Preparative separation of crocins and geniposide simultaneously from gardenia fruits using macroporous resin and reversed-phase chromatography

Reversed-Phase Medium-Pressure Liquid Chromatography Purification of Omega-3 Fatty Acid Ethyl Esters Using AQ-C18

Omega-3 fatty acids are in high demand due to their efficacy in treating hypertriglyceridemia and preventing cardiovascular diseases. However, the growth of the industry is hampered by low purity and insufficient productivity. This study aims to develop an efficient RP-MPLC purification method for omega-3 fatty acid ethyl esters with high purity and capacity. The results indicate that the AQ-C18 featuring polar end-capped silanol groups outperformed C18 and others in retention time and impurity separation. By injecting pure fish oil esters with a volume equivalent to a 1.25% bed volume on an AQ-C18 MPLC column using a binary isocratic methanol-water (90:10, v:v) mobile phase at 30 mL/min, optimal omega-3 fatty acid ethyl esters were obtained, with the notable purity of 90.34% and a recovery rate of 74.30%. The total content of EPA and DHA produced increased from 67.91% to 85.27%, meeting the acceptance criteria of no less than 84% set by the 2020 edition of the Pharmacopoeia of the People's Republic of China. In contrast, RP-MPLC significantly enhanced the production efficiency per unit output compared to RP-HPLC. This study demonstrates a pioneering approach to producing omega-3 fatty acid ethyl esters with high purity and of greater quantity using AQ-C18 RP-MPLC, showing this method's significant potential for use in industrial-scale manufacturing.

Enhancing the purification of crocin-I from saffron through the combination of multicolumn countercurrent chromatography and green solvents

Crocin-I, a valuable natural compound found in saffron (Crocus sativus L.), is the most abundant among the various crocin structures. Developing a cost-effective and scalable purification process to produce high-purity crocin-I is of great interest for future investigations into its biological properties and its potential applications in the treatment of neurological disorders. However purifying crocin-I through single-column preparative chromatography (batch) poses a yield-purity trade-off due to structural similarities among crocins, meaning that the choice of the collection window sacrifices either yield in benefit of higher purity or vice versa. This study demonstrates how the continuous countercurrent operating mode resolves this dilemma. Herein, a twin-column MCSGP (multicolumn countercurrent solvent gradient purification) process was employed to purify crocin-I. This study involved an environmentally friendly ethanolic extraction of saffron stigma, followed by an investigation into the stability of the crocin-I within the feed under varying storage conditions to ensure a stable feed composition during the purification. Then, the batch purification process was initially designed, optimized, and subsequently followed by the scale-up to the MCSGP process. To ensure a fair comparison, both processes were evaluated under similar conditions (e.g., similar total column volume). The results showed that, at a purity grade of 99.7%, the MCSGP technique demonstrated significant results, namely + 334% increase in recovery + 307% increase in productivity, and - 92% reduction in solvent consumption. To make the purification process even greener, the only organic solvent employed was ethanol, without the addition of any additive. In conclusion, this study presents the MCSGP as a reliable, simple, and economical technique for purifying crocin-I from saffron extract, demonstrating for the first time that it can be effectively applied as a powerful approach for process intensification in the purification of natural products from complex matrices.

Gardenia yellow pigment: Extraction methods, biological activities, current trends, and future prospects

Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.

A countercurrent chromatography solvent system based on deep eutectic solvents for separation of cis- and trans-crocetin from Gardenia jasminoides Ellis

Due to the structural similarity and large difference in concentration, the separation of trans- and cis-crocetin has been challenging, and the cis-crocetin is usually neglected. In this work, a countercurrent chromatography method was developed for the quick separation of trans-crocetin and cis-crocetin from the hydrolytic extract of Gardenia jasminoides Ellis. High purity of trans-crocetin (>95%) and cis-crocetin (>91%) were prepared simultaneously for the first time through a novel biphasic system based on deep eutectic solvents, n-heptane/n-butyl alcohol/13 mmol/L Na2 CO3 in water/acetamide-benzyltrimethylammonium chloride (4:1, mol/mol) (4:7:9:1, v/v). The addition of deep eutectic solvent significantly improved the separation efficiency. The two targets can be easily recovered from the separation system through simple acidification and precipitation. It has potential for preparative separations on a large scale.

