刺五加口服液中总黄酮含量测定

刺五加口服液是以刺五加为主要原料加工制成，黄酮类成分为其主要活性成分之一，为有效地控制该药的内在质量，制定了总黄酮的含量测定方法，作为其质量控制的指标之一。１仪器与试药１．１仪器：日本岛津UV－１６０A可见－紫外分光光度计。１．２试药：芦丁对照品（中国药品生物制品检验所提供）；刺五加口服液（完达山制药厂提供，批号０１０３１０，０１０１２０，０１０４２５）；其它化学试剂均为AR级。２实验方法２．１最大吸收波长及稳定性考察：精密量取芦丁对照品液和样品液各５．０ml，分别置２５ml容量瓶中，准确加０．１mol／…     

云南松花粉中总黄酮含量的测定

以黄苓甙为标样，对云南松花粉中黄酮类化合物采用甲醇回流提取，用紫外分光光度法进行测定。结果表明：破壁云南松花粉中总黄酮含量达到510mg/100g。     

蜂胶及其产品中总黄酮含量测定

结合聚胺柱层析，利用分光光度法，对中国蜂胶及其产品蜂之宝进行总黄酮含量的测定，测定波长５１０ｎｍ，测定结果：蜂胶中总黄酮含量为５２．４７％，回收率为９７．５５％〈蜂之宝口服液中总黄酮含量为４４．３０，回收率为１００．７８％。     

云南松花粉中总黄酮含量的测定

以黄芩甙为标样,对云南松花粉中黄酮类化合物采用甲醇回流提取,用紫外分光光度法进行测定.结果表明破壁云南松花粉中总黄酮含量达到510mg/100g.     

安徽结香花蕾中总黄酮的含量测定

以芦丁为对照品,采用亚硝酸钠-硝酸铝为显色剂,利用紫外分光光度法测定结香花蕾中总黄酮的含量。芦丁在0.005～0.04 mg/mL浓度范围内与吸光度呈良好的线性关系(R²=0.9995),平均加样回收率为97.52%,RSD=0.21%(n=9)。试验结果表明:安徽不同产地来源的结香花中总黄酮含量在5.07%～8.61%。本方法测定结果准确、稳定、重复性好、简便可行,可用于安徽结香花的质量控制。     

葛根异黄酮与葛根素提取技术

葛根是豆科葛属植物的根。葛属植物在我国除新疆、西藏、青海外,各省均有分布,野生及栽培总面积初步统计为4×105 hm2左右,年产量150万吨以上。我国葛     

不同方法对爬山虎中总黄酮含量测定的影响

采用索氏提取法和回流提取法对爬山虎中总黄酮含量进行了提取 ,并用分光光度法进行了测定。结果表明 :爬山虎茎、叶、果中均有黄酮类化合物的存在 ,其中叶总黄酮含量最高 ,果最低 ;同时发现 ,用回流提取法提取所得爬山虎中总黄酮含量较索氏提取法要高。     

木枣不同发育时期总黄酮含量测定研究

笔者以木枣为研究材料,建立了一种枣果中总黄酮含量的测定方法,探讨了木枣在果实膨大期、白熟期、半红期和全红期的总黄酮变化规律.结果表明,本研究建立的黄酮测定方法精密度高、重复性好,操作简单方便,可用于枣果总黄酮含量测定.木枣中总黄酮含量呈先升高后降低的趋势,白熟期黄酮含量最高,达63.75 mg/g;全红期最低,仅2.0...     

