乙醇/磷酸氢二钾双水相体系提取洋葱黄酮工艺条件研究

该文对乙醇/磷酸氢二钾双水相体系提取洋葱黄酮的工艺条件进行研究,考察乙醇质量分数、磷酸氢二钾质量分数、洋葱粉添加量、提取温度和提取时间对洋葱黄酮提取率的影响。通过响应面试验设计及分析确定最佳提取条件。结果表明,乙醇/磷酸氢二钾双水相体系提取洋葱黄酮的最佳条件为:乙醇质量分数41.8%,磷酸二氢钾质量分数22%,洋葱添加量0.24 g,提取温度50℃、提取时间30 min,在此条件下,洋葱黄酮的提取率达5.32%。     

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.     

黄酮羧酸类化合物合成与生物活性研究进展

天然的黄酮类化合物一般不具有羧基,但在黄酮类化合物上引入羧基,便具有特殊的生理活性,这大大丰富了黄酮类化合物的家族,拓展了黄酮类化合物的应用范围及提高黄酮类化合物的生理活性。文章综述了黄酮羧酸类化合物的合成方法及其生理活性进展。     

茯苓-丹参共发酵体系及其产物对糖尿病小鼠降血糖作用的影响

采用茯苓真菌作为发酵菌株,丹参作为药性基质,在基础发酵培养基中进行双向发酵试验。确定种子液的最佳培养时间,对最佳丹参加入量和发酵时间进行探究,比较共发酵体系与单一体系对胞内多糖和胞外多糖及总黄酮含量的影响,比较共发酵体系与单一体系对糖尿病小鼠血糖水平的影响。结果显示,种子液的最佳培养时间为1 d,培养基中丹参最佳质量浓度为1 g/mL,最佳双向发酵时间为5 d。共发酵体系与单一体系相比显著增加了体系中胞外多糖(15.74 mg/mL)、胞内多糖含量(1.26 mg/mL),同时共发酵体系引入了丹参总黄酮(1.04 mg/mL)。共发酵体系与单一体系相比能有效降低糖尿病小鼠的血糖,提高糖尿病小鼠的葡萄糖耐受力。所制得的茯苓-丹参共发酵产物具有潜在降血糖作用,具有进一步开发保健品的价值。     

Tannin fraction from Ampelopsis grossedentata leaves tea (Tengcha) as an antioxidant and α‐glucosidase inhibitory nutraceutical

Leaf of Ampelopsis grossedentata is a new resource of functional foods with healthful properties. Antioxidant and α‐glucosidase inhibitory activities of water extract (made in the style of drinking), tannin fraction (TF) and dihydromyricetin (DMY) from A. grossedentata leaves were evaluated. The main component of TF was identified as gallotannins. DPPH and ABTS radical scavenging activities and reducing power of TF were superior to those of water extract, however, inferior to those of DMY. In no PBS wash protocol of cellular antioxidant activity assay, DMY and TF exhibited similarly, while in PBS wash protocol, the value of TF was higher than that of DMY. In addition, TF possessed the highest α‐glucosidase inhibitory activities (IC₅₀ = 1.94 μg mL^?1), followed by water extract (IC₅₀ = 23.10 μg mL^?1) and DMY (IC₅₀ = 72.21 μg mL^?1). The strong α‐glucosidase inhibitory activity of TF may attribute to the binding capacity to enzymes, as confirmed by fluorescence analysis.     

Phytochemical composition and bioactivities of lupin: a review

Lupin is a nonstarchy grain legume with high protein, dietary fibre and low fat contents. The industrial shift of lupin seed utilisation from feed to food has recently increased the scientific interest to explore its phytochemical composition and biological activities. Lupin seeds contain significant amounts of polyphenols, carotenoids, phytosterols, tocopherols, alkaloids and peptides with antioxidant, antimicrobial, anticarcinogenic and anti‐inflammatory activities. Among polyphenols, genistein and their derivatives (isoflavones) are of great importance because of their phytoestrogenic potential. This comprehensive review will help out the readers in understanding the phytochemicals present in lupin and their benefits.     

两种芹菜素衍生物与人血清白蛋白的相互作用

以黄酮类化合物芹菜素（4',5,7-三羟基黄酮）为原料,利用Mannich和磺化反应先后合成了两种芹菜素衍生物Ⅰ[8-(N,N-二乙基)-亚甲基胺基-4',5,7,-三羟基黄酮]、Ⅱ[8-(N,N-二乙基)-亚甲基胺基-4',5,7,-三羟基黄酮-3'-磺酸],并对其结构进行ESI-MS、1H-NMR、13C-NMR表征。利用荧光猝灭光谱、同步荧光光谱、紫外光谱法结合内滤光校正、分子对接研究了298、303、308 K时两种衍生物与人血清白蛋白（HSA）的相互作用机制。光谱法结果表明,衍生物Ⅰ、Ⅱ通过与HSA形成复合物而对HSA有荧光猝灭作用,猝灭原因是静态猝灭和非辐射能量转移,且衍生物与HSA的结合位点在HSA的亚结构域ⅡA附近,Ⅱ比Ⅰ更容易被转移和运输。热力学分析结果显示结合点数为1,且ΔH和ΔS均大于0,表明疏水作用为主要作用力。分子对接结果表明,两种衍生物与HSA均是通过疏水作用力和氢键结合于HSA的疏水空腔内,其中疏水作用为主要作用力,这与热力学结果相吻合。     

Novel acylflavones from Sideritis syriaca ssp. syriaca

In the framework of the detailed phytochemical analysis of the aerial parts of Sideritis syriaca, two novel acylflavones were isolated together with three acetylated flavone glycosides and acylated flavone glycosides. The novel acylflavones were identified as isoscutellarein 7-trans-p-coumarate and apigenin 7-,4′-bis(trans-p-coumarate). Their structures were elucidated by means of UV, 1D and 2D NMR, LC–DAD–MS and confirmed by HR-MS spectroscopy.     

水浮莲饮料及生产工艺研究

水浮莲富含黄酮类物质、胡萝卜素(维生素A原)等人体必需的营养素。水浮莲生长于长江以南的许多江河湖泊中，来源非常丰富。以其为原料，提取汁液，采用合理的工艺，可以制成具有一定保健功能的水浮莲饮料。