Gardenia (Gardenia jasminoides Ellis) fruit: a critical review of its functional nutrients, processing methods, health-promoting effects, comprehensive application and future tendencies

Gardenia fruit (GF) is the mature fruit of Gardenia jasminoides Ellis, boasting a rich array of nutrients and phytochemicals. Over time, GF has been extensively utilized in both food and medicinal contexts. In recent years, numerous studies have delved into the chemical constituents of GF and their associated pharmacological activities, encompassing its phytochemical composition and health-promoting properties. This review aims to provide a critical and comprehensive summary of GF research, covering nutrient content, extraction technologies, and potential health benefits, offering new avenues for future investigations and highlighting its potential as an innovative food resource. Additionally, the review proposes novel industrial applications for GF, such as utilizing gardenia yellow/red/blue pigments in the food industry and incorporating it with other herbs in traditional Chinese medicine. By addressing current challenges in developing GF-related products, this work provides insights for potential applications in the cosmetics, food, and health products industries. Notably, there is a need for the development of more efficient extraction methods to harness the nutritional components of GF fully. Further research is needed to understand the specific molecular mechanisms underlying its bioactivities. Exploring advanced processing techniques to create innovative GF-derived products will show great promise for the future.

Study on Purification, Identification and Antioxidant of Flavonoids Extracted from Perilla leaves

The flavonoids from Perilla leaves were extracted using flash extraction assisted by ultrasonic extraction with ethanol. Subsequently, macroporous resin was employed for the isolation and purification of these flavonoids, followed by an investigation into their antioxidant activity. The process conditions for the extraction of flavonoids from Perilla leaves were designed and optimized using a one-way experiment combined with a response surface methodology. The optimal extraction conditions were determined as follows: the liquid-solid ratio was 20:1, ethanol volume fraction of 60%, ultrasound temperature of 60 °C, ultrasound time of 10 min and flash evaporation time of 60 s. The optimal extraction rate of flavonoids is 9.8 mg/g. In terms of separation and purification, a high-performance macroporous resin (HPD450 resin) with high purification efficiency was selected through static analysis and adsorption experiments. The optimal enrichment conditions were as follows: loading concentration of 0.06 mg/mL, optimal loading concentration of 20 mL, elution concentration of 70% and 76 mL, providing a reference for the further development and utilization of Perilla leaf flavonoids.

Yellow pigment from gardenia fruit: structural identification and evaluation of cytotoxic activity in HepG2 cells by induction of apoptosis

The preparation process of yellow pigment (YP) from gardenia (Gardenia jasminoides) fruit was investigated, and the main components of YP were characterized by liquid chromatography-time of flight-mass spectrometer/mass spectrometer (LC-TOF-MS/MS). Furthermore, cytotoxic activity in HepG2 cells by induction of apoptosis was also evaluated. The preparation results indicated that the color value of YP was 498.34, which was 8.6 times higher than crude YP. Fifteen compounds in YP were identified, and crocins were the predominant compounds. The cell experiment results showed that YP inhibited the proliferation of HepG2 cells in a time- and dose-dependent manner. Moreover, YP also inhibited HepG2 cells in G2/M stage, increased the level of intracellular reactive oxygen species (ROS), and enhanced cell apoptosis. Real-time quantitative polymerase chain reaction (RT-PCR) analysis revealed the up-regulation of caspase-3, 8, 9, and bax and down-regulation of bcl-2 in HepG2 cells. Overall, these findings suggested that YP had potential cytotoxic activity in HepG2 cells by induction of apoptosis, which might be beneficial to human health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01133-9.

