Comprehensive Evaluation of Amino Acids and Polyphenols in 69 Varieties of Green Cabbage (Brassica oleracea L. var. capitata L.) Based on Multivariate Statistical Analysis

The biological activities of the primary metabolites and secondary metabolites of 69 green cabbage varieties were tested. The LC-MS detection method was used to determine the content of 19 free amino acids (lysine, tryptophan, phenylalanine, methionine, threonine, isoleucine, leucine, valine, arginine, asparagine, glycine, proline, tyrosine, glutamine, alanine, aspartic acid, serine, and glutamate). The content of 10 polyphenols (chlorogenic acid, gallic acid, 4-coumaric acid, ferulic acid, gentisic acid, cymarin, erucic acid, benzoic acid, rutin, and kaempferol) was determined by the HPLC detection method. Considering the complexity of the data obtained, variance analysis, diversity analysis, correlation analysis, hierarchical cluster analysis (HCA), and principal component analysis (PCA) were used to process and correlate amino acid or polyphenol data, respectively. The results showed that there were significant differences between the different amino acids and polyphenols of the 69 cabbage varieties. The most abundant amino acids and polyphenols were Glu and rutin, respectively. Both amino acids and polyphenols had a high genetic diversity, and multiple groups of significant or extremely significant correlations. The 69 cabbage varieties were divided into two groups, according to 19 amino acid indexes, by PCA. Among them, seven varieties with high amino acid content all fell into the fourth quadrant. The HCA of amino acids also supports this view. Based on 10 polyphenols, the 69 cabbage varieties were divided into two groups by HCA. Based on 29 indexes of amino acids and polyphenols, 69 cabbage varieties were evaluated and ranked by PCA. Therefore, in this study, cabbage varieties were classified in accordance with the level of amino acids and polyphenols, which provided a theoretical basis for the genetic improvement of nutritional quality in cabbage.     

Identification of absorbed constituents and in vivo metabolites in rats after oral administration of Physalis alkekengi var. franchetii by ultra‐high‐pressure liquid chromatography quadrupole time‐of‐flight mass spectrometry

The calyces of Physalis alkekengi var. franchetii (Chinese Lantern, JDL) are well‐known as traditional Chinese medicine owing to its various therapeutic effects. However, the bioactive constituents responsible for the pharmacological effects of JDL and their metabolites in vivo are still unclear to date. In this paper, an ultra‐high‐pressure liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UHPLC/Q‐TOF‐MS/MS) method was established to identify absorbed constituents and in vivo metabolites in rat biological fluids after oral administration of JDL. Based on the proposed strategy, 33 compounds were observed in dosed rat biosamples. Twelve of 33 compounds were indicated as prototype components of JDL, and 21 compounds were predicted to be metabolites of JDL. Finally, the metabolic pathways were proposed, which were glucuronidation, sulfation, methylation and dehydroxylation for flavonoid constituents and sulfonation and hydroxylation for physalin consitituents. This is the first systematic study on the absorbed constituents and metabolic profiling of JDL and will provide a useful template for screening and characterizing the ingredients and metabolites of traditional Chinese medicine.     

Total flavonoid content in varieties of Calendula officinalis L. originating from different countries and cultivated in Estonia

Total flavonoid contents in the inflorescences of different varieties of Calendula officinalis L. were investigated. The commercial seeds (20 samples) of varieties of C. officinalis originating from eight European countries were cultivated in home gardens in two different counties of Estonia. Total flavonoid contents, determined spectrophotometrically (λ = 370 nm), varied from each other by more than three times (0.21-0.68%) in the investigated varieties. The variety with the highest flavonoid content was 'Kablouna', produced by the Finnish company Siemen (0.68%). Other varieties with high flavonoid content, such as 'Touch of Red' produced by the Latvian company Kurzemes Seklas (0.55%), 'Golden Emperor' produced by the Finnish company Suvipiha (0.50%), 'Pomyk' from Poland (0.50%), etc., may also be preferred for cultivation as natural sources, as they are also rich in flavonoids. The amount of total flavonoids depends on the variety and/or the place and time of cultivation. There appeared to be no conclusive relationship between the total flavonoid content and the colour of ligulate and tubular florets of C. officinalis.     

