基于百度学术搜索引擎的马铃薯糖苷生物碱研究态势分析

在茄科(Solonum)和一些百合科(Liliaceae)植物中存在着一类天然次生代谢产物糖苷生物碱(steroidal glycoalkaloids, SGAs),对于植物体来说,该物质具有抗拒病原微生物侵袭、昆虫采食以及化感效应等,但对于人畜来说,虽然该物质具有抑制癌细胞增长和调节风味等作用,但在马铃薯(SolonumtuberosumL.)块茎中含量较高时可导致人畜中毒、甚至死亡。研究分析近年来的马铃薯SGAs研究态势,结果表明,相关发文量总体呈逐渐增加的趋势,关于马铃薯SGAs的研究已渗透到许多学科,并与之形成了多个交叉学科,通过统计分析,总结出在该领域核心的相关研究人员和研究机构。因此,掌握马铃薯SGAs研究态势,对研究马铃薯SGAs以及其在马铃薯块及其制品中食用安全性具有重要意义。     

Effects ofSolanum glycoalkaloids on chemosensilla in the Colorado potato beetle

Steroidal glycoalkaloids, found in species of the Solanaceae, elicit bursting activity in galeal and tarsal chemosensilla of adult Colorado potato beetles. The effect has an average latency of 6–12 sec, depending on the sensillum/alkaloid combination. A 20-sec alkaloid treatment is often suffficient to render galeal sensilla unresponsive to gamma-aminobutyric acid, normally an effective stimulant. The alkaloids have similar effects on galeal sensilla of larval Colorado potato beetles and on labellar chemosensilla of the blowfly. It is concluded that these compounds act independently of any specialized chemoreceptor in the Colorado potato beetle, and that association of the Colorado potato beetle with solanaceous plants has not led to evolution of a specific receptor forSolanum glycoalkaloids.     

Host-plant acceptance by geographic populations of the colorado potato beetle,Leptinotarsa decemlineata

We used a detailed analysis of feeding behavior to investigate the role of solanaceous alkaloids as sensory-based feeding deterrents for the Colorado potato beetle,Leptinotarsa decemlineata (Say). Experiments were conducted on three geographic, host-adapted populations of beetles to determine whether evolutionary changes in host use have been accompanied by behavioral adaptations to alkaloids. Solanine and tomatine, steroidal glycoalkaloids found in two regional host plants, did not reduce leaf consumption or significantly alter behavior patterns of newly emerged beetles, including those from populations that normally will not feed on plants containing the compounds. Atropine, a tropane alkaloid found in several taxonomically related nonhost species, caused a significant increase in sampling behavior (indicating direct action on the sensory system) and reduced acceptance of treated potato leaves. We propose that variable acceptance of host plants among regional populations ofL. decemlineata has evolved independently of adaptations to alkaloids at the sensory level. To establish that secondary compounds such as atropine influence host choice in nature, field observations are needed to confirm that beetles routinely encounter, and sample, nonhost species.     

基于固相基质分散的高效液相色谱-串联质谱法测定茄科蔬菜及其制品中龙葵素的含量

目的建立高效液相色谱-串联质谱法测定茄科蔬菜及其制品中龙葵素α-茄碱和α-卡茄碱含量。方法样品采用0.1%甲酸水溶液:乙腈=1:1(V:V)提取,C18固相基质分散净化,经过色谱柱BEHAmide (2.1mm×100 mm, 1.7μm)分离,以2 mmol/L乙酸铵的0.1%甲酸水溶液:2 mmol/L乙酸铵的乙腈溶液为流动相进行梯度洗脱,柱温40℃,流速0.4m L/min,多反应模式监测,外标法定量。结果α-茄碱和α-卡茄碱在5～1000ng/m L内线性关系良好(r20.999)。α-茄碱方法检出限和定量限范围分别为0.1～1 mg/kg, 0.3～3 mg/kg;α-卡茄碱检出限和定量限分别为0.03～0.3 mg/kg, 0.1～1 mg/kg;在低、中、高3水平添加下,α-茄碱回收率为90.7%～108.0%,α-卡茄碱回收率为89.8%～102.7%,相对标准偏差均小于5.6%(n=6)。结论本方法快速简便、准确度好、灵敏度高等特点,适用于大批量茄科蔬菜及其制品中α-茄碱和α-卡茄碱的测定。     

