长舟马先蒿化学成分研究

为了进一步研究玄参科长舟马先蒿的化学成分,我们从其全草的乙醇提取物中分离得到1个新环烯醚萜苷和12个已知化合物。根据波谱数据(1D,2D-NMR,HSQC,HMBC,ROESY,MS)分别鉴定为gardoside methylester(1)、7-O-acetylgardoside methyl ester(2)、verbascoside(3)、leucosceptoside A(4)、jionoside D(5)、martynoside(6)、2″-O-acetylmartynoside(7)、uridine(8)、adenosine(9)、benzyl alcohol-O-β-D-xylopyranosyl-(1→2)-β-D-gluco-pyranoside(10)、2-phenylethyl O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside(11)、apigenin(12)、lariciresinol-4′-O-β-D-glucopyranoside(13),其中7-O-acetylgardoside methyl ester(2)为一个新化合物。     

短瓣花中的微量新环肽成分

从中国民间草药短瓣花（Brachystemma calycinum D.Don)干燥根的乙醇提取物中分离得到4个新的微量环八肽,命名为短瓣花环肽A、B、C和D。经光谱分析鉴定。它们的结构分别为cyclo(Pro^1-Phe-Leu-Ala^1-Thr-Pro^2-Ala^2-Gly)(1)、cyclo(Pro^1-Ala-Phe-Trp-Asp-Pro^2-Leu-Gly)(2)、cyclo(Pro^1-Ⅱe-Gly-Pro^2-Val-Ala^1-Ala^2-Tyr)(3)和cyclo(Pro-OMet-Trp-Ⅱe-Gly-Ala-Leu-Asp)(4)。     

绿槽枝衣的化学成分

从地衣绿槽枝衣( Sulcaria virens) 中分离得到一个新的亚油酸异丙叉衍生物, 通过波谱学方法包括2D-NMR 确定其化学结构为: 9, 10-O-异丙叉基- (12 Z)-十八碳烯酸(1) 。同时还得到其它12 个已知化合物:( 9 Z, 12 Z )-十八碳二烯酸(2), 扁枝衣二酸(3), ( R ) -松萝酸(4), 枕酸甲酯( 5), 黑茶渍素(6) , virensic acid ( 7), abieslactone (8), 3α-羟基羊毛甾-7, 24-二烯-26, 23 R-内酯(9), 蒲公英赛醇(10 ), 蒲公英赛酮 ( 11 ), (22 E , 24 R )-5α, 8α-过氧麦角甾-6, 22-二烯-3β-醇(12) 和2, 2′-四氢角鲨烯(13)。     

Sceletium tortuosum的化学成分研究

为研究南非传统药用植物Sceletium tortuosum的化学成分,采用溶剂法对其地上部分进行提取和萃取,通过多种柱色谱、重结晶及高效液相色谱等方法进行系统地纯化分离,利用理化性质并结合现代分析方法鉴定化合物结构。从S.tortuosum乙酸乙酯部位中分离得到11个化合物,鉴定为3′,4′-dimethoxy[1,1′-biphenyl]-4-ol(1)、N-(4-hydroxyphenethyl)isobutyramide(2)、4-乙酰苯酚(3)、吲哚-3-甲醛(4)、7-酮-豆甾醇(5)、7-酮基-β-谷甾醇(6)、loliolide(7)、3,5,6-trihydroxy-7-megastigmen-9-one(8)、去甲基丁香色原酮(9)、cyclo(L-Pro-L-Ala)(10)、N-trans-feruloyl-3-methyldopamine(11)。化合物1～11均为首次从该属植物中分离得到,其中化合物1和2为新天然产物。     

Two New Triterpenes from the Orchid Pholidota yunnanensis Rolfe

Two novel triterpenes (1 and 2) were isolated from the orchid Pholidota yunnanensis Rolfe.Using chemical and spectral analyses (UV, IR, MS, 1D-NMR and 2D-NMR), these two triterpenes were established as 25-methylenecyclopholidonyl p-hydroxy-trans-cinnamate (1; named pholidotine A) and 25methylenecyclopholidonyl p-hydroxy-cis-cinnamate (2; named pholidotine B).     

