Effect of drought stress on content and composition of seed alkaloids in narrow-leafed lupin, Lupinus angustifolius L.

The effect of drought stress at three growth stages on seed alkaloid content in two sweet (W26 and Polonez) and one bitter variety (Zubr) of spring sown Lupinus angustifolius L. was investigated in a lysimeter experiment on sandy soil in Denmark. Full irrigation resulted in medium alkaloid content. Drought stress during the vegetative phase increased alkaloid content to 0.094, 0.192 and 2.55% of seed dry matter, respectively. At the flowering stage alkaloid content decreased to 0.070, 0.152 and 1.99%, while drought stress during pod-filling increased alkaloid content for the determinate variety W26 to 0.097%, but decreased it to 0.161 and 1.98% for the two indeterminate varieties Polonez and Zubr, respectively. Drought during either flowering or pod-filling resulted in an increased mean seed weight and a reduced number of seed per square metre. Alkaloid content was negatively correlated to seed weight. The alkaloid composition differed for the three genotypes, and was affected by drought treatment. Compared to the bitter variety the sweet varieties were characterized by reduced concentrations of lupanin, 13-hydroxylupanin and angustifolin, whereas spartein, isolupanin and isoangustifolin were little affected.     

1,5-Diazacyclohenicosane,a New Cytotoxic Metabolite from the Marine Sponge Mycale sp

A new cyclic diamine, 1,5-diazacyclohenicosane (1), was isolated from samples of the marine sponge Mycale sp. collected at Lamu Island (Kenya). Its structure was determined by a combination of spectroscopic techniques, including (+)-HRESIMS and 1D and 2D NMR spectroscopy. The compound displayed cytotoxicity at the μM level against three human tumor cell lines.     

海南地不容中总生物碱的提取及含量测定

采用正交试验法优选海南地不容的提取工艺并进行含量测定。以提取的总生物碱为考察指标,醇的体积分数、提取功率、提取时间、次数、料液比分别为考察因素,设计正交试验确定超声提取总生物碱的最优工艺。以盐酸小檗碱为对照品,利用分光光度法在418 nm处测定海南地不容中总生物碱的含量。最佳工艺为醇体积分数80%、超声提取30 min、功率160 W、料液体积比1∶20、提取2次。小檗碱在0.0~18.0μg/mL范围内线性关系良好(r=0.999 4)。平均回收率为99.03%,RSD=2.38%(n=6)。总生物碱含量可达到4.67%。确定的提取工艺简单,用时少,提取率高。建立的测量方法简单、灵敏度高、重现性好,适用于海南地不容中总生物碱的含量测定。     

翅果油树叶片中生物碱抑菌活性研究

采用酸性乙醇浸提翅果油树叶片中的生物碱,经硅胶柱层析纯化,所得生物碱对7种细菌和3种真菌进行抑菌作用试验。结果表明：翅果油树叶片中生物碱对细菌和真菌均有一定的抑制作用,对青枯菌的抑制作用明显强于对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的抑制作用;对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和4种青枯菌（OD1、DB1、DC1和M5）的最低抑菌浓度分别为0.016、0.032、0.016、0.016、0.032、0.016 g/mL和0.016 g/mL;对根霉和青霉表现出较强的抑制作用,而对曲霉的抑制作用较弱。     

马铃薯糖苷生物碱处理后枸杞鲜果的转录组学分析

为探明马铃薯糖苷生物碱（potato glycoside alkaloid,PGA）处理后枸杞鲜果的基因表达变化规律,以枸杞鲜果为试材,利用新一代高通量测序技术Illumina HiSeq^TM 4000对PGA不同处理时间的枸杞鲜果果肉组织进行转录组测序分析,采用生物信息学方法对差异基因进行功能注释和通路分析。结果显示,经PGA处理2、4和6 d后,枸杞鲜果的差异表达基因分别为22 966、19 474和13 904个,在处理后第2天差异表达基因数量最多。GO功能注释结果显示,细胞组分数据库中细胞组分及细胞器的分类条目富集较显著;分子功能数据库中参与结合蛋白功能、催化活性、结构分子活性以及转运活性的分类条目富集较显著;生物学过程数据库中代谢过程、细胞进程、信号有机体进程及生物调节的分类条目富集较显著。经PGA处理后第2天,有4 557个差异表达基因显著富集到1 227条代谢通路上;处理后第4天,有16 096个差异表达基因显著富集到11 155条代谢通路上;处理后第6天,有13 038个差异表达基因显著富集到2 206条代谢通路上。表明PGA作为诱导因子能够显著诱导采后鲜果的抗病基因,在枸杞采后病害的抗性效应中发挥着重要作用。     

