Two New Triterpenoid Saponins from Akebia quinata （Thunb.） Decne.

Two new triterpenoid saponins, hederagenin 3-O-α-L-arabinopyranosyl-（1→〉2）-α-L-arabinopyranoside named akeboside La （compound 1）, oleanolic acid 3-O-α-L-arabinopyranosyl-（1→〉2）-β-D-glucopyranoside named akeboside Lb （compound 2）, along with five known saponins, oleanolic acid 3-O-α-L-rhamnopyranosyl-（1→〉2）-α-L- arabinopyranoside （compound 3）, hederagenin 3-O-α-L-rhamnopyranosyl-（1→〉2）-α-L-arabinopyranoside （compound 4）, oleanolic acid 3-O-β-D-xylopyranosyl-（1→〉3）-α-L-rhamnopyranosyl-（1→〉2）-α-L-arabinopyranoside （compound 5）, 3-O-α-L-rhamnopyranosyl-（1→〉2）-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-（1→〉4）-α-D- glucopyranosyl-（1→〉6）-β-D-glucopyranoside （compound 6）, 3-O-α-L-rhamnopyranosyl-（1→〉2）-α-L-arabinopyranosyl hederagenin 28-α-L-rhamnopyranosyl-（1→〉4）-β-D-glucopyranosyl-（1→〉6）-β-D-glucopyranoside （compound 7） were isolated from the n-butanol part of the 80% ethanol extracts of the dried stems of Akebia quinata （Thunb.） Decne. Compound 5 was isolated from plants of genus Akebia for the first time. The structures were elucidated on the basis of physicochemical properties and spectral data.     

Glycosides from Roots of Cyathula officinalis Kuan

To search for new and bioactive compounds from traditional Chinese medicines, a new glycoside,3-O-[α-L-rhamnopyranosyl-(l-→3)-(n-butyl-β-D-glucopyranosiduronate)]-28-O-β-D-glucopyranosyl oleanolic acid (1), was isolated from the roots of Cyathula officinalis Kuan, along with 3-O-(methyl-β-D-glucopyranosiduronate)-28-O-β-D-glucopyranosyl oleanolic acid (2), 3-O-β-D-glucopyranosyl oleanolic acid (3), 3-O-β-D-glucuronopyranosyl oleanolic acid (4), 3-O-[α-L-rhamnopyranosyl-(l→3)-(β-D-glucuronopyranosyl)] oleanolic acid (5), 3-O-(β-D-glucuronopyranosyl)-28-O-β-D-glucopyranosyl oleanolic acid (6), 28-O-β-D-glucuronopyranosyl-(1→4)-β-D-glucopyranosyl hederagenin (7), 3-O-[α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranosyl]-28-O-β-D-glucopyranosyl oleanolic acid (8), and 3-O-[β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranosyl]-28-O-β-D-glucopyranosyl oleanolic acid (9). The structures of these compounds were determined based on spectral and chemical evidence. The 50 per cent growth-inhibiting (GI50) of compounds 1 and 5 against MDA-MB-231(a human breast cancer cell line) was 3.44 × 10-4 and 4.66 × 10-4 mol/L, respectively.     

白花刺参中两个新三萜皂甙

从著名藏药白花刺参（Morina nepalensis var.alba Hand.-Mazz)的水溶性部分分离到2个新三萜皂甙-刺参甙K（1）和刺参甙L（2）,以及一个已知三萜皂甙mazusaponinⅠ（3)。应用波谱和化学方法,刺参甙K和刺参甙L的结构分别鉴定为3-O-α-L-arabinopyranosyl-（1→）-β-D-xylopyranosyl siaresinolic acid(1)和3-O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl siaresinolic acid28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside(2)。     

羽叶点地梅的化学成分

首次从中国特有的单属单种植物羽叶点地梅(Pomatosace filicula Maxim.)分离到13个化合物.应用波谱技术(尤其是2D-NMR:TOCSY,HMQC,HMBC)及化学方法鉴定了它们的结构.其中,化合物3为一新的三萜皂苷类化合物,其结构为13β,28-epoxy-16-oleananone-3-O-[α-L-rhamnopyranosyl-(1→6)-O-β-D-glucopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl-(1→2)]-β-D-glucopyranoside,命名为羽叶点地梅甲苷(pomatoside A).     

