Glycosylated tetrahydrosalens as multifunctional molecules for Alzheimer's therapy
作者:Tim Storr、Lauren E. Scott、Meryn L. Bowen、David E. Green、Katherine H. Thompson、Harvey J. Schugar、Chris Orvig
DOI:10.1039/b902545f
日期:——
The tetrahydrosalens N,N′-bis(2-hydroxybenzyl)-ethane-1,2-diamine (H2L1), N,N′-bis(2-hydroxybenzyl)-(−)-1,2-cyclohexane-(1R,2R)-diamine (H2L2), N,N′-bis(2-hydroxybenzyl)-N,N′-dimethyl-ethane-1,2-diamine (H2L3), N,N′-bis(2-hydroxybenzyl)-N,N′-dibenzyl-ethane-1,2-diamine (H2L4), and N,N′-bis(2-(4-tert-butyl)hydroxybenzyl)-ethane-1,2-diamine (H2L5), as well as their prodrug glycosylated forms, GL1–5, have been prepared and evaluated in vitro for their potential use as Alzheimer's disease (AD) therapeutics. Dysfunctional interactions of metal ions, especially those of Cu, Zn, and Fe, with the amyloid-β (Aβ) peptide are hypothesised to play an important role in the aetiology of AD, and disruption of these aberrant metal–peptide interactions via chelation therapy holds considerable promise as a therapeutic strategy. Tetrahydrosalens such as H2L1–5 have a significant affinity for metal ions, and thus should be able to compete with the Aβ peptide for Cu, Zn, and Fe in the brain. This activity was assayed in vitrovia a turbidity assay; H2L1 and H2L3 were found to attenuate Aβ1–40 aggregation after exposure to Cu2+ and Zn2+. In addition, H2L1–5 were determined to be potent antioxidants on the basis of an in vitro antioxidant assay. GL1–5 were prepared as metal binding prodrugs; glycosylation is intended to prevent systemic metal binding, improve solubility, and enhance brain uptake. Enzymatic (β-glucosidase) deprotection of the carbohydrate moieties was facile, with the exception of GL4, demonstrating the general feasibility of this prodrug approach. Finally, a representative prodrug, GL3, was determined to be non-toxic over a large concentration range in a cell viability assay.
四氢萨林(tetrahydrosalens)N,N′-双(2-羟基苯基)-乙烷-1,2-二胺(H2L1)、N,N′-双(2-羟基苯基)-(−)-1,2-环己烷-(1R,2R)-二胺(H2L2)、N,N′-双(2-羟基苯基)-N,N′-二甲基-乙烷-1,2-二胺(H2L3)、N,N′-双(2-羟基苯基)-N,N′-二苄基-乙烷-1,2-二胺(H2L4)以及N,N′-双(2-(4-叔丁基)羟基苯基)-乙烷-1,2-二胺(H2L5),连同它们的前药糖苷化形式GL1–5,已被合成并在体外评估其作为阿尔茨海默病(AD)治疗剂的潜力。金属离子(特别是铜、锌和铁)与淀粉样β(Aβ)肽的功能失调相互作用被假设在阿尔茨海默病的病因中发挥重要作用,通过螯合疗法破坏这些异常的金属–肽相互作用被认为是一种极具前景的治疗策略。像H2L1–5这样的四氢萨林对金属离子有显著亲和力,因此应该能够与Aβ肽竞争大脑中的铜、锌和铁。通过浊度测定法在体外检测这种活性;H2L1和H2L3在Cu2+和Zn2+的存在下被发现能够减弱Aβ1–40的聚集。此外,根据体外抗氧化剂测定,H2L1–5被确定为有效的抗氧化剂。GL1–5作为金属结合的前药制备;糖苷化旨在防止系统性金属结合,提高溶解度并增强大脑摄取。除了GL4以外,碳水化合物部分的酶(β-葡萄糖苷酶)去保护过程相对容易,证明了这一前药方法的一般可行性。最后,一种代表性前药GL3在细胞活性测定中被确定在较大浓度范围内是非毒性的。