amyloid beta induced memory impairment in mice. However, the influence of Noni on cholinergic system has not been explored so far. Therefore, present study was designed to investigate effect of Noni fruit on memory, cerebral blood flow (CBF), oxidative stress and acetylcholinesterase (AChE) activity in scopolamine induced amnesia model.

MATERIALS AND METHODS

Mice were orally treated with ethanolic extract of Noni fruit and chloroform, ethyl acetate and butanol fractions of ethanolic extract for three days. Scopolamine was administered 5 min prior to acquisition trial and memory function was evaluated by passive avoidance test. CBF was measured by laser doppler flowmetry. AChE activity and oxidative stress parameters were estimated in mice brain at the end of behavioral studies. Further, effect of ethanolic extract and its fractions (5-400 μg/ml) on AChE activity was measured in vitro.

RESULTS

Scopolamine caused memory impairment along with reduced CBF, increased AChE activity and oxidative stress in mice brain. Ethanolic extract of Noni fruits and its chloroform and ethyl acetate fractions significantly improved memory and CBF. However, butanol fraction had no effect. Further, increased oxidative stress and AChE activity following scopolamine was significantly attenuated by ethanolic extract of Noni and its fractions. Moreover ethanolic extract and its fractions showed dose dependent inhibition of AChE activity in vitro.

CONCLUSION

These observations suggest that Noni may be useful in memory impairment due to its effect on CBF, AChE and oxidative stress.

[Study on chemical constituents of Drosera peltata var. multisepala]

Chemical investigatation of Drosera peltata var. multisepala led to the isolation of eleven compounds using various chromatographic techniques. The structures of these compounds were elucidated as isoshinanolone-4-O-beta-D-glucoside (1), isoshinanolone (2), epi-isoshinanolone (3), plumbagin (4), droserone (5), droserone-5-O-glucoside (6), quercetin (7), kaempferol (8) , gossypetin-8-O-glucoside (9), 3,3'-dimethoxy ellagic acid (10), and ellagic acid (11) by their physicochemical properties and spectral data analysis. Compound 1 was a new compound. Compounds 3, 8, 10, and 11 were isolated from this plant for the first time.

Effect of hydrothermal processing on phenolic acids and flavonols contents in selected brassica vegetables

BACKGROUND

Commonly occurring diseases can have the origin in oxidative processes ongoing in the human body. Vegetables of Brassicaceae family are the essential sources of natural antioxidants, especially phenolic compounds, in the human diet. The research was aimed to estimate the content of phenolic compounds in selected vegetables and their quantity changes during hydrothermal processes.

MATERIAL AND METHODS

The vegetables subjected to analysis were: kale, broccoli, Brussels sprouts, and white and green cauliflower. The fresh and processed (blanched, cooked, frozen, cooked after freezing) vegetables were freeze-dried. The levels of phenolic acids and flavonols by HPLC method were estimated.

RESULTS

The presence of derivatives of hydroxycinnamic acid, mainly of caffeic acid, p-coumaric acid, sinapic acid and of flavonols - kaempferol, and in smaller amounts of quercetin was found. The largest amounts of above components were present in kale (total 94.4 mg•100 g-1 of fresh matter), whereas the smallest amounts were found in white and green cauliflower - 3.6 mg•100 g-1 f.m. and 3.03 mg•100 g-1 f.m., respectively. The applied technological processes contributed to lover amounts of all tested compounds depending on the process and the vegetable kind. The biggest loses, up to 70-80%, took place during cooking of raw and previously frozen vegetables.

CONCLUSIONS

Analysed Brassicaceae were characterized by high contents of the investigated flavonoids. The best source of those compounds was kale whereas the smallest amounts of searched components were presented in cauliflowers. The used hydrothermal processes led to losses of searched compounds.

[Study on quality control methods for different varieties of Meconopsis of Gansu]

OBJECTIVE

To establish the quantitative determination method and TLC identification of Meconopsis and study the Vis-UV spectrum character for fast identification.

METHODS

Meconopsis were identified by TLC, and the content of quercetin was determined by HPLC.

RESULTS

The acid hydrolyze condition was HCl-80% MeOH(8:25) 90 degrees C calefaction by water for 1.5 hour. The condition of HPLC: Hypersil-Keystone-C18 (250 mm x 4.6 mm, 5 microm) column, MeOH-Water (50: 50) as mobile phase, detection wavelength at 360nm, flow rate at 1.0 mL/min, column temperature at 35 degrees C, quercetin showed a good linear relationship at a range of 0.01 - 0.12 microg, r =0.9997. The average recovery was 98.83%, and RSD was 1.69% (n = 9). The contents of quercetin in Meconopsis integrifolia and Meconopsis quintuplinervia of Gansu were 0.1135 mg/g and 0.0842 mg/g respectively.