仙茅苷丙--仙茅根茎的新酚苷成分

从仙茅(Curculigo orchioides Gaertn.)根茎中分离得到4个化合物,分别为curculigoside(1)、curculigoside B(2)、curculigoside C(3)和2,6-dimethoxyl benzoic acid(4).其中,化合物3为一个新的酚苷类成分,命名为仙毛苷丙,用现代波谱方法(1H-NMR、13C-NMR、2D-NMR和ESI-MS)鉴定其化学结构为5-羟基-2-O-β-D-吡喃葡萄糖基苄基-3′-羟基-2′,6′-二甲氧基苯甲酸酯.     

泽漆的化学成分研究

采用多种分离材料包括硅胶、Sephadex LH-20和反相RP-18从泽漆的95%乙醇提取物的正丁醇部位分离得到12个化合物,经过波谱学方法分别鉴定为Helioscopin D(1),Isofraxidin(2),Swertiamarin(3),13-Car-boxyblumenol C(4),4,4′-dimethoxy-3′-hydroxy-7,9′,7′9-diepoxyligan-3-O-β-D-glucopyranoside(5),(+)-Syringa-resinol-4′-O-β-D-glucoside(6),2S,3R-2,3-Dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-benzofuran-5-(trans)propen-1-ol-3-O-β-glucoside(7),Quinquenin L1(8),(6R,9S)-megastigman-3-one-4,7-ene-9-ol-9-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside(9),2R,3R-2,3-Dihydro-2-(4′-hydroxy-3′-methoxyphenyl)-3-(glucosyloxymethyl)-7-methoxy-benzofuran-5-propanol(dihydrodehydrodiconiferyl-alcohol-β-D-glucoside)(10),Thy-midine(11),和Deoxyuridine(12)。其中化合物1为一个降倍半萜类新化合物,其余化合物从该种中首次分离。     

墨西哥落羽杉的化学成分

从墨西哥落羽杉(Taxodium mucronatum)枝叶中首次分离得到10个化合物,通过MS与NMR等方法将它们分别鉴定为quercetin 3′-methoxy-3-O-β-D-galactopyranoside(1),quercetin 3′-methoxy-3-O-β-D-arabinopyrano-side(2),quercetin 3′-methoxy-3-O-α-L-arabinofuranoside(3),quercetin(4),avicularin(5),quercetin 3-O-β-D-ga-lactopyranoside(6),(7′S,8′R)-4,7′-epoxy-3,3′-dimethoxy-4,9,3′,4′,9′-lignanepentol-4′-O-β-D-glucopyranoside(7),(7′S,8′S)-3,3′-dimethoxy-9,4′,9′-trihydroxy-4,8′-oxyneolignan-7′-O-β-D-glucopyranside(8),methyl shikimate(9)和β-sitosterol(10)。     

红树植物内生真菌Penicillium sp.中两个甾体化合物的研究

从红树植物内生真菌Penicillium sp.的发酵液中分离纯化了两个甾体类化合物,通过各种波谱实验(1D-NMR,2D-NMR,ESI-MS)确定为:麦角甾-4,6,8(14),22-四烯-3-酮(1)和麦角甾-5,7,22-三烯-3-醇(2),1对于3α-HSD脱氢酶在250μm浓度下有较弱的活性。     

类芒齿黄芪地下部分化学成分研究

为了解类芒齿黄芪( Astragalus camptodontoides)主要化学成分,从其地下部分甲醇提取物的乙酸乙酯部位分离出19个单体化合物,通过现代波谱分析及理化性质等手段分别鉴定为异补骨脂黄酮(1),4′-hydroxy-isolonchocarpin (2),5-去氧山豆根黄酮(3),shinflavanone (4),khonklonginols H (5),4′-O-methylpreglabridin (6),3′-hydroxy-4′-O-methylglabridin (7),4′-O-methylglabridin (8),8-prenyl-phaseollinisoflavan (9),xambioona (10),光甘草酚(11),粗毛甘草素H (12),methylnissolin (13),邻苯二甲酸异丁酯(14),邻苯二甲酸丁酯异丁酯(15),β-谷甾醇(16),胡萝卜苷(17),齐墩果酸(18),(2S,3S,4R,9E)-1,3,4-trihydroxy-2-[(2′R)-2′- hydr-oxytetraco-sanoylamino]-9-octadecene (19)。化合物1~19均为首次从该植物中获得,化合物1~7为首次从黄芪属(Astraga-lus)植物中分离得到。     

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.     

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.     

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