薄层扫描法测定毛两面针三种生物碱的含量

从广西大瑶山产毛两面针中提取到了鹅掌楸碱(Ⅰ)、白屈菜红碱(Ⅱ)、氯化两面针碱(Ⅲ)三种生物碱,用薄层扫描法(TLCS)同时测定其含量,并与玉林、百色两面针中的同种生物碱进行对比。研究表明,毛两面针和两面针均含Ⅱ、Ⅲ,在毛两面针还能检测到Ⅰ的存在,其含量为0.00957%。     

广西十个不同产地的两面针中活性成分的分析

采用HPLC法对广西十个不同产地的两面针中具有抗肿瘤活性的氯化两面针碱和具有镇痛活性的 L-芝麻脂素的含量进行了分析和比较。发现在不同产地的两面针中氯化两面针碱和L-芝麻脂素的含量差别 都较大,广西百色的两面针中氯化两面针碱含量和L-芝麻脂素的含量均最高,氯化两面针碱0．467％,L-芝麻 脂素0．160％;广西金秀的两面针中氯化两面针碱含量和L-芝麻脂素的含量均最低,氯化两面针碱0．0490％, L-芝麻脂素0．0370％。分析的色谱柱为HYPERSIL BDS C18,测定氯化两面针碱的条件为,流动相乙腈: 0．02 mol／L KH2PO4溶液(34:66),流速为1．0 mL／min,柱温40℃,检测波长329 nm,进样量为20μL;测定 L-芝麻脂素的条件为,流动相乙腈:水(50:50),流速为1．0 mL／min,柱温40℃,检测波长287 nm,进样量为 20μL。该研究为两面针在抗肿瘤药物和镇痛等方面的开发利用提供了可靠的理论依据,具有重要应用价值。     

氯化两面针碱的提取分离、全合成及药理活性的研究进展

两面针是我国民间常用的传统中药之一,从根部提取分离到的氯化两面针碱是两面针植物多种生物活性的主要有效成分。当前,直接从植物中提取分离有效成分的方法不仅回收率低、成本高,而且氯化两面针碱存在水溶性差和生物利用度低的问题,因此大多学者致力于改造其结构以提高活性和利用度,同时探索高效经济的全合成方法以满足研究和生产的需求。该文以国内外相关文献为基础,对氯化两面针碱的提取、分离纯化、结构化合物的全合成路线以及药理活性机制的研究进展做一综述,总结目前研究中存在的不足,并对今后的研究重点做出展望,旨在为今后深入研究两面针碱及衍生物活性改造、解析作用机制、开发基于此结构的创新药物分子等提供理论依据。     

超声波提取两面针中的总碱

在提取两面针总碱时,超声提取法与回流提取法相比较,具有省时、节能、提出率高的等优点。     

巴山花椒根的化学成分研究

首次报道从芸香科花椒属植物巴山花椒（ＺａｎｔｈｏｘｙｌｕｍｐａｓｈａｎｅｎｓｅＮ．Ｃｈａｏ）根中分到９种结晶性化合物,经物理常数测定、光谱分析及化学方法,分别鉴定了两面针碱（Ⅰ）、β－谷甾醇（Ⅱ）、氧化两面针碱（Ⅲ）、胡萝卜甙（Ⅳ）、１－芝麻素（Ⅴ）、去甲白屈菜红碱（Ⅵ）、异地卡灵（Ⅶ）及另一化合物Ｙａｎｇａｍｂｉｎ（Ⅸ）。晶Ⅷ的结构尚待证实。     

两面针基原植物考证及其活性成分含量分析

该研究选取广西不同类型的两面针为材料,通过查阅文献对两面针基原植物进行考证,用反相高效液相色谱法(RP-HPLC)对两面针原变种及变种中的5种活性成分进行定量分析。结果表明:(1)毛两面针[Zanthoxylum nitidum (Roxb) DC. f. fastuosum How ex Huang]早已并入两面针原变种[Z. nitidum (Roxb.)DC. var. nitidum];虽然毛两面针与毛叶两面针中文名称相似,但不可认为是同一个变种。(2) RP-HPLC结果显示两面针原变种及变种均不含毛两面针素。(3) 5种活性成分在不同类型中存在显著性差异。(4)根据5种活性成分含量数据,对9份两面针样品进行聚类分析,结果划分为4组,与两面针形态划分一致。这不仅理清了"毛叶两面针"与"毛两面针"存在的混淆问题,而且还比较了不同形态类型间的活性成分含量,为两面针质量控制和资源的合理应用开发提供了参考。     

