黄花三宝木枝条的化学成分研究II

为了解黄花三宝木(Trigonostemon lutescens Y.T.Chang et J.Y.Liang)的化学成分,采用硅胶柱色谱与Sephadex LH-20凝胶柱色谱从黄花三宝木乙醇提取物的石油醚与正丁醇萃取部分共分离11个化合物,其结构分别鉴定为:ent-kaurane-3β,16β-diol(1)、(3R,6R,7E)-3-hydroxy-4,7-megastigmadien-9-one(2)、palmarumycin JC2(3)、(±)-3-(3,4,5-trimethoxyphenyl)-1,2-propanediol(4)、赤式-愈创木基甘油-β-O-4′-松柏基醚(5)、苏式-愈创木基甘油-β-O-4′-松柏基醚(6)、3-hydroxymethyl-5-(3-hydroxypropyl)-7-methoxy-2-{3-methoxy-4-[1-(3,4-dimethoxybenzyl)-2-hydroxyethyl]phenyl}-2,3-dihydrobenzofuran(7)、ancistrocline(8)、hamatine(9)、东莨菪苷(10)和紫丁香苷(11)。上述化合物均为首次从该种植物中分离得到,其中化合物1、3~11为首次从该属植物中分离得到。     

肋果茶中的萜类化学成分研究

从肋果茶(Sladenia celastrifolia)95％乙醇提取物的乙酸乙酯部位中分离得到15个萜类化合物,经波谱学方法分别鉴定为sladeniafolin A(1),grasshopper ketone (2),(3S,5R,6S,7E,9R) -7-megastigmene-3,6,9-triol (3),hedytriol (4),(3S,5R,6R,7E,9R) -3,5,6,9-tetrahydroxy-7-megastigmene(5),1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′-trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien -2-one (6),2α,3α,19α,23-tetrahydroxyurs-12-en-28-oic acid (7),2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid(8),pomolic acid(9),3-O-acetyl pomolic acid(10),ursaldehyde (11),camarolide (12),3β-hydroxyurs-11-en-13β(28) -olide (13),3β-hydroxy -11α,12α-epoxy-urs-13β,28-olide (14)和28-0-β-D-glucopyranosyl euscaphic acid (15).以上化合物均首次从该植物中分离得到,其中1为新的C9裂环烯醚萜.     

天名精萜类成分及其抗肿瘤活性研究

为进一步研究天名精植物的化学成分及其抗肿瘤活性。本研究采用多种色谱技术(硅胶、RP-C_(18)、Sephadex LH-20以及制备型HPLC等)对天名精石油醚部位的化学成分展开了系统研究,从中分离得到9个萜类化合物。根据理化性质、光谱数据和结合参考文献鉴定化合物为:8-hydroxy-9,10-diisobutyryloxy-thymol(1)、8,10-dihydroxy-9-isobutyryloxy-thymol(2)、9-hydroxy-thymol(3)、10-hydroxy-8,9-dioxy-isopropylidene-thymol(4)、8-hydroxy-9,10-dioxy-isopropylidene-thymol(5)、(3R,6R,7E)-3-hydroxy-4,7-megastigmadien-9-one(6)、blumenol A(7)、4-(3-oxobut-l-enylidene)-3,5,5-trimethylcyclohex-2-en-l-one(8)、loliolide(9)。以上所有化合物均为首次从该种植物分离得到,其中化合物3～8为首次从该属植物分离得到。这些化合物在40μM浓度下对白血病(HL60)、肺癌(A549)、肝癌(SMMC7721)、乳腺癌(MCF7)以及结肠癌(SW480)五株人肿瘤细胞具有抑制作用。其中,首次报道化合物2对MCF-7和SW480有细胞毒活性,其抑制率分别为72%和81%。     

牛皮消化学成分研究

通过硅胶、Sephadex LH-20和反相RP-18等多种分离材料从牛皮消的甲醇提取物的乙酸乙酯部位分离得到12个化合物,经过核磁、质谱等方法分别鉴定为(5R,3E)-5-methoxy-6-hydroxy-6-methyl-3-hepten-2-one(1)、咖啡酸甲酯(2)、邻苯二甲酸甲酯(3)、邻苯二甲酸正丁异丁酯(4)、丹皮酚(5)、香草醛(6)、对羟基苯甲醛(7)、1-(4’-hydroxyphenyl)-propan-1,2-dione(8),(R)-2-hydroxy-1(4-hydroxy-3-methoxypheny)propan-1-one(9)、3-hy-droxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(10)、二-(2-乙基己基)—邻苯二甲酸酯(11)、东莨菪内酯(12),其中化合物1为新化合物,其余化合物从该种中首次分离。     

马尾松中的抗氧化成分

从马尾松(Pinus massoniana)枝条中分离得到21个已知化合物,经波谱学方法将其结构鉴定为7,13,15-abietatrien-18-oic acid (1),12-methoxy-7,13-abietadien-18-oic acid (2),15-methoxy-7,13-abietadien-18-oic acid methyl ester(3),12-hydroxydehydroabietic acid(4),dehydroabietic acid(5),15-hydroxydehydroabietic acid methyl ester (6),3β-methoxyserrat-14-en-21-one (7),3β-methoxy-30-hydroxyserrat-14-en-21-one(8),β-sitosterol (9),(±)-pinoresinol(10),(±)-matairesinol(11),(-)-nortrachelogenin(12),balanophonin (13),cedrusin (14),pinocembin (15),5-methoxypinosylvin (16),pinosylvin (17),1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-l,3-diol(18),cleistophostaudin(19),lignoceryl ferulate(20)和coniferaldehyde (21).其中化合物12,14,18和21在DPPH抗氧化模型上显示一定的抗氧化活性,其EC50值分别为11.36,6.76,14.07和13.33 μg· mL-1.化合物2～4,6～8,10,11,13,15～21均是从该植物中首次分离得到.     

