冷冻结晶法和尿素包合法降低播娘蒿种子油中芥酸的初步研究

利用冷冻结晶法和尿素包合法分离播娘蒿种子油中的亚油酸和α-亚麻酸,降低其中的芥酸。先冷冻结晶处理,再尿素包合时尿素用量可减少,分离效果好,亚油酸和α-亚麻酸的收率高。实验结果表明,当V(脂肪酸):M(尿素):V(甲醇)为1:2:4时,回收样品里亚油酸和α-亚麻酸的总含量达到了95%,而芥酸的含量小于1%。亚油酸和α-亚麻酸的回收率为83.3%。     

华山松籽油的成分分析及其抗氧化的研究

通过气相色谱 GC 分析了华山松籽油的主要脂肪酸组成.结果表明:华山松籽含油率为56.5%,其中主要含有亚油酸63%,油酸26%,棕榈酸5%,硬脂酸2%,花生酸1%,芥酸1%,不饱和脂肪酸总量达90%.抗氧化研究采用Schaal烘箱法63±1℃,即在松籽油中加入几种不同的抗氧化剂进行加速氧化.结果表明:抗氧化剂二丁基对甲苯酚、没食子酸丙酯、特丁基对苯二酚对松籽油有明显的抗氧化作用,其中特丁基对苯二酚效果较好,柠檬酸对其具有协同增效作用,添加50mg/kg柠檬酸,抗氧化效果显著.VE无显著作用.     

华山松籽油的制取及性质研究

华山松籽有机溶剂萃取出油率为41％。油的相对密度(25℃)0.9243、折光率(25℃)1.4770、皂化值153.4、酸值0.24、碘值142.1,过氧化值9.9。油的主要脂肪酸有:亚油酸(44.60％)、油酸(22.42％)、亚麻油酸(19.14％)、异油酸(4.68％)、棕榈酸(4.62％)、硬脂酸(1.87％)、花生酸(2.02％)和其他酸(2.61％)。不饱和脂肪酸含量较高(占90.9％)。与药用沙棘籽油进行了性质和脂肪酸组成比较,初步证明其质量指标优于沙棘油,脂肪酸组成与沙棘油相似。推断华山松籽油可作为医疗保健、食品工业等油源加以开发利用。     

红松子油中皮诺敛酸的纯化及降脂活性评价

以红松子油为原料,采用尿素包合法纯化皮诺敛酸,通过脂肪酸与尿素的比例、尿素与乙醇的比例、包合温度及包合时间等因素对皮诺敛酸含量及产率的影响,优化了尿素包合法的工艺参数,最终确定了皮诺敛酸的最佳纯化条件为：脂肪酸与尿素的比例为1：6.5（w/w）,尿素与90%乙醇的比例为1：4（w/v）,包合温度为-10℃,包合时间12 h。在上述条件下,经GC-MS检测获得了纯度为58.3%的皮诺敛酸,回收率为51.8%,经二次尿素包合纯化后可获得纯度为72.5%的皮诺敛酸,回收率为64.7%。为了评估皮诺敛酸的降脂活性,以油酸诱导HepG2细胞成脂,最终确定40 μmol·L^-1的皮诺敛酸能显著的降低HepG2细胞内甘油三酯及总胆固醇的水平。     

气相色谱质谱联用技术对栝楼籽油亚麻酸和亚油酸含量的分析

通过皂化法和尿素包合法对热榨、冷榨栝楼（Trichosanthes kirilowii）籽油进行提取,采用气相色谱-质谱联用（GC-MS）技术检测分析栝楼籽油中亚麻酸、亚油酸成分、含量。结果表明,热榨栝楼籽油中亚麻酸相对含量为4.16%～11.58%,亚油酸相对含量为68.62%～95.84%。冷榨栝楼籽油中不含亚麻酸成分。此方法适用于栝楼籽油的成分分析。     

优化尿素包和法富集鼠尾藻中多不饱和脂肪酸工艺

利用响应曲面分析法优化尿素包和法富集鼠尾藻中多不饱和脂肪酸的工艺,分别以亚油酸(LA,Y1)、亚麻酸(GLA,Y2)、十八碳四稀酸(SA,Y3)、花生四稀酸(AA,Y4)、二十碳五稀酸(EPA,Y5)、总的不饱和脂肪酸(PUFAs,Y6)为响应变量,采用三因素中心复合旋转设计来研究尿素脂肪酸质量比值(X1),结晶温度(X2),结晶时间(X3)对响应变量的影响,并建立二次多项式数学模型.实验表明,最佳工艺条件为尿素脂肪酸质量比值3.5,结晶温度-5℃,结晶时间20.4 h,在此工艺条件下,最大多不饱和脂肪酸的总量可达85.02%.     

