SE-HPLC/ICP-MS/ESI-MS联用技术用于富镉植物中镉的形态研究

用不同形态的镉培养液(氯化镉、硝酸镉、镉-EDTA、草酸镉和柠檬酸镉)对不同种类的蕨类植物(狗脊、舌厥、石松、瓦韦和石韦)进行培养。研究发现,镉在植物体不同部位的富集量是有差异的(富集量：根>茎>叶);对SEC-HPLC截取出的植物鳌合肽(PCs)研究表明,不同形态的镉能不同程度的诱发植物体中PCs的合成,从而PCs与Cd配位,降低镉的毒性,发现的配体主要为PC₃,iso-PC₃(βAla)和iso-PC₂(βAla)。文章还研究了不同形态镉胁迫下的蕨类植物各部位中镉的分布情况,并且对植物体中经镉诱导形成的PCs-Cd配合物的形态进行研究,进而对其解毒机理进行探讨。     

Euryjanicins E–G,poly-phenylalanine,and poly-proline cyclic heptapeptides from the Caribbean sponge Prosuberites laughlini

A new investigation of the active sponge extracts of Prosuberites laughlini collected off the West coast of Puerto Rico has yielded three new cyclic heptapeptides, namely euryjanicins E (1)–G (3), containing multiple phenylalanine and proline residues. In CDCl₃ solution, each euryjanicin F (2) and G (3) exists as an inseparable complex mixture of conformational isomers. The molecular structures of 1–3 were elucidated by a combination of chemical degradation, extensive ESI-MS/MSⁿ analyses, and 2D NMR methods. The elucidation of the absolute configuration was achieved by HPLC following analysis of the acid hydrolysates after derivatization with Marfey's reagent. When assayed against the National Cancer Institute 60 tumor cell line panel, the new cyclic peptides did not display significant in vitro cytotoxicity.