Extraction,identification and enzymatic synthesis of acylated derivatives of anthocyanins from jaboticaba (Myrciaria cauliflora) fruits

Polyphenols were extracted from the skin of jabuticaba fruits (Myrciaria cauliflora). Their total concentration and in vitro antioxidant activity were analysed by the DPPH and ABTS methods. The corresponding results (dry basis) were 1290 mg gallic acid equivalent (GAE)?(100 g)^?1, 98% of DPPH radical inhibition and 120 μm TEAC?g^?1 (ABTS method). All these values are at least as higher as average values reported in the literature for other fruits. A more specific analysis of the fractions of phenolic compounds was also performed by HPLC‐MS. Ellagic acid, quercetin, rutin, delphinidin‐3‐glucoside and cyanidin‐3‐glucoside were the main compounds detected; the latter two were the most abundant. The crude extract was subjected to enzymatic acylation assays in order to synthesise new esters with new potential techno‐functionalities. Palmitic acid was used as acyl donor and lipase B of Candida antactica (CALB) as biocatalyst. HPLC‐MS evidenced the formation of palmitic monoesters in connection with the delphinidin‐3‐glucoside and cyanidin‐3‐glucoside fractions.     

紫茄子皮飞燕草色素苷的分析及其苷元的制备

以紫色茄子皮为材料,期望分离纯化得到价格昂贵的高纯度飞燕草色素单体。利用光谱及质谱技术对紫色茄子皮的花青素苷进行了定性分析,鉴定出4种花青素苷,且均为连接不同糖配体的飞燕草色素苷。然后优化飞燕草色素的提取纯化条件,结果表明,提取剂为含1%盐酸的60%乙醇溶液、料液比为1:20时提取效果最佳。利用AB-8型大孔树脂初步纯化飞燕草色素苷,发现随着洗脱剂乙醇浓度的升高,得到的飞燕草色素苷溶液浓度先升高后降低,当乙醇浓度为30%时洗脱效果最好,此时洗脱液在530 nm下的紫外吸收值为0.49。运用高温酸水解的方法可获得飞燕草色素苷元,即飞燕草色素。对酸水解后获得的飞燕草色素苷元依次利用AB-8型大孔树脂和C18柱层析进行分离纯化,得到飞燕草色素单体,最后通过结晶沉淀的方法获得了纯度大于98%的飞燕草色素单体粉末。研究为分离纯化飞燕草色素提供了一种切实可行的方法。     

Thermodynamic characteristics of copigmentation reaction of acylated anthocyanin isolated from blue flowers of Scutellaria baicalensis Georgi with copigments

Anthocyanin extracts are increasingly used as food colorants. So far, anthocyanins have not been broadly used in foods and beverages, since they are not as stable as synthetic dyes. Copigmentation between anthocyanins and copigments is the main colour‐stabilizing mechanism. The process of copigmentation between isolated acylated anthocyanin and rutin, QSA or baicalin has been observed using UV–vis spectrophotometry. The thermodynamic parameters were correlated to the structure and position of the substituents in the interacting molecules. The acylated anthocyanin was isolated from cultivars of Scutellaria baicalensis Georgi flowers and purified by column chromatography by our own method and has been identified by ¹H‐/¹³C‐NMR spectroscopy and electrospray mass spectrometry as delphinidin‐3‐O‐(6‐O‐malonyl)‐β‐D ‐glucopyranosyl‐5‐O‐β‐D ‐glucopyranoside. Copyright © 2004 Society of Chemical Industry     

Influence of partial rootzone drying on the composition and accumulation of anthocyanins in grape berries (Vitis vinifera cv. Cabernet Sauvignon)

Background and Aims: The aim of the study was to investigate anthocyanin composition and accumulation in grape berries in response to the partial rootzone drying (PRD) irrigation technique.
Method and Results: The experiment was on Vitis vinifera cv. Cabernet Sauvignon, wherein PRD had a 40% water deficit relative to the control treatment. PRD decreased berry weight compared with the control, but did not influence total anthocyanin concentration. A significant increase in glucosides of delphinidin, cyanidin, petunidin and peonidin was found in response to PRD from the onset of anthocyanin accumulation (veraison), while malvidin-glucosides were unaffected by the irrigation treatment. The PRD treatment did not cause changes in the proportions of acetyl-, 3- p -coumaroyl- and monoglucoside anthocyanins. Wines produced from the treatments showed no difference in total monomeric anthocyanin, but relative increases (15%) in wine colour density, total tannin and polymeric pigment occurred in response to the PRD treatment. The anthocyanin composition of the wines reflected the response shown in the grapes, where the relative contribution of non-malvidin anthocyanins to total anthocyanins was significantly increased in wines from the PRD treatment.
Conclusions: The differences in anthocyanin composition observed in response to PRD could not be accounted for by changes in bunch microclimate, and most likely reflect differences in the methylation step of anthocyanin synthesis.
Significance of the Study: The observed changes in anthocyanin composition under the PRD irrigation system have not been previously reported in response to water deficit, and may reflect a unique response to within-vine signalling induced by PRD.     

