我国28种鹅膏菌主要肽类毒素的检测分析*

利用高效液相色谱(HPLC)技术对产于我国的28种鹅膏菌的主要肽类毒素(鹅膏毒肽和鬼笔毒肽)进行了检测分析,并和采于欧洲(德国)的毒鹅膏Amanita phalloides作对照,结果表明,3种东亚所特有的鹅膏菌(灰花纹鹅膏、致命鹅膏和黄盖鹅膏白色变种)和欧洲毒鹅膏所含毒素种类多、含量高,其子实体菌盖部位主要毒素总量分别达到12583.7μg/g、8152.6μg/g、1058.2μg/g、7456.2μg/g干重子实体,这4种鹅膏菌可称之为剧毒鹅膏菌。其它25种鹅膏菌中有10种检测出含有微量鹅膏毒肽,含量在19.5μg/g-151.2μg/g之间。在4种剧毒鹅膏菌中,子实体组织部位不同,毒素含量以及鹅膏毒肽和鬼笔毒肽在其中的分布也不一样,菌盖中的毒素含量最高,菌柄的毒素含量次之,菌托中的毒素含量最低;对于灰花纹鹅膏、致命鹅膏和黄盖鹅膏白色变种,无论在菌盖、菌柄和菌托中,鹅膏毒肽类毒素的含量都高于鬼笔毒肽类毒素,尤其以α-amanitin的相对含量最高;而在欧洲毒鹅膏中,菌盖、菌柄和菌托中都以鬼笔毒肽为主,尤其以phallacidin的相对含量最高,并且从菌盖至菌柄到菌托,鬼笔毒肽的相对含量依次增加。     

我国28种鹅膏菌主要肽类毒素的检测分析

利用高效液相色谱(HPLC)技术对产于我国的28种鹅膏菌的主要肽类毒素(鹅膏毒肽和鬼笔毒肽)进行了检测分析,并和采于欧洲(德国)的毒鹅膏。Amanita phalloides作对照,结果表明,3种东亚所特有的鹅膏菌(灰花纹鹅膏、致命鹅膏和黄盖鹅膏白色变种)和欧洲毒鹅膏所含毒素种类多、含量高,其子实体菌盖部位主要毒素总量分别达到12583．7μg／g、8152．6μg／g、1058．2μg／g、7456．2μg／g干重子实体,这4种鹅膏菌可称之为剧毒鹅膏菌。其它25种鹅膏菌中有10种检测出含有微量鹅膏毒肽,含量在19．5μg／g—151．2μg/g之间。在4种剧毒鹅膏菌中,子实体组织部位不同,毒素含量以及鹅膏毒肽和鬼笔毒肽在其中的分布也不一样,菌盖中的毒素含量最高,菌柄的毒素含量次之,菌托中的毒素含量最低;对于灰花纹鹅膏、致命鹅膏和黄盖鹅膏白色变种,无论在菌盖、菌柄和菌托中,鹅膏毒肽类毒素的含量都高于鬼笔毒肽类毒素,尤其以α-amanitin的相对含量最高;而在欧洲毒鹅膏中,菌盖、菌柄和菌托中都以鬼笔毒肽为主,尤其以phallacidin的相对含量最高,并且从菌盖至菌柄到菌托,鬼笔毒肽的相对含量依次增加。     

我国鹅膏菌新发现种--致命鹅膏(Amanita exitialis)的肽类毒素分析

采用高效液相色谱(HPLC)技术对在广州发现的鹅膏菌新种——致命鹅膏(Amanita exitialis)不同组织部位的肽类毒素(鹅膏毒肽和鬼笔毒肽)的含量进行了分析,结果表明,致命鹅膏是一种剧毒蘑菇,其毒素含量相当高,子实体中组织部位不同,毒素含量以及鹅膏毒肽和鬼笔毒肽在其中的分布也不一样,菌盖中的毒素含量最高,达8152．6μg／g干重,菌柄的毒素含量次之,为3742．3μg／g干重,菌托中的毒素含量最低,只有1142．5μg／g干重;在菌盖、菌柄和菌托中都以鹅膏毒肽为主,尤其以α-amanitin的相对含量最高,但从菌盖至菌柄到菌托,鬼笔毒肽尤其是Phallacidin的相对含量依次增加。     

