首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
胶粘香茶菜素的化学结构   总被引:4,自引:3,他引:1  
从胶粘香茶菜叶的乙醚提取物中分得两个二萜化合物‘经各项光谱数据和化学反应确定,其中一个为四环二萜化合物,对映-贝壳杉烷-16β,17-二醇(ent-kauran-16β,17-diol)(1);另一个为三环二萜对映-异海松烷型(ent-isopimarane type)新化合物,命名为胶粘香茶菜素(glutinosin)(2)。对映-异海松烷型二萜化合物的分离和鉴定,对于从化学上阐明香茶菜属植物中大量存在的对映-贝壳杉烯型四环二萜化合物的生源关系有一定的学术意义。  相似文献   

2.
毛萼香茶菜中的三个新的对映—贝壳杉烷型二萜   总被引:6,自引:0,他引:6  
从采自云南省江川县的毛萼香茶菜的甲醇提取物中分离得到3个新的6,7-螺断-对映-贝壳杉烷型二萜;表毛萼甲素,毛萼晶N和毛萼晶O,同时还分离到2个已知化合物,毛萼甲素及毛萼晶L,并修正了毛萼甲素的结构。  相似文献   

3.
疏花毛萼香茶菜中一新的对映-贝壳杉烷型二萜   总被引:1,自引:0,他引:1  
从疏花毛萼香茶菜(Isodon eriocalyx var.laxiflora)叶中分离得到一新的对映-贝壳杉烷型二萜,命名为疏花丁素(1),通过波谱方法鉴定了它的结构。此外,还分离得到6个已知对映-贝壳杉烷型二萜化合物:疏花甲素(2),毛萼晶A-C(3-5)和Q(6),毛萼乙素(7),以及cirsimaritin(8)和2α-羟基乌索酸(9)。  相似文献   

4.
从毛萼香茶菜中分得8个二萜,3-乙酰毛萼结晶S、毛萼结晶甲、毛萼结晶乙、毛萼结晶丙、毛萼结晶丁、trichrokaurin、edonicin和eriocalyxin B。其中3-乙酰毛萼结晶S为新的对映-贝壳杉烷型二萜。由波谱法确定其结构。  相似文献   

5.
从蕨类植物里白( Hicriopteris glauca) 的丙酮提取物中分离得到10 个化合物, 包括一个新的对映-贝壳杉烷型二萜化合物, 其化学结构通过各种波谱学方法鉴定为ent-2-β-hydroxyl-16-ene-kauran-19-oic acid(1)。  相似文献   

6.
从毛萼香茶菜的叶的甲醇提取物中分离得到两个二萜化合物,coetsoidinA和毛萼晶P,它是目前从香茶菜属分离到的仅有的两个B环具有α,β-不饱和酮结构的对映-贝壳杉烷型二萜事物,其中毛萼晶P为新化合物  相似文献   

7.
黄鞘蕊花的化学成分   总被引:4,自引:1,他引:3  
从黄鞘蕊花(Coleus xanthanthus C. Y. Wuet Y. C. Huang)中分得8种成分。其中1个是新的醌式二萜,命名为黄鞘蕊花甲素,其结构为17-methyl(15→16)abieo-16-methoxy-2α-acetoxy-coleon U.7个已知化合物。coleon U(2),sugiol(3),β—谷甾醇,胡萝卜甙,三十三烷醇,三十三烷和二十八烷酸。  相似文献   

8.
从中华双扇蕨(Dipteris chinemis)中分离得到一个新的对映贝壳杉烷型二萜和反式桂皮酸的二聚体:16β—hydroxy-17-[(Z)-p-coumaroyl]-ent-kauran-19-oic acid,命名为dipterinoid A(1)。同时首次从该植物中分离得到其他13个已知化合物。  相似文献   

9.
大果大戟中的一个对映-贝壳杉烷型二萜   总被引:1,自引:0,他引:1  
从大果大戟的根部首次分离得到一个对映-贝壳杉烷型二萜,利用波谱方法鉴定为ent-16α,17-dihydrox-ykauran-3-one(1)。首次对化合物1在甲醇中的碳谱和氢谱数据进行了全归属。  相似文献   

10.
蕨类植物里白中一个新的对映-贝壳杉烷型二萜化合物   总被引:1,自引:1,他引:0  
从蕨类植物里白(Hicriopteris glauca)的丙酮提取物中分离得到10个化合物,包括一个新的对映-贝壳杉烷型二萜化合物,其化学结构通过各种波谱学方法鉴定为ent-2-β-hydroxyl-16-ene-kaurdn-19-oic acid (1)。  相似文献   

11.
12.
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

13.
14.
15.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

16.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

17.
18.
19.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

20.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号