isonaringin and neohesperidin

Drug discovery from complex mixtures, like Chinese herbs, is challenging and extensive false positives make it difficult to obtain compounds with anti-Alzheimer's activity. In this study, a continuous method comprised of accelerated solvent extraction coupled with online two-dimensional countercurrent chromatography was developed for the efficient, scaled-up extraction and separation of six bioactive compounds from Citrus limon peels: neoeriocitrin, isonaringin, naringin, hesperidin, neohesperidin, and limonin. These active compounds were isolated and purified from the raw plant materials by two-dimensional countercurrent chromatography separation via two sets of an n-hexane/n-butanol/methanol/water solvent system: 0.23:1.00:0.25:1.13 and 0.47:1.00:0.38:1.46, v/v/v/v. The compounds were collected in yields of 0.22, 0.25, 0.10, 0.31, 0.29, and 0.28 mg/g, respectively, with purities of 95.79, 96.47, 97.69, 97.22, 98.11, and 98.82%, respectively. Subsequently, a simple and efficient in vitro method was developed for rapidly evaluating the acetylcholinesterase inhibitory activities of six bioactive components. Furthermore, the PC12 cell model and the in vitro metabolism of cytochromes P450 were employed to verify the monomers obtained from the continuous method. The results demonstrated that these six bioactive extracts from the C. limon peels were strong acetylcholinesterase inhibitors.

Topics: Animals; Cholinesterase Inhibitors; Citrus; Countercurrent Distribution; Cytochrome P-450 Enzyme System; Disaccharides; Flavanones; Flavonoids; Hesperidin; PC12 Cells; Plant Extracts; Rats; Solvents

In the present study, a green and efficient extraction method using deep eutectic solvents as extraction solvent was developed for extracting the four major active compounds narirutin, naringin, hesperidin and neohesperidin from Aurantii Fructus.. A series of tunable deep eutectic solvents were prepared and investigated by mixing choline chloride or betaine to different hydrogen-bond donors, and betaine/ethanediol was found to be the most suitable extraction solvent. To achieve the best extraction yield, the primary factors affecting the extraction efficiency, such as hydrogen-bond acceptor/hydrogen-bond donor ratio, water content in deep eutectic solvents, extraction temperature, solid/liquid ratio and extraction time, were investigated.. The optimal extraction conditions were 40% of water in betaine/ethanediol (1:4) at 60°C for heated extraction of 30 min and solid/liquid ratio 1:100 g/mL. Under the optimum extraction condition, the extraction yields of narirutin, naringin, hesperidin, and neohesperidin were 8.39 ± 0.61, 83.98 ± 1.92, 3.03 ± 0.35 and 35.94 ± 0.63 mg/g, respectively, which were much higher than those of methanol as extraction solvent (5.5 ± 0.48, 64.23 ± 1.51, 2.16 ± 0.15 and 30.14 ± 0.62 mg/g).. The present results showed that deep eutectic solvents could be promising green and efficient solvents for extraction of the bioactive ingredients from traditional Chinese medicine.

Topics: Chromatography, High Pressure Liquid; Disaccharides; Flavanones; Green Chemistry Technology; Hesperidin; Hydrogen Bonding; Reference Standards; Solvents; Spectrophotometry, Ultraviolet

The hydrolytic activity of the recombinant β-glucosidase from Pyrococcus furiosus for the flavanone glycoside hesperidin was optimal at pH 5.5 and 95 °C in the presence of 0.5% (v/v) dimethyl sulfoxide (DMSO) and 0.1% (w/v) Tween 40 with a half-life of 88 h, a Km of 1.6 mM, and a kcat of 68.4 1/s. The specific activity of the enzyme for flavonoid glycosides followed the order hesperidin > neohesperidin > naringin > narirutin > poncirin > diosmin > neoponcirin > rutin. The specific activity for flavanone was higher than that for flavone or flavonol. DMSO at 10% (v/v) was used to increase the solubility of flavanone glycosides as substrates. The enzyme completely converted flavanone glycosides (1 g/L) to flavanone aglycones and disaccharides via one-step reaction. The major flavanone in grapefruit peel, grapefruit pulp, or orange peel extract was naringin (47.5 mg/g), naringin (16.6 mg/g), or hesperidin (18.2 mg/g), respectively. β-Glucosidase from P. furiosus completely converted naringin and narirutin in 100% (w/v) grapefruit peel extract to 22.5 g/L naringenin after 12 h, with a productivity of 1.88 g L(-1) h(-1); naringin and narirutin in 100% (w/v) grapefruit pulp extract to 8.1 g/L naringenin after 9 h, with a productivity of 0.90 g L(-1) h(-1); and hesperidin in 100% (w/v) orange peel extract to 9.0 g/L hesperetin after 9 h, with a productivity of 1.00 g L(-1) h(-1). The conversion yields, concentrations, and productivities of flavanone aglycones in this study are the highest among those obtained from citrus extracts. Thus, this enzyme may be useful for the industrial hydrolysis of flavanone glycosides in citrus extracts.

