甘灵茶抗氧化成分的提取工艺研究

为了开发甘灵茶的应用价值,采用DPPH法对甘灵茶提取液的抗氧化性进行了研究。以提取液清除DPPH的效果为评价指标,采用单因素试验和正交试验,研究了甘灵茶的提取温度、pH值、提取时间、甘灵茶用量对抗氧化物质提取效果的影响,获得了提取的最佳工艺参数。结果显示：提取甘灵茶抗氧化物质的最优水平组合为提取温度为60℃、溶剂pH值为8.5、提取时间为15min、甘灵茶用量为3%,此条件下DPPH清除率为86.24%,多酚含量为0.187mg/mL,多糖含量为0.244mg/mL。     

黄粉虫油超声振荡有机溶剂提取工艺研究

目的：以黄粉虫幼虫为原料,研究超声振荡有机溶剂法提取黄粉虫油脂的工艺。方法：对溶剂量、温度、时间等影响黄粉虫油提取率的因素进行单因素研究,并进行多因素正交试验确定黄粉虫油脂的最佳提取条件。结果：正交试验得到最佳试验组合为A3B1C3D2,即黄粉虫量20g、醇酮量30mL、提取温度40℃、提取时间20min。在此条件下,黄粉虫幼虫油提取率达18.36%,得到的黄粉虫油浅黄色、透明、香味纯正。     

葡萄皮色素提取条件的综合研究

利用葡萄饮料厂生产加工的废料葡萄皮提取天然色素,并对影响色素提取率的因素如:提取溶剂的选择、提取剂用量、提取温度、提取时间及提取pH等条件进行研究,初步确定获得最大提取收率的条件,即:以无水乙醇为提取剂,葡萄皮重(g)与提取剂的用量(mL)之比为1 7,提取温度60~80℃,时间为70min,pH为2~4。同时对提取次数进行了研究,结果表明提取2次较好。     

纤维素酶法提取川牛膝多糖

以得率为评价指标,采用纤维素酶提取川牛膝多糖。对药材粒径、酶的用量、酶解温度、酶解时间、溶剂p H、液固比和提取时间等因素进行了考察,结合正交试验设计,得到最佳工艺条件:药材粒径550~830μm、酶用量4 mg/g、酶解温度50℃、酶解时间90 min、溶剂p H5.0、液固比60(m L/g)和提取时间30 min,发现在此条件下,川牛膝多糖得率为71.70%。     

变色疣柄牛肝菌子实体水溶性粗多糖的提取方法

试验就变色疣柄牛肝菌多糖的提取方法进行了初浅探索,结果表明变色疣柄牛肝菌干燥子实体萃取粗多糖较佳的条件为:粒度以粉碎60目筛、提取剂为蒸馏水、选择菌盖、选择料水比为1∶35(W/V)、沉淀剂达到85%的乙醇浓度、萃取温度选择在80℃、萃取时间为3 h、提取2次可得到粗多糖3%~5%。正交试验表明影响变色疣柄牛肝菌多糖得率的主次因素为乙醇浓度、提取温度、提取时间、料水比,各因素的最佳配合、最优工艺为A3B2C1D3,即乙醇浓度为85%、温度80℃、时间3 h、料水比为1∶15,在此条件下多糖得率为5.008%,提取粗多糖含量在47.995%。     

苦参酮的热稳定性及其提取工艺研究

考察了苦参酮的热稳定性,并用正交实验方法优选了苦参酮的提取工艺。结果发现,苦参酮在50℃下较稳定;以苦参酮的相对提取率为考察指标,在所考察的范围内,影响苦参酮相对提取率的主要因素依次为：提取时间〉乙醇浓度〉温度〉溶剂用量,其中提取时间和乙醇浓度对苦参酮的相对提取率影响显著;苦参酮的最佳提取工艺为：提取温度50℃,提取时间120min,容积用量（mL/g）25：1,乙醇浓度（v／v）：80％,相对提取率达到99．6％。优化后的提取工艺能较高效率地提取苦参酮。     

超声波法提取剑花总皂苷工艺研究

利用超声波法,采用正交实验对剑花总皂苷提取工艺进行研究。结果表明,提取剑花总皂苷的最优条件为:粒度80目,最佳溶剂水,超声时间40 min,溶剂挥干温度80℃,料液比1:20。     

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％。     

胡芦巴水溶性甾体皂苷的提取分离工艺研究

以薯蓣皂苷元的提取率为指标,应用L9(3^4)正交试验设计优化了从脱多糖、脱脂胡芦巴豆粉中提取甾体皂苷的工艺条件,并且筛选了ZTC澄清剂对胡芦巴甾体皂苷水提取液的澄清条件。实验结果表明,影响水提取的主次因素为：提取次数＞提取温度＞固液比＞提取时间;最佳水提取条件为：固液比为1：10,在70℃下提取3次,每次120min得出胡芦巴种子水提取液的澄清条件如下：ZTCl 1澄清剂的加入次序是先加B组分再加入A组分;澄清剂B和A的最佳用量分别为1．0g/L和O．5g／L;加入组分A或B后在80℃下作用30min即可达到澄清目的。     

循环超声提取肉苁蓉中苯乙醇糖甙类化合物的研究

研究了循环超声提取肉苁蓉中苯乙醇糖甙类化合物的工艺条件。实验结果表明,将肉苁蓉粉碎至40目,以甲醇提取较为适宜。超声提取苯乙醇糖甙类化合物的最优工艺条件是：提取温度为60℃。超声功率为1500W,提取时间为20min。在此条件下,苯乙醇糖甙类化合物的提取量为73．8mg／g,相当于60℃甲醇热浸5h的提取量,为索氏抽提法提取量(81．2mg／g)的90．9％。     

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.