大果大戟的化学成分

从大果大戟的根部首次分离得到11个化合物。利用波谱方法鉴定为β-香树素(1),β-香树素乙酸酯(2),3β-乙酰化羽扇豆烯醇(3),baccatin(4),2个caffeic mters(5a,5b),棕榈酸-1-甘油酯(6),棕榈酸(7),东莨菪内酯(8),β-谷甾醇(9)和胡萝卜甙(10)。其中5a,5b是第一次在大戟属中得到;并对5a,5b的碳谱和氢谱数据进行了全归属。     

万丈深的化学成分

万丈深（ＣｒｅｐｉｓｐｈｏｅｎｉｘＤｕｎｎ）为菊科还阳参属植物,分布于云南等地。有祛风散寒、消炎解毒的作用,用于治疗感冒,上呼吸道感染,支气管炎等。其化学成分尚未见报道。对该植物地下部分的化学成分进行研究,分离得到８个化合物。经分析鉴定为：蒲公英赛醇（ｔａｒａｘｅｒｏｌ,１）,α－香树素乙酸酯（α－ａｍｙｒｉｎａｃｅｔａｔｅ,２）,β－香树素乙酸酯（β－ａｍｙｒｉｎａｃｅｔａｔｅ,３）,α－香树素（α－ａｍｙｒｉｎ,４）,β－香树素（β－ａｍｙｒｉｎ,５）,β－谷甾醇（β－ｓｉｔｏｓｔｅｒｏｌ,…     

杠柳枝皮的化学成分研究(英文)

将杠柳枝皮粉末的乙醇提取物悬浮于水后,依次用石油醚、乙酸乙酯和正丁醇萃取.对乙酸乙酯萃取物采用各种柱层析进行多次分离后得到4个化合物,经波谱分析,鉴定它们的结构分别为β-香树素乙酸酯(1)、β-香树素(2)、periplogenin(3)和perilocoside N(4),其中化合物1和2是首次从该植物中分离得到.     

叶下珠中黄酮类化学成分及其生物活性

利用色谱分离方法与现代波谱分析技术,对叶下珠乙酸乙酯提取物的化学成分进行了系统的研究。从中分离鉴定了14个黄酮类化合物,分别为槲皮素-3-(4"-O-乙酰基)-O-α-L-鼠李糖-7-O-α-L-鼠李糖苷(1)、槲皮素-7-O-α-L-鼠李糖苷(2)、槲皮素-3-O-α-L-鼠李糖苷(3)、槲皮素-3-O-β-D-葡萄糖苷(4)、芸香甙(5)、槲皮素(6)、山柰酚(7)、山柰酚-3-O-α-L-鼠李糖苷(8)、木犀草素(9)、木犀草素-7-O-β-D-葡萄糖苷(10)、蒙花苷(11)、山柰酚-3-O-β-芸香糖苷(12)、柚皮苷(13)、橙皮苷(14)。除5~7外的所有化合物均从该植物中首次分离。对分离所得的化合物进行了体外细胞毒和抗氧化活性测试,结果显示化合物6、9和10表现出一定的细胞毒活性,所有化合物均具有不同程度的抗氧化活性。     

青檀树皮中的化学成分

从我国特有的单种属药用植物青檀（Pteroceltis tatarinowii Maxim.）的树皮中分离鉴定出10个化合物,其结构分别为：N－p－香豆酰酪胺（paprazine,1）、丁香脂酚－4－O－β－D－葡萄糖甙（2）、丁香脂酚－4,4′－二－O－β－D－葡萄糖甙（liriodendrin,3）、甲基丁二酸（4）,香草酸（5）、甲基肌醇（6）、β－谷甾醇（7）、胡萝卜甙（8）、α－香树素（9）和β－香树素混合物（10）。这些化合物均为首次从青檀树皮中分离得到,其中化合物3为主要成分。     

牛奶菜中黄酮类成分的研究

从牛奶菜(Marsdenia sinensis Hemsl)根中分离得到6个黄酮类化合物,经光谱分析确定其结构为:芹菜素(1),(2S)-柚皮素(2),木犀草素(3),异牡荆素(4),8-C-β-D-Glucopyranosyl apigeninidin(5),5,7-二羟基色原酮(6)。所有化合物均为首次从该植物中分离得到,同时对分离得到的单体化合物进行细胞毒活性测试,化合物1～5均表现出较强的细胞毒活性。     

竹黄菌与竹红菌的化学成分及细胞毒活性比较研究

为研究竹黄菌与竹红菌化学成分及细胞毒活性的差异,本研究通过高效液相色谱(HPLC)分析结合常规色谱方法,分离鉴定了两种真菌的6个相同成分,分别为3个主要成分竹红菌甲素(1)、竹红菌乙素(2)和竹红菌丙素(3),以及3,6,8-三羟基-1-甲基口山酮(7)、3,8-二羟基-6-甲氧基-1-甲基口山酮(8)和过氧麦角甾醇(9)。另外,从竹黄菌中还分离得到11,11′-二去氧沃替西林(5)、麦角甾-7,22E-二烯-3β,5α,6β-三醇(10)和麦角甾-7,22E-二烯-2β,3α,9α-三醇(11),并首次从竹红菌中分离得到竹红菌丁素(4)、灰黄霉素(6)、化合物7和8。活性筛选发现,化合物5对三株肿瘤细胞NCI-H1975、HepG2和MCF-7有很强细胞毒活性,化合物1有较强细胞毒活性,而化合物6活性较弱。     

蜘蛛香的研究进展

本文介绍了国内外对中药蜘蛛香的生药学、化学成分、药理活性、组织培养、活性成分含量测定等的研究概况。蜘蛛香的化学成分有挥发油成分、环烯醚萜成分 (包括其酯和甙 )及其他一些成分。药理活性包括镇静催眠、抗菌、抗病毒、细胞毒、抗肿瘤和对循环系统的作用。活性成分含量测定包括挥发油 ,缬草素类成分 ,β -谷甾醇及总酸的测定。     

美丽金丝桃中的一个新桥环化合物

采用L1210细胞株对美丽金丝桃(Hypericum bellum Li)的粗提物及其分步萃取物进行了细胞毒试验,结果表明,美丽金丝桃的氯仿及乙酸乙酯萃取物具有细胞毒活性,其IC50分别为5．4和6．0μg/ml。在细胞毒试验结果指导下,同步对美丽金丝桃有效部位进行了化学成分分离。首次从该植物中得到3个化合物,通过理化数据测定及波谱数据分析,分别鉴定为4,4—二甲基—7α,8β—二羟基—3,5—二氧代二环[4．3．1]癸—1(10)—烯—2—酮(1),槲皮素(quercetin,2)及木犀草素(luteolin,3)。其中,1为一新桥环化合物,并通过2D NMR分析,对黄酮类化合物2及3的^13C NMR谱中的C5和C9数据指认进行了修正。     

羊耳朵叶化学成分的研究

从羊耳朵叶(密蒙花 Buddle ja officinalis Maxim的叶)中分得8个化合物,分别鉴定为3个萜:羽扇豆醇乙酸酯(lupeol acetute)(1),cycloeucalenol(2),chondrillasterol(3)和5个苯丙素酚甙:verbascoside((4),poliumoside(5),β-hydroxyacteoside(6),echinacoside(7)和cistanoside F(8)。化合物1,2,3为首次从该属植物中获得。     

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     

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.     

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.     

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.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.