Chemical Constituents from the Whole Plant of Cuscuta reflexa

Two new 2H-pyran-2-one glucosides,cuscutarosides A(1)and B(2),and one new steroidal glucoside,7β-methoxy-β-sitosterol 3-O-β-glucopyranoside(3),together with 12 known compounds(4-15)were isolated from the whole plant of Cuscuta reflexa(Convolvulaceae)collected from Myanmar.The chemical structures of these new compounds were elucidated based on extensive spectroscopic analysis.The antiobesity activity of these isolates was evaluated using porcine pancreatic lipase(PPL),and the antiplatelet aggregation activity was screened using rabbit platelets induced by thrombin,platelet-activating factor(PAF),arachidonate(AA),or collagen.7β-Methoxy-β-sitosterol 3-O-β-glucopyranoside(3)showed weak PPL inhibitory activity.Cuscutaroside A(1),its acetylated derivative(1a),and scrophenoside B(8)showed weak inhibitory activity against rabbit platelet aggregation induced by collagen.Compound 1a also showed inhibitory activity against rabbit platelet aggregation induced by AA.

Phytochemical screening and wound healing potential of Cuscuta reflexa

The present study was to investigate pharmacognostical, phytochemical and pharmacological properties of extracts from stem of Cuscuta reflexa Roxb. Standard procedures have been followed to evaluate the pharmacognostical properties and preliminary screening of phytochemicals of Cuscuta reflexa Roxb. Albino Wistar rats(either sex) weighing 150–200 g were taken and made to acclimatize by providing them with the appropriate room conditions in the experimental room. Excision wound model has been selected for analgesic and wound healing activity for evaluating potential of the water-extract and ethanolic extract from the stem of Cuscuta reflexa Roxb. The macroscopic and microscopic studies showed the various characteristic features of stems. Preliminary screening of phytochemicals reveled that alkaloids, glycosides, flavonoids were the major groups of phytochemicals present in the successive extracts. Water and ethanolic extracts from stem of Cuscuta reflexa Roxb at 200 mg/kg and 400 mg/kg were able to alleviate pain and wounds. It is concluded that the stems of Cuscuta reflexa Roxb have a markedly therapeutic potential to heal wound and may provide the pharmacological basis for its folk uses.

滇产菟丝子种子形态的观察

应用解剖镜和扫描电镜观察了产于云南的 3种 12份菟丝子的种子形态 ,结果如下 :( 1)大花菟丝子种脐线形或弧形凹陷 ,晕轮椭圆形具网状纹饰 ,种皮具条状纹饰 ,条纹宽大呈块状 ,绞链状连接 ,排列致密 ;( 2 )中国菟丝子的种脐呈衣领状突起 ,晕轮圆形具不规则网状纹饰 ,种皮具复网状纹饰 ;( 3)日本菟丝子的种脐线形或弧形凹陷 ,晕轮圆形至椭圆形 ,具规则的网状纹饰 ,种皮具规则条状纹饰或网状纹饰 ,条纹狭长 ,排列稀疏 ;( 4 )种子形态不仅可用于菟丝子种及变种的检疫和鉴定 ,而且支持形态聚类分析所得结论。

大花菟丝子对红树林三叶鱼藤的生物防治效果

为探索利用大花菟丝子(Cuscuta reflexa)作为生物防治工具来控制三叶鱼藤(Derris trifoliata)的潜力,以应对三叶鱼藤在红树林生态系统中的侵袭和扩散问题,在广西北海南流江和冯家江设置24个样方对三叶鱼藤进行大花菟丝子接种试验。首先采用人工接种和无人机投掷两种方式,将大花菟丝子茎段接种到三叶鱼藤上,通过比较初始覆盖面积和最终覆盖面积来计算大花菟丝子的死亡率;然后评估大花菟丝子对红树植物的安全性,定时观察红树植物上的大花菟丝子寄生情况和生长变化;最后使用饱和盐水和菟丝灵控制大花菟丝子的扩散。试验结果显示,大花菟丝子能够有效寄生在三叶鱼藤上,吸取其营养物质,阻碍其光合作用和水分吸收,最终导致三叶鱼藤营养不良而全株死亡,接种3个月后的三叶鱼藤死亡率可达91%。大花菟丝子对红树植物桐花树(Aegiceras corniculatum)、秋茄(Kandelia obovata)、卤蕨(Acrostichum aureum)和老鼠簕(Acanthus ilicifolius)无显著影响,无法成功寄生在这些红树植物上,且49 d后均死亡。菟丝灵和饱和盐水均能有效控制大花菟丝子,喷洒6 d后大花菟丝子死亡率达到100%。综上,利用大花菟丝子治理三叶鱼藤安全有效且可控。这种生物防治方法不仅环保,而且比传统的物理清除方法更加经济和可持续,利用无人机投掷大花菟丝子来防治三叶鱼藤的成本仅为人工清理的2%。本研究为利用大花菟丝子作为生物防治工具提供了科学依据,为红树林生态系统的有害生物管理提供了新的视角和方法。

欧亚大陆分布的大花菟丝子叶绿体基因组插入缺失分析(英文)

运用鸟枪法在 Illumina 测序仪上对亚洲分布的大花菟丝子 ( Cuscuta reflexa) 叶绿体基因组核苷酸全序列进行测定,并与已经发表的分布于欧洲的大花菟丝子进行了比较分析。研究结果表明亚洲分布的大花菟丝子叶绿体基因组总长度为 120 972 bp,由 79 499 bp 的长单拷贝区,8 369 bp 的短单拷贝区,以及两个16 552 bp 的反向重复区组成,其长度比欧洲分布的大花菟丝子小了 549 bp; 基因组总 GC 含量为 38. 3% ,稍高于欧洲分布的大花菟丝子。两地区的大花菟丝子叶绿体全基因组编码的功能基因完全相同,且基因排列顺序也完全一致。另外,经过进一步序列比对后发现亚洲分布的大花菟丝子与欧洲分布的存在 251 个插入和210 个缺失现象,总插入缺失及碱基替换长度分别为 7 649 bp 和 3 720 bp,最大的插入和缺失长度分别为426 bp 和 435 bp。很多插入缺失都是单碱基,但仍然存在四个长度超过 200 bp 的大突变,两个大的缺失发生在 ycf2 基因中,两个大的插入分别发生在 trnF-psbE 和 matK-trnQ 间隔区,详细的对比后发现大量的插入缺失都发生在大单拷贝区的基因间隔区,且插入缺失在反向重复区的发生频率较低。本研究首次报道不同大洲分布的同种异养植物的叶绿体全基因组比较分析,为研究这两个区域的居群多样性提供了基础资料。