共查询到20条相似文献,搜索用时 31 毫秒
1.
从栓皮栎(Quercus variabilisBl.)虫瘿中分离了2对平衡互变异构体和4个单体化合物,通过光谱数据和化学方法鉴定:G-1为1-O(3′-没食子酰基)没食子酰基-β-D-葡萄吡喃糖和1-O-(4′-没食子酰基)没食子酰基-β-D-葡萄吡喃糖的平衡互变异构体,G-2为3-O-没食子酰基-没食子酸和4-O-没食子酰基--没食子酸的平衡互变异构体,-3O一1,6-二-O没食子酰基-β-D-葡萄吡喃糖,G-4为1,2,3,6-四-O-没食子酰基-β-D-葡萄吡喃糖,G-5为1-O-没食子酰基-β-D-葡萄吡喃糖,G-6为没食子酸甲酯。对G-1、G-3和G-4进行初步的抗肿瘤、抗脂质过氧化和抗血小板聚集活性实验。 相似文献
2.
白蔹单宁化学成分的研究 总被引:12,自引:0,他引:12
从白蔹Ampelopsis japonica(Thunmb.)Makino的乙酸乙酯提取物中分离出5个单宁化合物。经光谱分析和化学方法鉴定,它们为没食子酸(gallic acid,1),1,2,6-三氧-没食子酰基-β-D-吡喃葡萄糖(1,2,6-tri-O-galloy1-β-D-glucopyranoside,2),1,2,3,6-四氧-没食子酰基-β-D-吡喃葡萄糖(1,2,4,6-tetr 相似文献
3.
4.
《天然产物研究与开发》2020,(3)
本文对紫娟茶的化学成分进行分离纯化及其抗炎、抗氧化活性进行考察。实验采用现代分离纯化方法,从紫娟茶中共分离得到12个化合物,根据波谱学数据进行结构鉴定为:山柰酚(1)、(+)-表儿茶素(2)、(-)-表儿茶素-3-O-没食子酸酯(3)、杨梅素(4)、表没食子儿茶素-3-O-(3″-O-甲基)没食子酸酯(5)、槲皮素(6)、没食子酸(7)、表没食子儿茶素没食子酸酯(8)、3-O-没食子酰基奎宁(9)、小木麻黄素(10)、1,4,6-三-O-没食子酰基-β-D-葡萄糖(11)、咖啡因(12),其中化合物9为首次从紫娟茶中分离得到。化合物11表现出良好的抗氧化活性,化合物1、3、4、6、8~11均具有显著的抗炎活性。 相似文献
5.
石香薷中化学成分的研究 总被引:12,自引:0,他引:12
从石香薷(Mosla chinensis Maxim .)中分离到10 个化合物,经光谱分析、化学方法及与已知化合物对照,分别鉴定为:6-甲基三十三烷(1)、β-谷甾醇(2)、熊果酸(3)、5-羟基-6,7-二甲氧基黄酮(4)、5-羟基-6-甲基-7-O-β-D-吡喃木糖(3→1)-β-D-吡喃木糖双氢黄酮甙(5)、5,7-二羟基-4-甲氧基黄酮(6)、洋芹素(7)、山奈素-3-O-β-D-葡萄糖甙(8)、桑色素-7-O-β-D-葡萄糖甙(9)、鼠李柠檬素-3-O-β-D-芹糖(1→5)芹糖-4-O-β-D-葡萄糖甙(10)。其中,化合物5和10 为新化合物 相似文献
6.
云南普洱茶原料晒青毛茶的化学成分 总被引:47,自引:6,他引:41
从云南临沧地区生产普洱茶的原料晒青毛茶中分离到 2 1个化合物 ,通过波谱分析分别鉴定为 :(- )表儿茶素、 (- )表没食子儿茶素、 (- )表没食子儿茶素 - 3-O -没食子酸酯、 (- )表儿茶素 - 3-O -没食子酸酯、 (- )表阿福豆素 - 3-O -没食子酸酯、 ( )儿茶素、 (± )没食子儿茶素、槲皮素、槲皮素 - 3-O - β -D -葡萄吡喃糖甙、芦丁、山奈酚、山奈酚 - 3-O - β -D -葡萄吡喃糖甙、山奈酚 - 3-O -芦丁糖甙、小木麻黄素 (strictinin)、 1,6 -O -二没食子酰基 - β -D -葡萄吡喃糖、茶倍素、绿原酸、 3α ,5α -二羟基 - 4 -α -O -咖啡酰基金鸡纳酸、松柏醇甙、没食子酸和咖啡因 相似文献
7.
印楝愈伤组织的化学成分 总被引:13,自引:0,他引:13
从印楝(Azadirachta indica A.Juss)的愈伤组织中,共分离鉴定出5个化合物,经理化性质和波谱分析分别确定为:柳杉酚⑴,豆甾醇⑵,软酯酸-1-甘油酯⑶,豆甾醇-3-O-β-D-吡喃葡萄糖甙⑷,豆甾醇-3-O-β-D-吡喃葡萄糖甙-6’-十六烷酸酯⑸。 相似文献
8.
红木荷树皮的化学成分 总被引:5,自引:0,他引:5
从红木茶树皮中分离出4个化学成分,经光谱解析和化学降解,分别被鉴定为α-菠甾醇,α-菠甾醇葡萄糖甙,表儿茶素和一新的三萜皂甙22-O-当归酰酯-3-O(α-L-鼠李吡喃糖基(1→2))-(β-D-葡萄吡喃糖基(1→2)-β-D-半乳吡喃糖基(1→4))-β-D-葡萄糖醛酸甙。 相似文献
9.
10.
自头序Song木70%EtOH提取物分得6个化合物,应用光谱技术(IR,MS,HNMR,^13CNMR,DEPT,2DNMR)及化学方法,确定了他们的结构,分别为β-谷甾醇(Ⅰ),胡萝卜甙(Ⅱ),齐墩果酸(Ⅲ),竹节参皂甙1(Ⅳ),竹节参皂甙Ⅳa(ChikusetsusapominⅣa)(Ⅴ),常春藤皂甙元-28-O-β-吡喃葡萄糖醛酸(1→4)-β-D-吡喃葡萄糖甙(Ⅵ),以上化合物均为首次从该 相似文献
11.
12.
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
13.
14.
15.
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
16.
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
17.
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
18.
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
19.