Effect of Water Stress Induced by Polyethylene Glycol on Growth, Proline Accumulation in Agave americana L.

The effect of water deficit was determined on both in vitro and soil seedling as well as in cells in suspension of Agave americana L.In order to do the establishment of cells,the formation of callus was induced;for it two auxins were evaluated:2,4-dichlorophenoxyacetic acid(2,4-D)and 4-mino-3,5,6-trichloropicolinic acid(picloram)at three concentrations(0.25,0.5 and 0.75 mg L−1)in three explants(leaf,root and meristems)cultured in MS semisolid medium.The callogenesis response was related to the type and section of the explant,as well as the regulator used,and a cell suspension was established using 0.5 mg L−1 naphthaleneacetic acid(NAA)+0.5 mg L−1 Benzylaminopurine(BAP).Seedlings were exposed to polyethyleneglycol(15%and 30%w/v)with a water potential of−0.87 and−2.67 MPa,respectively,under soil conditions.Water stress was applied through restricted irrigation.Fresh weight,root system growth,and chlorophyll concentration were some of the parameters that were affected by the effect of water deficit on A.americana L.Chlorophyll concentration values were significantly decreased by 15 at 30%PEG(19.6 SPAD units)compared to the control treatment.In in vitro plants,the highest concentration of proline was found in the roots,being the treatment with 30%polyethylene glycol where the highest concentration of this osmoregulator was obtained(62.5 mg g−1 DW).Under restricted irrigation conditions,an increase in proline concentration was observed both in the aerial part(2.2μg 100 g−1 DW)and in the root system(1.8μg 100 g−1 DW).However,the concentrations found were approximately ten times greater,less than those found under in vitro conditions.Therefore,the accumulation of proline can be considered an indicator of stress in Agave Americana L.growth in vitro.

Two New Steroidal Glycosides from Fermented Leaves of Agave americana

Two new spirostanol glycosides named agamenoside A and B, were isolated from the fermented leaves of Agave americana. Their structures were elucidated as (23S, 25R)-5a -spirostan-3b, 6a, 23-triol 3-O-a-L-rhamnopyranosyl-(13)- b-D-glucopyranosyl-(12)-[b-D- xylopyranosyl-(13)]-b-D-glucopyranosyl-(14)-b-D-galactopyranoside (1) and (25R)-5a-spiro- stan-3b, 6a-diol 3-O-b-D-glucopyranosyl-(12)-[ b-D-xylopyranosyl-(13)]- b-D-glucopyra- nosyl-(14)- b-D-galactopyranoside (2) by a combination of chemical and spectral methods.

A New Pregnane Glycoside from Fermented Leaves of Agave americana

A new minor pregnane glycoside was isolated from the fermented leaves of Agave americana. Its structure was elucidated as (20S)-5a-pregnane-3? 20-diol 20-O--D-glucopyrano- side (1) by spectral methods.

Cytocompatible cellulose nanofibers from invasive plant species Agave americana L.and Ricinus communis L.:a renewable green source of highly crystalline nanocellulose

In this study,the fibers of invasive species Agave americana L.and Ricinus communis L.were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers.Cellulose nanofibers were obtained by two methods,based on either alkaline or acid hydrolysis.The morphology,chemical composition,and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM)together with energy-dispersive X-ray spectroscopy(EDX),dynamic light scattering(DLS),X-ray diffraction(XRD),and Fourier transform infrared(FTIR)spectroscopy.The crystallinity indexes(CIs)of the cellulose nanofibers extracted from A.americana and R.communis were very high(94.1%and 92.7%,respectively).Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T)cells were also performed.The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e.,0-500μg/mL).Our results showed that the nanocellulose extracted from A.americana and R.communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.

