Bioactive Compounds and Antioxidant Capacity of Strawberry Jams

Strawberries represent the main source of ellagic acid derivatives in the Brazilian diet. They are also good sources of flavonoids, mainly anthocyanins, and phenolic acids, to which many beneficial effects have been attributed. However, as the fruit is not available all the year, the objective of this work was to determine whether the jams could also represent a good source of bioactive compounds. In the current study, five different commercially available strawberry jams were characterized in relation to flavonoids, total phenolics, free and total ellagic acid contents, and antioxidant capacity. Anthocyanins were detected only in two jams at very low content. Kaempferol glycosides were the main flavonoids present (from 0.38 to 1.05 mg/100 g fresh weight, FW), while quercetin glycosides were present in the range 0.14–1.20 mg/100 g FW. Free and total ellagic acid content ranged from 0.4 to 2.9 mg/100 g FW, and from 17.0 to 29.5 mg/100 g FW, respectively. Total phenolics varied from 58 to 136 mg/100 g FW, and the antioxidant capacity from 0.55 to 0.76 μmol BHT (Butylhydroxytoluene) equivalents/g FW. Overall, results indicated that jams can also represent a good source of antioxidant compounds, although compared to the fruit important losses seem to occur.     

Flavonoids from Acalypha indica

Four known kaempferol glycosides, mauritianin, clitorin, nicotiflorin and biorobin, have been isolated from the flowers and leaves of Acalypha indica. Some formerly published NMR data were corrected.     

超声波提取-分光光度法测定海金沙草药中的总黄酮

[目的]优选海金沙草药中总黄酮的最佳提取工艺,并测定海金沙中总黄酮的含量。[方法]采用超声波提取海金沙中的总黄酮,以无水乙醇为提取剂,通过正交试验探讨溶剂浓度(乙醇浓度)、超声提取时间、温度和提取次数等条件对提取结果的影响,并采用分光光度法测定其含量。[结果]最佳提取条件为:乙醇浓度60%,温度25℃,超声时间10 min,提取次数为3次。将所得的结果与常规的水提取法和索氏提取法进行比较,其总黄酮的提取含量达到了4.12%。[结论]该方法与其他常规方法相比,具有简洁、方便、提取速度快和节能的优点,并提高了提取效率。     

蒲公英黄酮的超声辅助提取工艺研究

[目的]优选超声辅助提取蒲公英总黄酮的条件。[方法]以总黄酮提取率为考察指标,应用单因素试验和正交试验,研究乙醇浓度、料液比、提取时间等因素对蒲公英超声提取的影响,并优选出最佳超声提取条件。[结果]最佳超声提取条件为:在超声功率为120W的情况下,以浓度60%乙醇为溶剂,料液比为1∶30(g/ml),反应时间30 min,超声温度70℃;在此条件下,总黄酮提取率为4.02%。[结论]该方法优选出了蒲公英总黄酮的最佳超声提取条件,为蒲公英黄酮类的工业化生产提供了理论依据。     

超声微波双辅助法提取沙棘叶黄酮

[目的]优化得出沙棘叶总黄酮提取的最佳工艺参数。[方法]以新疆青河的沙棘叶为研究对象,利用超声微波双辅助法提取沙棘叶中的总黄酮。首先进行超声时间、超声温度、乙醇体积分数、微波功率、微波时间等单因素试验;根据单因素试验结果采用响应面分析法对提取工艺进行优化;然后与乙醇回流提取、微波辅助提取、超声辅助提取结果进行比较。[结果]超声微波双辅助提取沙棘叶黄酮的最佳工艺条件为,在超声条件不变(即超声时间25 min、超声温度60℃)时,乙醇浓度68.1%、固液比1∶17.7 g/ml、微波火力80%、辐射时间3.33 min,沙棘叶总黄酮含量为42.75 mg/g;超声微波双辅助提取所得黄酮含量比乙醇回流提取、微波辅助提取、超声辅助提取分别高出14.67%、24.04%、36.63%。[结论]该研究可为沙棘叶总黄酮的提取开辟新的途径。     

