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从唇形科瘿花茶菜(Rabdosia rosthornii)叶的乙醚抽出物中分出2个新的微量成分,瘿花丙素和丁素。基于详细的光谱分析,包括应用二维核磁共振数据,瘿花丙素和化学结合分别确定为对映-11α-乙酰氧基-7β,13β,19-三羟基贝壳杉-16烯-15-酮(1)和对映-11α-乙酰氧基-7β,12β,14α-三羟基贝壳杉-16烯-15-酮(2)。 相似文献
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毛萼鞘蕊花甲素的结构 总被引:2,自引:1,他引:1
从毛萼鞘蕊花(Coleus esquirolii(L(?)vl. )Dunn.)的茎、叶中分离鉴定了一个新的二萜化合物,毛萼鞘蕊花甲素(对映-17-乙酰氧基-贝壳杉烷-16β-醇),和三个已知化合物,对映-贝壳杉烷-16p,17-二醇,齐墩果酸和β-谷甾醇。 相似文献
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西北蔷薇果实化学成分的研究 总被引:6,自引:0,他引:6
从西北蔷薇(Rosa davidii Crep.)果实中分得11个化合物,经波谱方法鉴定为:2α,3β,19β-三羟基-齐墩果烷-12-烯-28-酸(1)2α,3β-二羟基-乌苏烷-28(13)-内酯(2)、arjunic acid(3)、蔷薇酸(4)、2α,3β-二羟基乌苏酸(5)、齐墩果酸(6)、山奈素(6)、tiliroside(8)、槲皮素(9)、胡萝卜甙(10)和β-谷甾醇(11)。其中1和2为首次发现的新化合物。 相似文献
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毛喉鞘蕊花的化学成分 总被引:6,自引:4,他引:2
从毛喉鞘蕊花分离得到两个新二萜醌 :鞘蕊酮S(1) ,鞘蕊酮T(2 )和六个已知成分 :α 雪松醇 ,愈创木酚甘油醚 ,芫花素 ,鞘蕊醇B ,β 谷甾醇 ,豆甾醇。依据光谱和化学方法 ,它们的化学结构已被鉴定 相似文献
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麻疯树根的化学成分研究 总被引:15,自引:0,他引:15
从麻疯树(Jatropha curcas L.)的根中分离到13 个化合物,经理化常数和波谱鉴定(IR、1H-NMR、13C-NMR、EIMS和FABMS)分别为∶5α-豆甾烷-3,6-二酮(1)、川皮甙(2)、β-谷甾醇(3)、蒲公英脑(4)、2S-正二十四饱和脂肪酸甘油酯-1(5)、5-羟基-6,7-二甲氧基香豆素(6)、麻疯树酚酮A(7)、麻疯树酚酮B(8)、6-甲氧基-7-羟基香豆素(9)、caniojane (10)、3-羟基-4-甲氧基-苯甲醛(11)、3-甲氧基-4-羟基苯甲酸(12)和胡萝卜甙(13). 其中,化合物5 为未见报道的新化合物,化合物1、2、9、10、11、12 为首次从该植物中分得,10 为含有过氧基团的二萜化合物. 7 和8 为一对四环二萜的立体异构体,并在碱中相互转化 相似文献
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从直距翟雀花(Delhinium orthocentrun Franch.)全草的甲醇提取物中分离得到了3个降二萜生物碱,通过NMR,MS等波谱分析将其结构鉴定为7,10-二羟基8,1、4,16三甲氧基19,20-二去氢乌头烷(7β,8β,14α,16β)(1),20-乙基-2,3-二去氢-6,10二羟基-7,8-二氧亚甲菜-1,14,16-三甲氧基乌头烷(1α,6β,14α,16β)(2)和翼北 相似文献
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Profiles of SARS-CoV-2 RNA and Antibodies in Inpatients with COVID-19 not Related with Clinical Manifestation: A Single Centre Study 下载免费PDF全文
Zhao Li Gao Ruqin Lu Roujian Wang Huijuan Deng Yao Niu Peihua Jiang Fachun Huang Baoying Liang Jiwei Jia Jing Zhang Feng Wang Wenling Wu Guizhen Tan Wenjie 《中国病毒学》2021,36(5):1088-1092
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
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
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
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
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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
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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
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