莱菔子脂肪酸成分的GC-MS分析

采用索氏提取法提取莱菔(Raphanussativus)种子中的脂肪酸成分,进行甲酯化处理后用气相色谱-质谱联用技术分离和鉴定脂肪酸成分的组成和含量。结果表明,从莱菔子中共分离鉴定出12种脂肪酸成分,占总量的99.32%,主要包括芥酸(32.47%)、油酸(29.07%)、亚油酸(9.45%)、亚麻酸(8.41%)、棕榈酸(4.31%)和硬脂酸(2.08%)等脂肪酸,其中饱和脂肪酸占9.25%,不饱和脂肪酸高达90.07%。     

南五味子脂溶性成分的GC-MS分析

目的:对南五味子脂溶性成分进行研究。方法:采用索氏提取法提取脂溶性成分,甲酯化后用GC-MS联用技术分离鉴定其组成和含量。结果:脂溶性成分的得率为15．42％。鉴定了32个化合物,占样品总量的91．95％,其中脂肪酸成分的量占81．30％。含量较高的化合物为亚油酸(57．63％),油酸(13．37％),棕榈酸(7．16％)。结论:首次对南五味子脂溶性成分进行了分析,主要为脂肪酸,不饱和脂肪酸占优势。     

白马骨挥发性化学成分研究

采用水蒸气蒸馏法从白马骨中提取其挥发性成分,再通过气-质联用(GC-MS)技术对所提取的挥发性成分进行分离鉴定,共测定了其中的43种成分.已成功鉴定的成分占样品总量的88.87%,其主要成分为脂肪酸,占挥发性成分总量的52.12%,其次为烯烃化合物12.66%,醇类化合物8.97%,酮类化合物5.90%,酯类化合物3.84%,烷烃化合物3.28%,醛类化合物2.10%.     

超声波法提取野生石蒜中加兰他敏

石蒜是我国丰富的野生资源之一,其鳞茎富含重要药用成分加兰他敏。为了获得石蒜中加兰他敏的超声波提取方法,以野生石蒜为原料,用乙醇作提取剂,探讨了超声波提取加兰他敏的工艺条件,并与常规溶剂法进行了比较。分析了料液比、超声波功率、提取温度、提取时间、提取次数等因素对加兰他敏提取效果的影响,运用正交实验L9(34)确定了最佳提取工艺条件。结果显示,超声波提取加兰他敏的最佳工艺条件为:料液比1:6,超声波功率250 W,提取温度60℃,提取时间1.5 h,提取2次;加兰他敏的提取率为94.6%,产率为0.0543%;提取物中加兰他敏含量为15.53%。与常规溶剂法相比,超声波法具有用时少、提取率高、提取次数少等优点,整体效果优于常规溶剂法。     

香榧与油茶籽中脂肪酸成分的GC-MS分析

用石油醚提取香榧与油茶籽油,经过皂化、甲酯化处理,利用气相色谱-质谱(GC-MS)联用技术对其脂肪酸组成进行了检测。研究结果表明:香榧籽油共检测出6种脂肪酸,油茶籽油中共检测出5种.均以油酸和亚油酸为主。其中,香榧籽油中二者占总量的67.91%.油茶籽油中二者占总量的51.38%.本文对比分析了香榧籽油和油茶籽油中脂肪酸的主要成分及含量,为这两种木本食用油的开发利用提供理论基础。     

红树植物红海榄脂肪酸的GC-MS分析

采用索氏提取法对红树植物红海榄(Rhizophora stylosa)叶中的脂肪酸进行提取,甲酯化后利用气相色谱-质谱联用仪对脂肪酸成分进行分离和鉴定,鉴定出了12种脂肪酸,占脂肪酸总量的84.95%,其中主要包括十六酸(棕榈酸)(40.49%),9-十八碳烯酸(油酸)(17.24%),9,12-十八碳二烯酸(亚油酸)(11.24%)等。     

五种昆虫脂肪酸组分与含量分析

采用了索式提取法提取了5种昆虫的脂肪,5种昆虫粗脂肪含量分别为其干重的10.03%,13.41%,25.53%,19.05%和21.32%。并用气相色谱法分析了5种昆虫脂肪酸的组成和含量。结果显示,5种昆虫都富含不饱和脂肪酸即油酸、亚油酸、亚麻酸,在脂肪总量中该3种不饱和脂肪酸的含量分别为油葫芦Gryllus testaceus77.22%、烟夜蛾Heliothis assulta71%、灰斑古毒蛾Orguia ericae67.9%、银纹夜蛾Argyrogramma agnata57.14%、白薯天蛾Herse convolvuli56.17%,特别是昆虫脂肪中亚麻酸的含量明显高于日常食用动植物油脂。研究结果表明昆虫脂肪酸组成和含量非常适于食用和药用,是极好的脂肪酸源。     

赤雹籽脂肪油化学成分的研究

对赤雹籽中的脂肪油进行分析,为寻找活性成分提供依据,方法：采用GC-MS-PC联用技术.结果：从赤雹籽脂肪油中分离得到51种化合物,鉴定了其中的16种,占检出总量的59.56%.脂肪油甲酯化物的主要成分为亚油酸甲酯,相对含量为33.85%.     

木兰科四种植物种子油的提取及脂肪酸成分分析

采用超声波辅助提取法和微波辅助提取法同时提取白玉兰、凹叶厚朴、深山含笑和醉香含笑四种木兰科植物的种子油,种子油甲酯化后,运用气相色谱—质谱联用技术测定其脂肪酸成分。结果表明:四种植物种子油的提取率不同,白玉兰平均为27.35%、凹叶厚朴23.34%、深山含笑31.66%,醉香含笑9.27%。不同提取方法所得到的种子油脂肪酸成分和相对含量不同,但四种种子油的主要脂肪酸成分相同,包括油酸、亚油酸、硬脂酸和棕榈酸。     

响应面法优化微波辅助提取山苍子核仁油的研究

通过微波辅助提取技术结合响应面法优化山苍子核仁油提取条件,以期建立更高产率的提取方法。该研究在单因素设计基础上,选取液料比、微波功率、萃取时间、萃取温度4个主要因素,分析这4个因素对山苍子核仁油提取率的影响。结果表明:通过建立多元回归拟合分析,得出山苍子核仁油提取最佳工艺条件为液料比1∶16,萃取温度为69℃,微波功率为337 W,萃取时间为63 min,在此条件下山苍子核仁油提取率为37.42%,与环己烷溶剂回流法相比较提取率提高了30.11%。气质联用仪分析结果显示,山苍子核仁油主要成分有16种占总成分的88.21%,鉴定出10种脂肪酸占总成分的78.24%,饱和脂肪酸有4种占总成分的43.23%,不饱和脂肪酸有6种占总成分的35.01%,脂肪酸中含量最高的为月桂酸(31.36%)。该研究结果表明该方法严谨、可靠,采用微波辅助提取山苍子核仁油是可行的。     

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.