High-Purity Preparation of Enzyme Transformed Trans-Crocetin Reclaimed from Gardenia Fruit Waste

The recovery of physiologically bioactive ingredients from agricultural wastes as an abundant and low-cost source for the production of high value-added mutraceuticlas has been recognized and supported for the commercial interests and sustainable managements. In the extraction of geniposide for the development of natural food colorants from the dried fruits of Gardenia jasminoides Rubiaceae, the gardenia fruit waste (GFW) still remaining 0.86% (w/w) of crocins has always been discarded without any further treatments Until now, there was no simple and effective protocol for high-purity trans-crocein (TC) preparation without the coexistence of non-biologically active cis-crocein from GFW. We proposed an effective process to obtain the compound as follows. Crocins were extracted firstly by 50% of ethanol in the highest yield of 8.61 mg/g (w/w) from GFW. After the HPD-100 column fractionation in the collecting of crocins, the conversion ratio of 75% of crocins to crocetins can be obtained from the commercial available enzyme- Celluclast® 1.5 L. The crocins hydrolyzed products, were then separated through the HPD-100 resin adsorption and finally purified with the centrifugal partition chromatography (CPC) in single-step to obtain TC in a purity of 96.76 ± 0.17%. Conclusively, the effective enzyme transformation and purification co-operated with CPC technologies on crocins resulted in a high purity product of TC may be highly application in the commercial production.

Purification of Crocin-I from Gardenia Yellow by Macroporous Resin Columns In-Series and Its Antidepressant-Like Effect

In this study, the purification of crocin-I from Gardenia yellow by macroporous resin columns in-series was systematically investigated. The in-series macroporous adsorption resins consisting of XAD 4 and XAD 1600N resins were selected on the basis of the evaluation of performance and separation characteristics of 17 kinds of resins, including the adsorption capacities, desorption ratio, and separation degree. According to the analysis results, the optimum conditions were as follows: bed volume ratio of XAD 4 and XAD 1600N resins, sample volume, flow rate, and methanol concentration were 3 : 1, 5 BV, 15 BV/h, and 70%, respectively (BV was the bed volume of XAD 4 resin). After one run treatment, the separation degree of crocin-I at 254 nm and 440 nm decreased from 1.92 to 0.08 ( $D_{C-254\text{nm}}$ ) and from 0.71 to 0.36 ( $D_{C-440\text{nm}}$ ), respectively. The results showed that the in-series macroporous resins revealed a high capacity in the purification of crocin-I. Meanwhile, in the animal experiment, the forced swimming tests were regulated by crocin-I and Gardenia yellow, which demonstrated that crocin-I was the main constituent of Gardenia yellow and had potential antidepressant biological activities.

Preparation of multiresponsive hydrophilic molecularly imprinted microspheres for rapid separation of gardenia yellow and geniposide from gardenia fruit

In this work, a robust method for the separation of gardenia yellow and geniposide from gardenia fruit was developed based on a molecularly imprinted solid phase extraction (MISPE) procedure. First, hydrophilic molecularly imprinted microspheres (HMIMs) were prepared using gardenia yellow as the template via reversible addition fragmentation chain transfer (RAFT) precipitation polymerization. The resultant HMIMs demonstrated the multiresponsiveness to pH, temperature, and magnetism, achieving controllable uptake and release of gardenia yellow and easy recovery by external magnets. Meanwhile, the HMIMs possessed high adsorption capacity, fast binding kinetics, specific recognition, and reusability. Finally, a MISPE approach using HMIMs as adsorbent was developed for extraction of gardenia yellow and purification of geniposide after optimization of the adsorption and elution conditions. Thus, efficient separation of gardenia yellow and geniposide with relative purities of 99.77 ± 0.05% (94.04 ± 0.10% recovered) and 94.50 ± 0.62% (95.40 ± 0.86% recovered), respectively, was achieved.

Isolation and Purification of Kudinosides from Kuding Tea by Semi-Preparative HPLC Combined with MCI-GEL Resin

Background:

Kuding tea, a Traditional Chinese drink, has a history of thousands of years in China. Triterpenoid saponins in Kuding tea are regarded as one of the major functional ingredients.

Objective:

The aim of this paper was to establish separation progress for the isolation and purification of five triterpenoid saponins (kudinoside A, C, D, F, G) from Kuding tea.