松籽油的干式酶法提取工艺优化与理化性质分析

应用单因素实验设计对干式酶法松籽油提取工艺进行优化。结果表明,干式酶法提取松籽油最佳制备工艺为：0.2%淀粉酶、料液比为6：1、酶解温度为55℃、酶解时间为8 h,所得最大出油率为90.2%,残油率为6.2%。经检测最佳制备条件提取的松籽油不饱和脂肪酸的含量为90.09%,其中油酸含量为26.84%,介酸含量为2.41%、亚油酸含量为46.25%、皮诺敛酸为14.59%;饱和脂肪酸中棕榈酸含量为6.5%、硬脂酸为3.41%。松籽油酸价为2.61 mg·g^-1、过氧化值为1.56 mmol·kg^-1、丙二醛含量为0.41 mg·kg^-1。所有检测结果均高于《中华人民共和国粮食行业标准LS/T 3242-2014》松籽油中质量标准的要求。     

高速匀质-微波辅助提取红松籽油工艺及其品质评价

以红松籽仁为原料,以无水乙醇为提取溶剂,优化高速匀质-微波辅助提取红松籽油的工艺,考察了匀质速度、匀质时间、液料比、微波温度、微波功率及微波时间对红松籽油提取率的影响,最终确定了红松籽油最佳提取条件为：匀质速度12 000 r·min^-1,匀质时间120 s,液料比20 mL·g^-1,微波温度60℃,微波功率700 W,微波时间50 min。在上述条件下,红松籽油最优提取率可达60.3%。利用GC-MS对得到的红松籽油的脂肪酸成分进行了分析,其主要成分为棕榈酸、皮诺敛酸、亚油酸、反-13-十八碳烯酸、顺-13-十八碳烯酸、硬脂酸,不饱和脂肪酸含量高达85.55%,其中松籽油所含有的特异性不饱和脂肪酸-皮诺敛酸含量可达13.65%。此外,对该工艺提取得到的红松籽油的抗氧化活性及理化性质进行了评估,发现红松籽油清除DPPH自由基能力强,其IC₅₀值为0.095 4 g·mL^-1。此外,红松籽油过氧化值和酸值较低,碘值较高,表明红松籽油是一种品质优良的天然油脂。     

油松种子油中顺-5,11,14-二十碳三烯酸的分离鉴定

本实验从油松(Pinus tabulaeformis Carr.)种子油中用尿素包合法和柱层析结合的方法分离出一种不常见的脂肪酸,经GC、UV、MS、NMR和IR分析确证该酸为顺-5,11,14-二十碳三烯酸,此酸芬兰T.Lehtinen美国T.Takagl已有报道。     

β-环糊精包合红松籽油的制备工艺及生物利用度评价

介绍了单因素法优化红松籽油包合物的制备工艺,在最优条件下制备的红松籽油包合物固化率为70.95%,包合物含油率为26.88%。且对红松籽油和红松籽油包合物脂肪酸组分、粒径、电位和生物利用度进行对比。研究结果表明,包合物中红松籽油的各组分含量与红松籽油中各组分含量无明显差异,其中皮诺敛酸的含量为14%~16%。红松籽油包合物的平均粒径为177.3±2.6 nm,电位为-33.01±1.4 mV。红松籽油包合物组的血药最大浓度（Cmax）是红松籽油组的1.27倍,t1/2a是红松籽油的1.42倍;AUC值是红松籽油1.56倍;平均滞留时间（MRT）是红松籽油的1.04倍。因此,通过本实验说明红松籽油包合物与水溶液形成乳剂,粒径减小,水溶性增大,增加了包合物在体内的t1/2a和平均滞留时间（MRT）,提高了皮诺敛酸在体内的吸收。     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

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.     

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).