有效去除马铃薯中龙葵素方法的探究

目的探究一种日常生活中简单有效去除马铃薯中龙葵素的方法。方法对马铃薯进行分组贮藏实验,通过不同预处理方法(如去芽孔径大小、不同加工形状、不同浓度食醋水溶液或柠檬酸水溶液浸泡等)处理后采用液相色谱串联质谱法测定龙葵素含量,研究龙葵素含量的变化情况。结果对于轻微发绿或发芽马铃薯,可以进行削皮、去芽处理后,进行水浸、食醋水溶液浸、柠檬酸水溶液浸处理5～15 min,均可降低马铃薯中约70%～80%龙葵素。结论此方法实用性和可操作性强,可有效预防家庭、餐馆以及食堂等龙葵素中毒事件发生,对保障人民食品安全具有重要意义。     

Bioassays of segregating plants

Solanum chacoense is a wild potato species resistant to the Colorado potato beetle,Leptinotarsa decemlineata. Most genotypes ofS. chacoense synthesize the glycoalkaloids solanine (sol) and chaconine (chac) and are hosts of the beetle. A few rare genotypes have a gene(s) for acetylation of carbon-23 of the steroid aglycone of sol and chac. Laboratory bioassays and replicated field tests of clones differing in the presence or absence of the acetyl moiety showed that acetylation of sol and chac markedly affects the response of both adults and larvae to the foliage. Adult feeding deterrency conferred by acetylated forms of sol and chac (leptines) in leaf-disk preference tests was consistent with the degree of antixenosis measured in the field. Development of larvae on foliage of clones with leptines was also inhibited. The studies support the validity of using laboratory bioassays of plants segregating for levels of a suspected defense compound to determine the role the compound has in defending the plant from attack by an insect predator in the field.     

龙葵碱对雄性小鼠睾丸毒性的初步研究

目的初步探讨龙葵碱的睾丸毒性。方法选择雄性昆明小鼠行体内精子畸形实验;体外原代培养建立睾丸支持细胞测试系统,用噻唑蓝(MTT)法检测不同浓度龙葵碱对支持细胞的细胞毒作用,计算半数抑制浓度(IC50)。结果体内实验显示,龙葵碱致使受试小鼠精子畸形;2.75μmol/L龙葵碱即对睾丸支持细胞产生毒作用,随着龙葵碱剂量增加,细胞毒作用增强,IC5022.29μmol/L。结论龙葵碱可致雄性小鼠精子畸形,干扰雄性小鼠生精功能,对雄性小鼠睾丸有毒作用。     

Interactions of Aphid Herbivory and Nitrogen Availability on the Total Foliar Glycoalkaloid Content of Potato Plants

In plant growth room (PGR) and open-air pot (OAP) experiments, potato cvs King Edward and Maris Piper were grown under two nitrogen levels or two different nitrogen release patterns. Plants were subjected to infestation by peach potato aphids Myzus persicae (Homoptera: Aphididae). Total glycoalkaloid (GA) levels were measured in the foliage of both infested and non-infested plants, before, during and after aphid infestation. In the PGR experiment, aphid infestation reduced the amounts of total GAs in both cultivars. This reduction is attributed to the sugar deficiency induced in the plants owing to the dense aphid colonization. Results from the OAP experiment showed a temporal increase of GAs produced by potato cv. King Edward plants subjected to aphid infestation. Elevated amounts of nitrogen in the nutrient solutions (PGR experiment) reduced total GAs, while no differences were observed between manure and fertilizer treated plants (OAP experiment). It is concluded that the source of available nitrogen does not affect foliar GA synthesis in potatoes, and as a consequence, does not affect its endogenous chemical defense against insect herbivory. The case for insect-induced chemical defense mechanisms as triggered by low rates of aphid infestation is discussed.