羊角拗茎的化学成分及其抗炎活性研究

探讨羊角拗茎的化学成分及其抗炎活性,采用硅胶、Sephadex LH-20等色谱分离技术分离纯化羊角拗茎乙醇提取物的乙酸乙酯萃取物中的化合物,通过质谱和核磁共振等波谱技术对其结构进行鉴定,确定出了13个化合物,包括常春藤皂苷元(1)、(-)-loliolide(2)、(3 S,5 R,6 S,7 E)-3,5,6-trihydroxy-7-megastigmen-9-one(3)、(3 R,6 R,7 E)-3-hydroxy-4,7-megastigmadien-9-one(4)、松脂素(5)、表松脂素(6)、4,4′-dihydroxy-3,3′-dimethoxybenzophenone(7)、6-羟基柚皮素(8)、东莨菪素(9)、6-羟基-7,8-二甲氧基香豆素(10)、吲唑(11)、香草酸(12)、对羟基苯甲酸(13)。其中化合物1~4和6~13为首次从羊角拗中分离得到。采用LPS诱导小鼠单核巨噬细胞RAW 264.7体外细胞炎症模型测试结果表明,化合物5能显著抑制NO的产生,IC₅₀值为18.09±1.09μM。     

肾茶化学成分研究

采用色谱法从肾茶中分离得到18个化合物,利用波谱学方法鉴定了它们的结构,分别命名为(7'S,8'S)-8-epiblechnic acid diacetate(1)、threo-2-(4-hydroxy-3,5-dimethoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(2)、9-hydroxy-4,7-megastigmadien-3-one(3),dehydrololiolide(4),3-hydroxy-4-oxo-7,8-dihydro-β-ionone(5)、3-hydroxy-7,8-dehydro-β-ionol(6)、3-hydroxy-5,6-epoxy-β-ionone(7)、loliolide(8)、threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxy-propan-1-ol(9)、erythro-2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(10)、松脂醇(11)、(+)-丁香脂素(12)、(+)-(7R,7'R,7'R,7''R,8S,8'S,8'S,8''S)-4',4''-dihydroxy-3,3',3',3'',5,5'-hexame-thoxy-7,9':7',9-diepoxy-4,8':4',8''-bisoxy-8,8'-dineolignan-7',7'',9',9''-tetraol(13)、fragransin B1(14)、fragransin B2(15)、fragransin B3(16)、sacidumol A(17)和5,6,7,3',4'-五甲氧基黄烷酮(18)。其中化合物1和2为新化合物,除了化合物12和18外,其余化合物均为首次从肾茶属中被分离得到。化合物1由于含有二个乙氧基,因此其可能产生于分离过程,我们采用ECD计算确定了其绝对构型。     

海南红树植物角果木的二萜类化学成分研究

研究海南红树植物角果木的二萜类化学成分。通过硅胶、Sephadex LH-20柱色谱以及高效液相色谱等分离纯化手段,从角果木醇提物中共分离得到10个二萜类化合物,运用现代波谱技术鉴定了它们的结构,分别为:(5S*,8S*,9S*,10R*,13S*)-2,16-dihydroxydolabr-4R*,18-epoxy-3,15-dione(1)、tagalsin B(2)、ent-5α,2-oxodolabr-3-ene-3,15,16-triol(3)、(5S*,8S*,9S*,10R*)-3,13S*-dihydroxy-15,16-dinorlabr-3-en-2-one(4)、(5S*,8S*,9S*,10R*,13S*)-3-hydroxy-16-nor-2-oxodolar-3-ene-15-oic acid(5)、(5S*,8S*,9S*,10R*)-13S*,18-dihydroxy-15,16-dinordolabr-4(18)-ene-3-one(6)、(5S*,8S*,9S*,10R*,13S*)-18-hydroxy-16-nor-3-oxodolabr-4(18)-en-15-oic acid(7)、(5S*,8S*,9S*,10R*)-13S*-hydroxy-4S*,18-epoxy-15,16-dinordolabr-1-en-3-one(8)、ent-8(14)-pimarane-16,18-dihydroxy-15-one(9)、ent-8(14)-pimarane-15,18-diol(10)。其中化合物1为新化合物,化合物3和5为首次从角果木中分离得到。     

地衣内生菌Myxotrichum sp.的代谢产物的研究

采用硅胶柱色谱,重结晶,高效液相色谱等分离方法从地衣内生菌Myxotrichum sp.的发酵液中共分离得到10个化合物,根据理化性质和波谱数据分别鉴定为:麦角甾醇(1),(3β,5α,8α,22E,24R)-5,8-epidioxy-ergosta-6,9(11),22-trien-3-ol(2),麦角甾醇过氧化物(3),7-羟基-2,5-二甲基色原酮(4),7,8-dihydro-7,8-dihy droxy-3,7-dimethyl-2-benzopyran-6-one(5),7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone(6),Anhydroful vic acid(7),柠檬霉素(8),2,3二羟柠檬菌素(9),柠檬菌素(10)。化合物4~10的体外抑制人白血病细胞K562实验表明,该七种化合物均表现非常弱的细胞毒活性。     

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。     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.