排序方式: 共有62条查询结果,搜索用时 15 毫秒
41.
Sun YJ Li ZL Chen H Liu XQ Zhou W Hua HM 《Bioorganic & medicinal chemistry letters》2011,21(12):3794-3797
Three new aryltetralin lignans, 4-acetyl-4-demethyl-podophyllotoxin (1) and sinolignans A, B (2-3), and two new natural products (4-5), were isolated from the roots and rhizomes of Sinopodophyllum emodi together with twelve known lignans (6-17). Their structures and stereochemistry were elucidated on the basis of spectroscopic evidence, and circular dichroism (CD) method. The cytotoxic activities of all isolated compounds were evaluated against HeLa and KB cell lines. Compared with etoposide, compounds 1, 6-9, and 13 showed more potent cytotoxicities against two tumor cell lines. On the basis of IC50 values, deoxypodophyllotoxin (7) was about 579 and 1123 times more toxic than etoposide in HeLa and KB cell lines, respectively. The preliminary SAR study indicated that an oxygenated group at C-7′ might decrease cytotoxicity against two cell lines, which was different from most previous studies. However, this needs to be systematically verified by extensive pharmacological experiments. 相似文献
42.
青刺果播种育苗技术的初步研究 总被引:1,自引:0,他引:1
采用随机区组设计了青刺果不同播种时间和不同播种方法试验,进行青刺果不同育苗方式对比研究。结果表明:青刺果的育苗宜随采随播,其种子出苗率达72.4%,随着种子储藏时间的后移,出苗率显著下降,干藏与沙藏对种子出苗率的影响差异不明显;裸根苗和容器苗苗木生长质量上无明显差别,随采随播到当年雨季造林时(9月)苗木嫩小,不宜上山造林,但容器苗此时可造林。 相似文献
43.
遮荫对新疆紫草育苗的影响 总被引:1,自引:0,他引:1
目的 探讨新疆紫草育苗的最佳遮荫条件.方法 采用不同的遮荫条件,研究了遮荫处理对新疆紫草原生苗生长量和成活率的影响.结果 结果表明,不同强度的遮荫处理对原生苗的叶面积、成活率、地下生长量影响显著.适度遮荫可以增加叶面积和地下生长量,提高幼苗成活率,结论 采用30%遮荫率的遮荫处理能够同时满足增加生长量和提高成活率的要求,同时避免了叶片先端的日灼伤害. 相似文献
44.
Pradeep Kumar Naik Md. Afroz Alam Harvinder Singh Vinod Goyal Swarup Parida Sanjay Kalia T. Mohapatra 《Physiology and Molecular Biology of Plants》2010,16(2):135-148
Total synthesis of podophyllotoxin is an expensive process and availability of the compound from the natural resources is an important issue for pharmaceutical companies that manufacture anticancer drugs. In order to facilitate reasoned scientific decisions on its management and conservation for selective breeding programme, genetic analysis of 28 populations was done with 19 random primers, 11 ISSR primers and 13 AFLP primer pairs. A total of 92.37 %, 83.82 % and 84.40 % genetic polymorphism among the populations of Podophyllum were detected using RAPD, ISSR and AFLP makers, respectively. Similarly the mean coefficient of gene differentiation (Gst) were 0.69, 0.63 and 0.51, indicating that 33.77 %, 29.44 % and 26 % of the genetic diversity resided within the population. Analysis of molecular variance (AMOVA) indicated that 53 %, 62 % and 64 % of the genetic diversity among the studied populations was attributed to geographical location while 47 %, 38 % and 36 % was attributed to differences in their habitats using RAPD, ISSR and AFLP markers. An overall value of mean estimated number of gene flow (Nm) were 0.110, 0.147 and 0.24 from RAPD, ISSR and AFLP markers indicating that there was limited gene flow among the sampled populations. 相似文献
45.
桃儿七不同器官中营养成分分布状况及其生态学意义 总被引:5,自引:0,他引:5
植物生殖生态学是植物学领域中刚刚兴起并迅速发展的学科 ,近年来生活史进化理论的研究 ,使繁殖分配 (reproductiveallocation (RA ) )与繁殖投资(reproductiveeffort (RE) )研究成为植物生态学研究的主要焦点[7] 。目前在植物繁殖分配与繁殖投资研究中 ,通常用生物量作为衡量指标 ,这种方法遇到两个疑难问题 :一是各种成分在植物器官中的含量及比例各不相同 ,而且各种成分在植物生长发育过程中所起的生理功能也是不等价的 ,因此 ,在重量相同时 ,各器官的综合营养价值及生理功能是不等价的 ,生… 相似文献
46.
中药紫草的化学成分和药理学研究进展 总被引:6,自引:0,他引:6
本文对中药紫草(Arnebia
euchroma(Royle)Johnst.,Lithospermum erythrorhizon Sieb.et Zucc.和A.guttata Bunge的干燥根)的化学成分和药理作用的研究进展进行了综述. 相似文献
48.
pH值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响 总被引:2,自引:0,他引:2
报道了不同pH值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响。结果表明,新疆紫草细胞具有自我调节其培养液pH值的功能。适合于细胞生长及紫草宁衍生物形成的pH值为5.6±0.40。BAP、2,4-D、NAA或IBA对细胞生长无显著的促进作用,且都会抑制紫草宁衍生物的形成。在生长培养基中添加1.0mg/l IAA和0.5mg/lKT可促进细胞生长,而在生产培养基中附加0.1mg/lKT和0.75─1.0mg/lIAA则有利于紫草宁衍生物含量及产量的提高。 相似文献
49.
50.