Two New Spirostanol Steroidal Sapogenins from Fermented Leaves of Agave americana

Two new spirostanol sapogenins named agavegenin A and B were isolated from the fermented leaves of Agave americana L. Their structures were elucidated as (23S, 25R)-5a- spirostan-3b, 6a, 11a, 23-tetraol (1) and (23S, 25S)-5a-spirostan-3b, 23, 27-triol (2) by spectral methods.

Study on Flowering, Cultivation, and Reproduction of Agave americana Var. Marginata Hort. (Agavaceae)

Agave americana Var. Marginata Hort. （Agavaceae） is a perennial herb. This paper summarized its classification, distribution, morphological characteristics, habit, flowering and fruiting, cultivation and reproduction, as well as multiple uses in daily life, which provided references for the exploitation and utilization of Agave americana Vat. Marginata Hort. （Agavaceae）.

锰超富集植物垂序商陆(Phytolacca americana L．)的认定

针对目前国内锰超富集植物商陆属(Phytolacca)植物名称混乱的状态,在重新审查锰超富集植物——商陆(Phytolacca acinosa Roxb.)的野外标本和温室培养植物的基础上,比对中国科学院昆明植物所标本馆的腊叶标本,并查阅相关文献资料,以期正确认定锰超富集累植物的学名。结果表明,湘潭锰矿尾矿废弃地原生的锰超富集植物实为垂序商陆(Phytolacca americana L.),国内外相关研究论文中出现的商陆和美洲商陆实为垂序商陆的同物异名。这一植物名称的认定,将对避免锰超富集植物研究重复进行、保证相关研究正常有序开展具有重要意义。

美洲商陆(Phytolacca americana L.)——一种新的Mn积累植物

通过野外调查和水培试验,研究了锰在美州商陆体内积累情况及对其生长发育的影响,发现并鉴定出美洲商陆(Phytolacca am ericana L.)是一种新的M n积累植物。调查结果发现,美洲商陆对土壤中高含量的锰有很强的忍耐、吸收和积累能力,叶片中M n含量为5160￣8000m g·kg-1,平均为6490m g·kg-1。营养液培养试验证明,美洲商陆对生长介质中的M n有很强的忍耐能力,当生长介质中M n浓度高达10m m ol·L-1,叶片中M n含量达到11.76g·kg-1,植株仍生长正常。地上部M n含量及其积累量均随生长介质中M n浓度的增加而增加,当生长介质中M n浓度为50m m ol·L-1时,叶片中M n含量达到47.06g·kg-1。结果表明,美洲商陆是我国发现的一种新的M n积累植物,为今后探明植物积累M n的机理和M n污染土壤的植物修复提供了一种新的种质资源。

美洲大蠊(Periplaneta americana L.)抗菌肽杀菌作用初步观察

报道了美洲大蠊(PeriplanetaamericanaL.)抗菌肽对大肠杆菌(EscherichiacoliK88)的作用过程.电镜观察表明,美洲大蠊抗菌肽首先使细菌的外层及细胞质膜损伤,形成开口,导致内容物外泄而死亡,最后菌体崩解成碎片.

不同生境美洲商陆(Phytolacca americana L.)根系差异表达蛋白筛选

某铀尾矿区生长着大量美洲商陆（Phytolacca americana L.）,目前还未见美洲商陆耐受及富集铀相关蛋白质组学研究报道。为了找到铀耐受及富集表达相关蛋白,建立了铀尾矿区和对照区2种不同生境美洲商陆根系蛋白质组研究技术。通过全蛋白质制备条件优化、2DE电泳条件摸索以及染色方法选择,得到了重现性好、分离效果和清晰度都很高的美洲商陆根系双向电泳差异凝胶图谱。经软件分析,筛选出了铀耐受及富集相关蛋白24个,上调表达11个、下调表达13个。

Comparison between Decolorization Effects of Activated Carbon and Macroporous Resin on Periplaneta americana L. Skimmed Cream

