不同地区红景天植物红景天苷含量比较研究

采用高效液相色谱法(HPLC)测定了6种不同地区红景天植物红景天苷含量.以甲醇为提取溶剂,室温超声提取45 min,HPLC测定条件:岛津C18柱(4.6×250 mm,5 μm);流动相为甲醇∶水=3∶7;柱温25℃;检测波长为275 nm.结果表明,红景天苷含量分别为:大花红景天0.36%,狭叶红景天(狮子七)0.32%,宽果红景天0.14%,白三七0.04%,在小丛红景天、洮河红景天中未检测到红景天苷.     

丽江产红景天的化学成分研究

从丽江产红景天粗提物中分离得到了14个化合物,经波谱数据分别鉴定为二十六烷醇(1-hexamsanol,1),β-谷甾醇(β-sitosterol,2),胡萝卜苷(daucostexol,3),酪醇(tyrosol,4),红景天苷(salidroside,5),没食子酸(galic acid,6),山奈酚(kaempferol,7),草质素-7-O-(3″-β-D-葡萄糖基)-α-L-鼠李糖苷(rhodiosin,8),德钦红景天苷(rhodionin,9),对羟基苯甲酸(4-hydroxybenzoic acid,10),geranyl 1-O-α-L-arabinopyranosyl(1→6)-β-D-glucopyranoside(11),2,7-anhydro-β-D-heptul-opyranoses(the altro isomer,12),乙酸二十六烷醇酯(cerotylacetate,13),1,2,3,4,6-五没食子酰基-β-D-喃葡萄糖(1,2,3,4,6-pentagalloyl-β-D-glucopyranose,14)。根据分离所得的单体,用HPLC对商业化粗提物色谱中的8个峰进行了指认,并测定了云南千山生物工程有限公司利用不同工艺流程所得四批粗提物中红景天苷的含量。     

四川阿坝产野生大花红景天不同器官中红景天苷含量的比较

大花红景天[Rhodiola crenulata（Hook.f.et Thoms）H．Ohba]为药材红景天的基原植物,是珍稀的药食兼用天然植物资源之一[1-2]。红景天具有益气活血、通脉平喘、扶正固本的作用[1],主要含黄酮类、有机酸类、多糖类、苷类、香豆素类和挥发性成分等,其中包含的重要生物活性成分有红景天苷、红景天素、酪醇、二苯甲基六氢吡啶和超氧化物歧化酶（SOD）等,还含有维生素及人体必需的多种大量和微量元素,营养价值极高[3-5]。红景天具有抗疲劳、抗缺氧、强壮机体、抗心肌缺血、抗肿瘤和保护神经细胞等作用,红景天药材或其提取物已成为多种中成药、食品、饮料和化妆品的重要原料旧[6]。     

德钦红景天的化学成分

从云南产德钦红景天Ｒｈｏｄｉｏｌａ ａｔｕｎｔｓｕｅｎｓｉｓ（Ｐｒａｅｇ．） Ｆｕ 的根及根茎中首次分离得到８ 个化合物。根据各项光谱数据及化学反应鉴定其中一个新黄酮甙的结构为３ , ５ , ７ , ８ － 四羟基－黄酮４′－ 氧－ α－ Ｌ－ 鼠李糖吡喃甙, 命名为德钦红景天甙（ｒｈｏｄｉｏｌａｔｕｎｔｏｓｉｄｅ, ２） , 另外７ 个已知化合物分别是草质素－ ８ － 甲醚（ｈｅｒｂａｃｅｔｉｎ － ８ － ｍｅｔｈｙｌｅｔｈｅｒ,１） , 槲皮素（ｑｕｅｒｃｅｔｉｎ ,３） , 芦丁（ｒｕｔｉｎ,４） , 酪醇（ｔｙｒｏｓｏｌ,５） , 红景天甙（ｓａｌｉｄｒｏｓｉｄｅ,６） , 没食子酸（ｇａｌｌｉｃ ａｃｉｄ,７） 和β－谷甾醇（ － ｓｉｔｏｓｔｅｒｏｌ,８） 。     

HPLC法测定红景天居群中红景天苷的分布式样

本文以HPLC法作为测定红景天苷的方法,调查红景天苷在红景天不同种、不同居群中的分布式样。实验中采集不同种、同种不同居群、同居群不同个体的红景天样品,进行红景天苷的含量测定。结果表明红景天苷在不同红景天中分布差异较大,同种不同居群间多型性、居群内及个体间多态性显著。HPLC比法简便、快速、准确、重复性好,适用于研究红景天苷在药用红景天居群中的分布。     