Degradation of N‐(1‐Deoxy‐d‐xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐xylulos‐1‐yl)proline using thermal treatment

The formation and degradation of N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)proline, derived from the secondary amine Maillard reaction in xylose‐amino acid model solutions, were detailed in this study. The identification and quantitative analysis of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline were carried out using high‐performance anion‐exchange chromatography and high‐performance liquid chromatography. The formation of intermediate and advanced products derived from N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline was also tested using an UV‐Vis spectrophotometer to gain a better comparing of the degradation process of the two important Maillard reaction products using thermal treatment. Results showed that the degradation of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine was more significant than N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline. Moreover, xylose was tested in the degradation products of both N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline, which indicated that the degradation of N‐substituted 1‐amino‐1‐deoxyketoses was a reversible reaction to form reducing sugar.     

Absorption of N-phenylpropenoyl-L-amino acids in healthy humans by oral administration of cocoa (Theobroma cacao)

Besides flavan-3-ols, a family of N-phenylpropenoyl-L-amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC-MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid (6) and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC-MS/MS before and after beta-glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O-glucuronides nor their O-sulfates. In order to screen for caffeic acid O-glucuronides as potential NPA metabolites, urine samples were screened by means of LC-MS/MS for caffeic acid 3-O-beta-D-glucuronide and 4-O-beta-D-glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O-methylation or reduction of the N-phenylpropenoyl moiety in NPAs.     

Urinary 2-ethyl-3-oxohexanoic acid as major metabolite of orally administered 2-ethylhexanoic acid in human

Human metabolism of 2-ethylhexanoic acid (2-EHA), which is a known metabolite of important phthalates, was investigated using 2-EHA-contaminated food. The results of our studies reveal that the major catabolic pathway of 2-EHA in human is beta-oxidation. The dominant final urinary metabolite was identified and quantified as 3-oxo-2-ethylhexanoic acid (3-oxo-2-EHA), but only after immediate methylation of the extract from urine and prior to GC-MS analysis. Former studies without the precaution of immediate methylation had found 4-heptanone as the major metabolite, which is obviously an artifact arising from the decarboxylation of 3-oxo-2-EHA.     

Improved determination of D-glucosamine hydrochloride in health foods by HPLC using 7-fluoro-4-nitrobenzo-2-oxa-l,3-diazole as a derivative

Abstract: This article presents an improved method to detect d ‐glucosamine hydrochloride in health foods. A simple precolumn derivatization procedure with 7‐flouro‐4‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD‐F) reagent was employed. The separation of the derivatized d ‐glucosamine hydrochloride (NBD‐d ‐glucosamine hydrochloride) was performed using a mobile phase consisting of acetonitrile, potassium dihydrogen phosphate (0.01 mol/L), and trifluoroacetic acid (350:649.74:0.26, volume ratio) at a flow rate of 1.0 mL/min with the column temperature 35 °C. Under the optimum chromatographic conditions, the peak area of NBD‐d ‐glucosamine hydrochloride compared with its absolute value of the peak area of NBD‐d ‐glucosamine hydrochloride in a standard solution concentration range from 1.0 to 500.0 mg/L showed a good linear calibration (R = 0.9999). Recoveries, at spiked concentrations of 10.0, 40.0, and 500.0 mg/L, varied between 97.2% and 102.6% with relative standard deviations ranging from 0.4% to 1.5%. The present method provides sufficient sensitivity as reflected by the values of limit of detection (LOD) and limit of quantification (LOQ). LOD was determined from the signal‐to‐noise ratios (S/N) of NBD‐d ‐glucosamine hydrochloride peak of at least 3 in the recovery test at 0.02 mg/L, and the estimated LOQ was 0.06 mg/L (S/N = 10). The proposed method was successfully applicable to detect d ‐glucosamine hydrochloride in health foods and drugs containing a variety of complex materials.     

