Designing amorphous formulations of polyphenols with naringin by spray-drying for enhanced solubility and permeability

Naringin (NAR), a major flavanone (FVA) glycoside, is a component of food mainly obtained from grapefruit. We used NAR as a food additive to improve the solubility and permeability of hydrophobic polyphenols used as supplements in the food industry. The spray-dried particles (SDPs) of NAR alone show an amorphous state with a glass transition temperature (T_g) at 93.2 °C. SDPs of hydrophobic polyphenols, such as flavone (FVO), quercetin (QCT), naringenin (NRG), and resveratrol (RVT) were prepared by adding varying amounts of NAR. All SDPs of hydrophobic polyphenols with added NAR were in an amorphous state with a single T_g, but SDPs of hydrophobic polyphenols without added NAR showed diffraction peaks derived from each crystal. The SDPs with NAR could keep an amorphous state after storage at a high humidity condition for one month, except for SDPs of RVT/NAR. SDPs with NAR enhanced the solubility of hydrophobic polyphenols, especially NRG solubility, which was enhanced more than 9 times compared to NRG crystal. The enhanced solubility resulted in the increased membrane permeability of NRG. The antioxidant effect of the hydrophobic NRG was also enhanced by the synergetic effect of NAR. The findings demonstrated that NAR could be used as a food additive to enhance the solubility and membrane permeability of hydrophobic polyphenols.     

RP—HPLC法测定不同产地枳实中的柚皮苷、橙皮苷及新橙皮苷

目的：建立同时测定枳实中柚皮苷、橙皮苷和新橙皮苷含量的方法。方法：采用反相高效液相色谱法分离检测柚皮苷、橙皮苷和新橙皮苷,色谱柱为HypersilODS2（250mm×4．6mm,5μm大连依利特公司）,流动相为乙腈-水（20：80）,流速为1．0mL／min,检测波长283nm,柱温为30℃。结果：柚皮苷、新橙皮苷在1．00～7．50μg,橙皮苷在0．40～3．00μg与峰面积呈良好的线性关系。柚皮苷、橙皮苷、新橙皮苷的平均回收率分别为100．56％（RSD：0．55％）、100．20％（RSD=1．00％）、101．14％（RSD=1．74％）。结论：该方法简便、准确、可靠、重复性好,可用于枳实药材的质量控制。     

Variation of bioactive furocoumarins and flavonoids in different varieties of grapefruits and pummelo

Grapefruit juice has been shown to increase the oral bioavailability of many therapeutic drugs. Certain citrus bioactive compounds such as furocoumarins and flavonoids have potent inhibitory effects on cytochrome P450 3A4 (CYP 3A4) enzyme and P-glycoprotein. The levels of these bioactive compounds in the grapefruit juice may affect the magnitude and mechanism of grapefruit juice-induced drug interaction. The levels of three furocoumarins such as dihydroxybergamottin (DHB), paradisin A and bergamottin and flavonoids have been separated and quantified using high-performance liquid chromatography (HPLC) in seven varieties of grapefruits and its parent pummelo. Considerable differences were observed in the levels of these bioactive compounds in different grapefruit varieties. Ray Red showed the lowest (0.492 ± 0.027 DHB μg/ml, 0.059 ± 0.001 μg/ml paradisin A and 0.344 ± 0.030 μg/ml bergamottin) levels of all three furocoumarins and Duncan contain the highest amount of DHB (2.587 ± 0.432 μg/ml) and bergamottin (1.004 ± 0.068 μg/ml), where as Star Ruby contain the highest levels of paradisin A. Pummelo contain the highest levels of naringin (4.587 ± 0.061 mg/ml), while Rio Red showed the lowest level (1.986 ± 0.145 mg/ml) of naringin.     

柑桔发酵酒脱苦技术研究

柑枯发酵酒中苦味物质主要由柠檬苦素,柚皮苷等组成,本研究采用吸附法,酶制剂等脱苦方法,确定最佳酶制剂脱苦工艺参数。     

High pressure-temperature effects on enzymatic activity: Naringin bioconversion

Initially exploited in chemistry and physics, high-pressure technology has gained importance in various fields.     

Comparative study of flavonoid and scoparone accumulation in different Citrus species and their susceptibility to Penicillium digitatum

