四种国产地衣的化学成分

本文报遣柄果牛皮叶(Sticta henryana),多形树发(Alectoria variabilis),宽瓣肾岛衣漂白变型(Nephromopsis stracheyi f. ectocar pisma)和顶果珊瑚枝(Stereocaulon pomiferum)四种地衣的化学成分。根据光谱数据分析,从中分离得到的18个化合物被鉴定为5-甲基-β-苔黑酚酸甲酯(methyl 5-methy-β-orcinolcarboxylate),苔色酸(orsellinic acid),扁枝衣酸(everainic acid),苔色酸甲酯(methyl orsellinate),赤星衣酸乙酯(ethyl hematommate),β-苔黑酚酸甲酯(methyl β-orcinolcarboxylate),假杯点素A(pseudocyphellarin A),黑茶渍素(atranorin),茶渍酸(lecanoric acid),斑点酸(stictic acid),降斑点酸(norstictic acid),藻纹苔酸(salazinic acid),富马原岛衣酸(fumarprotocetraric acid),左旋和右旋松萝酸(usnic acid),左旋地衣硬酸〔(-)-lichesterinic acid〕,右旋原地衣硬酸〔( )-protolichesterinic acid〕和无羁萜(friedelin)。其中5-甲基-β苔黑酚酸甲酯系首次从植物中得到。分析结果表明,顶果珊瑚枝可作为一种较好的苔香型香原料。     

金丝带缩酚酸类化学成分研究

对采自青海省的金丝带[Lethariella zahlbruckneri(Dr.)Krog.]的乙酸乙酯部分进行研究,采用硅胶柱色谱、半制备高效液相和重结晶技术进行分离纯化,通过1 H-NMR、13 C-NMR技术对化合物结构进行鉴定,结果共分离鉴定了5个化合物,包括:1个缩酚酸类:雪茶素(5);4个缩酚酸和缩酚酸环醚裂解产物:赤星衣酸甲酯(1),β-苔黑酚酸甲酯(2),苔色酸甲酯(3)和苔色酸乙酯(4)。其中化合物1、3、4、5均为首次从该植物中分得。     

黑龙江省两种地衣植物化学成分研究

本文报道石蕊科的两种地衣植物的化学成分。我们从地衣植物林石蕊(Cladonia arbusculd),雀石蕊(Cladonia stellaris)中分离鉴定了松萝酸(Usnicacid)、黑茶渍素(Atranorin)、珠光酸(Perlatolic acid)和四个相应的单芳环衍生物:赤星衣酸(Haematornmic acid)、赤星衣酸乙酯(Uthyl haematommate)、2-羟基-4-甲氧基-6-正成基苯甲酸(2-hriroxy-4-methoxy-6-n-pentylbenzoic acid)、2,4-二羟基-6-正戊基苯甲酸(2.4-dihydroxy-6-n-pentylbenzoic acid)。上述资料,对开发利用这种植物提供了科学依据。     

四种药用地衣的化学成分

从四种药用地衣中分离鉴定了黑茶渍素(1),降斑点酸(2),8′-乙氧基-降斑点酸(3),(—)-placodiolic acid(4),松萝酸(5),珠光酸(6),伏勒米醇(7)和五个相应的单芳环衍生物:β-苔黑酚酸甲酯(8),赤星衣酸(9),赤星衣酸乙酯(10)。2-羟基-4-甲氧基-6-正戊基苯甲酸(11)和2,4-二羟基6-正戊基苯甲酸(12)等12个化合物。其中金丝带[Le-thariella zahlbruckneri(DR.)]中含1,4,8,和10金丝刷[Lethariella cladonioids(Nyl·)Krog.Syn.]中含1,2,3,8和9,雀石蕊[Cladonia stellaris(Opiz.)Pouzar & Vezda]中含1,5,6,11和12黑石耳[Dermatocarpon miniatum(L.)Mann.]中含7,4被鉴定为前人报道的桔黄色素(canarionic acid)。     

针芽肺衣的化学成分

从针芽肺衣(Lobaria isidiophora)中共得到9个化合物,分别鉴定为针肺晶(isidiphoin),斑点酸(stictic acid),降斑点酸(norstictic acid),隐斑点酸(cryptostictic acid),茶渍酸(lecanoric acid),网脊衣酸A、B(retigeric acid A, B)和苔色酸甲酯、乙酯(methyl, ethyl orsellinates)。其中针肺晶为一新的缩酚酮,根据光谱和化学分析,推定了其结构。     

