Jun Sang

Extraction optimization and identification of anthocyanins from Nitraria tangutorun Bobr. seed meal and establishment of a green analytical method of anthocyanins

This study aimed to extract and identify anthocyanins from Nitraria tangutorun Bobr. seed meal and establish a green analytical method of anthocyanins. Ultrasound-assisted extraction of anthocyanins from N. tangutorun seed meal was optimized using response surface methodology. Extraction at 70°C for 32.73 min using 51.15% ethanol rendered an extract with 65.04mg/100g of anthocyanins and 947.39mg/100g of polyphenols. An in vitro antioxidant assay showed that the extract exhibited a potent DPPH radical-scavenging capacity. Eight anthocyanins in N. tangutorun seed meal were identified by HPLC-MS, and the main anthocyanin was cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (18.17mg/100g). A green HPLC-DAD method was developed to analyse anthocyanins. A mixtures of ethanol and a 5% (v/v) formic acid aqueous solution at a 20:80 (v/v) ratio was used as the optimized mobile phase. The method was accurate, stable and reliable and could be used to investigate anthocyanins from N. tangutorun seed meal.

An approach for extraction, purification, characterization and quantitation of acylated-anthocyanins from Nitraria tangutorun Bobr. fruit

In the present study, a systematic approach for extraction, purification and analysis of acylated-anthocyanins from Nitraria tangutorun Bobr. fruit was explored. Six acylated-anthocyanins in N. tangutorun fruit were identified by HPLC-MS/MS, and a rapid and efficient HPLC-DAD method was developed to analyze the acylated-anthocyanins. Ultrasonic-assisted extraction conditions of acylated-anthocyanins were optimized using response surface methodology, extraction at 70xa0°C for 32xa0min using 70% methanol solution (0.1% HCl, v/v) rendered an extract with 80.37u2009±u20092.66xa0mg/100xa0g of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and 97.88u2009±u20094.06xa0mg/100xa0g of total acylated-anthocyanins. Nine macroporous resins were investigated for preliminary purification of acylated-anthocyanins. According to the static/dynamic adsorption and desorption tests, XDA-6 macroporous resin exhibited the maximum potential for preparing acylated-anthocyanins. The purity of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (43.30xa0mg/g) in purified acylated-anthocyanins was 201.89 times of that of the extract (0.21xa0mg/g), and the purity of total acylated-anthocyanins increased from 0.36 to 56.44xa0mg/g. Besides, the stability (t1/2) of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and total acylated-anthocyanins increased by more than five-fold after purification using XDA-6. The established methods of analysis, extraction and purification of acylated-anthocyanins were hopefully utilized in food industry.

Development of a green two-dimensional HPLC-DAD/ESI-MS method for the determination of anthocyanins from Prunus cerasifera var. atropurpurea leaf and improvement of their stability in energy drinks

This study aimed to develop a green two-dimensional HPLC-DAD/ESI-MS method for analysing anthocyanins from Prunus cerasifera var. atropurpurea leaf and improve their stability in energy drinks by the addition of phenolic acids. Ethanol and tartaric acid solutions were used as mobile phases for one-dimensional HPLC-DAD for quantitative analysis of anthocyanins, and the primary anthocyanins were identified as cyanidin-3-O-galactoside, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside using two-dimensional HPLC-MS. Method validation showed that the developed method was accurate, stable and reliable for the analysis of P. cerasifera anthocyanins. The effects of gallic, ferulic and caffeic acid on the stability of cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and total anthocyanins from P. cerasifera leaf in energy drinks were evaluated, and the degradation of P. cerasifera anthocyanins ideally followed a first-order model (R > 0.98). Gallic acid showed stronger protective effects on P. cerasifera anthocyanins in energy drinks, and adding/increasing ferulic and caffeic acids accelerated the degradation reactions.

Partition Behaviors of Different Polar Anthocyanins in Aqueous Two-Phase Systems and Extraction of Anthocyanins from Nitraria tangutorun Bobr. and Lycium ruthenicum Murr.