葛根中异黄酮和淀粉的提取工艺研究

对葛根［Ｐｕｅｒａｒｉａｌｏｂａｔａ（Ｗｉｌｌｄ．）Ｏｈｗｉ．］中的异黄酮和淀粉的提取工艺进行了研究。以葛根素为对照品进行了葛根及其木质部、韧皮部、浸膏中总黄酮的含量测定；以吸附树脂法进行了黄酮的分离，并用高效液相色谱法对其进行含量测定。结果表明：葛根先以适当溶剂提取，总黄酮，残渣再提取淀粉，总黄酮回收率为７５％～８６％，淀粉得率为１３％～２０％；经大孔吸附树脂分离后的提取物中含７５％以上的葛根素；木质部总黄酮含量较高，在提取总黄酮时应加以利用。     

吴起野生沙棘不同部位总黄酮含量测定

对吴起野生沙棘不同部位的总黄酮含量进行了测定,发现沙棘果泥中总黄酮含量最高为814.03mg/100 g,其次为沙棘果皮、果油、果渣等,沙棘杆中含量最少为90.39 mg/100 ml,这将为吴起沙棘总黄酮的进一步开发利用提供理论依据。     

水浸提沙棘叶总黄酮的工艺研究

研究了水浸提法从沙棘叶中提取黄酮的工艺，该工艺路线是，沙棘叶先脱脂，后经热水浸提，酸沉淀分离杂质，再用低浓度乙醇淋洗，进一步分离杂质，最终使产品总黄酮达8.4%，这种工艺使总黄酮得率高达1.05%。而且操作简便，成本降低，是提以沙棘黄酮可行的工艺路线。     

发酵对沙棘果泥中黄酮苷元含量影响的实验研究

用分光光度法测定不同发酵时间的沙棘果泥中黄酮苷元的含量，并对测定方法进行了考察。在波长430nm处，沙棘果泥黄酮测定的线性范围为10．5-10μg/ml，r=0.9994，加样回收率为99．1％，相对偏差为0.044，提示检测方法准确，结果可靠。沙棘果泥中黄酮苷元含量随发酵时间呈一定的变化趋势。     

应用碱性助提剂提取沙棘叶总黄酮初探

根据沙棘叶总黄酮的特性，确定了在控制pH值条件下加入助提剂提取沙棘叶总黄酮的新工艺。该工艺操作方便，显著降低生产成本，提高了TFH得率。     

正交设计法优化沙棘果渣中总黄酮的提取工艺

研究了从沙棘果渣中提取总黄酮的工艺,考察了提取溶剂、乙醇浓度、提取温度、提取时间及剂量对提取效果的影响,最后通过正交实验确定了最佳工艺条件;80℃下采用60%的乙醇浸提,固液比1:7,回流提取3次,每次1h.     

Measuring stem water content in four deciduous hardwoods with a time-domain reflectometer

New technologies in time-domain reflectometry offer a reliable means of measuring soil water content. Whether these same technologies can be used or adapted to estimate the water content of other porous media, such as the woody tissue of forest trees, has not been thoroughly addressed. Therefore, curves relating the apparent dielectric constant (K(a)) to volumetric water content (g cm(-3)) were constructed for large-diameter stems of red maple (Acer rubrum L.), white oak (Quercus alba L.), chestnut oak (Q. prinus L.), and black gum (Nyssa sylvatica Marsh.). This information was combined with previously published data and a proposed "universal" calibration equation for wood was derived. Stainless-steel rods (15-cm wave guides) were inserted into 160 trees (30 to 49 per species) growing in an upland oak-hickory forest and stem water contents estimated monthly during 1994 and 1995 with a time-domain reflectometer (TDR). Volumetric water contents in April ranged from 0.28 g cm(-3) for red maple to 0.43 g cm(-3) for black gum, with no evidence that water content changed as a function of stem diameter. Stem water contents estimated during 1994 (a wet year) increased from May to July, reached a maximum in midsummer (0.41 to 0.50 g cm(-3)), and then decreased in November. During 1995 (a dry year), stem water contents for red maple and black gum (two diffuse-porous species) decreased from May to August, reached a minimum in September (0.29 to 0.37 g cm(-3)), slightly increased in October and November, and then decreased in December. A different trend was observed during 1995 for white oak and chestnut oak (two ring-porous species), with water contents remaining fairly stable from May to August, but decreasing abruptly in September and again in December. Stem water contents estimated with a TDR broadly agreed with gravimetric analyses of excised stem segments and increment cores, although there was evidence that overestimation of water content was possible with TDR as a result of wounding following wave guide installation. Nonetheless our results hold promise for the application of TDR to the study of stem water content and to the study of whole-plant water storage.     