氯化两面针碱对小鼠溃疡性结肠炎的干预作用及其机制*

目的:探讨氯化两面针碱(NC)通过靶向miR-31对葡聚糖硫酸钠(DSS)诱发小鼠结肠炎的保护作用及其机制。方法:用1%DSS诱发小鼠溃疡性结肠炎(UC)。30只雄性C57BL/6小鼠随机分为正常对照组(Control)(n=7),DSS组(n=8),DSS+NC组(7.27 mg/kg)(n=8)和NC组(n=7),饮水给予DSS,灌胃给予氯化两面针碱。造模周期为3周,分别为Control组和NC组每天饮用无菌水,DSS组和DSS+NC组第一周饮用1% DSS水,第2周正常饮水,第3周1% DSS水。造模最后一周给予Control组和DSS组小鼠0.5% 羧甲基纤维素钠(CMC-Na)灌胃,DSS+NC组和NC组给予NC灌胃。造模完成后,观察小鼠结肠炎相关的疾病活动指数(DAI),HE染色进行结肠组织病理评分,qPCR检测小鼠结肠组织miR-31的表达水平,Western blot检测小鼠结肠组织炎症蛋白NF-κB和COX-2的表达情况。结果:①与DSS组相比,DSS+NC组的 DAI 显著降低(P＜0.01),结肠病理损伤明显改善;②与Control组相比,DSS组小鼠结肠组织miR-31表达显著升高(P＜0.01),DSS+NC组miR-31的表达水平显著低于DSS组(P＜0.05);③与DSS组相比,DSS+NC组中的炎症蛋白NF-κB和COX-2表达水平显著下降(P＜0.05)。结论:氯化两面针碱对DSS诱导的小鼠溃疡性结肠炎有明显的治疗作用,其抗炎机制与下调miR-31的表达有关。     

广西两面针野生种质资源调查研究

采用实地调查和走访调查相结合的方法对两面针在广西的野生种质资源情况进行调查。结果表明:广西民间使用两面针药材的基源植物有18种(含变种)。正品两面针有2个变种,原变种和毛两面针,原变种下又分为3个类型。两面针的植物形态和群落特征与生长的地形地貌有一定的相关性,原变种类型一通常生于丘陵地区,原变种类型二、类型三和毛两面针通常生于石山地区,各变种和类型的形态特征主要区别在叶片质地和植株的被毛情况。两面针生长的群落结构乔木层构成通常比较单一,灌木层、草本层相对复杂。由于生境破坏和不合理采收,广西两面针分布面积正逐年减小,经调查后估算,总蕴藏量(干重)约为2600t,资源短缺十分明显。建议采取各种积极的办法保护两面针野生种质资源,保证两面针的可持续利用。     

大理翠雀中的新二萜生物碱

从大理翠雀根中分到五个二萜生物碱成分,其中两个成分分别鉴定为methylly-caconitine(3)和delsemine(4)。另三个成分为新二萜生物碱,命名为大理翠雀碱甲(talitine A)、大理翠雀碱乙(talitine B)及大理翠雀碱丙(talitine C)。经质谱、红外光谱、核磁共振氢谱、核磁共振碳谱等解析,碱乙和碱丙的化学结构分别为(1)和(2),碱甲的结构另文报告。     

滇产两面针中抗肿瘤活性生物碱成分研究

从滇产两面针的干燥根中分离得到12个化合物,通过其一维或二维核磁共振谱、质谱和理化性质的解析并结合文献鉴定了它们的结构,分别为9-去甲氧基两面针碱(1)、8-dehydroxyl-buesgenine(2)、6β-hydroxymenthyldihydronitidine(3)、花椒木精(4)、rhoifoline B(5)、两面针碱(6)、白屈菜红碱(7)、博落回碱(8)、白鲜碱(9)、γ-崖椒碱(10)、茵芋碱(11)和鹅掌楸碱(12)。其中,化合物1和2为新结构化合物。通过MTT法,首次评价了化合物1～12对黑色素瘤细胞WM9增殖的抑制活性,并发现化合物3和6对WM9细胞的增殖表现出较强的活性,半数抑制浓度(IC_(50))值分别为1.936μM和0.880μM,研究结果为抗肿瘤药物候选药物分子的发现提供了科学依据。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.