[Objective] The aim of this study was to investigate the decolorization ef- fects of activated carbon and macroporous resin on Periplaneta americana L. skimmed cream and compare the advantages and disadvantages of the two decolorization technologies. [Method] Periplaneta americana L. skimmed cream was decolored with activated carbon and macroporous resin, and freeze-dried to collect solid decolorization products. By investigating the yield, decolorization rate, protein retention rate and decolorization operation process, the advantages and disadvantages of the two decolorization technologies were compared. [Result] Both activated carbon and macroporous resin can be used for decolorization. To be specific, macroporous resin-decolorization is superior in the yield and protein retention rate, while activated carbon-decolorization is superior in decolorization rate and decolorization operation process. [Conclusion] Macroporous resin-decolorization can be used if protein is the main ingredient required in the experiment, while activated carbon-decolorization can be used if protein is not the main ingredient required.

垂序商陆配方颗粒的HPLC指纹图谱研究与商陆皂苷甲含量测定

目的为垂序商陆的质量控制提供参考。方法建立高效液相色谱(HPLC)法,测定19批垂序商陆配方颗粒指纹图谱并进行相似度评价、聚类分析(CA)和主成分分析(PCA),结合正交偏最小二乘-判别分析(OPLS-DA)筛查不同批次垂序商陆配方颗粒的差异成分;通过HPLC-ELSD测定配方颗粒中商陆皂苷甲成分。结果垂序商陆配方颗粒HPLC指纹图谱共标定了9个共有峰,通过与对照品比对,确定了峰1为腺苷、峰2为鸟苷、峰3为L-色氨酸、峰5为刺桐碱、峰8为商陆皂苷甲。19批垂序商陆配方颗粒指纹图谱相似度均在0.89以上,CA、PCA和OPLS-DA均将样品分为了3类,在OPLS-DA模型下,以VIP值大于1筛选出3个差异性标志物,分别为L-色氨酸(3号峰)、商陆皂苷甲(8号峰)和刺桐碱(5号峰)色谱峰。19批配方颗粒样品中商陆皂苷甲的含量在1.8~7.6 mg/g之间。结论所建立的HPLC指纹图谱,结合化学计量学分析方法和商陆皂苷甲含量测定方法,能较为全面地评价垂序商陆配方颗粒的质量。

红掌漆酶基因Lac的表达载体构建与剑麻转化

用RT-PCR从红掌品种亚利桑那的cDNA中扩增出漆酶基因Lac并得到的基因的全长。将Lac片段克隆到pMD18-T载体,然后将此基因插入pBI121的CaMV35S启动子后取代原载体中的GUS基因构成表达载体pBI121-Lac。通过冻融法将表达载体导入根癌农杆菌(Agrobacterium tumefaciens)LBA4404,并转化剑麻获得转基因植株。对转化植株进行的基因组PCR分析结果表明,Lac基因已成功的整合到剑麻的基因组中。转漆酶基因植株的获得为剑麻抗性的提高提供了可能性,并且为以后研究漆酶的具体功能提供了方便。

HPLC-ELSD法测定商陆不同部位中商陆皂苷甲的含量

目的:建立 HPLC-ELSD 法测定商陆中商陆皂苷甲的含量。方法:采用 Diamonsil C_(18)(5 μm,250 mm×4.6 mm)色谱柱,甲醇-水(75:25)为流动相,流速1.0 mL·min^(-1);蒸发光散射检测,ELSD 漂移管温度:74 ℃,载气流速:2.0 L·min^(-1)。结果:商陆皂苷甲进样浓度在26.6～532.5分g·mL^(-1)范围内有良好的线性关系(r=0.9995);平均回收率(n=5)为98.5%,RSD 为1.5%。结论:本方法简便,结果可靠、准确,可用于商陆的质量控制。

