Isolation and Purification of Geniposide, Crocin-1, and Geniposidic Acid from the Fruit ofGardenia jasminoidesEllis by High-Speed Counter-Current Chromatography

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.

Crocin-Phospholipid Complex: Molecular Docking, Molecular Dynamics Simulation, Preparation, Characterization, and Antioxidant Activity

Background

Crocin is a water-soluble carotenoid compound present in saffron (Crocus sativus L.), known for its wide range of pharmacological activities, including cardioprotective, hepatoprotective, anti-tumorigenic, anti-atherosclerosis, and anti-inflammatory effects.

Objectives

The instability of crocin, its low miscibility with oils, and poor bioavailability pose challenges for its pharmaceutical applications. This study aimed to design and prepare a crocin-phospholipid complex (CPC) and assess its physicochemical properties.

Methods

The study investigated the formation of the complex and its binding affinity through molecular docking. Molecular dynamics (MD) simulations were conducted to find the optimal molar ratio of crocin to phospholipid for the complex's preparation. The CPC was produced using the solvent evaporation method. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), nuclear magnetic resonance (NMR), and solubility studies were utilized to characterize and confirm the formation of CPC. Additionally, the in vitro antioxidant activity of crocin and CPC was evaluated.

Results

Molecular dynamic simulations explored molar ratios of 1: 1, 1: 1.5, and 1: 2 for crocin to phospholipid. The ratio of 1: 2 was found to be the most stable, exhibiting the highest probability of hydrogen bond formation. Molecular docking, FTIR, and NMR studies indicated hydrogen bond interactions between crocin and phospholipid, confirming CPC's formation. XRD and FE-SEM analyses showed a decrease in crocin's crystallinity within the phospholipid complex. Furthermore, the solubility of crocin in n-octanol was enhanced post-complexation, indicating an increase in crocin's lipophilic nature.

Conclusions

Phospholipid complexation emerges as a promising technique for enhancing the physicochemical characteristics of crocin.

Chemical Profiling and Molecular Docking Study of Agathophora alopecuroides

Natural products continue to provide inspiring chemical moieties that represent a key stone in the drug discovery process. As per our previous research, the halophyte Agathophora alopecuroides was noted as a potential antidiabetic plant. However, the chemical profiling and highlighting the metabolite(s) responsible for the observed antidiabetic activity still need to be investigated. Accordingly, the present study presents the chemical profiling of this species using the LC-HRMS/MS technique followed by a study of the ligand-protein interaction using the molecular docking method. LC-HRMS/MS results detected twenty-seven compounds in A. alopecuroides extract (AAE) belonging to variable chemical classes. Among the detected compounds, alkaloids, flavonoids, lignans, and iridoids were the most prevailing. In order to highlight the bioactive compounds in AAE, the molecular docking technique was adopted. Results suggested that the two alkaloids (Eburnamonine and Isochondrodendrine) as well as the four flavonoids (Narirutin, Pelargonidin 3-O-rutinoside, Sophora isoflavanone A, and Dracorubin) were responsible for the observed antidiabetic activity. It is worth mentioning that this is the first report for the metabolomic profiling of A. alopecuroides as well as the antidiabetic potential of Isochondrodendrine, Sophora isoflavanone A, and Dracorubin that could be a promising target for an antidiabetic drug.

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.

In Vitro Anti-Diabetic Activities and UHPLC-ESI-MS/MS Profile of Muntingia calabura Leaves Extract