Identification and quantification of benzimidazole metabolites of thiophonate-methyl sprayed on celery cabbage using SiO2@NiO solid-phase extraction in combination with HPLC-MS/MS

Thiophonate-methyl(TPM) is one of fungicides and pesticides widely used in agriculture field.However,the residue of its benzimidazole(BZD) metabolites in related agricultural products poses a potential risk to consumers.In this paper,nickel oxide nanoparticle-deposited silica(SiO_2@NiO) composite was used for the selective enrichment and purification of TPM's BZD metabolites in celery cabbage sprayed with TPM.Meanwhile,high-performance liquid chromatography coupled with precursor ion scan-mass spectrometry(HPLC-PIS-MS) and high-resolution MS/MS analysis(HR-MS/MS) was utilized for their qualitative and quantitative analysis.Twenty-one potential TPM's BZD metabolites were found and four of them were identified.One metabolite was discovered for the first time.Besides,a robust and sensitive quantitative method was developed with good linearities(R^2> 0.9972) within a wide range of 10.00-1000 ng/g.The detection limits of three known TPM's metabolites were within the range of 3.20-4.90 ng/g.Relative standard deviations(RSDs) of intra-day and inter-day precisions were less than 18.3%,which showed perfect reproducibility.The method was successfully applied to monitoring TPM's BZD metabolites in celery cabbage sprayed with TPM and the concentration versus time curves of TPM's metabolites in celery cabbage were plotted.This method is expected to be used to monitor BZD residues in various fruits and vegetables.     

Identification and characterization of active compounds and their metabolites by high-performance liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometry after oral administration of a herbal extract of Epimedium koreanum Nakai to rats

Epimedium is an important traditional Chinese medicine that is widely used throughout China as a tonic, aphrodisiac, and antirheumatic medicine. Flavonoids are considered to be the active compounds in Epimedium. In the study reported here, high-performance liquid chromatography coupled with Fourier transform-ion cyclotron resonance mass spectrometry (HPLC/FTICR-MS) was developed to identify active compounds and their metabolites after oral administration of a herbal extract of Epimedium koreanum Nakai to rats, using parent mass list triggered data-dependent multiple-stage accurate mass analysis at a resolving power of 100 000 in the external calibration mode. Nine flavonoids were identified in rats. The chemical formulae with unsaturation numbers calculated from accurate m/z values of precursor and product ions were used to assign the structures of metabolites and the chemical sites of metabolism. The mass accuracies obtained for all full-scan MS and MS(n) spectra were within 3 ppm (<1 ppm in most cases). The majority of the metabolites identified have been previously reported, but three compounds were noted for the first time in rats. By contrasting the analytical results obtained from the herbal extract with those obtained from biological specimens, the profile of flavonoid biotransformation in Epimedium was obtained and the metabolic pathways of these components, in rats, are described. The results should be of use in targeting potential active ingredients in Epimedium. Copyright (c) 2008 John Wiley & Sons, Ltd.     

Identification and quantitation of auxins in plants by liquid chromatography/electrospray ionization ion trap mass spectrometry

Auxin is an important phylohormone, which regulates specific physiological responses such as division, elongation and differentiation of cells. A new method using liquid chromatography/electrospray ionization ion trap mass spectrometry (LC/ESI-ITMS) has been developed for identification and quantitation of four auxins. Under the optimum conditions, four auxins (indole-3-acetic acid, indole-3-propionic acid, indole-3-butyric acid and 1-naphthylacetic acid) were completely separated and quantitated within 7 min with a minimum detection limit of 8.0 ng mL(-1) with relative standard deviations lower than 5.0%. This method also has been applied to analysis of auxins in Chinese cabbage where, even with a complicated serious background perturbation due to the natural biological matrix, the mean recoveries ranged from 77.5% to 99.8%. Finally, we discuss the MS-relevant properties of the identified auxins in detail.     

Elevated carbon dioxide increases contents of flavonoids and phenolic compounds, and antioxidant activities in Malaysian young ginger (Zingiber officinale Roscoe.) varieties

Zingiber officinale Roscoe. (Family Zingiberaceae) is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin) and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid), and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara) with CO(2) enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO(2) enrichment from 400 to 800 μmol mol-1 CO(2). These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC) results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO(2) conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO(2) concentration was increased from 400 to 800 μmol mol-1, free radical scavenging power (DPPH) increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO(2) enrichment.     

Flavonoid compounds and antibacterial mechanisms of different parts of white guava (Psidium guajava L. cv. Pearl)

Abstract

The flavonoid compositions, extracted from leaves, peel and flesh of white guava (Psidium guajava L. cv. Pearl), were identified and quantified by UPLC-ESI-QTOF-MS, HPLC-ESI-MS/MS and HPLC. The main components of three extracts all were quercetin-glycosides, but the proportion and content of quercetin-hexoside and quercetin-pentoside in each extract were different. Based on the measurements of MIC, MBC value and time killing curve, it emerged that 3 flavonoid extracts of white guava had good antibacterial effects on four pathogenic bacteria. White guava leaves flavonoids (WGLF) concentrations of 5.00?mg/mL and 0.625?mg/mL could change the micro-morphology of Escherichia coli and Staphylococcus aureus. It suggested that the antibacterial mechanism of WGLF on gram-positive and gram-negative bacteria was to destroy the structure and function of the cell membrane. It is indicated that the flavonoid extracts from white guava is a potential natural antimicrobial agent.     

