橙盖鹅膏多糖(AC-1)体外免疫调节活性、细胞毒性和抗肿瘤活性的研究

为研究橙盖鹅膏多糖的体外免疫调节活性、细胞毒性和抗肿瘤活性,本研究运用细胞学技术探究AC-1对T细胞、B细胞和RAW264.7三种免疫细胞的体外免疫调节活性;研究AC-1对小鼠成纤维细胞(L929)的细胞毒性以及对小鼠胃癌细胞(MFC)、小鼠肉瘤细胞(S180)的体外抗肿瘤活性。结果表明,AC-1能在体外显著刺激三种免疫细胞的增殖及RAW264.7细胞的吞噬,表明AC-1在增强机体免疫方面具有重要作用,进一步研究发现AC-1主要通过显著促进IgE和IgG的分泌来增强体液免疫。在浓度为5~20μg/mL时AC-1对L929细胞无显著的促进及抑制作用,说明AC-1对正常细胞无毒性;在浓度为10~20μg/mL时AC-1能显著抑制小鼠胃癌细胞(MFC)的生长,但对小鼠肉瘤细胞(S180)的抑制效果较弱,说明AC-1在体外能够直接抑制肿瘤细胞的生长,但对不同的肿瘤细胞具有不同的抑制效果。综上所述,橙盖鹅膏多糖(AC-1)在体外具有良好的免疫调节活性、抗肿瘤活性,但对不同的肿瘤细胞具有不同的抑制效果并且对正常细胞无毒性。     

Dynamic gene amplification and function diversification of grass-specific O-methyltransferase gene family

The plant O-methyltransferases are dependent on S-Adenosyl-l-methionine, which can catalyze a variety of secondary metabolites. Here we identified different number of OMT genes from the respective grass genomes. Phylogenetic analysis showed that this OMT gene family is a grass-specific gene family that is different from COMT. Most of genes were expanded by tandem and segment duplication after the species split from their progenitor. Furthermore, genes from Group I and two clusters from group II are only present in Panicoideae, which included Bx10 and Bx7 involved in the benzoxazinoids pathway, suggesting these genes could participate in insect resistance in Panicoideae. Gene expression profiles showed that OMT genes were preferentially expressed in vegetative stages, especially in roots. These results revealed that this grass-specific OMT gene family could affect the development of vegetative stages, and be involved in the benzoxazinoids pathway or suberin biosynthesis that was different from COMT.     

Efficient racemization of N‐phenylacetyl‐D‐glufosinate for L‐glufosinate production

Most amino acids contain chiral centres and exist as both D‐enantiomer and L‐enantiomer. The optically pure enantiomer is often more valuable than the racemate. Enzymatic resolution provides an effective strategy to obtain optically pure amino acids but often results in large amounts of unwanted isomer. In this study, optically pure L‐glufosinate (L‐PPT) was obtained by coupling amidase‐mediated hydrolysis of N‐phenylacetyl‐D,L‐glufosinate with racemization of N‐phenylacetyl‐D‐glufosinate (NPDG), which exclusively exhibits effective herbicidal properties compared with its D‐enantiomer. To improve the yield of L‐PPT, the racemization reaction conditions were optimized, and through single‐factor experiments, the optimal reaction temperature, reaction time, and mole ratio of phenylacetic acid to NPDG were determined to be 150°C, 30 minutes, and 1.5, respectively. The response surface methodology was applied to further optimize the racemization conditions, and the final yield of L‐PPT reached 96.13% with optimum reaction temperature of 154°C, reaction time of 23 minutes, and phenylacetic acid/NPDG mole ratio of 1.7, respectively. Moreover, adding a small amount of acetic anhydride further raised the yield of L‐PPT to 97.02%.     

