Determination of antioxidant activity and phenolic compounds of Muntingia calabura Linn. peel by HPLC‐DAD and UPLC‐ESI‐MS/MS

Antioxidant activity in Muntingia calabura Linn. peel was evaluated by DPPH radical, ORAC, ABTS cation radical, FRAP assays and total phenolic contents by different extraction conditions. In addition, a method for determination of phenolic compounds in calabura peel samples harvested in Brazil using methanol:water and magnetic stirring as the extraction method, HPLC‐DAD and UPLC‐ESI‐MS/MS analysis were developed. Calabura peel showed antioxidant activity for all extraction conditions and assays evaluated, the most polar solvents being more effective. The developed HPLC‐DAD method allowed the accurate determination of phenolic compounds, with recoveries in the range of 72–107% and precision values ≤4%, with exception for chlorogenic acid. Gallic acid was determined at the highest concentration levels, followed by myricetin, ferulic acid and vanillic acid. However, all the five proposed phenolic compounds were identified in calabura peel samples by UPLC‐ESI‐MS/MS. Thus, calabura peel, an uncommon edible fruit part, can be appointed as a rich source of phenolic compounds.     

Determination of purine alkaloids and catechins in different parts of Camellia assamica var. kucha by HPLC‐DAD/ESI‐MS/MS

BACKGROUND: Kucha (Camellia assamica var. kucha) is a novel wild tea resource grown in China and a tea plant containing a sizable amount of theacrine (1,3,7,9‐tetramethyluric acid). High‐performance liquid chromatography (HPLC) analysis of purine alkaloids and catechins in young leaves of Kucha has been reported previously. However, the compositions of purine alkaloids and catechins in other parts of the plant remain unknown, and more information about the chemical constituents of Kucha is also necessary for further research and development of this new tea resource. RESULTS: Using HPLC with diode array detection coupled with electrospray ionisation tandem mass spectrometry (HPLC‐DAD/ESI‐MS/MS), three purine alkaloids, seven catechins and four non‐catechin phenolic compounds were identified or tentatively identified in Kucha. Purine alkaloids and catechins in leaves at different developmental stages, flowers, stems, pericarps and seeds of the plant were also quantified for the first time by the HPLC method, which was fully validated. Recoveries of the quantified compounds ranged from 96.67 to 104.33%. CONCLUSION: The results showed that the total contents of purine alkaloids and catechins were highest in young leaves of Kucha. Theacrine was detected in all parts of the plant and found to be most abundant in pericarps. Copyright © 2009 Society of Chemical Industry     

HPLC-DAD-ESI-MS analysis of flavonoid compounds in 5 seedless table grapes grown in Apulian Region

Flavonoids present in skin extracts of red seedless table grape varieties Summer Royal, Autumn Royal, and Crimson, and white seedless varieties Carati and Thompson were analyzed by HPLC-DAD-MS, in 3 y of study (2006 to 2008). The anthocyanins, delphinidin-3-O-glucoside, cyanidin-3-O-glucoside, petunidin-3-O-glucoside (with their corresponding p-coumaroyl derivatives), peonidin-3-O-glucoside, and malvidin-3-O-glucoside (with their corresponding acetyl, caffeoyl, and p-coumaroyl derivatives) were found. In addition the flavonols quercetin-3-O-glucuronide, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaempferol-3-O-glucoside, kaempferol-3-O-galactoside, and the flavan-3-ols procyanidin B1, procyanidin B2, and catechin were also detected. Anthocyanins were the main flavonoids in red grapes ranging from 24 (Crimson) to 500 (Summer Royal) mg/kg fresh weight of grapes; consistent levels of flavonols and flavan-3-ols were also quantified in all varieties. To determine the effective climatic influence on flavonoids content in field conditions, viticultural practices have been developed, that could exclude the effects of direct solar radiation from confounding the assessment of those related to thermal conditions alone. A strong positive correlation was determined between flavonoids and temperature data that seem to be responsible for the difference of these metabolites along the years; furthermore, it has been possible to define a linear relationship (R(2) = 0.6871, P = 0.0057) between thermal amplitude and total flavonoids values in the red grapes. PRACTICAL APPLICATION: Grapes are economically the most important fruit species in the world and approximately 30% of its production is used as fresh fruit. Because of the very important role of flavonoids in food quality as well as their health-promoting properties, and considering that our experiments were performed along 3 consecutive years, gathered results in this research are quite promising to give a useful information on the flavonoid contents and their evolution in 5 seedless table grapes that are widespread in Mediterranean regions but also in California and South America, and are grown in a viticultural climate (Apulia, South Italy) very close to some regions of Spain, Turkey, Tunisia, and Israel.     