中国拟扁枝衣属的研究

拟扁枝衣属Pseudevernia隶属于子囊菌门Ascomycota,茶渍目Lecanorales,梅衣科Parmeliaceae.迄今已知6种,即粉芽拟扁枝衣P.soralifera,细拟扁枝衣P.cladonia、粗拟扁枝衣P.intensa、茶渍拟扁枝衣P.consocians、橄榄陶拟扁枝衣P.olivetorina及拟扁枝衣P.furfuracea。后三种地衣之界定是在形态特征相似但仍有区别的前提下,以其各自所含次生代谢产物之不同与地理分布区之差异为根据的。茶渍拟扁枝衣含有茶渍酸;裂芽发育良好而密度中等;裂片狭窄,为北美所特有。橄榄陶拟扁枝衣含橄榄陶酸;裂芽较稀少;裂片狭长;分布区以北欧为主,延伸至北非及西亚,如巴基斯坦。而拟扁枝衣则含袋衣酸;形态多变;分布区以南欧洲为主,遍布于整个欧洲,向南延伸至北非,向东延伸至亚洲,如蒙古等。本文首次报道了该属地衣在中国的分布。文中除了对拟扁枝衣进行形态、化学及分布类型的描述外,还配有该种的照片以及该属已知种的检索表。此外,这种地衣是欧洲高级香水配方成分中不可缺少的的生产原料之一。因此,该种在中国的发现对于香精工业原料的研究具有重要意义。另一重要香精原料地衣粉扁枝衣(Evernia prunastria)主要分布在欧洲,在亚洲迄今只知在日本有报道,在中国迄今尚未被发现。然而,扁枝衣(Evernia mesomorpha )在中国的分布却十分普遍。至于另一著名香料地衣粉芽肺衣(Lobaria pulmonaria)在中国的分布迄今仅见于东北地区。     

顶杯衣（Acroscyphus sphaerophoroides）的化学成分研究

对采自云南丽江老君山的顶杯衣（AcroscyphussphaerophoroidesL6v．）的化学成分进行了研究,从中分离得到9个化合物,利用谱学分析方法与文献对照,确定了它们的化学结构。分别鉴定为：甲基茶渍酸（methylle—canorate,I）、茶渍酸（1ecanoricacid,Ⅱ）、三苔色酸（gyrophoricacid,Ⅲ）、地衣酚（orcinol,Ⅳ）、苔色酸甲酯（Methylorsellinate,V）、天精（skyrin,VI）、内赤藓醇（meso—erythritol,Ⅶ）、伏勒米醇（volemitol,Ⅷ）及棕榈酸（palmit—icacid,Ⅸ）。其中化合物I、Ⅱ、Ⅳ、V为首次从顶杯衣中分离得到。化合物Ⅲ和Ⅵ是顶杯衣的主要特征性成分。     

小花杜鹃中两个新的木脂素

研究小花杜鹃(Rhododendron minutiflorum)的化学成分及其α-葡萄糖苷酶抑制活性。采用正相硅胶、ODS、Sephadex LH-20和HPLC等多种色谱技术,从小花杜鹃的95%乙醇提取物中分离得到9个化合物,通过波谱分析和文献数据对比,鉴定其结构分别为rhodominutinan A(1)、rhodominutinan B(2)、3,4-di(4-hydroxy-3-methoxybenzyl)tetrahydrofuran(3)、venkatasin(4)、苔色酸甲酯(5)、苔黑酚羧酸乙酯(6)、2,4-二羟基-3,6-二甲基苯甲酸甲酯(7)、芹菜素(8)、山奈酚(9)。其中化合物1和2为新的木脂素,化合物3~9为首次从小花杜鹃中分离得到。通过α-葡萄糖苷酶抑制剂体外筛选模型评价化合物的潜在降血糖活性,结果表明化合物8和9具有较好的α-葡萄糖苷酶抑制活性,IC₅₀值分别为57.51±6.35、54.70±3.67μM。     

中国拟扁枝衣属的研究

拟扁枝衣属Pseudevernia隶属于子囊菌门Ascomycota,茶渍目Lecanorales,梅衣科Parmeliaceae。迄今已知6种,即粉芽拟扁枝衣P.soralifera、细拟扁枝衣P.cladonia、粗拟扁枝衣P.intensa、茶渍拟扁枝衣P.consocians、橄榄陶拟扁枝衣P.olivetorina及拟扁枝衣P.furfuracea。后三种地衣之界定是在形态特征相似但仍有区别的前提下,以其各自所含次生代谢产物之不同与地理分布区之差异为根据的。茶渍拟扁枝衣含有茶渍酸;裂芽发育良好而密度中等;裂片狭窄,为北美所特有。橄榄陶拟扁枝衣含橄榄陶酸;裂芽较稀少;裂片狭长;分布区以北欧为主,延伸至北非及西亚,如巴基斯坦。而拟扁枝衣则含袋衣酸;形态多变;分布区以南欧洲为主,遍布于整个欧洲,向南延伸至北非,向东延伸至亚洲,如蒙古等。本文首次报道了该属地衣在中国的分布。文中除了对拟扁枝衣进行形态、化学及分布类型的描述外,还配有该种的照片以及该属已知种的检索表。     

乌桕桕脂中甾醇和其它成分分离鉴定

通过柱层析、薄层层析等化学方法,从乌桕桕脂中分离得到甾醇及脂肪酸酯类化合物。经气相色谱和气-质联用分析,鉴定出下列化合物:β-谷甾醇、菜油甾醇、Δ~7-豆甾烯醇、肉豆蔻酸甲酯、肉豆蔻酸乙酯、棕榈酸甲酯、硬酯酸甲酯和硬酯酸乙酯。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

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.     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).