黑刺菝葜中的甾体皂苷

从黑刺菝葜(Smitax scobinicaulis C.H.Wringh)根茎中再次分离得到2个新的甾体皂苷化合物,经理化、光谱分析及与标准样品对照,鉴定化合物Ⅲ为(25D)螺甾-5-烯-3β,17α,27-三羟基-3-O-β-D-吡喃葡萄糖-(1→4)-O-[α-L-吡喃阿拉伯糖(1→6)]-β-D-吡喃葡萄糖甙。化合物Ⅳ为(25D)螺甾-3β,17α,27-三羟基-3-O-β-D-吡喃葡萄糖-(1→4)-O-[α-L-吡喃阿拉伯糖(1→6)]-β-D-吡喃葡萄糖甙。     

传统中药漆姑草（Sagina japonica）中的C-27甾体成分

利用Diaion HP 20及硅胶柱层析进行化合物的分离,从乙酸乙酯萃取部位分离得到了4个化合物,借助多种光谱技术进行结构鉴定分别鉴定为(25R)-螺甾-5-烯-1β,3β-二醇1-O{O-α-L-鼠李吡喃糖苷-(1→2)-O-[β-D-木糖吡喃糖苷-(1→3)]1β-D-岩藻吡喃糖苷}(ophiopogonin D,1),(25R)-ruscogenin 1-O-[2-O-(乙酰基)-α-L-鼠李吡喃糖苷-(1→2)][β-D-木糖吡喃糖苷-(1→3)]-β-D-岩藻吡喃糖苷(2),(25R)-rascogenin 1-O-[3-0-(乙酰基)-α-L-鼠李吡喃糖苷-(1→2)][β-D-木糖吡喃糖苷-(1→3)]-β-D-岩藻吡喃糖苷(3),蜕皮甾酮(4).所有化合物均为首次从该植物中分得.     

一种百合甾体皂苷纯度及糖链结构核磁共振法分析

采用多种NMR分析技术,首次对百合甾体皂苷(25R,26R)-26-甲氧基螺甾烷-5-烯-3β-α-L-鼠李糖-(1→2)-[β-D-葡萄糖-(1→6)]-β-D-葡萄糖苷的1H和13C NMR信号进行了全归属,特别是应用选择性的1D TOCSY和1D NOESY核磁共振分析技术,对该化合物1中的氢谱信号严重重叠的糖链进行了详细的分析,提出了一套对甾体皂苷糖链信号进行全归属的核磁共振法.在确认其结构的基础上,建立了核磁共振法(1H NMR)测定该化合物1的纯度,给出了完整的实验条件,线性回归系数为0.9998,重复性实验RSD为0.58％,稳定性实验RSD为0.24％,操作简单、快速准确,且不需要其它对照品,是中药化学对照品纯度研究的一个有益补充.     

广西蜘蛛抱蛋中一种甾体皂甙定性定量研究

为了进一步开发和利用广西甾体药源植物奠定基础 ,对广西蜘蛛抱蛋 (Aspidistra retusa K.Y.Langet.S.Z.Huang)块茎甾体皂甙化合物进行了提取分离。在分离得化合物中含量最高的甾体皂甙化合物 4经鉴定为 :偏诺甾体四糖皂甙 ,即 pennogenin-3-β-O-β-D-glucopyranosyl[-α-L-rhamno-pyranosyl(1 -2 ) ]-α-L-rham-no-pyanosyl(1 -4 ) -α-L-rhamnopyranosyl(1 -4 )。该化合物为首次从蜘蛛抱蛋属植物中分离得到。经 HPLC测定其在广西蜘蛛抱蛋中的含量为 1 .5 95 %。     

川麦冬中的新Ｃ２７甾体甙

从百合科植物川麦冬（Ophiopogon japonicus Ker-Gawl.)块根中分离得到４个Ｃ２７甾体甙类化合物,其中两个为新化合物：ophipojaponin A(1)和Ｂ（２）。它们的结构通过波谱和化学方法鉴定为：pennogenin3-O-[２′－acety-α－L-rhamnopyranosyl(1→2)]-β－D-xylopyranosyl(1→3)-β－D-glucopyranoside(1),26-O-β－Ｄ-glucopyranosyl-(22ξ,２５Ｒ）,－３β,14α,２２ξ,26-tetrahydroxyfurost-5-ene 3-O-α－Ｌ－rhamnopyranosyl(1→2)]-β－Ｄ-xylopyrano-syl(1→3)-β－D-glucopyranoside(3)and ruscogenin 1-O-[α－L-rhamnopyranosyl(１→２）]-β－D-xy-lopyranosyl(1→3)-β－D-fucopyranoside(4)。     

