
大型担子菌分布广泛,种类繁多,它们是重要的食药用资源的宝库。萜类化合物是其主要活性成分之一,包括倍半萜、二萜和三萜等,这些化合物具有预防、缓解或治疗癌症、抑郁症、糖尿病和高血脂症等多种疾病的功效。目前,从担子菌中分离出的二萜类化合物基本骨架结构特征主要为鸟巢烷 (cyathanes) 型、截短侧耳素 (pleuromutilins) 型、guanacastanes型、海松烷 (pimaranes) 型、松香烷 (abietanes) 型和毛皮伞烷 (crinipellins) 型6大类型。本文综述了担子菌中二萜类化合物的结构特点、生物活性和生物合成的研究进展,对参与担子菌中二萜化合物生物合成的二萜合成酶进行了分类,对两种重要的二萜化合物生物合成途径进行了系统总结和论述。本文将为未知二萜化合物生物合成途径及关键基因功能解析提供参考。
本研究对盐地碱蓬内生菌Neocamarosporium sp. ZLM-26的活性次级代谢产物进行了挖掘。采用薄层色谱、硅胶柱色谱、高效液相色谱等分离方法,从该菌株大米培养基发酵产物的乙酸乙酯萃取物中分离得到6个单体化合物,经波谱学解析和文献数据对比,鉴定6个化合物分别为:5-butyl-6-(hydroxymethyl)-2H-pyran-2-one(1)、(7S)-xylariolide E(2)、(6S)-xylariolide D(3)、diaporpyrone A(4)、4-hydroxybenzaldehyde(5)和2-(2-hydroxyethyl)phenol(6)。分别采用CCK-8法和96孔板法评估了6个化合物的抗肿瘤和抗菌活性。结果显示,6个化合物(50 μmol/L)对胰腺癌细胞株SW1990、PANC-1的增殖无明显抑制作用;而化合物4对大肠杆菌有较好的增殖抑制活性,化合物5、6对铜绿假单胞菌有较好的增殖抑制活性。化合物1为1个新的天然产物,本研究首次报道了其核磁数据和抗菌活性。此外,化合物1–4均为首次从新凸轮孢菌属真菌中分离得到。
研究广叶绣球菌多糖(polysaccharides, SLPs)对小鼠CD8 + T细胞活化、增殖分化以及效应阶段的影响,探索广叶绣球菌多糖对CD8 + T细胞的免疫应答调控机制。通过腹腔注射环磷酰胺溶液(80 mg/kg)构建免疫低下小鼠模型,灌胃广叶绣球菌多糖(低、中、高剂量分别为100、200、400 mg/kg),连续饲养20 d后处死,取脾脏和胸腺。血细胞分析仪测定血常规;MTT检测脾T淋巴细胞的扩增能力;流式细胞术分析脾脏CD8 + T细胞表面CD28、CTLA-4和PD1以及树突状细胞表面MHC Ⅰ、CD80和PD-L1的表达量;ELISA测定外周血中TNF-α、IFN-γ、IL-2、IL-10、穿孔素、颗粒酶B的含量;RT-PCR测定脾脏Psmb9、Psmd9、TAP1、TAP2、IFN-γ、IL-2、JAK1、JAK2、STAT1、STAT3、SOCS-3和Blimp-1的mRNA表达量;Western blot测定pJAK2/JAK2、pSTAT3/STAT3和Blimp-1的蛋白表达量。试验表明广叶绣球菌多糖高剂量组脾脏指数显著升高,外周血中红细胞、白细胞、淋巴细胞、单核细胞、血小板的含量显著升高(P<0.05或P<0.01);多糖中、高剂量组脾T淋巴细胞的扩增能力显著增强(P<0.05);中、高剂量组CD8 + T细胞含量显著降低,CD8 + T细胞表面PD-1分子含量显著降低,树突状细胞表面PD-L1分子含量显著降低、MHC Ⅰ细胞含量显著升高(P<0.05或P<0.01);多糖高剂量组TNF-α、IFN-γ、IL-2、穿孔素和颗粒酶B的含量显著极显著升高(P<0.05或P<0.01),IL-10的含量显著降低(P<0.05);中、高剂量组Psmb9、Pmsd9、TAP1、TAP2和Blimp-1的mRNA含量显著升高(P<0.05或P<0.01),JAK1、JAK2、STAT1和STAT3的mRNA和蛋白表达量显著降低(P<0.05或P<0.01)。多糖中高剂量组Blimp-1蛋白表达量显著升高(P<0.05),多糖组与阳性对照组趋势一致。因此,认为广叶绣球菌多糖能够调节MHC Ⅰ类抗原加工呈递分子,并通过JAK2/STAT3信号通路促进CD8 + T细胞的活化、增殖分化和效应杀伤过程,从而调控CD8 + T细胞的免疫应答,起到改善小鼠免疫低下的作用。
金针菇是重要的食药用菌,具有很高的经济价值。随着金针菇全基因组序列的公布、多组学分析、转基因技术、基因编辑技术的发展,越来越多的研究者开始关注金针菇重要性状(如生长速度、菌柄长度、生物活性物质含量等)相关的分子调控机制以及关键基因的发掘。本文综述了分子生物学技术在金针菇研究中的应用并分析了不同技术的利弊;同时,系统介绍了金针菇菌丝和子实体生长发育、温度应答、生物活性物质代谢、蓝光响应等重要生物学过程中调控基因的最新研究进展,并对未来金针菇分子生物学研究的方向进行了展望,旨在为我国金针菇产业的发展提供有价值的参考。
The polysaccharide content, total phenol content, weight average molecular weight distribution, Fourier transform infrared spectroscopy, monosaccharide composition, antioxidant activities and immune activities in vitro of graded ethanol precipitation derived crude polysaccharides of Sanghuangporus vaninii fruiting bodies were compared. Pearson correlation analysis was used to analyze the compositional characteristics and activities of graded ethanol precipitation derived crude polysaccharides. The results showed that the physicochemical properties and activities of different ethanol components derived crude polysaccharides were quite different. The polysaccharide content of graded ethanol precipitation derived crude polysaccharides increased with the increase of ethanol precipitation concentration. The content of total phenol was higher in 20% ethanol gradients, and lower in 50% ethanol gradients. The weight average molecular weight decreased with the increase of ethanol precipitation concentration. The infrared spectrum showed that the hydroxyl vibrational peak of the polysaccharide in the 70%alcoholic fraction was not significant and correlated with low molecular weight distribution of the polysaccharide. In terms of monosaccharide composition, fructose and mannose contents were higher in 50% ethanol gradients, while glucose content was higher in 20% and 70% ethanol gradients. Correlation analysis results show that total phenolic content in crude polysaccharides of the basidiomata showed a significant positive correlation with DPPH and ABTS free radical scavenging activity. All the three crude polysaccharide fractions could activate NO release from RAW 264.7 cells and promote their secretion of immunomodulatory factors such as tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) and interleukin-1β(IL-1β). There was a significant positive correlation between NO release and polysaccharide content, and S50 with lower total phenolic content and higher galactose and fructose content had better immune activity in vitro.This study provides a reference for the study of polysaccharide effective components of Sanghuangporus vaninii.