HPLC法测定落葵果实中黄酮类化合物的含量

[目的]建立落葵果实中黄酮类化合物的含量测定方法。[方法]以芦丁为对照品,色谱柱为Eclipse Zorbax XDB-C18(4.6 mm×150 mm,5μm),流动相为无水甲醇-水(55∶45,V/V),流速为0.8 ml/min;检测波长为358 nm,柱温为室温。[结果]在色谱条件下芦丁标准曲线回归方程为Y=20.889X-17.147(R2=0.998 2),在2.00～40.0μg/ml浓度范围内,浓度与峰面积的线性关系良好,平均回收率大于96%,RSD小于2.0%,用该法测得落葵果实黄酮含量为179.0μg/g。[结论]该方法样品处理简单,检测高效快速,结果准确可靠,重现性良好,适合于落葵果实中黄酮类化合物的含量测定。     

Flavonoids with antiplasmodial and cytotoxic activities of Macaranga triloba

A new flavanone derivative, malaysianone A (1), four prenylated flavanones, 6-prenyl-3'-methoxyeriodictyol (2), nymphaeol B (3), nymphaeol C (4) and 6-farnesyl-3',4',5,7-tetrahydroxyflavanone (5), and two coumarins, 5,7-dihydroxycoumarin (6) and scopoletin (7), were isolated from the dichloromethane extract of the inflorescences of Macaranga triloba. The structures of these compounds were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR and mass spectrometry. The cytotoxic activity of the compounds was tested against several cell lines, with 5 inhibiting very strongly the growth of HeLa and HL-60 cells (IC(50): 1.3 μg/ml and 3.3 μg/ml, respectively). Compound 5 also showed strong antiplasmodial activity (IC(50): 0.06 μM).     

大麦籽粒4种主要黄酮类化合物含量基因型与环境互作分析(英文)

[目的]该研究旨在研究其黄酮类化合物的基因型与环境互作分析,以在栽培和育种等方面提高大麦籽粒的黄酮类化合物含量。[方法]该研究通过高效液相色谱技术研究了种植在昆明,曲靖,保山地区大麦籽粒儿茶素,杨梅素,槲皮素,山柰酚的含量,并对这几种黄酮类化合物的基因型,环境及基因型×环境四大大麦黄酮含量的相互作用的变化进行了研究。[结果]结果表明,儿茶素和山奈酚含量的基因型方差、环境方差和G×E互作方差趋势相同,为基因型变异>环境变异>G×E互作变异,均达到极显著水平;槲皮素和总黄酮含量的基因型方差、环境方差和G×E互作方差趋势相同,为基因型变异>G×E互作变异>环境变异,均达到极显著水平;杨梅素含量的基因型方差和环境方差均达到极显著水平,G×E互作方差达显著水平;杨梅素含量的基因型变异>环境变异>G×E互作变异;总黄酮含量的基因型变异>环境变异>G×E互作变异。不同大麦品种,紫光芒大麦和宽颖大麦在曲靖,昆明,保山三个地区都具有较高的槲皮素含量,其他大麦几乎不含槲皮素,研究中发现,紫光芒大麦和宽颖大麦的籽粒颜色为紫色,而其他品种的大麦籽粒颜色均为黄色。[结论]该研究中的四种黄酮类化合物及总黄酮都是主要受遗传控制及遗传环境相互作用。紫色大麦籽粒中具有较高的槲皮素含量。     

松针功能性成分及应用研究进展

介绍了松针中黄酮类化合物、莽草酸、木脂素等化学成分功能特性的研究成果,介绍了不同功能性成分的提取分离方法,并介绍了松针综合应用的研究进展,为进一步研究松针中的功能性成分提供依据。     

不同越冬处理对苹果幼树抽条和黄酮质量分数的影响

以富士和金富苹果为材料,采用建造阳畦、缠薄膜、“小温室”越冬等方法,调查不同越冬方式对2a生苹果幼树越冬抽条的影响,测定越冬期枝条电导率和黄酮质量分数变化.结果表明,苹果幼树越冬期枝条电导率呈先降再升的趋势,最低值在12月下旬,萌芽前最高,萌芽前枝条电导率的高低与幼树抽条呈正相关;枝条黄酮质量分数则表现为先升后降的趋势,最高值在2月下旬,萌芽前最低,越冬期幼树抽条率与枝条韧皮部黄酮质量分数变化幅度呈正相关.“小温室”与树体缠膜幼树越冬抽条率低,其枝条电解质渗出率和黄酮质量分数均显著低于阳畦和对照.不同品种间,富士枝条电导率稍低于金富,但变幅较大,其黄酮变幅高于金富.树体缠薄膜和“小温室”方法是目前甘肃沿黄地区苹果幼树安全越冬最有效的方法.