Topics: beta-Glucosidase; Citrus; Detergents; Disaccharides; Flavanones; Flavonoids; Food Industry; Glycosides; Hesperidin; Hydrogen-Ion Concentration; Hydrolysis; Kinetics; Plant Extracts; Pyrococcus furiosus; Solvents; Substrate Specificity; Temperature

The phytochemical content and the antioxidant activity (AA) of physiological drop of the main citrus species grown in China were investigated. Among the flavonoids, hesperidin was found mostly in mandarin and sweet orange, naringin was found mostly in sour orange, pummelo, grapefruit and a hybrid (Gaocheng), narirutin was found in most varieties, neohesperidin was found in Gaocheng and Huyou, and nobiletin and tangeretin were found in most varieties. Hydroxycinnamic acids were the main phenolic acids present, ferulic acid and caffeic acid were the dominant in most cases. There was a greater amount of free (extractable) than bound (insoluble) phenolic acids. Levels of limonoids were higher in Foyou, Eureka lemon, and Gaocheng than those in the other cultivars. The highest level of synephrine was found in Ponkan and Weizhang Satsuma. AA was highest in Ponkan and Weizhang Satsuma and lowest in Huyou, pummel, and lemon. These results suggest that physiological drop of citrus fruits have good potential as sources of different bioactive compounds and antioxidants.. Physiological drop of citrus fruits may be a good resource of bioactive compounds including flavonoids, phenolic acids, limonoids, synephrine, and a good material of nutraceuticals.

Topics: Antioxidants; China; Citrus; Coumaric Acids; Dietary Supplements; Disaccharides; Flavanones; Flavones; Fruit; Hesperidin; Hydroxybenzoates; Limonins; Plant Extracts; Synephrine

Grapefruits (Citrus paradisi Macfad) contain several phytochemicals known to have health maintaining properties. Due to the consumer's interest in obtaining high levels of these phytochemicals, it is important to understand the changes in their levels by common household processing techniques. Therefore, mature Texas "Rio Red" grapefruits were processed by some of the common household processing practices such as blending, juicing, and hand squeezing techniques and analyzed for their phytochemical content by high performance liquid chromatography (HPLC). Results suggest that grapefruit juice processed by blending had significantly (P < 0.05) higher levels of flavonoids (narirutin, naringin, hesperidin, neohesperidin, didymin, and poncirin) and limonin compared to juicing and hand squeezing. No significant variation in their content was noticed in the juice processed by juicing and hand squeezing. Ascorbic acid and citric acid were significantly (P < 0.05) higher in juice processed by juicing and blending, respectively. Furthermore, hand squeezed fruit juice had significantly higher contents of dihydroxybergamottin (DHB) than juice processed by juicing and blending. Bergamottin and 5-methoxy-7 gernoxycoumarin (5-M-7-GC) were significantly higher in blended juice compared to juicing and hand squeezing. Therefore, consuming grapefruit juice processed by blending may provide higher levels of health beneficial phytochemicals such as naringin, narirutin, and poncirin. In contrast, juice processed by hand squeezing and juicing provides lower levels of limonin, bergamottin, and 5-M-7-GC. These results suggest that, processing techniques significantly influence the levels of phytochemicals and blending is a better technique for obtaining higher levels of health beneficial phytochemicals from grapefruits. Practical Application:  Blending, squeezing, and juicing are common household processing techniques used for obtaining fresh grapefruit juice. Understanding the levels of health beneficial phytochemicals present in the juice processed by these techniques would enable the consumers to make a better choice to obtain high level of these compounds.

Topics: Ascorbic Acid; Beverages; Chromatography, High Pressure Liquid; Citric Acid; Citrus paradisi; Disaccharides; Flavanones; Flavonoids; Food Handling; Furocoumarins; Glycosides; Hesperidin; Limonins; Plant Extracts