西南远志中皂苷类成分的分离与鉴定

采用乙醇回流提取,通过硅胶柱、HPD100大孔树脂、Sephadex LH-20、半制备HPLC分离方法,运用现代谱学方法从西南远志中分离并鉴定了4个齐墩果酸型皂苷类化合物,均为顺反异构体,所用实验方法并不能有效分开。他们分别是:(E/Z)-PolygalasaponinXLIV(1),3-O-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyr-anosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-[6-O-acetyl-β-D-glucopyranosyl-(1→3)]-{4-O-([E/Z)-3,4-dimethoxycinnamoyl}]-β-D-fucopyranosyl ester(2),(E/Z)-PolygalasaponinXXX(3)(,E/Z)-senegasaponin C(4),均为首次从该种植物中分离得到。     

金铁锁的新三萜皂甙

从金铁锁（Psammosilene tunicoides W.C.Wu et C.Y.Wu)根部分离得到5个齐墩果烷型五环三萜皂苷,它们的结构通过波谱和化学方法分别鉴定为：3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin(1),3-O-β-D-galactopyranosyl-(1→2)-[β-D-galactopyranosyl-(1→3)-β-D-glucuronopyranosyl-gypsogenin(2),3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyra-nosyl-gypsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside(LobatosideI,3),3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)-β-D-glucuronopyranosylgypsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranosyl(1→2)-β-D-fucopyranoside(4),3-O-β-D-galactopyranosyl-(1→）-β-D-glucuro-nopyranosyl-grpsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-6-O-acetylglucopyranosyl-(1→3)-β-D-glucuro-nopyranosyl-gypsogenin-28-O-β-D-xylopyranosyl-(1→4)-[β-D-6-O-acetylglucopyranosyl-(1→3)]-α-L-rh-amnopyranosyl(1→2)-β-D-fucopyranoside(5),其中5为新化合物,1和2为首次从自然界中分离得到。     

羽叶点地梅的化学成分

首次从中国特有的单属单种植物羽叶点地梅(Pomatosace filicula Maxim．)分离到13个化合物。应用波谱技术(尤其是2D—NMR：TOCSY,HMQC,HMBC)及化学方法鉴定了它们的结构。其中,化合物3为一新的三萜皂苷类化合物,其结构为13β,28-epoxy-16-oleananone-3-O-[α-L-rhamnopyranosyl-(1→6)-O-β-D-glucopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl-(1→2)]-β-D-glucopyranoside,命名为羽叶点地梅甲苷(pomatoside A)。     

秦岭产珠子参根茎的皂甙成分

从陕西省秦岭产珠子参（Panax japonicus C.A.Meyer var.major(Burk.)Wu et Feng)的根茎中分离得到7个皂甙,经13CNMR快速原子轰击质谱（FAB－MS）等测定,并与标准品对照,其中6个分别鉴定为已知竹节参甙（chikusetsusa ponin)V(即人参甙Rg),IVa,齐墩果酸－28－O－β－D－葡萄哟喃糖甙（oleanolic acid 28-O-β－glucopyranoside),人参甙（ginsenoside)Rg2,Re以及三七甙（notoginsenoside)R2.另一皂甙为竹节参甙IV,甲酯（chikusetsusa ponin IVa methyl ester),即齐墩果酸－（3－O－β－D－葡萄吡喃糖醛酸甲酯）－28－O－β－D－葡萄吡喃糖甙（oleanolie acid-(3-O-β－D－glucorunopyranosyl-methylate)-28-O-β-D-glucopyranoside),系首次从植物中分离得到,对陕西省秦岭产和云南丽江产的珠子参根茎的皂甙成分进行了比较和讨论。     

秦岭产珠子参根茎的皂甙成分

从陕西省秦岭产珠子参（Panax japonicus C.A.Meyer var.major(Burk.)Wu et Feng)的根茎中分离得到7个皂甙,经13CNMR快速原子轰击质谱（FAB－MS）等测定,并与标准品对照,其中6个分别鉴定为已知竹节参甙（chikusetsusa ponin)V(即人参甙Rg),IVa,齐墩果酸－28－O－β－D－葡萄哟喃糖甙（oleanolic acid 28-O-β－glucopyranoside),人参甙（ginsenoside)Rg2,Re以及三七甙（notoginsenoside)R2.另一皂甙为竹节参甙IV,甲酯（chikusetsusa ponin IVa methyl ester),即齐墩果酸－（3－O－β－D－葡萄吡喃糖醛酸甲酯）－28－O－β－D－葡萄吡喃糖甙（oleanolie acid-(3-O-β－D－glucorunopyranosyl-methylate)-28-O-β-D-glucopyranoside),系首次从植物中分离得到,对陕西省秦岭产和云南丽江产的珠子参根茎的皂甙成分进行了比较和讨论。     

水团花药材对照品的研究

采用柱色谱分离法对水团花的根进行了单体化合物的分离,并对所分得的Quinovic acid-3β-O-β-D-glucopyranosyl-（28→1）-β-D-glucopyranosyl ester和Noreugenin进行了结构确证;结合该药材的药理活性研究,以此两种成分分析为指标,确立了药材的对照品.     

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.