From synthetic control to natural products: a focus on N‐heterocycles

Natural products containing a N‐heterocycle motif are widespread in nature and medicinal plants, in particular, have proved to be a source of almost unlimited N‐derived structures with high molecular diversity. Because of their intrinsic potential for use in both biomedical and agricultural applications, there is a general need for new compounds and for the synthesis of ‘natural‐inspired’ analogues. Importantly, transition of a natural product from discovery to a ‘market lead’ is associated with an increasingly challenging demand for more of the compound, which cannot be met by isolation from natural plant sources, often due to low extraction yields and uneven availability of the plant source itself. Synthesis remains the most reliable approach to provide valuable products for the market. In this review, a comprehensive overview of our contribution to synthetic access to N‐derived natural products is given. Major strengths of the proposed methodologies are discussed critically. © 2019 Society of Chemical Industry     

植物生物碱的杀虫作用及应用

植物生物碱是植物在与昆虫协同进化过程中形成的一大类具有防御功能的次生代谢物质,在植物害虫的综合治理中具有重要作用.本文对植物生物碱的分类、杀虫作用方式、作用机理及作为杀虫剂在新农药开发中的作用和植物生物碱的应用前景作了综述,并对桑树生物碱的应用进行了展望.     

雷公藤胚状体培养合成雷公藤甲素与总生物碱的初步研究

雷公藤(Tripterygium wilfordii Hook.f.)是一种多年生的木质藤本植物,生长周期长,次生代谢产物含量低,野生自然资源已经无法满足对其药用与农用的需求。为解决自然资源的短缺并保护雷公藤植物野生资源的生态环境,通过细胞工程技术生产雷公藤药用与农用活性物质是解决自然资源短缺,保护生态环境的途径之一。本研究中的雷公藤愈伤组织诱导自扦插一年生雷公藤叶片,将获得的愈伤组织建立细胞悬浮体系,诱导悬浮细胞得到生长稳定的胚状体培养体系。研究结果显示,添加60 mL/L椰汁的1/2 MS液体培养基可诱导愈伤组织形成浅绿色的胚状体,分离后的胚状体在1/2 MS添加0.5 mg/L a-萘乙酸(NAA)的液体培养基中可继续增殖分化。通过对接种量、培养基、装液量和pH值等培养条件的筛选和优化,在1/2MS培养基添加1.0 mg/L NAA和30 g/L蔗糖,胚状体接种量为1.5 g/100 mL,pH值调至5.8,250 mL三角瓶中装液量为120 mL时最适合胚状体的培养生长;添加内生真菌诱导子,以生物量为指标,在1/2MS+0.5 mg/L NAA+30 g/L蔗糖+Y1(叶的内生菌),pH 5.8时雷公藤甲素在胚状体中的含量是叶中的1.07倍,是自然根皮粉中的1.44倍;在1/2MS+0.5 mg/L NAA+30 g/L蔗糖+G4(根的内生菌),pH 5.8时胚状体中总生物碱量17.02倍于叶中总生物碱量,1.46倍于自然根皮粉中总生物碱量。对3龄小菜蛾(Plutella xylostella)的毒杀试验表明,胚状体提取物与根皮粉提取物相似,100 mg处理浓度下,72 h时死亡率均在90%以上。通过雷公藤叶愈伤组织诱导的雷公藤胚状体培养体系,其次生代谢物(雷公藤甲素与雷公藤总生物碱)含量与野生雷公藤叶和根皮中的相当,胚状体提取物的杀虫活性与雷公藤根皮粉的杀虫活性无明显差异,说明雷公藤胚状体可作为解决雷公藤植物资源短缺的一条途径,为进一步研究和利用雷公藤这一植物资源提供基础资料。