我国鹅膏菌新发现种——致命鹅膏(Amanita exitialis)的肽类毒素分析

采用高效液相色谱（HPLC）技术对在广州发现的鹅膏菌新种——致命鹅膏(Amanita exitialis)不同组织部位的肽类毒素(鹅膏毒肽和鬼笔毒肽)的含量进行了分析,结果表明,致命鹅膏是一种剧毒蘑菇,其毒素含量相当高,子实体中组织部位不同,毒素含量以及鹅膏毒肽和鬼笔毒肽在其中的分布也不一样,菌盖中的毒素含量最高,达8152.6μg/g干重,菌柄的毒素含量次之,为3742.3μg/g干重,菌托中的毒素含量最低,只有1142.5μg/g干重;在菌盖、菌柄和菌托中都以鹅膏毒肽为主,尤其以αamanitin的相对含量最高,但从菌盖至菌柄到菌托,鬼笔毒肽尤其是Phallacidin的相对含量依次增加。     

大孔吸附树脂联合葡聚糖凝胶Sephadex LH20分离制备鹅膏肽类毒素的研究

鹅膏菌肽类毒素是蘑菇中毒导致死亡的最主要因素,同时也是生物学研究领域的一种重要工具试剂,但由于其结构相似,分离制备单体化合物比较困难。通过4种大孔吸附树脂对致命鹅膏Amanita exitialis子实体中主要肽类毒素组分的静态吸附与解吸附性能比较,结果表明XAD16的吸附能力最强,同时也有较强的解吸附能力,但XAD16柱层析梯度洗脱时对毒素分离效果差,表明XAD16只具有吸附富集鹅膏肽类毒素的特性但不适于分离。经XAD16柱层析富集的毒素成分,通过葡聚糖凝胶sephadex LH20柱层析分离,结果表明sephadex LH20柱层析对鹅膏肽类毒素具有较好的分离效果,经过2次sephadex LH20柱层析,获得了5个纯度达50%–80%的鹅膏肽类毒素单体化合物,进一步利用半制备高效液相色谱系统(HPLC)纯化,分离得到了7个纯度达95%以上的鹅膏肽类毒素单体,其中5个经质谱分析鉴定为:α‐鹅膏毒肽(α‐amanitin)、β‐鹅膏毒肽(β‐amanitin)、脱氧二羟毒伞素(desoxoviroidin)、羧基三羟鬼笔毒肽(phallisacin)和羧基二羟鬼笔毒肽(phallacidin)。     

东北地区非鹅膏属真菌中鹅膏肽类毒素的分布

本文采用高效液相色谱（HPLC）法对采自中国东北地区的95份非鹅膏属真菌样本进行鹅膏肽类毒素（α-amanitin、β-amanitin、phalloidin）检测。为获得更准确的实验结果,对57份阳性反应样品利用UPLC-MS/MS进一步测定,值得注意的是,测定结果中褶纹丝盖伞Inocybe leiocephala确认同时含有以上3种毒素。本研究通过检测鹅膏肽类毒素在非鹅膏属真菌中的分布,对误食中毒事件的发生起到一定程度的预防和警示作用,另一方面筛选出含有鹅膏肽类毒素的新型毒菌资源,为毒菌资源的开发利用提供基础资料。     