Occurrence of chlorophyll precursors in leaves of cabbage heads--the case of natural etiolation

In the interior of cabbage (Brassica oleracea) heads (kale, white cabbage, Brussels sprouts), natural leaf etiolation takes place due to a limited light access and chlorophyll biosynthesis is inhibited in a consequence. Instead, apart from carotenoids, whose biosynthesis is not light-dependent, chlorophyll precursors accumulate, mainly protochlorophyllide and to a smaller extent also chlorophyllides a and b. Protochlorophyllide was also detected in green, light-exposed leaves of heads of all the investigated cabbage varieties. Protochlorophyll was not found in the investigated leaves. The analysis of xanthophylls composition showed that the central leaves of kale and white cabbage heads contain relatively high amounts of trans-neoxanthin and lutein epoxide which are found only in trace amounts in green leaves. This is the first systematic study on natural occurrence of chlorophyll biosynthesis precursors in different cabbage varieties.     

Fast and automated characterization of major constituents in rat biofluid after oral administration of Abelmoschus manihot extract using ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry and MetaboLynx

In drug metabolism research, the setting up of a complex series of mass spectrometry experiments and the subsequent analysis of the large amounts of data produced are often time‐consuming. In this paper, we describe a strategy using ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry (UPLC/QTOFMS) with automated data analysis software (MetaboLynx?) for fast analysis of the metabolic profile of flavonoids in Abelmoschus manihot. Rat plasma and urine samples collected 1 h and 0–12 h after oral administration of Abelmoschus manihot were analyzed by UPLC/QTOFMS within 15 min. The post‐acquisition data were processed using MetaboLynx. With key parameters carefully set, MetaboLynx is able to show the presence of a wide range of metabolites with only a limited requirement for manual intervention and data interpretation time. A total of 16 and 38 metabolites were identified in plasma and urine compared with blank samples. The results indicated that methylation and glucuronidation after deglycosylation were the major metabolic pathways of flavonoid glycosides in Abelmoschus manihot. The present study provided important information about the metabolism of flavonoid glycosides in Abelmoschus manihot which will be helpful for fully understanding the mechanism of action of this herb. Furthermore, this work demonstrated the potential of the UPLC/QTOFMS approach using MetaboLynx for fast and automated identification of metabolites from Chinese herbal medicines. Copyright © 2010 John Wiley & Sons, Ltd.     

Phytochemical analysis of Achillea ligustica All. from Lipari Island (Aeolian Islands)

A complete chemical investigation of Achillea ligustica All. growing at Lipari (Aeolian Island, Sicily) has been carried out. Seventeen metabolites have been isolated and characterised from dichloromethane and methanol extracts of flowers and aerial parts, and GC/MS analyses of petroleum ether extracts was carried out, revealing a composition in sesquiterpenoids similar to those reported for populations from Greece, Sicily and Algeria, showing the presence of (3RS,6RS)-2,6-dimethyl-1,7-octadiene-3,6-diol (1), 2,6-dimethyl-octa-3(E),7-diene-2,6-diol (2), iso-seco-tanapartholide (3) from DCM fraction. In addition from the methanolic extract of the aerial parts, peculiar flavonoid glucuronides have been isolated: i.e. apigenin-7-O-glucuronide (12) and quercetin 3-O-glucuronide (14). These metabolites have been reported in this species for the first time. The isolated flavonoids were previously recognised in several species of this complex genus and for this reason seems to be highly retained secondary metabolites of importance from the chemotaxonomic point of view.     

A new isoflavane-4-ol derivative from Melilotus officinalis (L.) Pall.

A new isoflavane derivative, melilofficinaside together with seven other metabolites including coumarin, uridine, methyl-α-d-fructofuranoside, and flavonoid glucosides were isolated from the aerial parts of Melilotus officinalis (L.) Pall.     

Quantitative HPTLC separation of flavonoid glycosides in the taxonomy of elm (Ulmus spp.)

Summary The flavonoid glycosides of elm (Ulmus spp.) leaves have been separated by means of HPTLC on silica gel and quantitative analysis carried out by densitometry. The results obtained were used for discriminant analysis in order to investigate whether the flavonoid pattern could be used for the classification of elms. The results readily showed the different provenance of four species and the attribution of an unknown sample to a species can be carried out. This result is important as it offers a chemical tool in the taxonomy of the elm. The classification method is compared with one based on qualitative data from two-dimensional chromatography of the flavonoid aglycones. It was found to exhibit much better results than those obtained from the cluster analysis of these qualitative data.     

Screening and identification of major phytochemical compounds in seeds,sprouts and leaves of Tuscan black kale Brassica oleracea (L.) ssp acephala (DC) var. sabellica L.

