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排序方式: 共有329条查询结果,搜索用时 11 毫秒
61.
用普通差速离心分离了甘蓝型油菜(Brassica napus)九二13系的叶绿体,并以苯酚、氯仿及RNase处理,纯化了叶绿体DNA.经BamHⅠ,EcoRⅠ,HindⅢ,SalⅠ与SmaⅠ五种限制酶酶解,电泳分析,估算出该环状叶绿体DNA分子周长约为140.5千碱基对(kbp),即分子量约92.7×10~6道尔顿(daltion).以质粒pBR325为载体,将叶绿体DNA的BamHⅠ酶解片段,引入大肠杆菌中克隆,得到了三个重组体. 相似文献
62.
锦灯笼中无机元素含量测定 总被引:4,自引:0,他引:4
采用ICP-AES法检测了要笼果实及其干燥宿萼中无机元素含量。结果表明,锦灯笼含有丰富的对人体有益的无机元素,具较高的营养价值。 相似文献
63.
Anew and 20 known compounds were isolated from Bidens pilosa L. var. minor (Blume) Sherff. The new compound was determined as 7‐phenyl‐hepta‐4,6‐diyne‐2‐ol by various physical techniques (MS, IR, UV, 1H‐, 13C‐NMR, and 2D‐NMR). 相似文献
64.
Oil pumpkin (Cucurbita pepo L. var. Styriaca) is an economically important horticultural plant cultivated for oil production. After harvesting seeds, the residual biomass
has a limited application and is usually left in the field. An experimental study was performed to evaluate the chemical composition
of the seeded fruit oil pumpkin biomass (OP) dried by solvent-exchange using ethanol. The sugar composition of polysaccharides
obtained by sequential extraction with water and dilute alkali indicated the prevalence of pectic polysaccharides. Hemicelulloses
were released in higher amounts in the alkaline step. The chemical composition of OP and its individual tissues (peel, flesh
and hairy flesh) was investigated and compared to the corresponding preparations of standard pumpkin (SP, Cucurbita pepo L.). The content of components (on oven-dry basis), calculated from the analysis data of the individual tissues, was estimated
for OP: 7.9 % ash, 7.6 % Klason lignin, 19.3 % pectin (as uronic acids), 34.1 % neutral carbohydrates, and 27.4 % α-cellulose
and for SP: 6.4 % ash, 4.0 % Klason lignin, 20.9% pectin (as uronic acids), 38.1% neutral carbohydrates, and 29.2 % α-cellulose,
respectively. The OP biomass showed a higher proportion of hemicelluloses. 相似文献
65.
66.
Fingerprint analysis,multi‐component quantitation,and antioxidant activity for the quality evaluation of Salvia miltiorrhiza var. alba by high‐performance liquid chromatography and chemometrics 下载免费PDF全文
Salvia miltiorrhiza Bge. var. alba C.Y. Wu and H.W. Li has wide prospects in clinical practice. A useful comprehensive method was developed for the quality evaluation of S. miltiorrhiza var. alba by three quantitative parameters: high‐performance liquid chromatography fingerprint, ten‐component contents, and antioxidant activity. The established method was validated for linearity, precision, repeatability, stability, and recovery. Principal components analysis and hierarchical clustering analysis were both used to evaluate the quality of the samples from different origins. The results showed that there were category discrepancies in quality of S. miltiorrhiza var. alba samples according to the three quantitative parameters. Multivariate linear regression was adopted to explore the relationship between components and antioxidant activity. Three constituents, namely, danshensu, rosmarinic acid, and salvianolic acid B, significantly correlated with antioxidant activity, and were successfully elucidated by the optimized multivariate linear regression model. The combined use of high‐performance liquid chromatography fingerprint analysis, simultaneous multicomponent quantitative analysis, and antioxidant activity for the quality evaluation of S. miltiorrhiza var. alba is a reliable, comprehensive, and promising approach, which might provide a valuable reference for other herbal products in general to improve their quality control. 相似文献
67.
Effect of steeped black tea (Camellia sinensis (L.) var. assamica) on immunoglobulin titer (IgM and IgG) and lymphocyte proliferation in responses to hepatitis B vaccine inBALB/c mice has been investigated. The study was divided into two stages i.e. the determination of immunoglobulin titer and the test of lymphocytes proliferation. In the first stage mice were divided into 5 groups each consisting of 5 mice. Group I, II and III was given steeped black tea respectively with a dose of 600 mg/kg bw; 1.2 g/kg bw and 2.4 g/kg bw. Group IV was given Stimuno® with a dose of 6.5 mg/kg bw, and group V was given aquadest as negative control. All groups were induced by hepatitis B vaccine on day-0 (after 7 days of acclimatization). Serum was taken on day-14 and 21 for measurement of IgM titer and IgG, respectively. In the second stage, the mice were grouped as in the first stage, then all groups were induced by hepatitis B vaccine at day-0 and day-7. On day-27 lymphocyte was isolated and then tested for the growth and proliferation of lymphocytes. The results of this study showed that the steeped black tea has an effect in increasingIgM and IgG titer of BALB/cmice induced by hepatitis B vaccine, where the most effective dose was 1.2 g/kg bw. Steeped black tea also could increase lymphocytes proliferation in mice BALB/cinduced by hepatitis B vaccine, where the most effective dose was 1.2 g/kg bw. 相似文献
68.
锦灯笼果实的化学成分研究 总被引:1,自引:0,他引:1
从锦灯笼中分离得到5个甾体类化合物,分别鉴定为酸浆素A(1,alkekengilin A)、酸浆素B(2,alkekengilin B)、酸浆苦素D(3,physalin D)、酸浆苦素P(4,physalin P)、4,7-二去氢新酸浆苦素B(5,4,7-didehydro-neophysalin B).其中酸浆素A(1,alkekengilin A)和酸浆素B(2,alkekengilin B)为新的天然产物.运用现代波谱技术对上述化合物的结构进行了确证. 相似文献
69.
Two novel tricyclic diterpenoids rubescensins U (1) and V (2) were isolated from the leaves of Isodon rubescens var. taihangensis. They were elucidated as a 8,15-seco-ent-kauranoid and an ent-abietanoid, respectively, by 1D and 2D NMR spectra, and single crystal X-ray analysis. Compound 1 is the first example of an 8,15-seco-ent-kaurane from the plants genus Isodon. A discussion of their biogenesis is described. 相似文献
70.
火焰原子吸收光度法测定维药芜菁的微量元素 总被引:1,自引:0,他引:1
为探讨微量元素与芜菁的药效关系,用火焰原子吸收分光光度法测定了维药芜菁中的K,Na,Ca,Fe,Cu,Co,Zn,Mn,Mg等9种元素含量。结果表明,芜菁含有丰富的人体必需微量元素,其中K,Na,Ca,Zn的含量更显著;方法的回收率在93.7%~102.5%之间,RSD值在0.39%-1.3%之间,能用于维药芜菁中多种微量元素的同时测定。为芜菁的进一步研究和综合开发利用提供了新的科学依据。 相似文献