Mineral profile in globe artichoke as affected by genotype, head part and environment

BACKGROUND: The globe artichoke is an important vegetable, widely consumed in the Mediterranean Basin, and is spreading also to other parts of the world. The mineral profile of globe artichoke has been very little investigated. The purpose of this work was to evaluate the content of some essential macrominerals (Na, K, Ca, Mg) and microminerals (Fe, Cu, Mn, Zn) in nine genotypes of globe artichoke in relation to different head parts (bracts and receptacle), locations and seasons. RESULTS: The mineral profile was significantly affected by genotype, head fraction, location and season. Great variation was found among studied genotypes. ‘Blanc Hyerois’, Harmony F1', ‘Madrigal F1’ and ‘Violetto di Provenza’ showed high levels of both macro‐ and micromineral content. In particular, these, as well as other genotypes, had a higher content in the receptacle (edible part) than in the bracts. The globe artichoke had a high level of K and mainly, compared to some vegetables, low Na/K ratio, which is important in preventing hypertension and cardiovascular diseases. CONCLUSIONS: The results obtained partially improve the lack of data in the literature and this knowledge could be used to develop different crop managements and/or breeding programmes to improve the mineral composition, and thereby enhance human nutrition and health. Copyright © 2010 Society of Chemical Industry     

Comparison of Polyphenol Profile and Inhibitory Activities Against Oxidation and α‐Glucosidase in Mulberry (Genus Morus) Cultivars from China

Mulberry (genus Morus) is a significant source of polyphenols, which can promote positive effects on human health. China has various mulberry cultivars, however, many Chinese mulberry cultivars have been only minimally studied. To solve this lack of research, 8 mulberry cultivars (Da10, Tang10, Yueshen74, Yuefenshen, Longsang, Ningxia1hao, Taiwanguosang, and Baiyuwang) from 4 regions of China were assessed to determine their polyphenol profiles using HPLC‐MS/MS and then tested for their antioxidant and anti‐α‐glucosidase activities in vitro. A total of 18 nonanthocyanins and 4 anthocyanins were quantified in mulberry cultivars; among these polyphenols, chlorogenic acid, quercetin 3‐O‐rutinoside, and cyanidin 3‐O‐glucoside were confirmed as the major phenolic acid, flavonol derivative, and anthocyanin, respectively. Two types of stilbene compounds, piceid, and piceatannol, were detected for the 1st time in all mulberry cultivars. Moreover, the methanolic extracts of different mulberry cultivars showed disparate antioxidant and α‐glucosidase inhibitory activities, and this discrepancy was mainly attributed to varying the anthocyanin content. Based on our results, Taiwanguosang is proposed to be a good candidate suitable for further process due to its high level of anthocyanins.     

The profile in polyphenols and volatile compounds in alcoholic beverages from different cultivars of mulberry

Abstract: Mulberry fruits have different chemical compositions because of cultivar variation. In this study, polyphenol profile and volatile composition of alcoholic beverages produced from different mulberries of Da 10, Hongguo 2 hao, and Hongguo 1 hao were investigated. Statistically significant differences were detected in the chemical composition of the analyzed alcoholic beverage samples. The beverage of Da 10 possessed the highest content of total phenols, total flavonoids, and total anthocyanins, which was determined by spectrophotometry analysis, contrarily Hongguo 1 hao beverage showing the lowest. Phenolic acids and flavonols were analyzed by high performance liquid chromatography analysis. Protocatechuic acid was the main phenolic acid in all analyzed alcoholic beverage samples, and its concentration ranged from 8.20 mg L^?1 (Hongguo 1 hao beverage) to 29.98 mg L^?1 (Da 10 beverage). High level of flavonols was found in both Da 10 and Hongguo 2 hao beverage samples, whereas Hongguo 1 hao beverage sample was characterized with lower level of flavonols. Furthermore, volatile compounds were analyzed by solid phase microextraction‐gas chromatography mass spectrometry analysis. The amount of esters varied widely among the 3 alcoholic beverage samples. The concentration of aliphatic alcohols in Hongguo 2 hao and 1 hao beverage samples was higher than Da 10 sample, whereas Da 10 beverage sample contained more aromatic alcohols than the others. Hongguo 1 beverage sample showed the highest concentration of acetic acid. This study demonstrated that quantitative differences of phenolic compounds and volatile compounds among cultivars were significant, which highly affected the quality of alcoholic beverage from mulberry. Practical Application: Mulberry fruits had different chemical compositions because of cultivar variation. The analyzed Da 10 cultivar of mulberry appeared to be a good raw material for alcoholic beverage‐making because of its high level of total sugar and acidity. This study demonstrated that alcoholic beverages from mulberry contain high amounts of polyphenols. These bioactive compounds may act synergistically to promote health, and reduce risk factors of chronic diseases.     

