Large-scale isolation of high-purity anthocyanin monomers from mulberry fruits by combined chromatographic techniques

Native Mexican black bean purified anthocyanins fractionated by high-performance counter-current chromatography modulate inflammatory pathways

In addition to their pigment properties, the potential health benefits of anthocyanins have made them a subject of interest in recent years. This study aimed to obtain purified anthocyanin fractions from native Mexican black bean cultivars using Amberlite XAD-7 resin column and HPCCC and evaluate their anti-inflammatory properties using RAW 264.7 cells. The major anthocyanins in the purified anthocyanin fractions were delphinidin 3-glucoside (61.8%), petunidin 3-glucoside (25.2%), and malvidin 3-glucoside (12.2%). Purified anthocyanin fractions at 12.5 μg/mL effectively prevented LPS-induced ERK1/ERK2 phosphorylation and reduced the protein expression of COX-2 and mRNA expression of iNOS. Results showed that purified anthocyanin fractions have the potential to modulate the inflammatory response by inhibiting the production of pro-inflammatory mediators through the ERK1/ERK2 and NF-κB pathways. This study suggests that anthocyanins from black beans could be used as a natural strategy to help modulate inflammation-associated diseases.

Effect of vacuum freeze drying and hot air drying on dried mulberry fruit quality

Two different drying methods (vacuum freeze-drying and hot-air drying) were used to dry mulberry of three varieties 'Baiyuwang'(D1), 'Longsang'(D2) and 'Zhongshen.1'(D3), and the fresh fruit of each variety was used as the control. The effects of different processing conditions on the physical characteristics, nutrients, functional components and antioxidant activity of mulberry fruit were analyzed. The results show that after different drying methods, after vacuum freeze-drying, the physical properties of dried mulberry fruit such as wettability, hygroscopic property and water retention, soluble protein, ascorbic acid and other nutrients, functional components such as polyphenols, resveratrol, chlorogenic acid and anthocyanin, and antioxidant activities such as DPPH free radical scavenging ability and ABTS free radical scavenging ability were superior to hot air drying (P < 0.01). It was concluded that vacuum freeze drying was more beneficial for retaining the original quality of mulberry than hot air drying. This study can provide a retaining theoretical basis for mulberry deep processing and comprehensive development and utilization.

Recovery of value-added anthocyanins from mulberry by a cation exchange chromatography

Anthocyanins are often targets in polyphenol analysis. However, it's hard to effectively separate anthocyanin from copigments such as phenolic acid and flavanols due to their similar structure. Thus, a cation exchange chromatography with 001 × 7 has been developed, which is available for anthocyanins isolation both on a small and large scale. The optimal process condition of anthocyanins isolation was determined. Compared to the macroporous adsorbent resins and Strong Cation Exchange resin (SCX), 001X7 shows greater economic advantages in large-scale purification of anthocyanins. More than 95% purity of the anthocyanin fraction can be achieved through this approach. This method shows a path to provide large quantities of copigments-free anthocyanins from mulberry polyphenols for the further study of its biological effects and may be extended to other analytical methods of polyphenol isolation from other plant materials.

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An economic cation-exchange resin 001X7 was used for anthocyanins purification.

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Large-scale separation of anthocyanins and copigments was achieved by resin 001X7.

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The separation condition was optimized and the purity of anthocyanins reached 95%.

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The cation resin 001X7 is cost-effective and has industrial application potential.

Inhibitory Effect on Acrolein by Cyanidin-3-O-glucoside and Its Acrolein Adducts from the Pigment of Mynica Red

Acrolein (ACR), the simplest α,β-unsaturated aldehyde, possesses high reactivity and toxicity both in vitro and in vivo and results in various chronic diseases. This has attracted increasing interest from researchers to screen various bioactive compounds to control it. In this article, we attempted to discover a new attribute of cyanidin-3-O-glucoside (C3G), including its ACR-scavenging capacity, reaction pathway, and possible application. Our findings revealed that C3G could capture ACR to form mono- and diadducts at room temperature by using liquid chromatography-mass spectrometry, and we further synthesized and elucidated the structures of C3G-ACR and C3G-2ACR using HRMS and 2D NMR. The structural data validated that there were two active sites of C3G for trapping ACR: at C-6 in the A-ring and C-5' in the B-ring. In addition, we found that C3G-ACR exhibited a more remarkable clearing ability than C3G within a short time. More than 65.9% of ACR was eliminated by C3G-ACR within 5 min via further formation of C3G-2ACR, but there was no obvious effect of C3G on ACR. When the incubation time was extended to 120 min, C3G could remove up to 83.2% of ACR. Subsequently, we also observed that mynica red (>5% C3G), as a pigmented food additive, could efficiently eliminate ACR generated in the Chinese liquor model and real red bayberry wine products to form C3G-ACR and C3G-2ACR. Both adducts increased significantly, by 10 times to a 100 times, after adding mynica red to red bayberry wine products for 24 h; they also increased rapidly with prolonged incubation time in the liquor-mynica red model system. Therefore, our findings suggest that C3G or mynica red may be developed as a promising novel ACR inhibitor in fruit wine and assembled alcoholic drinks or as a health food.