This study aimed to investigate the partition behaviors of various polar anthocyanins in NaH2PO4/(NH4)2SO4-ethanol aqueous two-phase systems (ATPS) and to extract anthocyanins from Nitraria tangutorun Bobr. and Lycium ruthenicum Murr. Anthocyanins in Hibiscus sabdariffa L., Morus atropurpurea Roxb., N. tangutorun, and L. ruthenicum were profiled using HPLC-ESI-MS/MS and HPLC-DAD, and the partition behaviors of total anthocyanins and main anthocyanins were studied. The partition coefficient of anthocyanins increased with increased hydrophobicity, and low-polarity anthocyanins exhibited a higher preference for the top phase in NaH2PO4/(NH4)2SO4-ethanol ATPS. Additionally, the NaH2PO4-ethanol ATPS gave higher selectivity and total anthocyanin yield than the (NH4)2SO4-ethanol system. Extraction at 65xa0°C for 45xa0min and at 45.5xa0°C for 45xa0min using 28% NaH2PO4 and 26% ethanol (w/w) led to the recovery of 98.91xa0±xa00.03% of N. tangutorun anthocyanins (3.62xa0±xa00.05xa0mg/g) and 99.84xa0±xa00.01% of L. ruthenicum anthocyanins (13.16xa0±xa00.29xa0mg/g) from raw material; more than 70% of total sugars were removed in a single step. NaH2PO4-ethanol aqueous two-phase extraction is a promising method for extracting anthocyanins from N. tangutorun and L. ruthenicum.

Deep eutectic solvent-based extraction coupled with green two-dimensional HPLC-DAD-ESI-MS/MS for the determination of anthocyanins from Lycium ruthenicum Murr. fruit

This study aimed to extract and separate total anthocyanins from Lycium ruthenicum Murr. by combining deep eutectic solvents (DES) with macroporous resin chromatography and to develop green analytical methods for the determination of anthocyanins. Choline chloride/1,2-propanediol (1u2006:u20062, mol mol−1) containing 10% water (v/v) was screened as the optimal extraction solvent, and extraction at 52 °C for 45 min using a liquid/solid ratio of 20u2006:u20061 gave the maximum extraction yield of total anthocyanins (4.45 ± 0.07 mg g−1). According to the static/dynamic adsorption and desorption tests, LS-32 macroporous resin has the ability to separate anthocyanins from DES with a recovery ratio above 95%. An off-line heart-cutting two-dimensional HPLC-DAD/ESI-MS method was developed for the qualitative and quantitative analysis of L. ruthenicum anthocyanins using environmentally friendly mobile phases. Ethanol and a tartaric acid solution (0.3 mol L−1) were used as the mobile phases of the first-dimensional HPLC-DAD method, and 15 anthocyanin peaks were detected within 17 min. The second-dimensional HPLC-MS method was used to identify the main anthocyanin peaks in the first dimension. Method validation showed that the developed method was accurate, stable and reliable for the analysis of L. ruthenicum anthocyanins. The present study provides an excellent alternative green method for the preparation and determination of anthocyanins from plant material.

Extraction and characterization of anthocyanins from Nitraria tangutorun bobr. dry fruit and evaluation of their stability in aqueous solution and taurine-contained beverage

This study aimed to extract and identify anthocyanins from Nitraria tangutorun Bobr. dry fruit and evaluate the stability of anthocyanins in aqueous solution and taurine-contained beverage. Extraction at 68xa0°C for 30xa0min using 54% ethanol rendered an extract with 386.22xa0mg/100xa0g of anthocyanins. Fourteen anthocyanins in N. tangutorun dry fruit were identified using HPLC-DAD-ESI-MS/MS, and six of them were found in N. tangutorun dry fruit for the first time. The stability of anthocyanins and changes in color density and antioxidant activity of anthocyanin aqueous solution were evaluated at various pH and temperature levels using an accelerated thermal-stability assay. The degradation of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and total anthocyanins and the loss of color density followed first-order model at studied conditions (R2u2009>u20090.91); and the loss of antioxidant activity followed first-order model at 80 and 90xa0°C (R2u2009>u20090.94). The Ea of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and total anthocyanins were higher at pH 3 than that at pH 4 and 5 implying that the degradation of them at a lower pH level was more susceptible to temperature. Although the anthocyanins and color density were markedly loss with increasing the pH and temperature levels, the anthocyanin aqueous solution exhibited remarkable antioxidant capacity. In the beverage with or without taurine, the thermal degradation of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside and total anthocyanins also followed first-order model (R2u2009>u20090.91), and 300xa0mg/100xa0mL of taurine provides protection for the stability of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (t1/2=438.61xa0min) and total anthocyanins (t1/2=391.53xa0min). N. tangutorun anthocyanins is promising natural food pigments.