Antioxidant activity and total phenolic content in Cirsium five species from north-east region of Poland

Methanolic extracts from inflorescences and leaves of five Cirsium species: C. arvense, C. oleraceum, C. palustre, C. rivulare and C. vulgare and CHCl3, Et2O, EtOAc, n-BuOH fractions obtained from those extracts were investigated for their antioxidant activity. The antioxidant activity measurement, expressed as Total Antioxidant Status, ranged from 0.98 to 2.71 mM/l. The total phenolic content of the samples varied from 12 to 804 mg/g. There was a positive correlation between the total phenolic content and antioxidant activity for MeOH extracts and EtOAc fractions (R2=0.95, 0.8 respectively).     

A method for routine measurements of total sugar and starch content in woody plant tissues

Several extraction and measurement methods currently employed in the determination of total sugar and starch contents in plant tissues were investigated with the view to streamline the process of total sugar and starch determination. Depending on the type and source of tissue, total sugar and starch contents estimated from samples extracted with 80% hot ethanol were significantly greater than from samples extracted with a methanol:chloroform:water solution. The residual ethanol did not interfere with the sugar and starch determination, rendering the removal of ethanol from samples unnecessary. The use of phenol-sulfuric acid with a phenol concentration of 2% provided a relatively simple and reliable colorimetric method to quantify the total soluble-sugar concentration. Performing parallel sugar assays with and without phenol was more useful for accounting for the interfering effects of other substances present in plant tissue than using chloroform. For starch determination, an enzyme mixture of 1000 U alpha-amylase and 5 U amyloglucosidase digested starch in plant tissue samples more rapidly and completely than previously recommended enzyme doses. Dilute sulfuric acid (0.005 N) was less suitable for starch digestion than enzymatic hydrolysis because the acid also broke down structural carbohydrates, resulting in overestimates of starch content. After the enzymatic digestion of starch, the glucose hydrolyzate obtained was measured with a peroxidase-glucose oxidase/o-dianisidine reagent; absorbance being read at 525 nm after the addition of sulfuric acid. With the help of this series of studies, we developed a refined and shortened method suitable for the rapid measurement of total sugar and starch contents in woody plant tissues.     

Antioxidant activity, reducing power and total phenolic content of some lichen species

The total antioxidant activity, total phenolic content and reducing power of methanol and water extracts of four lichen species, Bryoria fuscescens, Dermatocarpon intestiniformis, Peltigera rufescens and Pseudevernia furfuracea, were determined in vitro. Water and methanol extracts of P. rufescens showed the highest antioxidant activity. However, there was no correlation between antioxidant activity and total phenolic content of the extracts. Although the methanol extract of P. furfuracea had the highest total phenolic contents, it exhibited low antioxidant activity. In contrast, there was a strong correlation between reducing power and total antioxidant activity of the extracts. The highest reducing power was determined for the methanol extract of P. rufescens.     

Dependence of colour and discolouration on total extractive content of African Padauk and Jatoba

This study is about relationships between total extractive contents, heartwood colour and light-induced discolourations of the tropical species African Padauk (Pterocarpus soyauxii Taub) and Jatoba (Hymenaea courbaril L.). Wood surface colour was measured spectrophotometrically before and after light irradiation. Subsequently, the total extractive content was determined and linked to the colour parameters. Total extractive content varied between 6 % (Jatoba) and 27 % (African Padauk). The fact that non-irradiated Jatoba appeared lighter and more yellow with higher extractives contents, opposed the often assumed relationship that more heartwood extractives cause darker wood. For light-irradiated Jatoba wood only the reddishness was more intense when samples had higher extractive content. In contrast, light-irradiated African Padauk showed significant differences in all colour parameters as extractives varied. High overall colour change in African Padauk due to light irradiation was observed; however, no relationship with the extractive content existed. In contrast, discolouration rate of Jatoba wood strongly varied with its extractive content. Individual wood species react differently during exposure to light and therefore require specific surface treatment to maintain the desired colour appearance and colour stability.