Methods:

Nine types of resins, including seven macroporous resins and two MCI-GEL resins, were firstly used for purifying triterpenoid saponins by the adsorption and desorption tests. Further dynamic adsorption/desorption experiments were carried out to obtain the optimal parameters for the five targeted saponins. Then the purification of five triterpenoid saponins (kudinoside A, C, D, F, G) was completed by semi-preparative high-performance liquid chromatography (semi-pHPLC).

Results:

As of optimized results, the HP20SS MCI-GEL was selected as the optimal one. The data also showed that 65.24 mg of refined extract including 7.04 mg kudinoside A, 3.52 mg kudinoside C, 4.04 mg kudinoside D, 4.13 mg kudinoside F, and 34.45 mg kudinoside G, could be isolated and purified from 645.90 mg of crude extract in which the content of five saponins was 81.51% and the average recovery reached 69.76%. The final contents of five saponins increased 6.91-fold as compared to the crude extract.

Conclusion:

The established separation progress was highly efficient, making it a potential approach for the large-scale production in the laboratory and providing several markers of triterpenoid saponins for quality control of Kuding tea or its processing products.

Rapid isolation and characterization of crocins, picrocrocin, and crocetin from saffron using centrifugal partition chromatography and LC-MS

This study demonstrates a simple method for one-step isolation of the main secondary metabolites of a hydroalcoholic extract of Crocus sativus stigmas (saffron) using step-gradient centrifugal partition chromatography. The analysis was performed in dual and elution-extrusion mode, using five biphasic systems of the solvents heptane/ethyl acetate/butanol/ethanol/water in ratios of 4:10:0:4:10, 1:13:0:4:10, 1:12:1:4:10, 1:10:3:4:10, and 1:7:6:4:10. Five major crocins, picrocrocin, and crocetin were directly isolated in one step. Scaling up to preparative level, allowed the recovery of significantly high quantities of pure compounds, especially trans-crocin-4, saffron's principal crocin. Comparing dual-mode and elution-extrusion, in dual-mode, the trans-crocin-4 containing fractions were co-eluted with a high amount of free β-d-glucose. In contrast, absence of free β-d-glucose was observed in the corresponding trans-crocin-4 fractions obtained by the second method denoting its superiority against dual-mode. Initiating analysis with the 4^th solvent-system afforded selective isolation of trans-crocin-4, with reduction in experimental time and solvent consumption. Structure elucidation was performed by nuclear magnetic resonance spectroscopy, liquid chromatography with mass spectrometry, and high-resolution tandem mass spectrometry. The proposed methodology comprises an integrated approach for the purification and characterization of biologically active saffron components in a fast, selective, and environmentally friendly manner.

Separation and purification of both tea seed polysaccharide and saponin from camellia cake extract using macroporous resin

A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB-8, NKA-9, XDA-6, and D4020) tested, AB-8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB-8 resin-based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large-scale production of tea seed polysaccharide and tea seed saponin from camellia cake.

Isolation and purification of diastereoisomeric flavonolignans from silymarin by binary-column recycling preparative high-performance liquid chromatography

Silymarin extracted from Silybum marianum (L.) Gaertn consists of a large number of flavonolignans, of which diastereoisomeric flavonolignans including silybin A and silybin B, and isosilybin A and isosilybin B are the main bioactive components, whose preparation from the crude extracts is still a difficult task. In this work, binary-column recycling preparative high-performance liquid chromatography systems without sample loop trapping, where two columns were switched alternately via one or two six-port switching valves, were established and successfully applied to the isolation and purification of the four diastereoisomeric flavonolignans from silymarin. The proposed system showed significant advantages over conventional preparative high-performance liquid chromatography with a single column in increasing efficiency and reducing the cost. To obtain the same amounts of products, the proposed system spends only one tenth of the time that the conventional system spends, and needs only one eleventh of the solvent that the conventional system consumes. Using the proposed system, the four diastereoisomers were successfully isolated from silymarin with purities over 98%.