Fungi of the genus Penicillium are responsible for substantial post-harvest losses in Citrus fruits. The results obtained following artificial inoculation of Citrus fruits with Penicillium digitatum showed that the degree of fungal development depended on the Citrus species. Thus, the mature fruit of Citrus paradisi were more susceptible to this fungus than the mature fruit of Citrus limon, Citrus sinensis,Citrus clementina Hort. ex Tan., and Citrus unshiu (mak) Marc. The results point to an inverse correlation between the degree of susceptibility of Citrus species to this fungus and the flavanone content – hesperidin in C. sinensis, C. clementina Hort. ex Tan. and C. unshiu (mak) Marc.; naringin in C. paradisi and the flavanone hesperidin and the flavone diosmin in C. limon. Thus, in C. sinensis,C. clementina Hort. ex Tan and C. unshiu (mak) Marc. the highest levels of the polymethoxyflavones, sinensetin, tangeretin, heptamethoxyflavone and nobiletin, were observed in the least susceptible varieties and viceversa. In the case of C. paradisi, no significant differences were detected in the polymethoxyflavone levels between varieties, while in C. limon, polymethoxyflavones were hardly detectable. The production of scoparone was observed in all the species and varieties studied after inoculation with the fungus, especially in C. limon fruits. Based on the evidence, it seems that flavanones, flavones, polymethoxyflavones (phytoanticipins) and scoparone (a phytoalexin) may well be involved in the defence mechanisms of Citrus fruits against P. digitatum. Depending on the Citrus species in question, the relative participation of one group of secondary compounds or another may vary.     

Exploring the phytochemical content and the antioxidant potential of Citrus fruits grown in Cyprus

The physicochemical and phytochemical profile as well as the antioxidant properties of the most important Citrus fruits grown in Cyprus [orange (Citrus sinensis, cv. ‘Valencia’), grapefruit (Citrus paradisi, cvs. ‘White Marsh’, ‘Star Ruby’, ‘Rio Red’) and an interspecific hybrid (Citrus reticulata x Citrus sinensis, cv. ‘Mandora’)] were determined. ‘Valencia’ fruit exhibited the highest phenolic, flavonoid and ascorbic acid content, as well as a higher antioxidant potency, followed by ‘Mandora’ fruit and the three grapefruit cultivars. HPLC indicated significant diversity on flavanones among the examined fruits, while LC-MS analysis revealed the presence of hydroxycinnamic acid derivatives, polymethoxyflavones and a furocoumarin. Overall, this study provides supporting evidence for the superiority of ‘Valencia’ orange fruit as an excellent source of bioactive compounds. In addition, to the best of our knowledge, this is the first study thoroughly describing the phytochemical profile of ‘Mandora’ fruit, an interspecific hybrid cultivated in Cyprus.     

Molecular mechanisms of the naringin low uptake by intestinal Caco-2 cells

Naringin, the main flavanone of grapefruit, was reported to display numerous biological effects: antioxidant, hypocholesteremic, anti-atherogenic and favoring drug absorption. Naringin absorption mechanisms were studied in Caco-2 cells (TC7 clone). We investigated the possible involvement of several membrane transporters implicated in polyphenolic compounds intestinal transport (sodium-dependent glucose transporter 1, monocarboxylate transporter, multidrug-associated resistance proteins 1 and 2, and P-glycoprotein). Naringin was poorly absorbed by Caco-2 cells, according to its low value of apparent permeability coefficient (P(app) = 8.1 +/- 0.9 x 10(-8) cm/s). In the presence of verapamil, a specific inhibitor of P-glycoprotein, cellular uptake was increased by almost threefold after 5 min, and P(app) was doubled after 30 min. Our results indicated the involvement of P-glycoprotein, an ATP-driven efflux pump, capable of transporting naringin from the Caco-2 cell to the apical side. This phenomenon could explain, at least in part, the low absorption of this flavanone at the upper intestinal level.     

高效液相色谱法测定胃苏颗粒中橙皮苷和柚皮苷含量

目的：用高效液相色谱法测定胃苏颗粒中橙皮苷和柚皮苷的含量。方法：采用DiamonsilTMC18（4．6mm×150mm,5μm）色谱柱;乙腈一磷酸水（pH=3．5）（22：78,V/V）为流动相,流速为1．2mL／min;检测波长为283nm。结果：待测组分与其他组分分离度良好（R〉1．5）,橙皮苷和柚皮苷线性范围分别为0．25～1．49μg和0．093～0．56μg,橙皮苷和柚皮苷的平均回收率分别为99．2％,98．8％,RSD分别为1．6％,2．3％。结论：高效液相色谱法是测定胃苏颗粒中橙皮苷和柚皮苷成分的一种简便、有效的方法。     

水溶性食物纤维强化柑桔汁饮料的开发研究─再论中国产HB801吸附树脂对柑桔苦味物质的脱除效果

本试验对已吸附树脂脱苦处理后的柑桔皮果胶液，用于水溶性食物纤维强化柑桔汁饮料的开发进行了研究。在以前研究的基础上［１］，对３种吸附树脂不同处理的样品中残留的苦味成分柚皮苷和柠碱的含量，应用高效液相色谱仪进行了分析。证明了中国产ＨＢ８０１的脱苦效果稍优于目前国际果汁饮料业界常用的美国产ＡｍｂｅｒｌｉｔｅＸＡＤ－２等。同时还试制了已经ＨＢ８０１脱苦处理后的柑桔皮果胶液作为水溶性食物纤维的强化柑桔汁饮料。为使普通柑桔皮果胶液适用于饮料生产，本文作了一些探索。