β-Cyclodextrin-assisted extraction and green chromatographic analysis of Hibiscus sabdariffa L. anthocyanins and the effects of gallic/ferulic/caffeic acids on their stability in beverages

This study aimed to develop a green approach for extraction and determination of anthocyanins from Hibiscus sabdariffa calyx using a hydroxypropyl-β-cyclodextrin (HPβ-CD)-assisted extraction technique coupled with HPLC-DAD analysis and to investigate the effects of gallic/ferulic/caffeic acids on the stability of H. sabdariffa anthocyanins in beverages. HPβ-CD-assisted extraction of total anthocyanins from H. sabdariffa calyx was optimized using a Box–Behnken design-response surface methodology, and extraction at 54xa0°C for 53xa0min using HPβ-CD aqueous solution (3.7xa0g/100 mL) gave the maximum extraction yield of total anthocyanins (4.82u2009±u20090.13xa0mg/g). A work-safe and rapid HPLC-DAD method was developed for analysing H. sabdariffa anthocyanins using ethanol and a tartaric acid aqueous solution as mobile phases, and the main anthocyanin peaks were determined as delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside using a two-dimensional HPLC-DAD/ESI-MS method. Method validation showed that the developed method was accurate, stable and reliable for the analysis of H. sabdariffa anthocyanins. Additionally, the degradation of delphinidin-3-O-sambubioside, cyanidin-3-O-sambubioside and total anthocyanins from H. sabdariffa calyx ideally followed a first-order model (R2u2009>u20090.98) in beverages alone or with additional phenolic acids. Gallic acid improved the stability of H. sabdariffa anthocyanins better than ferulic and caffeic acids, and adding/increasing ferulic and caffeic acids accelerated anthocyanin degradation.

Green Approach for Sample Preparation and Determination of Anthocyanins from Lycium ruthenicum Murr. Using a β- Cyclodextrin-Based Extraction Method Coupled with UPLC-DAD Analysis

This study aimed to develop and optimize a β-cyclodextrin (β-CD)-based technique for extracting anthocyanins from Lycium ruthenicum Murr. and to establish a ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) method for their analysis. β-CD solutions produced higher extraction yields of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside and total anthocyanins from L. ruthenicum fruit than did pure water and aqueous hydroxypropyl-β-cyclodextrin (HPβ-CD) and ethanol and methanol solutions. Extraction at 50xa0°C for 30xa0min using 1.65% β-CD solution and a liquid/solid ratio of 15:1 produced the optimal extraction yield of L. ruthenicum anthocyanins. A UPLC-DAD method was developed for the determination of L. ruthenicum anthocyanins using an ethanol-based mobile phase, and the primary anthocyanins were identified using two-dimensional LC-MS/MS. Method validation showed that the developed method was accurate, stable, and reliable for the analysis of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside and total anthocyanins from L. ruthenicum fruit. The present study showed that β-CD-based extraction coupled with UPLC-DAD analysis is an efficient and green method for the extraction and analysis of anthocyanins from L. ruthenicum fruit.

Anthocyanins from Nitraria tangutorun: qualitative and quantitative analyses, antioxidant and anti-inflammatory activities and their stabilities as affected by some phenolic acids

This study aimed to develop a UPLC-DAD-MS/MS method for the qualitative and quantitative analysis of anthocyanins from Nitraria tangutorun Bobr. fruit, investigate their antioxidant and anti-inflammatory activities, and evaluate the effects of gallic/ferulic/caffeic acids on their stabilities in beverages. A work-safe and efficient UPLC-DAD-MS/MS method was developed for the analysis of N. tangutorun anthocyanins using ethanol and a 0.1% formic acid solution as mobile phases, and 17 anthocyanins were determined within 12xa0min. N. tangutorun anthocyanins not only exhibited strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50u2009=u20090.5174xa0mg/mL), hydroxyl radical (·OH) (IC50u2009=u20090.4538xa0mg/mL) and superoxide radical (O2·) (IC50u2009=u20090.9929xa0mg/mL) scavenging capacities, but more importantly they potently inhibited the release of pro-inflammatory cytokines, including nitric oxide, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), in LPS-stimulated RAW 264.7 macrophage cells. Additionally, the degradation of cyanidin-3-O-(trans-p-coumaroyl)-diglucoside (MA) and total anthocyanins (TA) from N. tangutorun fruit ideally followed a first-order model (R2u2009>u20090.97) in beverages with or without phenolic acid addition. Gallic acid can effectively stabilize MA and TA in beverages, and 80xa0mg/100xa0mL of gallic acid increased the t1/2 values of MA and TA by 30.0% and 39.1%, respectively; however, adding/increasing the concentration of ferulic and caffeic acids accelerated anthocyanin degradation.