影响高山红景天细胞悬浮培养中细胞生长和红景天苷积累的几个因素(简报)

高山红景天细胞悬浮培养过程中,3mg·L916－BA、0．3mg·L－1NAA、60mmol·L－1氮源（其中NH_4~:NO_3~- 为1：1）、0．5～1．25mmol·L－1KH2PO4和200mg·L－1蛋白胨,较适合于细胞生长和红景天苷的积累。在适宜的接种量（3．2g·L-1）下细胞培养24d后,生物量达14．04g·L－1,干细胞中红景天苷含量为5．66mg·g-1。     

氮素营养水平对高山红景天生长和红景天苷含量的影响

在温室中采用砂培法以4种氮素营养水平(1．75、3．50、7．00和14．00mmol／L)培养移栽的高山红景天,50d后测定了生长状况和根的红景天苷含量。株高、全株生物量、地上部分生物量随氮水平的增加而增加,而根生物量、根冠比则随着氮水平的增加而降低。在氮水平为7mmol／L左右时,高山红景天根中红景天苷的含量和产量最高,而低氮水平和高氮水平均不利于红景天苷的积累。     

玫瑰红景天化学成分研究

采用大孔吸附树脂、硅胶柱、ADS-5C反相柱和制备HPLC色谱技术对新疆产玫瑰红景天根茎中的植物化学成分进行提取分离和纯化研究,从中分离得到15个化合物。通过理化方法及1H、13C NMR等方法鉴定为:对-O-β-吡喃葡萄糖基-苯-2-丁酮(1)、6’-O-没食子酰-红景天苷(2)、对-O-β-吡喃葡萄糖基-苯丙烯酸(3)、7-甲氧基香豆素(4)、表没食子儿茶素-3-没食子酸酯(5)、苯乙基-6-O-β-葡萄糖苷(6)、对羟基苯甲酸(7)、红景天苷(8)、肉桂醇-6’-O-α-吡喃阿拉伯糖基-O-β-吡喃葡萄弹苷(9)、肉桂醇-6’-O-α-吡喃木糖-O-β-吡喃葡萄弹苷(10)、肉桂醇-6’-O-α-呋喃阿拉伯糖基-O-β-吡喃葡萄弹苷(11)、肉桂醇-O-β-D-吡喃葡萄弹苷(12)、对-羟基-苯乙醇(13)、3,7-二甲基-2,6-二烯-1,4-二辛醇(14)、3,7-二甲基-2,6-二烯-1,4-二辛醇-O-β-吡喃葡萄糖苷(15)。其中化合物1～4为首次在玫瑰红景天发现。     

新疆大花红景天化学成分的HPLC-MS研究

采用高效液相色谱-电喷雾-四极杆-飞行时间串联质谱法(HPLC-ESI-Q-TOF-MS),分别在正负离子模式下对新疆产大花红景天(Rhodiola crenulata)提取物进行分离分析。通过精确质量测定和同位素峰形匹配(Sig-maFit)确定了化合物的元素组成。在正离子模式下,选择[M+H]+或[M+NH4]+准分子离子进行二级裂解对其结构进行分析。根据物质的元素组成和二级质谱信息,初步确定了新疆大花红景天提取物中的12种化合物。     

西藏红景天提取物延长线虫寿命和抗氧化活性探索

探讨红景天苷和西藏红景天粗提物对延长线虫寿命的影响及其体外抗氧化活性的比较。以红景天苷、红景天粗提物为研究对象、以Vc为阳性对照,分别检测以上三种物质对自由基的清除作用。结果表明红景天能够显著延长秀丽隐杆线虫的寿命;在相同浓度下,红景天苷清除DPPH自由基的EC50约为1291.53μg/mL,红景天提取物溶液约为489.76μg/mL;红景天苷清除羟自由基的EC50约为1120.94μg/mL,红景天提取物约为1068.37μg/mL;红景天苷清除超氧阴离子自由基的EC50约为55.57μg/mL,红景天提取物溶液约为40.49μg/mL。中药红景天中含有显著延长线虫寿命的抗氧化物质,而这种成分并非是红景天苷。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.