Design,synthesis and biological evaluation of novel aryl-acrylic derivatives as novel indoleamine-2,3-dioxygenase 1 (IDO1) inhibitors

Two series of novel aryl-acrylic derivatives were designed, synthesized, and screened in enzymatic and cellular inhibitory activities. All compounds showed moderate to significant potency. The SAR analyses indicated that the semicarbazone linker is better than the 1,2,3-triazole linker. Among semicarbazone compounds that R₁ bearing di-chain amino groups exhibited superior activities to those with morpholino group. Furthermore, compounds with electron-withdrawing groups at the 2-position or 4-position on the terminal phenyl ring were more active. Among these, compounds 7g, 7i, 7m and 7n exhibited the inhibitory potency in the low micromolar range and displayed negligible level of cytotoxicity against normal HeLa cells. In addition, the study suggested that the aryl-acrylic is an interesting novel scaffold for IDO1 inhibition for further development.     

Discovery of a new class of valosine containing protein (VCP/P97) inhibitors for the treatment of non-small cell lung cancer

Valosine containing protein (VCP/p97) is a member of the AAA ATPase family involved in several essential cellular functions and plays an important role in the ubiquitin-mediated degradation of misfolded proteins. P97 has a significant role in maintaining the cellular protein homeostasis for tumor cell growth and survival and has been found overexpressed in many tumor types. No new molecule entities based on p97 target were approved in clinic. Herein, a series of novel pyrimidine structures as p97 inhibitors were designed and synthesized. After enzymatic evaluations, structure-activity relationships (SAR) were discussed in detailed. Among the screened compounds, derivative 35 showed excellent enzymatic inhibitory activity (IC₅₀, 36?nM). The cellular inhibition results showed that compound 35 had good antiproliferative activity against the non-small cell lung cancer A549 cells (IC₅₀, 1.61?μM). Liver microsome stability showed that the half-life of compound 35 in human liver microsome was 42.3?min, which was more stable than the control CB-5083 (25.8?min). The in vivo pharmacokinetic results showed that the elimination phase half-lives of compound 35 were 4.57?h for ig and 3.64?h for iv, respectively and the oral bioavailability was only 4.5%. These results indicated that compound 35 could be effective for intravenous treatment of non-small cell lung cancer.     

Radiosynthesis of a carbon-11-labeled AMPAR allosteric modulator as a new PET radioligand candidate for imaging of Alzheimer’s disease

To develop PET tracers for imaging of Alzheimer’s disease, a new carbon-11-labeled AMPAR allosteric modulator 4-cyclopropyl-7-(3-[¹¹C]methoxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide ([¹¹C]8) has been synthesized. The reference standard 4-cyclopropyl-7-(3-methoxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide (8) and its corresponding desmethylated precursor 4-cyclopropyl-7-(3-hydroxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide (9) were synthesized from 4-methoxyabiline and chlorosulfonyl isocyanate in eight and nine steps with 3% and 1% overall chemical yield, respectively. The target tracer [¹¹C]8 was prepared from the precursor 9 with [¹¹C]CH₃OTf through O-[¹¹C]methylation and isolated by HPLC combined with SPE in 10–15% radiochemical yield, based on [¹¹C]CO₂ and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (A_M) at EOB was 370–740?GBq/μmol with a total synthesis time of 35–40-minutes from EOB.     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。     

HCMV IE86对恶性胶质瘤细胞凋亡及p53表达活性的影响

人巨细胞病毒(human cytomegalovirus,HCMV)能诱导肿瘤细胞恶性转化且抑制肿瘤细胞凋亡,但HCMV编码的主要即刻早期调控蛋白IE86在这一过程中是否发挥关键作用仍然未知。为探究IE86对基因修饰荷胶质瘤小鼠p53表达水平及恶性胶质瘤细胞凋亡情况的影响,本研究通过PCR技术鉴定基因修饰小鼠IE86表达情况;实时定量PCR技术检测IE86和p53mRNA表达水平变化;免疫组织化学方法检测p53和p21蛋白的表达水平;TUNEL检测肿瘤组织细胞凋亡情况。结果显示,成功构建了IE86基因修饰小鼠模型;与IE86阴性组相比IE86阳性组p53表达水平上升(P0.05),但p21表达水平下降(P0.05);IE86阳性组细胞抗凋亡能力增强(P0.05)。以上结果表明,在基因修饰的小鼠中IE86持续表达但p53转录活性的指示标志p21下调,且IE86可提高恶性胶质瘤细胞抗凋亡能力。