Xu Cai

Malus hupehensis (MH), as a natural resource, contains various active ingredients such as polyphenols, polysaccharides, proteins, amino acids, volatile substances, and other components. Increasingly, studies have indicated that MH showed a variety of biological activities, including antioxidant, hypoglycemic, hypolipidemic, anti-cancer, anti-inflammatory activities, and other activities. Hence, MH has attracted wide interest because of its high medical and nutritional value. It is necessary to review the active components and biological activities of MH. This paper systematically reviewed the chemical substances, biological activities, and potential problems of MH to further promote the related research of MH and provide an important reference for its application and development in medicine and food.

The partition coefficient ( K value) range of the calculated polarity value of compounds.

Ampelopsis grossedentata (AG) is an industrial crop in the grape family, which has been used as a dual‐purpose plant for medicine and tea with high medicinal values. However, little is reported on the separation technology of active components from AG and processing technology of AG products. High‐speed counter‐current chromatography (HSCCC) was applied to separate the principal component dihydromyricetin (DMY) from AG. DMY is added to starch‐based products to improve food quality. The interaction between corn starch (CS) and DMY was investigated to predict and control the structure and function of starch‐based foods. Results show that DMY with 97.13% purity was successfully obtained by HSCCC using a solvent system composed of light petroleum–ethyl acetate–methanol–water–trichloroacetic acid (1:3:1:3:0.01, v/v/v/v/v). Fourier‐transform infrared spectroscopy (FT–IR) exhibits that the interactions between CS and DMY included hydrogen bond and noncovalent bond. X‐ray diffraction (XRD) shows that DMY could increase the relative crystallinity of CS. Low‐field nuclear magnetic resonance results (LF–NMR) imply that DMY decreased the spin relaxation time ( T ₂ ) and inhibited the mobility of free water. Atomic force microscopy (AFM) results suggest that DMY changed the surface morphology of CS through hydrogen bond interaction. Moreover, the results of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) indicate that DMY could enlarge the pores and change the microstructure of CS–DMY complexes. The findings promote the development of industrial CS‐based products and utilization of corn crop.

In this study, secondary metabolites of Eurotium cristatum were isolated and purified by high-speed counter-current chromatography (HSCCC), and their hypoglycemic activities were studied. The general-useful estimate of solvent systems (GUESS) for counter-current chromatography was employed to select the appropriate solvent systems of n-hexane-ethyl acetate-methanol-water (HEMW, 4:6:5:5, v/v/v/v) for HSCCC practice, and three compounds were separated from the crude ethyl acetate extract of E. cristatum in one single step; 6.1 mg of Compounds 1, 5.6 mg of Compound 2 and 3.8 mg of Compound 3 were obtained from 100 mg of crude extract with a stationary phase retention of 75%. The compounds were then identified as emodin methyl ether, chrysophanol and emodin, respectively. The activity of the target compounds in the secondary metabolites of E. cristatum was verified by testing their inhibition on α-glucosidase activity and molecular docking simulation. The results showed that emodin, chrysophanol and emodin methyl ether had significant inhibitory effects on the α-glucosidase activity. This work confirmed the effectiveness of HSCCC in the separation of compounds in complex extracts and provided reference for further research and application of E. cristatum.

Malus hupehensis (M. hupehensis), an edible and medicinal plant with significant antioxidant and hypoglycemic activity, has been applied to new resource foods. However, the structural characterization and biological effects of its polysaccharides (MHP) are less known. The optimum extraction parameters to achieve the highest extraction efficiency (47.63%), the yield (1.68%) and purity of MHP (89.6%) by ultrasonic-assisted aqueous two-phase system (ATPS) were obtained under the liquid-to-solid ratio of 23 g/mL, ultrasonic power of 65 W, and ultrasonic time of 33 min. According to the analysis results, MHP was composed of Man, GlcA, Rha, GalA, Glc, Gal, Xyl, Ara, and Fuc, in which Ara and Gal were the main components, and the content of GlcA was the lowest. In in vitro activity analysis, MHP showed a significant antioxidant capacity, and an inhibition activity of α-glucosidase and the advanced glycation end products (AGEs) formation in the BSA/Glc reaction model. MHP interacted with α-glucosidase and changed the internal microenvironment of the enzyme, and inhibited the AGEs formation, which provides more evidence for the antihyperglycemic mechanism of MHP. The results suggest that ATPS is an efficient and environmentally friendly solvent system, and M. hupehensis has broad application prospects in functional foods, healthcare products, and pharmaceuticals.

Cranberry contains abundant anthocyanins. In this study, the extraction process for the microwave‐assisted extraction (MAE) of anthocyanins from cranberry was optimized using response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins (3.06 ± 0.05) mg/g from cranberry via MAE was obtained at extraction temperature of 50°C, extraction time of 8 s, ethanol concentration of 52% and solid‐to‐liquid ratio of 1:28 g/ml. The kinetic model of anthocyanins extraction from cranberry was established by plate model based on Fick's first Law, and the key model parameters (extraction rate constant and activation energy) were solved through the experimental results fitting. Results showed that the extraction rate constant increased significantly with the increase of extraction temperature. The activation energy of MAE anthocyanins from cranberry was 27.63 kJ/mol. The results indicated that the MAE process of anthocyanins was endothermic and controlled by mixing reaction and diffusion mechanism. The results provide a basis for industrial scale‐up and in‐depth study of anthocyanins in cranberry.Practical Applications: Anthocyanins are widely used as food colorants, antioxidants, and anticancer agents. Cranberry is rich in anthocyanins and can be used as a vital source of anthocyanins extraction. In this study, the extraction process for the microwave‐assisted extraction (MAE) of anthocyanins from cranberry was optimized using response surface methodology coupled with genetic algorithm to achieve of maximum anthocyanin yield, and the kinetic model of anthocyanins extraction from cranberry was established by plate model based on Fick's first Law, and the key model parameters (extraction rate constant and activation energy) were solved through the experimental results fitting.

