莳萝籽精油成分及消除亚硝酸钠研究

采用水蒸汽蒸馏法提取莳萝籽,以2.1%得油率获得精油,用GC-MS联机对精油进行了成分分析,检测出20种成分,解析鉴定了占精油97.136%的18个成分。主要成分相对含量分别为香芹酮54.587%,柠檬烯18.492%,芹菜脑11.949%。精油的消除NaNO2测定结果可知:当精油用量为0.25 mL时,消除率最大为78.4%。对水蒸汽蒸馏后的残渣用甲醇,乙醇以及丙酮萃取物分别进行萃取,萃取物收率分别为甲醇4.2%、乙醇2.3%和丙酮3.3%;萃取物的消除NaNO2测定结果可知:当萃取物溶液为0.4～1.0 mL时,清除率分别为:甲醇36.0%～39.6%,乙醇30.5%～36.5%,丙酮51.8%～55.8%。     

棘托竹荪菌托的化学成分及抑菌活性研究(Ⅰ)

用水蒸汽蒸馏法提取棘托竹荪菌托干品挥发油,得率为0.081%;用石油醚冷浸提菌托鲜品,得率为0.414%。应用GC-MS对提取物的化学成分进行研究,用HP-5MS柱分离,质谱法分别鉴定出41种和20种成分,其中有35种成分是首次从竹荪属中检测到的,其主要成分为:脂肪酸、醇、酮、倍半萜、芳香烃、酯等。提取物的抑菌效果:挥发油>石油醚提取物。挥发油对受试的霉菌、酵母菌、细菌都有强的抑制作用。     

正交设计优选超声辅助提取柑桔叶精油工艺研究

采用溶剂萃取法提取柑桔叶中的精油,并优化工艺条件。通过气相色谱、质谱等仪器对所提取的精油组分进行鉴定分析。最终得到最佳提取条件:用6倍石油醚浸泡4 h,超声60次,可得到较好产率,产率1.73%。利用气相色谱-质谱联用法对柑橘叶精油的化学组成进行分析,用归一化法测定其相对百分含量,共分离出387种成分,鉴定了其中的32种成分,占出峰物质总量的70.22%,主要成分为β-氧化石竹烯(10.15%)、十六烷酸(8.15%)、芳樟醇(6.31%)、α-甜橙醛(4.33%)、亚油酸(6.48%)、视黄醛(4.04%)等成分。     

秦芄挥发性成分研究

目的:研究秦芄(Radix Centianae Macrophyllae)中的挥发性成分.方法:利用水蒸气蒸馏法提取秦芄挥发油,用GC/MS进行测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量.结果:分离出8个组分,鉴定出7个化学成分.检出率为91.40%.秦艽挥发性成分大于1%的分别确定为萜品烯-4-醇1.224%,(E,E)-2,4-癸二烯醛1.295%,棕榈酸乙酯32.009%,棕榈酸54.608%.结论:首次报道了用GU/NS对秦艽挥发性成分的研究,为该类植物的研究开发提供必要的试验数据.     

新疆有毒植物骆驼蓬挥发油的化学成分测定

目的:研究骆驼蓬挥发油的化学成分.方法:利用水蒸气蒸馏法提取了新疆骆驼蓬挥发油,测的含量为0.04%.采用GC/MS技术对骆驼蓬的挥发油成分进行分离鉴定.结果:分离出18种成分确认其中17种成分.用峰面积归一化法确定了各成分的相对含量,其中主要成分为四氯乙烯(29.87%)、十二烷(16.44%)、十一烷(12.34%)、二(2-甲基丙基)邻苯二甲酸酯(9.09%)、1,3-二甲苯(7.57%)、乙苯(5.84%)1,2-二甲苯(2.81%).结论:四氯乙烯含量最高,通过分析评价为开发骆驼蓬农药提供科学依据.     

蒙椴树叶挥发油成分的气相色谱-质谱分析

采用水蒸气蒸馏法对蒙椴树叶挥发油进行提取,挥发油回收率约为0.6%(w);用气相色谱—质谱联用技术对挥发性成分进行分析,鉴定了45个化合物,占挥发油成分的80.35%以上。其中主要有己醇,己烯醇,贝壳杉烯和苯甲酸等     

菠萝蜜烟用香料香气成分分析及其在卷烟中应用的研究

本文采用GC/MS法对菠萝蜜烟用香料香气成分进行了全面的分析,共鉴定出45种成分,检出率占总成分的98.29%,主要是酯类化合物占42.22%,醇类化合物占24.49%,酸类化合物占21.83%等。通过菠萝蜜烟用香料在卷烟中增香保润效果的应用评价,研究菠萝蜜烟用香料中香气成分在卷烟中的应用效果。结果表明,菠萝蜜烟用香料对卷烟增香和保润具有较好的作用效果,具有重要的应用价值。     

青枣核果木枝叶石油醚部位脂溶性成分GC-MS分析

青枣核果木枝叶经溶剂提取法与硅胶柱层析法分离得到石油醚部位脂溶性成分A和B,采用气相色谱-质谱联用(GC-MS)技术用对其化学成分进行分离、鉴定及分析。从提取物A中鉴定了16种化学成分,主要为:角鲨烯(72.51%)、三十三烷(3.08%)、二十四烷(2.06%)。从提取物B中鉴定了16种成分,主要为:角鲨烯(47.82%)、棕榈酸乙酯(11.69%)、硬脂酸乙酯(5.43%)、木焦油酸乙酯(3.17%)、棕榈酸甲酯(3.14%)。本研究首次对青枣核果枝叶石油醚段脂溶性成分进行分析,表明青枣核果木枝叶中含有大量的活性成分角鲨烯。     

正交试验优化鼠疫活疫苗冻干稳定剂

目的优化皮上划痕用鼠疫活疫苗的稳定剂配方。方法采用正交试验,以鼠疫杆菌冻干存活率为检测指标,分别对乳糖、谷氨酸钠、硫脲和尿素4种成分组成的稳定剂配方,以及乳糖、蔗糖、谷氨酸钠、硫脲和尿素5种成分组成的稳定剂配方进行优化。结果 4种成分组成的稳定剂最佳组合为乳糖7.5%、谷氨酸钠0.5%、硫脲1.0%、尿素0.1%(均为质量分数),此配方可使菌体的冻干存活率达到(68.49±6.19)%;5种成分组成的冻干稳定剂最佳组合为乳糖7.5%、蔗糖7.5%、谷氨酸钠0.5%、硫脲0.5%、尿素0.1%(均为质量分数),此配方可使菌体的冻干存活率达到(74.71±6.34)%,均高于现有稳定剂配方。结论优化的两种稳定剂均对鼠疫杆菌具有较好的保护作用。     

代代花挥发油的超临界萃取及其在烟草中的应用

为了开发新的天然烟用香料,采用超临界流体萃取技术萃取代代花并优化了萃取工艺,GC-MS对挥发油成分进行了分离鉴定,并对其进行了卷烟加香试验.结果表明:①超临界萃取代代花的最佳工艺为:萃取压力40 MPa、萃取温度50℃萃取时间15 min、改性剂为20%乙醇;②代代花挥发油中共鉴定出45种挥发性成分,主要成分为柠檬烯、...     

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.