CONCLUSION

The method is simple, accurate and specific. It can be used for the quality control and fast identification of Meconopsis.

Analysis of eleven phenolic compounds including novel p-coumaroyl derivatives in lettuce (Lactuca sativa L.) by ultra-high-performance liquid chromatography with photodiode array and mass spectrometry detection

INTRODUCTION

Lettuce is a widely consumed vegetable and a good source of phenolic compounds. Several factors (genetic, agronomical and environmental) can influence the lettuce composition; their effects are not completely defined and more studies are needed on this topic.

OBJECTIVE

To develop an improved ultra-high-performance liquid chromatography (UHPLC) method to quantify the main target intact phenolic compounds in lettuce.

METHODOLOGY

UHPLC identification of the compounds was supported by PAD spectra and MS(n) analyses. Quantification was carried out by PAD, by creating matrix-matched calibration curves at the specific wavelength for each compound.

RESULTS

Sample pretreatment was simplified, with neither purification nor hydrolysis steps. Chromatographic conditions were chosen to minimise matrix interferences and to give a suitable separation of the major phenolic compounds within 27 min. The method allowed the quantification of 11 intact phenolic compounds in Romaine lettuces, including phenolic acids (caffeoyl and p-coumaroyl esters) and flavonoids (quercetin glycosides). Four p-coumaroyl esters were tentatively identified and quantified for the first time in lettuce.

CONCLUSION

The main intact phenolic compounds, including four novel p-coumaroyl esters, were simultaneously quantified in lettuce with optimal performances and a reduced total time of analysis. These findings make headway in the understanding of the lettuce phytochemicals with potential nutritional relevance.

Assessing the influence of genotype and temperature on polyphenol composition in cloudberry (Rubus chamaemorus L.) using a novel mass spectrometric method

A high-throughput abbreviated liquid chromatography mass spectrometric (ACMS) method was used to assess the relative influence of genotype and temperature on polyphenol composition in cloudberries. Principal component analysis (PCA) plots of the collated ACMS data showed a separation between crosses based on their female parents (Nyby or Fjellgull). Crosses with Nyby as the female parent had higher relative levels of masses assignable to certain ellagitannin derivatives. Crosses with Fjellgull had higher levels of distinctive masses assignable to quercetin derivatives (including a hydroxy-3-methylglutaroyl hexose derivative not previously identified in cloudberry) and anthocyanin derivatives. There was also a separation between samples grown at lower and higher temperatures, which was driven by m/z signals associated with ellagitannins and notably a major component, sanguiin H-6. Therefore, abbreviated MS techniques can discern genetic and/or environmental influences in polyphenol composition and can quickly assess quality in breeding programmes or in response to environmental changes.

Antiproliferative activity and standardization of Tecomella undulata bark extract on K562 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The bark of Tecomella undulata is primarily used in the treatment of syphilis, painful swellings and cancer by traditional healers. Also, it is claimed to be useful in treating urinary discharges, enlargement of spleen, leucorrhoea, leukoderma, tumors, liver disorders, gonorrhea, gout and promotes wound healing in Indian traditional system of medicine.

AIM

To establish a scientific validation for the antitumor effects of Tecomella undulata bark and explore the mechanistic pathway in chronic myeloid leukemia cell line, K562. The study was further extended to standardize the extract using quercetin as biomarker.

METHODS

Induction of apoptosis by chloroform extract of Tecomella undulata bark (CTUB) was determined by MTT, Annexin V and caspase activation assays. The cell cycle analysis was done by flow cytometer and nuclear staining by DAPI. The standardization of the extract was performed through reverse phase-HPLC method under PDA detection.

RESULT

Results clearly showed the induction of apoptosis by CTUB in K562 cells. The effect was found to be dose dependent, having IC(50) of 30 μg/ml with activation of FAS, FADD, caspase 8, caspase 3/7 and fragmentation of DNA. The bioactive CTUB was determined to possess 0.03% (w/w) of quercetin.

CONCLUSION

The investigation clearly demonstrated the potential antitumor effect of CTUB, thereby validating the traditional claim. Quercetin, known to have anticancer activity is being reported and quantified for the first time from the bark of Tecomella undulata.