Purification of Four Caffeoylquinic Acid Derivatives from the Flowers of Gynura Procumbens by HSCCC

Four caffeoylquinic acid derivatives from the Gunura procumbens flowers (GPF) were successfully isolated and purified by high-speed counter-current chromatography (HSCCC). Ethyl acetate-methanol-water (3:1:3, v/v/v) was the optimum biphasic solvent system, which was selected by high-performance liquid chromatography (HPLC) and run on a preparative scale where the lower aqueous phase was used as the mobile phase with a head-to-tail elution mode. Chlorogenic acid (3.83 mg), Isochlorogenic acid A (6.51 mg), Isochlorogenic acid B (4.38 mg) and Isochlorogenic acid C (4.47 mg) were obtained for the first time in an one-step HSCCC separation from 800 mg of the crude extracts. The purities of four compounds were determined to be >95% by HPLC. Chemical structures of each isolated compounds were identified by nuclear magnetic resonance and electrospray ionization mass spectrometry methods. It is worth noting that all the four compounds were isolated here for the first time from GPF and this work confirms the effectiveness of HSCCC for the separation of compounds contained in complex samples, and provides a foundation for further exploitation of G. procumbens.

Bioaccessibility and biotransformation of anthocyanin monomers following in vitro simulated gastric-intestinal digestion and in vivo metabolism in rats

Anthocyanins (ANCs) are phytochemicals with several health effects and undergo significant degradation and subsequent biotransformation during complex metabolic processes. The aim of the present study was to determine the bioaccessibility and biotransformation of cyanidin-3-glucoside (C3G) during the simulated gastric-intestinal digestion in vitro and the metabolism in rats in vivo. Characterization of C3G and its metabolites was conducted by HPLC-ESI-MS/MS. After gastric-intestinal digestion, C3G was detected with a recovery of 88.31% in the gastric-digestive system, and a small amount of methylated-C3G occurred. In the intestinal-digestive system, C3G occurred with a recovery of 6.05%, and mainly decomposed into protocatechuic acid (PCA) and 2,4,6-trihydroxybenzaldehyde. The pharmacokinetic trial of C3G in rats showed rapid elimination in plasma. In tissues, C3G underwent rapid absorption and metabolism into phenolic acids or their derivatives. C3G and methylated-C3G passed through the blood-brain barrier and caused rapid distribution of C3G in the brain. Understanding the conversion of C3G and its metabolites helps in the future design of dietary interventions and the exploration of biological activities of ACNs.

Enhancing the Potential Exploitation of Food Waste: Extraction, Purification, and Characterization of Renewable Specialty Chemicals from Blackcurrants ( Ribes nigrum L.)

Natural colorants were extracted from renewable botanical sources, specifically waste epicarp from the blackcurrant fruit pressing industry. A process was developed which used acidified water extraction followed by a solid-phase extraction (SPE) purification stage which allowed the production of an anthocyanin-rich extract in good yields (ca. 2% w/ w based on dry weight of raw material). The components in the extracts were extensively characterized by HPLC, mass spectrometry, IR, NMR, and UV-vis spectroscopy. HPLC confirmed presence of four anthocyanins: delphinidin-3- O-rutinoside (45%), cyanidin-3- O-rutinoside (31%), and the corresponding glucosides at 16% and 8%, respectively. On sequential liquid-liquid aqueous-organic partitioning of the post-SPE sample, monomeric anthocyanins (54.7%) and polymeric anthocyanins (18%) were found in the aqueous layer with 3- O-rutinosides of myricetin (3.1%) and quercetin (3.2%), while isopropylacetate achieved selective extraction of caffeic acid (3%), p-coumaric acid (5%), and myricetin (2.5%) and quercetin (3.2%) aglycons. 3- O-Glucosides of myricetin (3.1%) and quercetin (2%), along with nigrumin- p-coumarate (1%) and nigrumin ferulate (0.5%) were selectively extracted from the remaining aqueous fraction using ethyl acetate. This allowed for near total quantification of the blackcurrant extract composition.

Preparative separation of flavone dimers from Dysosma versipellis by counter-current chromatography: Trifluoroacetic acid as a solvent system modifier

The separation of natural products is grueling and time-consuming work with repeated isolations needed to obtain purified compounds. However, using counter-current chromatography, a unique liquid-liquid partition chromatography, constituents can usually be purified efficiently. During the separation of flavone dimers from Dysosma versipellis (Hance) by counter-current chromatography, the separation resolution and sample loading was impeded by the emulsification of the sample. By screening, trifluoroacetic acid was selected as the solvent modifier to eliminate the emulsification. Then, a quaternary solvent system of hexane/ethyl acetate/methanol/water (4:6:5:5 v/v/v/v) with trifluoroacetic acid at a low concentration of 0.5% v/v was used to purify the components from D. versipellis. Compared to that without trifluoroacetic acid, the separation resolution as well as the sample loading both increased greatly. In addition, flavone dimers in low concentrations could be enriched and purified at high sample loading. As a result, five podophyllotoxins and 11 flavonoids were purified and characterized by interpretation of spectroscopic data, in which two of eight flavone dimers were new and a known flavone dimer was first separated from this species.