Anti-diabetic compounds from natural sources are now being preferred to prevent or treat diabetes due to adverse effects of synthetic drugs. The decoction of Muntingia calabura leaves was traditionally consumed for diabetes treatment. However, there has not been any published data currently available on the processing effects on this plant’s biological activity and phytochemical profile. Therefore, this study aims to evaluate the effect of three drying methods (freeze-drying (FD), air-drying (AD), and oven-drying (OD)) and ethanol:water ratios (0, 50, and 100%) on in vitro anti-diabetic activities of M. calabura leaves. In addition, an ultrahigh-performance-liquid chromatography–electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) method was used to characterize the metabolites in the active extract. The FD M. calabura leaves, extracted with 50% ethanol, is the most active extract that exhibits a high α-glucosidase and α-amylase inhibitory activities with IC₅₀ values of 0.46 ± 0.05 and 26.39 ± 3.93 µg/mL, respectively. Sixty-one compounds were tentatively identified by using UHPLC-ESI-MS/MS from the most active extract. Quantitative analysis, by using UHPLC, revealed that geniposide, daidzein, quercitrin, 6-hydroxyflavanone, kaempferol, and formononetin were predominant compounds identified from the active extract. The results have laid down preliminary steps toward developing M. calabura leaves extract as a potential source of bioactive compounds for diabetic treatment.

Scale-Up Preparation of Crocins I and II from Gardeniajasminoides by a Two-Step Chromatographic Approach and Their Inhibitory Activity Against ATP Citrate Lyase

Crocins are highly valuable natural compounds for treating human disorders, and they are also high-end spices and colorants in the food industry. Due to the limitation of obtaining this type of highly polar compound, the commercial prices of crocins I and II are expensive. In this study, macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was used to purify crocins I and II from natural sources. With only two chromatographic steps, both compounds were simultaneously isolated from the dry fruit of Gardenia jasminoides, which is a cheap herbal medicine distributed in a number of countries. In an effort to shorten the isolation time and reduce solvent usage, forward and reverse rotations were successively utilized in the HSCCC isolation procedure. Crocins I and II were simultaneously obtained from a herbal resource with high recoveries of 0.5% and 0.1%, respectively, and high purities of 98.7% and 99.1%, respectively, by HPLC analysis. The optimized preparation method was proven to be highly efficient, convenient, and cost-effective. Crocins I and II exhibited inhibitory activity against ATP citrate lyase, and their IC₅₀ values were determined to be 36.3 ± 6.24 and 29.7 ± 7.41 μM, respectively.

Metabolite variations and antioxidant activity of Muntingia calabura leaves in response to different drying methods and ethanol ratios elucidated by NMR-based metabolomics

INTRODUCTION

Muntingia calabura from the Muntingiaceae family has been documented for several medicinal uses. The combinations of drying treatment and extracting solvents for a plant species need to be determined and optimised to ensure that the extracts contain adequate amounts of the bioactive metabolites.

OBJECTIVE

Evaluate the metabolite variations and antioxidant activity among M. calabura leaves subjected to different drying methods and extracted with different ethanol ratios using proton nuclear magnetic resonance (¹ H-NMR)-based metabolomics. Methodology The antioxidant activity of M. calabura leaves dried with three different drying methods and extracted with three different ethanol ratios was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) scavenging assays. The metabolites variation among the extracts and correlation with antioxidant activity were analysed by ¹ H-NMR-based metabolomics.

RESULTS

Muntingia calabura leaves extracted with 50% and 100% ethanol from air-drying and freeze-drying methods had the highest total phenolic content and the lowest IC₅₀ value for the DPPH scavenging activity. Meanwhile, oven-dried leaves extracted with 100% ethanol had the lowest IC₅₀ value for the NO scavenging activity. A total of 43 metabolites, including sugars, organic acids, amino acids, phytosterols, phenolics and terpene glycoside were tentatively identified. A noticeable discrimination was observed in the different ethanol ratios by the principal component analysis. The partial least-squares analysis suggested that 32 compounds out of 43 compounds identified were the contributors to the bioactivities.

CONCLUSION

The results established set the preliminary steps towards developing this plant into a high value product for phytomedicinal preparations.