Purification and characterization of a cationic peroxidase from artichoke leaves

Peroxidases are part of a large group of enzymes associated with cell wall biosynthesis, response to injury, disease, resistance and wound repair. Among peroxidase isoenzymes, a soluble cationic peroxidase (ALSP), not yet described, has been partially purified and characterized from artichoke leaves. The enzyme was shown to be a glycoprotein with a molecular weight of 51 000 and an isoelectric point of 9. The substrate specificity of the ALSP is characteristic of class III (guaiacol‐type) peroxidases. The ALSP was partially purified by ammonium sulfate precipitation, gel filtration, affinity chromatography, anionic exchange high‐performance liquid chromatography and isoelectrofocusing. The increase in specific activity was 43 times compared to the crude extract as estimated by the guaiacol assay. Three ALSP fragments were sequenced by tandem mass spectrometry de novo sequencing method. Copyright © 2007 Society of Chemical Industry     

高效液相色谱串联质谱鉴定甘薯叶中的主要化学组成

以2种肉色型甘薯叶—橘心甘薯叶(OFL)和白心甘薯叶(CFL)为原料,旨在采用高效液相色谱-电喷雾离子源-四级杆飞行时间串联质谱(HPLC-ESI-QTOF-MS/MS)比较2种甘薯叶DHPM提取物中的主要化合组成的差异。根据化合物的前体离子、MS/MS裂解规律、紫外图谱、保留时间,并与相关数据库和参考文献对照,对2种甘薯叶提取物中的主要化合物进行鉴定。结果表明,OFL是比CFL更好的抗氧化剂资源。从OFL和CFL中共鉴定出22种化合物,包括8种有机酸、3种氨基酸、4种羟基肉桂酸衍生物、3种黄酮和4种脂肪酸。因此,HPLC-ESI-QTOF-MS/MS是快速分析复杂植物提取物中化学组成的有效方法。     

Phenolic profile and changes in the antioxidant activity of crabapple (Malus domestica cv Royalty) fruit during maturation on the tree

The fruits of crabapple (Malus domestica cv Royalty) harvested at six times during fruit maturation on the tree (60, 80, 100, 120, 140 and 160 day after full bloom, DAFB) were evaluated for their antioxidant potentials by various assays such as DPPH, ABTS, superoxide anion, hydroxyl radical and ferric reducing power. Total phenolic and flavonoid were analysed and characterised using HPLC‐DAD‐MS/MS. Results showed that the Royalty fruits harvested on 60 DAFB had the strongest scavenging activity against DPPH, ABTS and radicals ( = 0.37 mg mL^?1,  = 0.19 mg mL^?1 and  = 4906.63 U L^?1) and ferric reducing power (FRAP = 2.85 mol Fe²⁺ per kg dw), which highly correlated with its high amount of total phenolics of 130.17 mg gallic acid equivalents (GAE) per gram dry weight and total flavonoid of 866.15 mg rutin equivalents (RE) per gram dry weight. Eight phenolic compounds were identified in the Royalty extract of 60 DAFB as caffeic acid, eriodictyol rhamnoside, phloretin hexoside I, coumaroyl guinic acid, quercetin hexoside, phloretin hexoside II, quercetin pentoside and quercetin rhamnoside. These findings suggest that Royalty could be potentially used as a promising source of natural antioxidants in the development of functional foods.     

Development of the Rhodiola rosea Fuqu and Rhodiola rosea soy sauce,and the determination of their functional properties

A mixed starter, composed of high‐quality Rhodiola rosea Fuqu, was developed. Compared with normal Fuqu, Rhodiola rosea Fuqu demonstrated higher spore numbers, spore germination rates, protease activity, liquefying amylase activity and total acid and amino acid nitrogen. Specifically, the spore number was 1.36 times that of regular Fuqu. Protease activity, liquefying amylase activity, total acid and amino acid nitrogen were 0.475 g/100 mL, 104.16 U/g dry Qu, 35.67 mmol/L and 26.08 g/100 mL, respectively. These values were 21.48, 7.41, 6.07 and 67.82% higher than the regular Fuqu. The Rhodiola rosea soy sauce indices were also better than those for the control. The DPPH scavenging abilities of R. rosea soy sauce, control soy sauce, market soy sauce 1 and market soy sauce 2 were 74.25, 44.01, 34.73 and 11.38%, respectively. The total phenolic content in these four samples was 387.38, 309.23, 212.85 and 202.60 mg GAE/g, respectively. As observed with the DPPH and total phenolic assay, the R. rosea soy sauce showed the highest antioxidant capacity. A simple, rapid, and sensitive determination method of salidroside in R. rosea Fuqu and R. rosea soy sauce using HPLC‐ESI‐MS/MS was developed and validated with multiple reaction monitoring in the negative mode.     