[Simultaneous determination of seven flavonoids in Nervilia fordii with HPLC]

The study is to develop an HPLC method for simultaneous determination of rhamnazin (1), rhamnocitrin (2), rhamnetin (3), rhamnazin-3-O-beta-D-glucopyranoside (4), rhamnazin-3-O-beta-D-xylopyranosyl-(1-->4)-beta-D-glucopyranoside (5), rhamnazin-3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside (6), and rhamnocitrin-3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside (7) in Nervilia fordii. The separation was performed on a Kromasil C18 column (250 mm x 4.6 mm, 5 microm) with 0.4% phosphoric acid-acetonitrile as the mobile phase in a gradient elution at a flow rate of 1.0 mL x min(-1). The detect wavelength was set at 256 nm, and the column temperature was set at 40 degrees C. There were good linear relationships between the logarithm values of concentrations and those of the peak areas of seven flavonoids (1-7) in the range of 0.55-70.00 microg x mL(-1) (r = 0.9997), 0.86-110.00 microg x mL(-1) (r = 0.9997), 0.39-50.00 microg x mL(-1) (r = 0.999 7), 0.55-70.00 microg x mL(-1) (r = 0.999 5), 1.33-170.00 microg x mL(-1) (r = 0.9998), 1.33-170.00 microg x mL(-1) (r = 0.9998), 0.16-20.00 microg x mL(-1) (r = 0.9995), respectively. The recoveries of the seven flavonoids were between 97.19%-99.45%, the relative standard deviations (RSDs) were between 0.91%-2.69%. The established method is rapid, accurate with high repeatability, which could provide scientific evidence for the quality control of Nervilia fordii.

Accumulation of orally administered quercetin in brain tissue and its antioxidative effects in rats

Quercetin is widely distributed in vegetables and herbs and has been suggested to act as a neuroprotective agent. Here, we demonstrate that quercetin can accumulate enough to exert biological activity in rat brain tissues. Homogenates of perfused rat brain without detectable hemoglobin contaminants were treated with β-glucuronidase/sulfatase and the released quercetin and its methylated form were analyzed using high-performance liquid chromatography (HPLC) with three different detection methods. Both quercetin and the methylated form were detected in the brain of quercetin-administered rats using HPLC-UV and HPLC with electrochemical detection and were further identified using HPLC-tandem mass spectrometry. Oral administration of quercetin (50mg/kg body wt) attenuated the increased oxidative stress in the hippocampus and striatum of rats exposed to chronic forced swimming. The possible transport of quercetin derivatives into the brain tissue was reproduced in vitro by using a rat brain capillary endothelial cell line, a model of the blood-brain barrier. These results show that quercetin could be a potent nutrient that can access the brain and protect it from disorders associated with oxidative stress.

Changes in phenolic content of tomato products during storage

The effect of storage on the total polyphenol content and individual phenolic compounds as well as on the hydrophilic antioxidant capacity of ketchups and tomato juices was studied. The total polyphenol content was determined using the Folin-Ciocalteu assay, and the antioxidant capacity of the hydrophilic fraction was determined using DPPH and ABTS(+) assays. Individual polyphenols were identified and quantified using liquid chromatography/electrospray ionization tandem mass spectrometry on a triple quadrupole. All analyses were carried out for ketchups and tomato juices after storage for 3, 6, and 9 months. The total polyphenol content and antioxidant capacity of the hydrophilic fraction decreased during storage of ketchups and tomato juices. Ketchups, in general, showed a slightly greater stability during storage than tomato juices. The most significant decrease was observed for quercetin followed by caffeic and ferulic acids, whereas glycosilated polyphenols showed greater stability during storage.

Primula spectabilis Tratt. aerial parts: morphology, volatile compounds and flavonoids

The vacuolar and epicuticular flavonoids and the volatiles of the leaves and parts of flower of P. spectabilis Tratt., an endemic species in the Italian Oriental Alps, were investigated. From a MeOH extract of the leaves two flavone glycosides, 8-C-β-glucopyranosylluteolin 7-O-α-arabinofuranoside (1) and 6-C-α-arabinofuranosylapigenin (2) were isolated, in addition to a flavone and three flavonols already known from species of Primula. From an EtOH extract of leaf exudates, 7,3',4'-tri-O-methylquercetin was obtained. The structures were elucidated on the basis of their 1D ¹H- and ¹³C NMR data and 2D NMR techniques, as well as of HPLC-MS. The volatiles emitted by the leaves were mainly constituted by non-terpene derivatives, followed by comparable proportions of hemiterpens, oxygenated monoterpenes and sesquiterpene hydrocarbons. In flowers, monoterpene hydrocarbons were the most represented chemical class followed by non-terpene derivatives. Different proportions of compounds were found when individual parts of flowers were examined separately; calyx produced a greater proportion (approx. 49.5%) of non-terpenes as its volatile metabolites. P. spectabilis has glandular trichomes in the hyaline margins of the epidermal depressions, distributed on the adaxial leaf blade. Glandular hairs were also present on the corolla. Correlations of phytochemical data with the morphological features of leaf, flower and glandular hair are discussed, and a hypothesis is proposed on the ecological roles of the flavonoids and volatile compounds on the general fitness of the species and cross-pollination strategies.