Discovery of a marine-derived bis-indole alkaloid fascaplysin, as a new class of potent P-glycoprotein inducer and establishment of its structure–activity relationship
摘要:
The screening of IIIM natural products repository for P-gp modulatory activity in P-gp over-expressing human adenocarcinoma LS-180 cells led to the identification of 7 natural products viz. withaferin, podophyllotoxin, 3-demethylcolchicine, agnuside, reserpine, seseberecine and fascaplysin as P-gp inducers. Fascaplysin (6a), a marine-derived bis-indole alkaloid, was the most potent among all of them, showing induction of P-gp with EC50 value of 25 nM. P-gp induction is one of the recently targeted strategy to increase amyloid-beta clearance from Alzheimer brains. Thus, we pursued a medicinal chemistry of fascaplysin to establish its structure activity relationship for P-gp induction activity. Four series of analogs viz, substituted quaternary fascaplysin analogs, D-ring opened quaternary analogs, D-ring opened non-quaternary analogs, and beta-carbolinium analogs were synthesized and screened for P-gp induction activity. Among the total of 48 analogs screened, only quaternary nitrogen containing analogs 6a-g and 10a, 10h-1 displayed promising P-gp induction activity; whereas non-planar non-quaternary analogs 9a-m, 13a-n, 15a-h were devoid of this activity. The P-gp induction activity of best compounds was then confirmed by western-blot analysis, which indicated that fascaplysin (6a) along with 4,5-difluoro analog of fascaplysin 6f and D-ring opened analog 10j displayed 4-8 fold increase in P-gp expression in LS-180 cells at 1 mu M. Additionally, compounds 6a and 6f also showed inhibition of acetylcholinestease (AChE), an enzyme responsible for neuronal loss in Alzheimer's disease. Thus, fascaplysin and its analogs showing promising P-gp induction along with AChE inhibition at 1 mu M, with good safety window (LS-180: IC50 > 10 mu M, hGF: 4 mu M), clearly indicates their promise for development as an anti-Alzheimer agent. (C) 2015 Elsevier Masson SAS. All rights reserved.
A direct synthesis of β-carbolines via a three-step one-pot domino approach with a bifunctional Pd/C/K-10 catalyst
摘要:
A rapid, microwave-assisted synthesis of beta-carbolines via a Successive condensation/cyclization/dehydrogenation approach is described. This methodology involves the coupling of various tryptamines with aromatic aldehydes/glyoxals. The product imine undergoes a Pictet-Spengler cyclization followed by a final dehydrogenation to yield beta-carbolines in a three-step domino reaction. The use of the bifunctional catalyst Pd/C/K-10 combined with microwave irradiation enabled the synthesis of beta-carbolines in short reaction times and in good to excellent yields. (C) 2009 Elsevier Ltd. All rights reserved.
Photoredox Generated Vinyl Radicals: Synthesis of Bisindoles and β-Carbolines
作者:Neha Chalotra、Ajaz Ahmed、Masood Ahmad Rizvi、Zakir Hussain、Qazi Naveed Ahmed、Bhahwal Ali Shah
DOI:10.1021/acs.joc.8b02193
日期:2018.12.7
A photoredox catalyzed approach enabling use of alkynes as surrogate of 2-oxoaldehydes/1,2-diones is reported. The method overcomes the difficulty associated with application of unsubstituted aliphatic α-oxoaldehydes, which has hitherto limited their general use. Indoles, tryptamine, and tryptophan methyl ester participated in the reaction to give a variety of α-oxo based analogues. Quantum yield investigations
Synthesis and application of β-carbolines as novel multi-functional anti-Alzheimer’s disease agents
作者:William Horton、Abha Sood、Swarada Peerannawar、Nandor Kugyela、Aditya Kulkarni、Rekha Tulsan、Chris D. Tran、Jessica Soule、Harry LeVine、Béla Török、Marianna Török
DOI:10.1016/j.bmcl.2016.11.067
日期:2017.1
The design, synthesis and assessment of β-carboline core-based compounds as potential multifunctional agents against several processes that are believed to play a significant role in Alzheimer’s disease (AD) pathology, are described. The activity of the compounds was determined in Aβ self-assembly (fibril and oligomer formation) and cholinesterase (AChE, BuChE) activity inhibition, and their antioxidant