美洲大蠊提取物对CCl_4诱导肝细胞损伤的研究

目的探讨美洲大蠊不同提取物(ML-A、ML-A_1、ML-A_2、ML-A_3、ML-A_4、ML-A_5)和肝龙浸膏对CCl_4诱导L-O_2肝细胞损伤的存活率的影响。方法培养L-O2肝细胞,24h后用60%饱和CCl_4体外诱导肝细胞损伤,培养6h,分为阴性对照组、溶剂对照组、CCl_4模型组、联苯双酯组、美洲大蠊提取物组、肝龙浸膏组,分别培养12,24,48,72h后,通过MTT法检测细胞活性。结果 CCl_4损伤后肝细胞存活率明显下降,与CCl_4模型组比较,除ML-A_1、ML-A_4和ML-A_5外,ML-A、ML-A2、ML-A3和肝龙浸膏均能提高CCl_4损伤L-O_2肝细胞的存活率,其中ML-A_2作用的损伤肝细胞存活率最高。结论美洲大蠊提取物ML-A、ML-A_2、ML-A_3和肝龙浸膏均能提高CCl4诱导肝细胞损伤的存活率。

美洲大蠊不同炮制品对CCl_4致小鼠急性肝损伤的保护作用

目的探索不同炮制方法下美洲大蠊对CCl_4致小鼠急性肝损伤的保护作用。方法采用CCl_4致小鼠急性肝损伤模型,各实验组按炮制给药方法分为空白组、模型组、原药组、清炒组、盐炙组、麸炒组、米炒组、联苯双酯组。连续给药1周后,除空白组外,各实验组腹腔注射0.2%CCl_4橄榄油溶液,禁食不禁水24 h后,摘除小鼠眼球取血,分离血清。测定血清谷草转氨酶(AST)、丙氨酸转氨酶(ALT)的活性;取肝脏测肝脏系数,固定于10%的甲醛溶液中,进行肝脏病理组织学考察。然后采用索式提取器测定各炮制组油脂含有量,采用考马斯亮蓝法测定各炮制组蛋白质含有量,采用苯酚-硫酸分光光度法测定各炮制组多糖含有量。结果与模型组比较,各炮制组与原药组均能显著降低小鼠肝脏系数,各炮制组能显著降低小鼠血清中AST、ALT水平(P<0.01),而原药组对小鼠血清中AST、ALT水平的降低与模型组比较不具显著性差异(P>0.05),HE染色表明麸炒组病变最轻。与原药组比较,各炮制组油脂含有量下降;蛋白质含有量以盐炙组最低,原药组最高;多糖含有量在盐炙组、清炒组均较高,在原药组、麸炒组、米炒组均较低。结论美洲大蠊各炮制品均能对CCl_4致小鼠急性肝损伤起保护作用,以米炒、麸炒组效果最佳,原药组效果最差。

HPLC法测定美洲大蠊药材中五种核苷类成分含量

目的用HPLC法测定美洲大蠊药材中五种核苷类成分含量。方法用石油醚对美洲大蠊粉末进行脱脂,以65%的乙醇为溶剂进行超声提取,乙腈溶解配制成美洲大蠊供试品溶液,使用Agilent色谱柱(9.4×250 mm;5μm),以纯水∶乙腈=95∶5为流动相,流速为0.5 mL/min,检测波长为254 nm,进样量取10μL,对照混合标品和单一标品对美洲大蠊供试品溶液进行含量测定。结果用HPLC法测定美洲大蠊药材中五种核苷类成分含量,灵敏度高,专属性好,可用于本品的含量测定。5种核苷浓度在一定范围内与峰面积呈良好线性关系(R^(2)>0.9941),精密度高,重复性好,稳定性佳,加样回收率均在97.58%~103.26%之间。结论该法实验过程简便、结果可靠、稳定,可用来测定美洲大蠊中核苷类成分的含量。