Identifications of inhibitors of IgE production by human lymphocytes isolated from ‘Cha Chuukanbohon Nou 6’ tea leaves

BACKGROUND: Tea (Camellia sinensis L.) is consumed all over the world and in especially large quantities in Japan and China, where it has been used not only as a daily beverage but also for medicinal purposes for thousands of years. Tea has been found to exhibit various bioregulatory activities, including antiallergic, anticarcinogenic, antimetastatic, antioxidative, antihypertensive, antihypercholesterolemic, anti‐dental caries and antibacterial effects, and to influence intestinal flora. RESULTS: Cha Chuukanbohon Nou 6 is a tea cultivar improved by the National Institute of Vegetable and Tea Science (NIVTS) in Japan. On comparing chemical constituents of 11 varieties of tea leaves by high‐performance liquid chromatography, we found two new major compounds in Cha Chuukanbohon Nou 6. Nuclear magnetic resonance spectroscopy revealed these compounds to be theogallin and 1,2‐di‐O‐galloyl‐4,6‐O‐(S)‐hexahydroxydiphenoyl‐β‐D ‐glucopyranose. The two were similar in chemical structure to strictinin, an inhibitor of immunoglobulin (Ig) production. Thus their effects on the production of Igs by peripheral blood lymphocytes were tested. Both compounds, like strictinin, inhibited IgE production. CONCLUSION: The results suggest Cha Chuukanbohon Nou 6 to be the basis of an antiallergic beverage. Copyright © 2009 Society of Chemical Industry     

The impact of the various chemical and physical factors on the degradation rate of bronopol

Bronopol (2‐bromo‐2‐nitropropane‐1,3‐diol) is used as preservative in cosmetic industry. Its main role in commercial products consists in protection of the cosmetic composition stability by inhibiting the development of micro‐organisms. Unfortunately, preservatives can also undergo the degradation processes. The aim of examinations was to prove that bronopol decomposes in aqueous solutions and storage conditions have a significance influence on its degradation rate. High‐performance liquid chromatography method (methanol/water with hydrochloric acid 5:95 v/v) with spectrophotometric detection (210 nm) was used for examining the decomposition rate of bronopol. The impact of chemical (addition of cosmetics components: citric acid and/or sodium dodecylsulfate) and physical (elevated and ambient temperature, sunlight or ultraviolet radiation and air access) factors has been elaborated. Bronopol decomposes most rapidly (independently on the sample surrounding conditions) when it is in solution with sodium dodecylsulfate, the inverse dependence is observed in the presence of two compounds – citric acid and sodium dodecylsulfate. Additionally, the elevated temperature causes the acceleration of decomposition. Bronopol degradation by‐products were also identified as methanol, formic acid, tris(hydroxymethyl)methane and 2‐bromo‐2‐nitroethanol.     

Reduction of fumonisin B₁ in corn grits by twin-screw extrusion

Abstract: This study was designed to investigate the fate of fumonisins in flaking corn grits during twin‐screw extrusion by measuring fumonisin B₁ (FB₁) and its analogs with a mass balance approach. Food grade corn grits and 2 batches of grits contaminated with FB₁ at 10 and 50 μg/g by Fusarium verticillioides M‐2552 were processed with or without glucose supplementation (10%, w/w) with a twin‐screw extruder. Extrusion reduced FB₁ in contaminated grits by 64% to 72% without glucose and 89% to 94% with added glucose. In addition, extrusion alone resulted in 26% to 73% reduction in the levels of fumonisin B₂ and fumonisin B₃, while levels of both mycotoxins were reduced by >89% in extruded corn grits containing 10% glucose. Mass balance analysis showed that 38% to 46% of the FB₁ species detected in corn extruded with glucose was N‐(deoxy‐D‐fructos‐1‐yl)‐FB₁, while 23% to 37% of FB₁ species detected in extruded corn grits with and without added glucose was bound to the matrix. It was also found that the hydrolyzed form of FB₁ was a minor species in extruded corn grits with or without added glucose, representing <15% of the total FB₁ species present. Less than 46% of FB₁ originally present in corn grits could be detected in the fumonisin analogues measured in this study. Research is needed to identify the reaction products resulting from extrusion processing of fumonisin‐contaminated corn products. Practical Application: Twin‐screw extrusion is widely used in food industry for its versatility. This technology may reduce the level of fumonisins in corn particularly with added glucose.