不同方法提取组培百里香精油质量及成分的比较分析

采用水蒸气蒸馏法、有机溶剂萃取法、CO2超临界萃取法3种提取方法提取组培百里香精油,比较分析精油得率、精油化学成分以及相对含量,以期得出最佳提取方法。结果表明：水蒸气蒸馏法提取的百里香精油得率为O．21％,主要化学成分为：百里酚（36．53％）、间伞花烃（14．13％）、松油烯（8．09％）和石竹烯（4．14％）;有机溶剂萃取法提取的精油得率为0．19％,主要化学成分为：1,2-苯二甲酸-单-2-乙基己基酯（55．23％）、百里酚（873％）、松油烯（5．23％）;CO2超临界萃取法提取的精油得率为0．27％,主要化学成分为：百里酚（26．68％）、3-苯基-2-丙烯酸-甲酯（21．55％）、间伞花烃（9．69％）。从精油得率、精油质量以及精油主要化学成分综合比较3种方法,水蒸气蒸馏法是提取百里香精油的最佳方法。     

千年桐种子油提取工艺研究及其主要脂肪酸成分分析

本文以氯仿、石油醚和正己烷-异丙醇(3:2,v/v)三种不同溶剂对千年桐种子油进行提取,比较了不同溶剂对种子出油率的影响,结果表明以氯仿为溶剂时出油率最高,达到了35％;并考查了提取时间和提取溶剂体积对出油率的影响.最终优化的提取工艺为:以氯仿为溶剂,液料比为12:1(v/w),提取时间6h,出油率达到了37％.提取的种子油经转酯化后,GC-MS分析其主要脂肪酸组分,结果表明千年桐种子油中总脂肪酸占总油酯的90.55％,其中棕榈酸3.87％,硬脂酸4.11％,亚油酸12.15％,油酸13.31％,亚麻酸12.09％,共轭亚麻酸51.20％和EPA(二十碳五烯酸)3.30％.千年桐种子油中富含不饱和脂肪酸,是一种良好的干性油.     

菜籽粕脱毒液中硫代葡萄糖苷提取工艺的研究

本文用两步萃取法从菜籽粕脱毒液中提取硫代葡萄糖苷,以3,5-二硝基水杨酸比色法测定硫代葡萄糖苷含量,采用单因素试验法,分别考察可能影响硫代葡萄糖苷提取效果的各种因素,确定了最佳工艺条件：第一步萃取剂为异辛烷,母液与异辛烷体积比为2：1,搅拌时间为30min,异辛烷萃取次数为2次,异辛烷单次萃取率达71．2％。硫代葡萄糖苷收率为83．7％。     

超声提取和超声水解法从野葛根中提取纯化葛根素和大豆苷元

采用超声法从野葛根中提取葛根异黄酮,再将提取物在盐酸水溶液中超声水解结合有机溶剂萃取法从野葛根中分离纯化葛根素和大豆苷元。葛根素收得率为1．2％,纯度为97．8％;大豆苷元收得率为0．5％,纯度为98．2％。超声法从野葛根中提取分离葛根异黄酮活性成分葛根素和大豆苷元具有省时、节能、提取率和产品纯度高的优点。     

超临界CO2萃取百合花挥发油的工艺研究

本文介绍了超临界CO2萃取百合花中挥发油的提取分离工艺,重点研究了超临界CO2萃取压力、温度、时间对出油率的影响。正交试验结果表明：影响超临界CO2萃取的主要因素为C3〉A2〉B2（A为萃取压力,B为萃取温度,C为萃取时间）;最佳工艺参数：SC-CO2萃取压力为18MPa,温度为50℃,时间为90min,流量为25L／min,所得百合花挥发油的出油率高达2．92％。     

