细叶香茶菜中两个新的对映-贝壳杉烷二萜化合物

从云南中甸产细叶香茶菜(Isodon tenuifolia (W. W. Smith) Kudo)的地上部分分离得到6个化合物, 它们的结构通过波谱方法得到鉴定。其中化合物1和2为新的对映-贝壳杉烷二萜化合物, 即细叶香茶菜甲素(3β,6α,15β-trihydroxy-1α,7β-diacetoxy-11β,16β-epoxy-ent-kaurane) (1) 和细叶香茶菜乙素(1α,6α,11β-trihydroxy-3β,7β-diacetoxy-ent-kaur-16-en-15-one) (2)。     

细锥香茶菜二萜的研究

从四川省峨眉山产细锥香茶菜[Rabdosia coetsa(Buch-Ham,ex,D.Don)Hara]乙醚抽提物中分得了一个新二萜化合物,命名为细锥香茶菜丁素(rabdocoetsin D),其结构经各项波谱数据和化学证据确定为1α,7β-二羟基-11β-乙酰氧基-对映-7β,20-环氧-贝壳杉-16-烯-15-酮(1)。另外还分离到3个已知二萜,细锥香茶菜乙素(rabdocoetsin B)、细锥香茶菜丙素(rabdocoetsin C)、瘿花香茶菜甲素(rosthorin A)。     

近无毛灰岩香茶菜的研究

从云南省会泽县产近无毛灰岩香茶莱〔Rabdosia calcicola (Hand. -Mazz.) Hara var. subculva (Hand. -Mazz.) C. Y. Wu et H. W. Li〕叶中分得两个二萜化合物,一个为新化合物,命名为灰岩香茶菜甲素(calcieolin A),另一个为已知化合物维西香茶菜甲素(weisiensin A),经各项光谱数据和化学反应确定,灰岩香茶菜甲素为3β-羟基-1α,6α,7β,11β-四乙酰氧基-对映-贝壳杉-16-烯-15-酮(1);维西香茶菜甲素结构应为3β,6α-二羟基-1α,7β,11β-三乙酰氧基-对映—贝壳杉-16-烯-15酮(2)。     

细叶香茶菜中两个新的对映—贝壳杉烷二萜化合物

从云南中甸产细叶香茶菜 (Isodontenuifolia (W .W .Smith)Kudo)的地上部分分离得到 6个化合物 ,它们的结构通过波谱方法得到鉴定。其中化合物 1和 2为新的对映_贝壳杉烷二萜化合物 ,即细叶香茶菜甲素 (3β ,6α ,15 β_trihydroxy_1α ,7β_diacetoxy_11β ,16 β_epoxy_ent_kaurane) (1)和细叶香茶菜乙素 (1α,6α ,11β_trihydroxy_3β,7β_diacetoxy_ent_kaur_16_en_15_one) (2 )。     

贵州紫云产黄花香茶菜的化学成分研究

采用甲醇回流提取和硅胶柱层析方法,从紫云产黄花香茶菜中分离得到6个化合物,结合1H-NMR、13C-NMR数据及文献资料鉴定为黄花香茶菜乙素(Ⅰ)、黄花香茶菜丁素(Ⅱ)、大萼变型香茶菜甲素(Ⅲ)、3β-Hydroxy-18α,19α-urs-20-en-28-oic acid(Ⅳ)、齐墩果酸(Ⅴ)和熊果酸(Ⅵ)。其中化合物Ⅳ为首次从该属植物中分离得到。     

胶粘香茶菜的化学成分

胶粘香茶菜(I.glutinosa C.Y.Wu et H.W.Li),为唇形科(Labiatae)香茶菜属(Isodon)植物,产于云南西北部及四川西南部,海拔2000-2300m的河谷两岸山坡砾石地或干燥灌丛中。从云南丽江产胶粘香茶菜中,已分离和鉴定了2种不同结构类型的二萜成分,为进一步比较不同地区产该种植物在化学成分上的差异,我们对大理苍山产胶粘香茶菜进行了研究。由2316g茎叶得149g提取物,然后经硅胶柱层析,依次用氯仿、氯仿-乙酸乙脂(8:2→4:6),乙酸乙酯梯度洗脱,除分离和鉴定了β-谷甾醇(β-sitosterol),胡萝卜甙(β-sitosterol-D-glucoside),乌苏酸(ursolic acid),山植酸(crataegolic acid)和丁二酸(butanedioic acid)外,还得到迄今从香茶菜属植物中分离得到的氧化程度最低的一个对映-贝壳杉烯型四环二萜类化合物:对映-贝壳杉烷-16β,17-二醇(ent—Kauran-16β,17-diol)(1)(2.8g)和具有抑制革兰氏阳性菌生长活性的松香烷(abitane)型二萜pisiferic acid(2)(1.2g)。pisiferic acid(2)系首次从该属植物中得到。     

腺花香茶菜中的对映-贝壳杉烯类二萜化合物

从昆明产腺花香茶菜(Isodon adenanthus (Diels) Kudo)的地上部分分离到8个化合物,通过波谱分析鉴定,化合物1-3为新的对映-贝壳杉烯类二萜化合物,命名为腺花香茶菜素N、0和P;4个已知二萜为白叶香茶菜戊素(4)、无毛狭叶香茶菜素C(5)、腺花香茶菜甲素(6)和白叶香茶菜乙素(7),同时得到一个高度不饱和脂肪酸9,16-二羰基-10,12,14-三烯-十八碳酸(8)。根据ROESY波谱,对化合物4的结构进行了修正。化合物1对K562细胞显示出明显的细胞毒活性(IC50=0．45μg／mL)。     

蓝萼香茶菜化学成分的研究

从长白山产蓝萼香茶菜[Ralxlosia Japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara]地上全草中分得13个化合物,根据理化常数和波谱学数据分别鉴定为：木栓酮(1)、β-谷淄醇(2)、乙酰熊果酸(3)、齐墩果酸(4)、熊果酸(5)、蓝萼香茶菜素A(6)、2α-羟基熊果酸(7)、2α,3α-二羟基熊果酸(8)、ent-7β,14α,15三羟基-16-贝壳杉烯-3-酮(9)、山香三萜二烯酸(10)、槲皮素(11)、β-谷甾醇3-O-β-D-吡喃葡萄糖苷(12)和果糖(13)。化合物8为第一次从该植物中分得,化合物10为第一次从该属植物中分得。     

白叶香茶菜的化学成分

从白叶香茶菜(Rabdosia leucophylla(Dunn)Hara)地上部分的乙醇提取物中分离出5个化合物,根据其波谱分析并结合化学方法分别鉴定为:白叶香茶菜戊素(1)、白叶香茶菜己素(2)、信阳冬凌草甲素(3)、maslinic acid(4)和胡萝卜甙(5)。其中1和2为新化合物,2的结构还通过X-单晶衍射得到证实。     

腺花香茶菜中的对映-贝壳杉烯类二萜化合物

从昆明产腺花香茶菜(Isodon adenanthus(Diels)Kudo)的地上部分分离到8个化合物,通过波谱分析鉴定,化合物1～3为新的对映-贝壳杉烯类二萜化合物,命名为腺花香茶菜素N、O和P;4个已知二萜为白叶香茶菜戊素(4)、无毛狭叶香茶菜素C(5)、腺花香茶菜甲素(6)和白叶香茶菜乙素(7),同时得到一个高度不饱和脂肪酸9,16-二羰基-10,12,14-三烯-十八碳酸(8).根据ROESY波谱,对化合物4的结构进行了修正.化合物1对K562细胞显示出明显的细胞毒活性(IC50=0.45 μg/mL).     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various