We report the spectrophotometric determination of total polyphenols, flavonoids, glucosinolates and antioxidant activity in seeds, seedlings and leaves of Tuscan black kale. The highest content of phytochemicals was observed in 10 days sprouts and antioxidant activity was maximum in 2, 4 days seedlings. Identification and characterisation of phytochemicals were performed by mass spectrometry (MS), high resolution and tandem MS with electrospray ionisation mode. Low-molecular-weight metabolites were evidenced in seeds while metabolites at high m/z range were detected in cotyledons and leaves. MS spectra evidenced different phenolic compounds (flavonoid caffeoyl glucose, hydroxycinnamic acid sinapine) and glucosinolates (glucoerucin, glucobrassicin and glucoraphanin) in function of developmental stage; galactolipids ω3 and ω6 were observed in leaves. Identification of stages with the highest phytochemicals content encourages the consumption of black kale sprouts and young leaves. Our research can support food and pharmaceutical industries for production of health promoting products from black kale.     

Negative ion 'chip-based' nanospray tandem mass spectrometry for the analysis of flavonoids in glandular trichomes of Lychnophora ericoides Mart. (Asteraceae)

This paper reports a method for the analysis of secondary metabolites stored in glandular trichomes, employing negative ion 'chip-based' nanospray tandem mass spectrometry. The analyses of glandular trichomes from Lychnophora ericoides, a plant endemic to the Brazilian 'cerrado' and used in traditional medicine as an anti-inflammatory and analgesic agent, led to the identification of five flavonoids (chrysin, pinocembrin, pinostrobin, pinobanksin and 3-O-acetylpinobanksin) by direct infusion of the extracts of glandular trichomes into the nanospray ionisation source. All the flavonoids have no oxidation at ring B, which resulted in a modification of the fragmentation pathways compared with that of the oxidised 3,4-dihydroflavonoids already described in the literature. The absence of the anti-inflammatory and antioxidant di-C-glucosylflavone vicenin-2, or any other flavonoid glycosides, in the glandular trichomes was also demonstrated. The use of the 'chip-based' nanospray QqTOF apparatus is a new fast and useful tool for the identification of secondary metabolites stored in the glandular trichomes, which can be useful for chemotaxonomic studies based on metabolites from glandular trichomes.     

Reactivity and Stability of Glucosinolates and Their Breakdown Products in Foods

The chemistry of glucosinolates and their behavior during food processing is very complex. Their instability leads to the formation of a bunch of breakdown and reaction products that are very often reactive themselves. Although excessive consumption of cabbage varieties has been thought for long time to have adverse, especially goitrogenic effects, nowadays, epidemiologic studies provide data that there might be beneficial health effects as well. Especially Brassica vegetables, such as broccoli, radish, or cabbage, are rich in these interesting plant metabolites. However, information on the bioactivity of glucosinolates is only valuable when one knows which compounds are formed during processing and subsequent consumption. This review provides a comprehensive, in‐depth overview on the chemical reactivity of different glucosinolates and breakdown products thereof during food preparation.     

Flavonoid glycosides and other constituents of Psorospermum androsaemifolium BAKER (Clusiaceae)

Two new flavonoid glycosides, namely 3'-(2',4'-dihydroxybenzyloxy)acanthophorin B (1b) and beta,2,3',4,4',6-hexahydroxy-alpha-(alpha-L-rhamnopyranosyl)dihydrochalcone (2) were isolated from the leaves of Psorospermum androsaemifolium together with quercetin (1), acanthophorin B (1a), alpha- (3) and beta-amyrine (3a), vismiaquinone (4), 12-hentriacontanol and hentriacontane. The structures of these secondary metabolites were established using detailed spectroscopic analysis and by comparison with published data. Compounds 1, 1a, 1b, 2, 3, 3a and 4 showed weak antifungal and antibacterial activities.     

Flavonoid profiling in three citrus varieties native to the Republic of Korea using liquid chromatography coupled with tandem mass spectrometry: contribution to overall antioxidant activity

A mixture of flavonoid components was isolated from the fruit peel of three varieties of citrus native to Republic of Korea, Citrus leiocarpa Hort. ex Tanaka (CLHT), Citrus aurantium L. (CAL) and Citrus erythrosa Hort. (CEH), via 70% methanol extraction followed by ethyl acetate elution over a silica gel cartridge. The flavonoid components of the mixture were analyzed via high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) in positive‐ion mode and a comparison of the reported data. Among 17 characterized components, two flavanones, four flavones and two coumarin derivatives in the fruit peel of the three varieties were identified for the first time. The individual characterized components were quantified via HPLC‐UV. The flavanones dominated in CAL, whereas the flavones prevailed in CLHT and CEH. The antioxidant activity of the flavonoid mixture of the fruit peel was determined via DPPH^?, ABTS^?+ and reducing power assays. The antioxidant activity of CEH and CAL was greater than that of CLHT. Copyright © 2011 John Wiley & Sons, Ltd.