白兰花被片发育过程中香精油化学成分的GC-MS分析

用固相微萃取法萃取白兰(Michelia alba Dc.)花被片不同发育阶段的香精油,并用GC-MS对其化学成分进行鉴定,峰面积归一化法测定各成分的相对含量.结果表明,白兰花被片5个发育时期的香精油的化学成分不同,分别鉴定出30、29、28、30和27种化学成分.含量较多的是萜类化合物、烷烃类物质、酯类化合物、酸类化合物和醇类化合物.有16种化学成分在3个以上时期能检测到,其中14种萜类化合物,1种胺类化合物和1种芳香化合物.有7种成分是第Ⅳ期独有的.由此推测,白兰花发育的第Ⅳ时期是窨制花茶或提取香精油的最佳时期,但在不能及时窨制花茶或提取香精油或远距离运输的情况下,选择第Ⅲ时期采摘更为合适.     

花椒挥发油的超临界CO2萃取法与水蒸气蒸馏法提取的比较

采用超临界萃取法与水蒸气蒸馏法从花椒中提取花椒挥发油,用GC—MS方法测定各种提取方法得到挥发油的化学成分及相对含量。结果表明,水蒸气提取挥发得率为3．8％（W／W）,主要成分为柠檬烯（22．75％）、沉香醇（21．70％）、罗勒烯（3,7-二甲基-1,3,7-辛三烯）（14．27％）等。超临界CO2萃取法挥发油得率为5．9％（W／W）,主要成分为柠檬烯（14．01％）、沉香醇（13．18％）、罗勒烯（3,7-二甲基-1,3,7-辛三烯）（26．23％）等。两种方法所得到的挥发进行比较,水蒸气蒸馏法分离法得到的挥发油中分离出78个峰,其中含量和相似度高的成分有31种,占86．31％。超临界CO2萃取法提取的花椒挥发油中分离出了152个峰,含量和相似度高的成分有36种,占74．72％。两种提取方法所得到的主要挥发油中有27种成分相同。     

GC-MS分析伊犁绢蒿挥发油化学成分

利用水蒸气蒸馏法提取伊犁绢蒿挥发油,出油率为0．25％。采用色谱-质谱-计算机联用技术,从检出的30个成分中鉴定出28个,所鉴定成分占挥发油色谱总峰面积的98．66％。其主要化学成分为α-苎酮(78．74％)、樟脑(6．17％)、桧烯醇乙酸酯(1．94％)、β-苎酮(1．40％)、乙酸乙酯(1．14％)等,占总挥发油成分的89．46％。     

黄樟油素新资源植物狭叶桂的研究

狭叶桂〔Ｃｉｎｎａｍｏｍｕｍｈｅｙｅａｎｕｍ（Ｎｅｅｓ）Ｈ．Ｗ．ＬｉｅｔＢ．Ｑ．Ｃｈｅｎｇ〕是一种新的资源植物,全株可提取芳香油,含黄樟油素６３％～９９％;鲜枝叶出油率为０．５１％～０．９６％,黄樟油素含量为９７％～９９％。用种子繁殖可保持母本优良性状,是一种具有发展价值的新香料植物     

酸水解法从葛根中提取分离葛根素和大豆苷元

本文报道了葛根黄酮的提取精制方法,以６０％乙醇为溶剂,６０℃温浸６ｈ的优化工艺条件下,采用逆流萃取法从葛根中提取葛根黄酮,其收得率为１９．２８％,含量５１．０５％。葛根黄酮提取物采用５％盐酸水解４ｈ,酸水解液用乙酸乙酯萃取放置析出葛根素,乙酸乙酯相经水洗、浓缩和重结晶可得大豆苷元。采用酸水解法可以将葛根黄酮中的葛根素及大豆苷元衍生物水解成葛根素和大豆苷元,有利于葛根素、大豆苷元的分离及产率的提高;该方法从葛根中提取分离葛根素和大豆苷元具有操作简便、产品纯度和产率高、成本低的特点。葛根素和大豆苷元产率分别为１．３６％和０．４５％,纯度为９８．３２％和９１．２５％。     

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.