Prospects and progress on crocin biosynthetic pathway and metabolic engineering

Crocins are a group of highly valuable apocarotenoid-derived pigments mainly produced in Crocus sativus stigmas and Gardenia jasminoides fruits, which display great pharmacological activities for human health, such as anticancer, reducing the risk of atherosclerosis, and preventing Alzheimer's disease. However, traditional sources of crocins are no longer sufficient to meet current demands. The recent clarification of the crocin biosynthetic pathway opens up the possibility of large-scale production of crocins by synthetic metabolic engineering methods. In this review, we mainly introduce the crocin biosynthetic pathway, subcellular route, related key enzymes, and its synthetic metabolic engineering, as well as its challenges and prospects, with a view to providing useful references for further studies on the synthetic metabolic engineering of crocins.

Efficient Synthesis of Crocins from Crocetin by a Microbial Glycosyltransferase from Bacillus subtilis 168

Crocins are the most important active ingredient found in Crocus sativus, a well-known "plant gold". The glycosyltransferase-catalyzed glycosylation of crocetin is the last step of biosynthesizing crocins and contributes to their structural diversity. Crocin biosynthesis is now hampered by the lack of efficient glycosyltransferases with activity toward crocetin. In this study, two microbial glycosyltransferases (Bs-GT and Bc-GTA) were successfully mined based on the comprehensive analysis of the PSPG motif and the N-terminal motif of the target plant-derived UGT75L6 and Cs-GT2. Bs-GT from Bacillus subtilis 168, an enzyme with a higher activity of glycosylation toward crocetin than that of Bc-GTA, was characterized. The efficient synthesis of crocins from crocetin catalyzed by microbial GT (Bs-GT) was first reported with a high molecular conversion rate of 81.9%, resulting in the production of 476.8 mg/L of crocins. The glycosylation of crocetin on its carboxyl groups by Bs-GT specifically produced crocin-5 and crocin-3, the important rare crocins.

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.

PEG functionalized selenium nanoparticles as a carrier of crocin to achieve anticancer synergism

Schematic representation of crocin extraction from saffron stigmas and possible mechanism of pH based crocin delivery system of PEG-SeNP induced apoptosis in lung cancer cell.

Systematic separation and purification of iridoid glycosides and crocetin derivatives from Gardenia jasminoides Ellis by high-speed counter-current chromatography

INTRODUCTION

Iridoid glycosides and crocetin derivatives are the main bioactive components of Gardenia. The processes of separation of these compounds reported in much of the literature are tedious, time consuming and require multiple chromatographic steps, which results in lower recovery and higher costs.

OBJECTIVE

To develop a high-speed counter-current chromatography (HSCCC) method for the systematic separation and purification of iridoid glycosides and crocetin derivatives on a preparative scale from Gardenia.

METHODS

After fractionation using HPD100 column chromatography, n-butanol:ethanol:water (10:1:10, v/v) was selected to purify gardenoside, 6β-hydroxy geniposide and geniposidic acid from fraction A; ethyl acetate:n-butanol:water (2:1.5:3, v/v) was used to isolate geniposide from fraction B; crocin-1, crocin-2, crocin-3 and crocin-4 were purified by hexane:ethyl acetate:n-butanol:water (1:2:1:5, v/v) from fraction C. The head-to-tail elution mode was used with a flow rate of 8.0 mL/min and a rotary speed of 600 rpm.

RESULTS

After HSCCC isolation, 151.1 mg of gardenoside, 52.2 mg of 6β-hydroxy geniposide and 24.5 mg of geniposidic acid were obtained from 800 mg of fraction A; 587.2 mg of geniposide was obtained from 800 mg of Fraction B; 246.2 mg of crocin-1, 34.2 mg of crocin-2, 24.4 mg of crocin-3 and 24.7 mg of crocin-4 were obtained from 1000mg of fraction C. Their purities were found by UPLC analysis to be 91.7%, 93.4%, 92.5%, 98.2%, 94.1%, 96.3%, 94.1% and 98.9% respectively.

CONCLUSION

The present results demonstrates that the main iridoid glycosides and crocetin derivatives in Gardenia can be obtained efficiently from extracts using HSCCC.