RESUMO
KEY MESSAGE: Tetraploidy improves overexpression of h6h and scopolamine production of H. muticus, while in H. senecionis, pmt overexpression and elicitation can be used as effective methods for increasing tropane alkaloids. The effects of metabolic engineering in a polyploid context were studied by overexpression of h6h in the tetraploid hairy root cultures of H. muticus. Flow cytometry analysis indicated genetic stability in the majority of the clones, while only a few clones showed genetic instability. Among all the diploid and tetraploid clones, the highest level of h6h transgene expression and scopolamine accumulation was interestingly observed in the tetraploid clones of H. muticus. Therefore, metabolic engineering of the tropane biosynthetic pathway in polyploids is suggested as a potential system for increasing the production of tropane alkaloids. Transgenic hairy root cultures of Hyoscyamus senecionis were also established. While overexpression of pmt in H. senecionis was correlated with a sharp increase in hyoscyamine production, the h6h-overexpressing clones were not able to accumulate higher levels of scopolamine than the leaves of intact plants. Applying methyl jasmonate was followed by a sharp increase in the expression of pmt and a drop in the expression of tropinone reductase II (trII) which consequently resulted in the higher biosynthesis of hyoscyamine and total alkaloids in H. senecionis.
Assuntos
Alcaloides/metabolismo , Hyoscyamus/genética , Engenharia Metabólica/métodos , Raízes de Plantas/genética , Ploidias , Tropanos/metabolismo , Vias Biossintéticas/genética , Diploide , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Hyoscyamus/classificação , Hyoscyamus/metabolismo , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Escopolamina/metabolismo , Especificidade da Espécie , Tetraploidia , Técnicas de Cultura de TecidosRESUMO
A series of 7-hydroxycoumarin derivatives connected by an amidic linker to the different amines were designed and synthesized as cholinesterase inhibitors. Most compounds showed remarkable inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Among them, N-(1-benzylpiperidin-4-yl)acetamide derivative 4r with IC50 value of 1.6 µM was the most potent compound against AChE. The selectivity index of compound 4r for anti-AChE activity was about 26. Moreover, the compound 4r significantly protected PC12 neurons against H2O2-induced cell death at low concentrations. The docking study of compound 4r with AChE enzyme showed that both CAS and PAS are occupied by the ligand.