美洲大蠊提取物CⅡ-3 UPLC指纹图谱研究

目的:建立美洲大蠊提取物CⅡ-3超高效液相色谱(Ultra Performance Liquid Chromatography,UPLC)指纹图谱,评价不同批次CⅡ-3样品的质量。方法:采用Phenomenex Gemini 5u C18110A(250 mm×4.6 mm)色谱柱分析美洲大蠊提取物CⅡ-3;柱温28℃;检测波长214 nm;流动相为乙腈-水(0.1%甲酸),进行梯度洗脱。依据相似度评价结果和化学计量学方法进行不同批次CⅡ-3质量评价。结果:建立了12批CⅡ-3指纹图谱,标定共有峰21个,其中11批样品相似度大于0.900。结论:首次建立了美洲大蠊提取物CⅡ-3的UPLC指纹图谱,为CⅡ-3质量控制提供科学依据。

脉冲电场对金边龙舌兰光合电子传递链和释放负离子能力影响

【目的】探明脉冲电场刺激对金边龙舌兰(Agave americana var.Marginata)光合电子传递链和释放负离子能力的影响。【方法】采用0 k V(对照,CK)、5 k V(T1)和7 k V(T2)3个不同脉冲电场处理刺激金边龙舌兰,比较和分析不同刺激下金边龙舌兰的叶绿素含量、快速叶绿素荧光诱导动力曲线(Rapid Chlorophyll Fluorescence Induction Kinetics Curve,OJIP曲线)、叶绿素荧光参数和负离子释放浓度的变化情况。【结果】(1)脉冲电场技术刺激金边龙舌兰后,两处理组叶绿素含量分别增长6.30%、6.70%,两处理组与CK组之间存在显著差异;(2)两处理组OJIP曲线,偏转(I)和最高峰(P)值均高于原点(O)和拐点(J)值,I-P段的上升趋势较O-J段平缓。同时,J-band均大于0,T2处理组峰值高于T1处理组;(3)叶绿素荧光参数均呈波动的变化趋势,其中最大荧光强度(F_(m))、单位面积捕获能量(TR_(o)/CS_(o))等整体呈现上升的趋势,PSⅡ光合系统潜在活性(F_(v)/F_(o))、PSⅡ受体侧电子传递体数(S_(m))等整体呈现下降的趋势,最大光量子效率(F_(v)/F_(m))、J点相对可变荧光强度(Vj)等整体变化不大。吸收光能为基础的性能指数(PIabs)均出现减小的趋势,其中T1处理组减小18.60%,T2处理组减小14.1%。CK处理组综合性能参数(PItotal)大于T1处理组和T2处理组;(4)T1处理组,脉冲电场刺激4 h相较于脉冲刺激3 h时,NAI浓度增长87.60%。T2处理组,脉冲电场刺激4 h后,相较于脉冲刺激3 h时,NAI浓度增长62.09%,其中在脉冲1~4 h,两处理组之间、二者与CK组之间NAI释放浓度存在显著差异。【结论】脉冲电场技术对金边龙舌兰光合电子传递链产生影响,进而对其释放负离子能力等产生影响。

拉巴豆替代控制对美洲商陆根际土壤微环境的影响

为探究拉巴豆替代控制对美洲商陆根际土壤微环境的影响,分别测定了美洲商陆单种及与拉巴豆按不同比例混种时根际土壤细菌、真菌和放线菌数量,及土壤全氮、全磷、全钾、碱解氮、速效磷、速效钾和有机质含量。结果表明:混种拉巴豆显著降低了美洲商陆根际土壤细菌数量、放线菌数量和所占比例、微生物总数、全磷、碱解氮、速效钾和有机质含量,显著提高了真菌所占比例,1∶3混种(S2L6)时细菌所占比例显著降低,1∶1(S4L4)和1∶3(S2L6)混种时真菌数量显著提高,全氮和速效磷含量显著降低。相关性分析表明根际土壤微生物数量和理化性质相互影响,由主成分分析综合排名可知1∶3混种时美洲商陆根际土壤肥力条件最差。综上所述,因为混种使美洲商陆根际土壤肥力降低,说明拉巴豆能够成功替代控制美洲商陆,1∶3混种最有利于美洲商陆的替代控制。