Phenolic compounds and antioxidant activity of tuberous root leaves

The antioxidant potential of five tuberous root leaves was evaluated. High performance liquid chromatography (HPLC/DAD) showed the presence of phenolic compounds in leaves, and the predominant ones were chlorogenic acids in carrot (458.79 mg.L^?1± 0.03): rosmarinic acid in sweet potato (222.05 mg.L^?1± 0.01) and quercetin in sweet potato (292.42 mg.L^?1± 0.01). Radish leaves showed a higher total in vitro antioxidant activity for all methods used in this study. The results indicated that these leaves were natural sources of antioxidants and, therefore, could be included in the health beneficial diet.     

Analysis of low molecular weight plant phenolics by thermospray liquid chromatography/mass spectrometry

High performance liquid chromatography-mass spectrometry using a thermospray interface and discharge ionisation has been conducted on a group of plant phenolic standards and on a wheat straw acid hydrolysate. Protonated molecules, [M + H]⁺, were observed for the phenolic standards and it was possible to identify several phenolic compounds in the hydrolysate. These results indicate that thermospray HPLC/MS has potential as a technique for determining the presence of useful marker compounds which are indicative of the progress of the lignification during plant growth.     

Characterisation of phenols and antioxidant and hypolipidaemic activities of Lethariella cladonioides

BACKGROUND: This study aimed to investigate the antioxidant and hypolipidaemic activities of an ethanol extract of Lethariella cladonioides (Nyl.) Krog (EE) and to characterise its chemical constituents. RESULTS: Nine phenols were identified as canarione, thamnolic acid, squamatic acid, vermicularin, norstictic acid, baeomycesis acid, lecanoric acid, barbatinic acid and usnic acid from analysis of EE by using high‐performance liquid chromatography with a diode array detector‐mass spectrometry. In antioxidant analysis in vitro, the highest scavenging rate of EEs on the 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) radicals, superoxide anion, hydroxyl radicals and hydrogen peroxide was 81.55 ± 1.95%, 81.84 ± 4.00%, 74.28 ± 3.71% and 74.28 ± 3.71%, respectively. Meanwhile, after administration of EE for 6 weeks in high fat/cholesterol diet mice, the most significant reduction in levels of serum triglyceride, serum total cholesterol, serum low density lipoprotein cholesterol and liver malondialdehyde were 24%, 20%, 15% and 35%, respectively. The most significant increase in levels of serum high density lipoprotein cholesterol and liver superoxide dismutase was 35% and 88%, respectively. CONCLUSION: L. cladonioides possesses strong antioxidant and hypolipidaemic activities. Copyright © 2011 Society of Chemical Industry     

Phenolic Compounds in Fresh and Dried Figs from Cilento (Italy), by Considering Breba Crop and Full Crop,in Comparison to Turkish and Greek Dried Figs

Fresh and dried figs are important components of the Mediterranean diet. In Cilento (Southern Italy), figs belonging to cultivar “Dottato” are used for the production of “PDO Cilento white figs,” as dried figs. In this article, we reported the characterization of the phenolic compounds in 19 fig samples: 9 fresh figs cultivar “Dottato” from Cilento (Italy), 10 dried fig samples from Cilento (2), Turkey (6), and Greece (2). The following phenolic compounds were identified and quantified by high‐performance liquid chromatography (HPLC)/UV‐DAD: chlorogenic acid, protocatechuic acid, vanillic acid, luteolin‐3,7‐di‐O‐glucoside, luteolin 7‐glucoside, apigenin‐7‐O‐rutinoside, rutin, quercetin‐3‐glucoside, and cyanidin‐3‐O‐rutinoside. A discriminative analysis between the peel and pulp of the samples was carried out. The 1st crop (“breba”) and the 2nd one (full crop) from Dottato figs were considered, as well as the effect of fig pollination. The majority of the phenolic compounds were predominant in the fig peel. Significant quantitative differences were found among fresh figs, whereas also some qualitative differences were obtained between fresh and dried figs from the same origin in Dottato cultivar, and among dried figs from different origins. Breba crop resulted richer in phenolics than figs of the 2nd crop. Considering the dried figs, the Turkish ones had the highest concentration in phenolic compounds. Other compounds such as the aminoacids tyrosine and tryptophan were also detected by HPLC‐DAD analysis in Dottato figs, probably due to the similarity of their chemical structure.