拟白蘑子实体化学成分研究

从高等真菌拟白蘑(Tricholomopsis rutalis)干燥子实体的甲醇提取物中分离并鉴定了6个化合物,它们分别是软脂酸甲酯(1)、软脂酸(2)、麦角甾-5,7,22-三烯-3β-醇(3)、5α,8α-过氧化麦角甾-6,22-二烯-3β-醇(4)、麦角甾-7,22-二烯-3β,5α,6β-三醇(5)和5α,8α-过氧化麦角甾-6,22-二烯-3β-O-葡萄糖苷(6).以上化合物均为首次从拟白蘑中获得.     

虎眼万年青属植物Ornithogalum thyrsoide 的甾体皂苷及黄酮类化学成分

运用硅胶、Sephadex LH-20、ODS柱层析及半制备高效液相色谱技术对一引种虎眼万年青属植物Ornithogalum thyrsoides的化学成分进行研究,从其乙醇提取物的乙酸乙酯部分分离得到7个化合物.通过MS、NMR等波谱技术确定其结构分别为(23S,24S,25S)-23,24-dihydroxyruscogenin- 1-O-α-L-rhamnopyranosyl(1 →2)-α-L-arabinopyranoside(1),(24S,25S)-3β,24-dihydroxyspirost-5 -en- 1β-yl O-α -L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside(2),β-胡萝卜苷(3)β-谷甾醇(4),山奈酚-4′-O-β-D-吡喃葡萄糖苷(5),千层纸素A(6)和汉黄芩素(7).其中,化合物1、5～7为首次从该属植物中分离得到.体外药理活性结果显示这7个化合物对HCT-8、Bel-7402、BGC-823、A549及A2780实体瘤细胞株无明显细胞毒活性.     

滇重楼地上部分的甾体皂甙

从滇重楼Paris polyphylla Sm. var. yunnanensis (Fr.) H-M.地上部分分离得到3个甾体皂甙,经光谱测定和化学降解证明其化学结构分别为:偏诺皂甙元3O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4))-β-D-葡萄吡喃糖甙(A);孕甾-5,16-二烯-3β-醇-20-酮,3β-O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4)〕-β-D-葡萄吡喃糖甙(B);孕甾-5,16-二烯-3β-醇-20-酮,3β-O-α-L-鼠李吡喃糖基(1→2)〔α-L-鼠李吡喃糖基(1→4)-α-L-鼠李吡喃糖基(1→4)〕-β-D-葡萄吡喃糖甙(C)。甙A、B和C在滇重楼根中尚未发现,甙C系首次从重楼属植物中获得,而甙A具有止血的活性。     

牛蒡根化学成分研究

从牛蒡根95%乙醇提取液中分离得到6个化合物,通过理化性质和波谱学方法鉴定出5个化合物分别为牛蒡子苷(1)、山柰酚(2)、腺苷(3)、羟基茄碱(4)、spirosl-3-O-α-L-rhamnopyrannosyl-(1→4)-O-β-D-galactopyr-anosyl(5),其中化合物2～5为首次从该种植物中分离得到。     

茶褐牛肝菌化学成分研究

为了解茶褐牛肝菌(Neoboletus brunneissimus)的化学成分,共分离鉴定了18个化合物,经理化性质和波谱分析,分别鉴定为5α,8α-环二氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(1)、5α,8α-环二氧-(22E,24R)-麦角甾-6,9(11),22-三烯-3β-醇(2)、(22E,24R)-麦角甾-7,22-二烯-3β-醇(3)、(24S)-麦角甾-7-烯-3β-醇(4)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(5)、(24S)-乙基胆甾烯-7-烯-3β,5α,6β-三醇(6),(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β,9α-四烯(7)、(22E,24R)-麦角甾-5,7,2-三烯-3β-醇(8)、3β-O-吡喃葡萄糖基-5α,8α-环二氧-(22E,24R)-麦角-6,22-二烯(9)、富马酸单甲酯(10)、富马酸(11)、琥珀酸(12)、反-2-癸烯二酸(13)、烟酸(14)、烟酰胺(15)、莽草酸(16)、亚油酸-α-甘油酯(17)和1-O-吡喃葡萄糖基-(2S,3R,4E,8E,2′R)-2-N-(2′-羟基棕榈酰)-9-甲基-4,8-鞘氨醇(18)。以上化合物均为首次从茶褐牛肝菌中分离得到,其中化合物6、9、13和17为首次从牛肝菌科高等真菌中分离得到。     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细