171596-43-3Relevant articles and documents
Diastereospecific Synthesis of Tetrahydroisoquinolines via Radical Cyclization: Application in the Synthesis of ent-Tadalafil
Barve, Indrajeet J.,Chiu, Wei-Jung,Lin, Yan-Liang,Sun, Chung-Ming
, p. 4041 - 4046 (2021/07/10)
An enantioselective synthesis of 1-substituted tetrahydroisoquinolines from L–Dopa methyl ester through intramolecular aryl radical cyclization is demonstrated. The strategy consists of bromination of (S)-2-amino-3-(2-bromo-4,5-dimethoxyphenyl)propanoate followed by condensation with various aldehydes to afford bromoimidate ester. Aryl radicals generated from bromoimidate ester under the radical generating conditions (nBu3SnH/AIBN) cyclizes via 6-endo mode to afford cis-1-substituted tetrahydroisoquinolines exclusively in 99% ee. The utility of this synthetic protocol is demonstrated in the synthesis of (6S, 12aS) Tadalafil (5 steps, 21%, 99% ee). (Figure presented.).
Design, synthesis and bio-evaluation of C-1 alkylated tetrahydro-β-carboline derivatives as novel antifungal lead compounds
Singh, Rahul,Jaisingh, Aanchal,Maurya, Indresh K.,Salunke, Deepak B.
, (2019/12/27)
The field of antifungal agent has become static and development of resistance by the pathogen as well as limited clinical efficacy of marketed drugs demand the constant development of new antifungals. The presence of hydrocarbon chain of specific length linked with various different heterocycles was found to be an important structural feature in various antifungal lead compounds. Based on the prominent antimicrobial activity of β-carboline derivatives, a set of C1 alkylated tetrahydro-β-carboline derivatives were proposed to be active against fungi. To validate and confirm the role of suitable alkyl chains linked to a β-carboline scaffold, few related analogues having C1 aryl substituents were also synthesized in one step via classic Pictet-Spengler reaction. The synthesized library was evaluated for its antifungal activity against C. albicans, C. krusei, C. parapsilosis, C. kefyr, C. glabrata, C. tropicalis and C. neoformans. One of the library members (compound 12c), with n-alkyl chain of eight carbons exhibited potent antifungal activity against C. glabrata and C. kefyr. The lead compound, being selectively toxic also demonstrated prominent synergy enhancing the potency of antifungal drugs up to 10-fold. The time kill kinetic studies confirmed the efficacy of compound 12c, where the results obtained were comparable to that of Amp B. FE-SEM analysis revealed the increased asymmetry, disintegration and roughness of cell surface which could be because of the possible interaction of compound 12c at membrane level or interference in cell wall structure. Apoptosis/necrosis detection assay confirmed the significant apoptotic activity in C. glabrata cells after 12c treatment which was responsible for the rapid killing of C. glabrata cells.
Design, Synthesis, and Biological Evaluation of Orally Available First-Generation Dual-Target Selective Inhibitors of Acetylcholinesterase (AChE) and Phosphodiesterase 5 (PDE5) for the Treatment of Alzheimer's Disease
Mao, Fei,Wang, Huan,Ni, Wei,Zheng, Xinyu,Wang, Manjiong,Bao, Keting,Ling, Dazheng,Li, Xiaokang,Xu, Yixiang,Zhang, Haiyan,Li, Jian
, p. 328 - 345 (2018/03/01)
Through drug discovery strategies of repurposing and redeveloping existing drugs, a series of novel tadalafil derivatives were rationally designed, synthesized, and evaluated to seek dual-target AChE/PDE5 inhibitors as good candidate drugs for Alzheimer's disease (AD). Among these derivatives, 1p and 1w exhibited excellent selective dual-target AChE/PDE5 inhibitory activities and improved blood-brain barrier (BBB) penetrability. Importantly, 1w·Cit (citrate of 1w) could reverse the cognitive dysfunction of scopolamine-induced AD mice and exhibited an excellent effect on enhancing cAMP response element-binding protein (CREB) phosphorylation in vivo, a crucial factor in memory formation and synaptic plasticity. Moreover, the molecular docking simulations of 1w with hAChE and hPDE5A confirmed that our design strategy was rational. In summary, our research provides a potential selective dual-target AChE/PDE5 inhibitor as a good candidate drug for the treatment of AD, and it could also be regarded as a small molecule probe to validate the novel AD therapeutic approach in vivo.