玫瑰红鹅膏主要肽类毒素的HPLC 测定及其对白色念珠菌的抑制活性

【目的】检测玫瑰红鹅膏中所含肽类毒素及其含量,并对其肽类毒素的抑制白色念珠菌活性进行研究。【方法】采用HPLC和ESI-MS法从玫瑰红鹅膏中分离并鉴定出所含肽类毒素,并采用HPLC法测定其子实体、菌盖及菌柄和菌托混合部分中肽类毒素的含量。同时,采用纸片法研究了玫瑰红鹅膏粗毒液和分离到的单品肽类毒素对白色念珠菌JLC31680和JLC31681的抑菌作用。【结果】分离并鉴定出α-鹅膏毒肽(α-AMA)、β-鹅膏毒肽(β-AMA)和二羟鬼笔毒肽(PHD)等3种肽类毒素。玫瑰红鹅膏子实体中α-AMA、β-AMA、PHD的含量分别为30.3168、6.9932和9.9459 mg/g;菌盖中含量分别为44.9573、11.0798和11.3025 mg/g;菌柄和菌托混合部分中:α-AMA 11.6904 mg/g和PHD 7.9775 mg/g,β-AMA未检出。粗毒液、α-AMA、β-AMA和PHD对白色念珠菌JLC31680均具有很好的抑制作用,抑制率分别达到11.96%、32.52%、23.29%(p<0.01)和15.46%(p<0.05);粗毒液和β-AMA对白色念珠菌JLC31681的最高抑制率分别为10.16%和11.10%(p<0.01),α-AMA对白色念珠菌JLC31681最高抑菌率为6.89%(p<0.05)。【结论】玫瑰红鹅膏中的三种肽类毒素的含量较高,是制备肽类毒素的新资源;其具有抑制白色念珠菌的活性,可开发利用。     

四种剧毒鹅膏菌肽类毒素的HPLC分离与鉴定

利用反相市郊和液相色谱（ＨＰＬＣ）、紫外吸收光谱、擀谱分析了灰花纹鹅膏Ａｍａｎｉｔａ ｕｌｉｇｉｎｅａ,白毒鹅膏Ａ．ｖｅｒｎａ,鳞柄白毒鹅膏Ａ．ｖｉｒｏｓａ,豹斑鹅膏Ａ．ｐａｎｔｈｅｒｉｎａ等四种剧毒鹅膏菌的肽类毒素,结果表明：Ａ．ｆｕｌｉｇｉｎｅａ、Ａ．ｖｅｒｎａ含有九种标样毒素中的七种,Ａ．ｖｉｒｏｓａ含有九种标样毒素中的七种,Ａ．ｖｉｒｏｓａ含有标样中的五种;Ａ．ｐａｎｔｈｅｒｉｎａ含有标样     

三种鹅膏菌培养条件及所产肽类毒素的比较研究

以外生菌根菌鹅膏菌属三个种Amanita muscaria,A.pseudoporphyria和A.fritillaria为研究材料,以生长速率为评价指标,对其最适生长温度、pH值、光照、培养基、C及N源的利用等基本培养条件及所产肽类毒素进行了比较研究。研究结果表明,三种菌株最适生长温度有差异,A.pseudoporphyria和A.fritillaria的最适温度为28℃,A.muscaria的最适温度为22℃;A.muscaria菌丝体生长的pH值范围为5-7,另外两个菌株的pH值范围为3-6;24h光照、12h光暗交替和24h黑暗对鹅膏菌的生长速率影响不大;SPDM培养基和MMN培养基都适合三种菌株的生长,但对于A.muscaria来说PDM培养基更适合其生长。鹅膏菌能够利用比较广泛的C、N源,但三个种在利用的C、N源种类上有一定的差别。通过抑芽法实验和HPLC分析分别表明三种鹅膏菌所含肽类毒素在种类和含量上有所不同,但都对绿豆发芽有一定的抑制作用。A.pseudoporphyria和A.fritillaria菌丝体中α-amanitin的含量分别为35.56μg/gDCW(drycellweight细胞干重)和26.02μg/gDCW,不含有phalloidin和β-amanitin;A.muscaria菌丝体中没有检测到α-amanitin、β-amanitin和phalloidin。结果表明供试的三种鹅膏菌在基本培养条件及所产肽类毒素方面存在种水平上的差异。     

β-鹅膏毒肽的反相高效液相色谱分离纯化*

用反相高效液相色谱,以0.02mol/L醋酸铵-乙腈为流动相的梯度洗脱模式,在295nm吸收值的条件下,灰花纹鹅膏菌Amanitafuliginea的肽类毒素可以被成功的分离和纯化。单个肽类毒素的鉴定是用反相高效液相色谱和质谱同时进行。用这一方法可从灰花纹鹅膏菌中分离纯化出β-鹅膏毒肽(β-amanitin),产量可达到:1158靏/g(干重),产品纯度达98%以上,回收率为95.3%。β-鹅膏毒肽的分子量为919.3Da。这个方法可用于其它鹅膏菌肽类毒素的分离纯化。     

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.