一年蓬的化学成分研究

利用柱层析、重结晶等分离手段,从菊科飞蓬属植物一年蓬的脂溶性成分中,分离得到5个化合物,经现代波谱手段鉴定它们为2个三萜：齐墩果-12-烯3β,23-丙叉基-28-醇(1)、齐墩果-12-烯3β-醇(2)和3个豆甾醇衍生物：豆甾-5-烯-3β,7a-二醇(3)、豆淄-4-烯3S,6α-二醇(4)、豆甾-7,24-二烯-3β-醇(5)。其中化合物1是苗次自天然界分离得到的化合物,且其^18C NMR数据及质谱数据为首次报道。对化合物1的酸水解反应得到了化合物齐墩果-12-烯-3β,23,28-三醇(1a),从而使化合物1的结构得到进一步确证。     

链霉属放线菌Streptomyces antibioticus H12-15发酵物的化学成分研究

对采集于近南海红树林底泥的抗生链霉菌H12-15发酵物中的次级代谢产物进行分离纯化,经多种柱色谱技术得到10个化合物,通过波谱学方法并结合文献数据比对,鉴定所分离得到的化合物分别为:放线菌素X2(1)、放线菌素D(2)、羊毛甾醇(3)、4,4-二甲基酵母甾醇(4)、麦角甾醇过氧化物(5)、24-甲基-5α-胆甾基-7,22-二烯-3β,6α-二醇(6)、麦角甾-3β,5α,9α-三羟基-7,22-二烯-6-酮(7)、麦角甾-3β,5α,9α,14α-四羟基-7,22-二烯-6-酮(8)、5α,6α-环氧麦角甾-8,14,22-三烯-3β,7α-二醇(9)、β-谷甾醇(10),化合物3~10均为首次从海洋来源链霉菌中分离得到。运用MTT法对这10个化合物进行体外抗肿瘤细胞活性的筛选,其中,化合物1和2具显著生长抑制活性,其IC50值均小于1.6μg/mL;化合物9表现出一定的细胞毒活性。     

白木香内生真菌Botryosphae riarhodina A13固体发酵产物的分离鉴定

运用硅胶柱、反相硅胶柱、凝胶柱、HPLC和薄层制备等色谱技术及重结晶从白木香内生真菌Botryosphaeria rhodina A13的固体发酵产物中分离纯化了10个化学成分,通过化合物波谱数据及理化性质鉴定它们的结构分别为豆甾-4-烯-3-酮(1)、豆甾-5-烯-3β-醇-7-酮(2)、豆甾-4-烯-3,6-二酮(3)、(22E,24S)-5α,6α-环氧基-24-甲基胆甾-8(14),22-二烯-3β,7α-二醇(4)、5,4'-二羟-7-甲氧基黄酮(5)、香草酸(6)、对甲氧基苯甲酸(7)、尿嘧啶(8)、2-甲氧基对苯二酚(9)、2-甲基-3,5-羟基色酮(10)。其中化合物1~10均为首次从该属真菌中分离得到,化合物4具有细胞毒活性。     

龙芽草化学成分研究

从药用植物龙芽草(Agrimonia pilosa Ledeb)全草的95%乙醇提取物中分离得到4个化合物,通过理化性质及波谱学方法分别鉴定为豆甾-5-烯-3β,7β-二醇(1)、豆甾-5-烯-3β7,α-二醇(2)、豆甾-3β6,α-二醇(3)和β-谷甾醇(4)。化合物1～3均为首次从龙芽草中分离得到。     

大花美人蕉根的化学成分研究

为了解大花美人蕉(Canna generalis)的化学成分,从其根的乙醇提取物中分离得到8个化合物。通过波谱数据分析,分别鉴定为去氢催吐萝芙木醇(1)、3,4-二羟基苯甲酸乙酯(2)、咖啡酸乙酯(3)、豆甾-4,22-二烯-3,6-二酮(4)、豆甾-4-烯-3,6-二酮(5)、豆甾烷-3,6-二酮(6)、β-谷甾醇(7)和豆甾醇(8)。上述化合物均为首次从该植物中分离得到。     

中国人参花化学成分研究

目的:对人参(Panax ginseng C.A.Mey.)花蕾的化学成分进行研究。方法:采用多种柱色谱技术进行分离纯化,并通过波谱分析方法鉴定化合物的结构。结果:分离鉴定了9个化合物,分别鉴定为咖啡碱(1)、胡萝卜苷(2)、豆甾醇3-O-葡萄糖苷(3)、α-菠甾醇(4)、7-豆甾烯-3β-醇(5)、人参皂苷Rk3(6)、人参皂苷Re(7)、人参皂苷Rg2(8)、谷甾醇(9)结论:其中化合物1为五加科植物中首次分离得到,化合物3、4、5为人参花中首次分离得到。     

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。     

角果胡椒的化学成分研究

从角果胡椒的乙醇提取物中分离得到6个甾醇,通过波谱方法鉴定它们的结构为5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(1),(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(2),(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3),豆甾醇-5,11-二烯-3β-醇(4),豆甾醇-3,6-二酮(5),sitoindosideΙ(6)。     

牛大力茎的化学成分研究

从牛大力(Millettia speciosa Champ.)茎95%乙醇提取物的乙酸乙酯部分分离得到了7个化合物,经波谱分析及与文献数据对照鉴定其结构为:4,2’,4’-三羟基查耳酮(1)、高丽槐素(2)、4’-羟基-7-甲氧基二氢黄酮(3)、谷甾-5-烯-3,7-二醇(4)、β-谷甾醇(5)、豆甾醇(6)和β-胡萝卜苷(7)。其中化合物3和4为首次从该植物中分离得到。     

海洋链霉菌H41-59甾醇类化学成分及其细胞毒活性研究

对来源于南海红树林底泥的海洋链霉菌H41-59发酵物中的次级代谢产物进行了分离纯化、结构鉴定及抗肿瘤细胞毒活性评价研究。经硅胶柱层析、Sephadex LH-20分子排阻层析和高效液相色谱等分离手段,从中分离得到了10个甾醇类化合物。通过核磁、质谱等方法,并结合与文献数据比对,鉴定分离得到的化合物分别为:麦角甾-7,22-二烯-3β,5α,6β-三醇(1)、麦角甾-7,22-二烯-3β,5α,6α-三醇(2)、麦角甾-7,22-二烯-3β,5α,6β,9α-四醇(3)、麦角甾-7,22-二烯-3β,5α,6β,25-四醇(4)、5α,6α-环氧麦角甾-8(9),22-二烯-3β,7α-二醇(5)、5α,6α-环氧麦角甾-8(14),22-二烯-3β,7α-二醇(6)、麦角甾-8(9),22-二烯-3β,5α,6β,7α-四醇(7)、麦角甾-8(14),22-二烯-3β,5α,6β,7α-四醇(8)、5α,6α-环氧麦角甾-8(14),22-二烯-3β,7β-二醇(9)、麦角甾-5,7,22-三烯-3β-醇(10),化合物1~10均为首次从海洋来源链霉菌中分离得到。采用MTT法对这10个化合物进行体外抗肿瘤细胞活性的筛选,发现均具有一定的细胞毒活性。其中,化合物5、7和8表现出较好的抑制活性,其IC50值均小于50μg/m L。     

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.     

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).