沉水植物苦草化学成分研究

通过使用乙酸乙酯溶剂对沉水植物苦草（Vallisneria natans）全草进行超声连续提取,采用硅胶柱色谱法和光谱分析法分离和鉴定化学成分。从苦草中分离到6个化合物：6,10,14-三甲基-2-十五酮（1）、棕榈酸（2）、4,22-二烯-3β-豆甾酮（3）、5α,豆甾烷-3,6-二酮（4）、硬脂酸（5）、棕榈酸乙酯（6）。化合物1—6为首次从该植物中发现。     

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)。     

白木香内生真菌Botryosphae riarhodina A13固体发酵产物的分离鉴定北大核心CSCD

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。     

三花枪刀药中萜类和甾体成分研究

采用正相硅胶和Sephadex LH-20等柱层析及半制备HPLC色谱法,从三花枪刀药的95%乙醇提取物中分离到15个化合物,运用现代波谱技术分别鉴定为6-羟基-9,13环大柱烷-4,9(13)-二烯-3-酮(1)、3β-羟基-β-紫罗酮(2)、3α-羟基-大柱烷-4,7E二烯-9-酮(3)、3α-羟基-5α,6α-环氧-7E-大柱烷-7-烯-9-酮(4)、黑麦草内酯(5)、pisiferadinol(6)、24-methylenecycloartanol(7)、α-香树脂醇(8)、3β-羟基-乌苏烷-11-烯-28,13β-内酯(9)、羽扇豆醇(10)、achilleol A(11)、6β-甲氧基麦角甾烷-7,22E-二烯-3β,5α-二醇(12)、6β-乙氧基麦角甾烷-7,22E-二烯-3β,5α-二醇(13)、豆甾烷-4-烯-3,6-二酮(14)、豆甾烷-4,22E-二烯-3,6-二酮(15)。化合物1为新天然产物,化合物2~15为首次从该植物中分离得到。化合物6、12、15对人乳腺癌MDA-MB-468、人胃癌AGS、人结肠癌HCT116、人宫颈癌Hela和人乳腺癌MDA-MB-231肿瘤细胞株具有显著的细胞毒活性。     

纸莎草的化学成分研究

采用正相硅胶柱、Sephadex LH-20、高效液相色谱、MCI等色谱方法从纸莎草全株中分离得到19个化合物,采用1D、2D NMR、质谱等技术鉴定化合物的结构,分别鉴定为:α-香附酮(1)、香附酸(2)、广藿香烯酮(3)、4,5,6,7,8,8a-六氢-3,4,8,8-四甲基-1H-3a, 7-亚甲基甘菊环-4-醇甲酸酯(4)、(6S)4-烯-广藿香醇(5)、桉烷双烯萜(6)、β-谷甾醇(7)、(24R)-24-乙基胆甾烷-4-烯-3,6-二酮(8)、豆甾-4,22-二烯-3-酮(9)、(24R)-24-乙基-5α-胆甾烷-3β,5-二醇-6-酮(10)、豆甾醇(11)、豆甾-4-烯-6β-醇-3-酮(12)、豆甾-3,6-二酮(13)、豆甾-4-烯-3-酮(14)、顺,顺-9,12-十八(碳)二烯酸(15)、棕榈酸甲酯(16)、正二十八烷酸(17)、3-壬基环氧乙烷-2-甲酸甲酯(18)、9,10-二氯-十八烷酸甲酯(19)。所有化合物均为首次从纸莎草中分离得到。化合物1、2、3、5、6、10、12、13、16能够明显抑制TNF-α所诱导的质粒转染的HEK293T细胞中NF-κB信号通路的激活,IC_(50)值在34.96～98.23μM之间。     

中药脱皮马勃的化学成分研究

为了研究脱皮马勃Lasiosphaera fenzliiReich.子实体的化学成分,通过石油醚索氏提取、硅胶柱色谱、葡聚糖凝胶色谱、重结晶分离纯化,从脱皮马勃子实体中分离得到了6个化合物,通过波谱数据分析分别鉴定它们为(22E,24R)-麦角甾-7,22-二烯-3β-醇(1),麦角甾-7,22-二烯-3,6-二酮(2),麦角甾-5α,8α-环二氧-6,22-二烯-3β-醇(3),麦角甾-5,7,22-三烯-3-醇(4),麦角甾-7,22-二烯-3-酮(5),硬脂酸(6),其中化合物1~3、6是首次从脱皮马勃中分离得到。     

齿菌子实体的化学成分研究

利用硅胶柱层析和Sephadex LH-20凝胶柱层析分离手段,从高等真菌齿菌(Hydnellumsp.No.2)子实体的甲醇提取物中分离鉴定了7个化合物,经现代光谱学技术鉴定为麦角甾-7,22-二烯-3β-醇(1)、5α,8α-过氧麦角甾-6,22-二烯-3β-醇(2)、(22E,24R)-3β-羟基-24-甲基胆甾-5,22-二烯-7-酮(3)、对羟基苯甲酸甲酯(4)、(24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(5)、Tuberoside(6)和脑苷脂B(7)。化合物4、5、6、7为该属首次报道。     

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。     

海洋真菌Fusarium sp.次级代谢产物的研究

采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、开放ODS柱色谱以及HPLC等方法从海洋真菌Fusarium sp.的菌丝体中分离得到5个化合物,通过波谱数据及理化性质分别鉴定为3β,15β-二羟基-(22E,24R)-麦角甾-5,8(14),22-三烯-7-酮(1)、3β,5α,9α-三羟基-(22E,24R)-麦角甾-7,22-二烯-6-酮(2)、(22E,24R)-麦角甾-7,22-二烯-3β,5α,6β-三醇(3)、5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(4)和丁二酸(5).其中化合物1和2首次从该属真菌中分离得到.     

赤芝孢子化学成分研究

从赤芝(Gunoderm lucidum )孢子脂溶部分分到六个甾体化合物,根据化学及光谱解析等方法鉴定为麦角甾-7,22-二烯-3β,5α,6β-三醇(Ⅰ),麦角甾-7,22-二烯-3β,5α,6α-三醇(Ⅱ),麦角甾-7,9,22-三烯-3β,5α,6α-三醇(Ⅲ),麦角甾醇棕榈酸酯(Ⅳ),麦角甾-4,6,8(14),22-四烯-(3)酮(Ⅴ),以及麦角甾醇(Ⅵ)。     

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     

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.