An efficient strategy for the selection of active compounds from blueberry based on counter-current fractionation and bioassay-guided separation was established in this study. Blueberry extract showed potential α-glucosidase inhibitory activity. After extraction by different solvents, the active components were enriched in water. The water extract was divided into six fractions via high-speed counter-current chromatography to further track the active components. Results indicated that the α-glucosidase inhibition rate of F4 was remarkable higher than the others. Cyanidin-3-glucoside (C3G) with a purity of 94.16% was successfully separated from F4 through column chromatography, and its structure was identified by ultraviolet spectral, Fourier-transformed infrared spectroscopy, high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, ¹H nuclear magnetic resonance (NMR), and ¹³C NMR. The interaction mechanism between C3G and α-glucosidase was clearly characterized and described by spectroscopic methods, including fluorescence and circular dichroism (CD) in combination with molecular docking techniques. C3G could spontaneously bind with α-glucosidase to form complexes by hydrogen bonds. The secondary structure of α-glucosidase changed in varying degrees after complexation with C3G. The α-helical and β-turn contents of α-glucosidase decreased, whereas the β-sheet content and the irregular coil structures increased. Molecular docking speculated that C3G could form hydrogen bonds with α-glucosidase by binding to the active sit (Leu 313, Ser 157, Tyr 158, Phe 314, Arg 315, and two Asp 307). These findings may be useful for the development of functional foods to tackle type 2 diabetes.

For a rapid enrichment and separation of minor components from Malus hupehensis, the selection of suitable solvent system is the great challenge for liquid–liquid extraction with a three‐phase solvent system and high‐speed counter‐current chromatography. According to the concept of “like dissolves like,” the similarity of the average polarity between solvent system and target compounds was the significant characteristic of liquid–liquid extraction with a three‐phase solvent system and high‐speed counter‐current chromatography separation. The polarity parameter model provides a way to calculate the polarity of unknown compounds. Under the guidance of the polarity, an efficient enrichment and separation approach was established through liquid–liquid extraction and high‐speed counter‐current chromatography with solvent systems composed of n‐hexane‐ethyl acetate‐acetonitrile‐water (5:3:5:7, v/v), n‐hexane‐ethyl acetate‐methanol‐water (1:2:1:2, v/v), respectively. Thus, the total content of minor compounds was increased from 2.6% to 17.2%, and two novel compounds (6´´‐O‐coumaroyl‐2´‐O‐glucopyranosylphloretin and 3´´´‐methoxy‐6´´‐O‐feruloy‐2´‐glucopyranosylphloretin) were obtained. The discovery of the new dihydrochalcones expanded the structural diversity of compounds produced by the genus Malus. The experimental results demonstrated that compound polarity can be described by the polarity parameter model and is an important reference for investigating optimum solvent systems for liquid–liquid extraction with a three‐phase solvent system and high‐speed counter‐current chromatography.

Cranberry contains abundant anthocyanins. In this study, the extraction process for the ultrasound‐assisted extraction (UAE) of anthocyanins from cranberry was optimized using response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins (7.25±0.02) mg/g from cranberry via UAE was obtained at extraction temperature of 53 °C, ultrasound power of 310 W, ultrasound time of 33 min and ethanol concentration of 52%. High‐speed countercurrent chromatography (HSCCC) was used to separate and enrich main anthocyanins from cranberry. The purified anthocyanins components were analyzes by HPLC‐MS². Seven major kinds of anthocyanins were detected and identified for the first time peonidin‐3‐(6‐malon)‐glucoside with purity of 82.13% and pelargonidin‐3‐(6‐malon)‐glucoside with purity of 85.37% in cranberry. Hence, ultrasound assisted extraction of anthocyanins was an effective and rapid method. This method has a broad application prospect in the extraction of bioactive substances from natural plant resources.

Blueberry wine residues produced during the wine-brewing process contain abundant anthocyanins and other bioactive compounds. To extract anthocyanins from blueberry wine residues more efficiently, a novel procedure of ultrasound-assisted deep eutectic solvent extraction (UADESE) was proposed in this work. The extraction process was optimized by response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins (9.32 ± 0.08 mg/g) from blueberry wine residues by UADESE were obtained at water content of 29%, ultrasonic power of 380 W, extraction temperature of 55 °C, and extraction time of 40 min. The AB-8 macroporous resin combined with Sephadex LH-20 techniques was used to purify the crude extract (CE) obtained under optimum extraction conditions and analyze the anthocyanins composition by HPLC-ESI-MS/MS. The cyanidin-3-rutinoside with purity of 92.81% was obtained. The HepG2 antitumor activity of CE was better than that of the purified anthocyanins component. Moreover, CE could increase the intracellular reactive oxygen species levels and the apoptosis, and arrest HepG2 cells in the S phases. These findings provided an effective and feasible method for anthocyanins extraction, and reduced the environmental burden of this waste.