16851-69-7Relevant academic research and scientific papers
Synthesis and biological evaluation of indoloquinoline alkaloid cryptolepine and its bromo-derivative as dual cholinesterase inhibitors
Nuthakki, Vijay K.,Mudududdla, Ramesh,Sharma, Ankita,Kumar, Ajay,Bharate, Sandip B.
supporting information, (2019/06/20)
Alkaloids have always been a great source of cholinesterase inhibitors. Numerous studies have shown that inhibiting acetylcholinesterase as well as butyrylcholinetserase is advantageous, and have better chances of success in preclinical/ clinical settings. With the objective to discover dual cholinesterase inhibitors, herein we report synthesis and biological evaluation of indoloquinoline alkaloid cryptolepine (1) and its bromo-derivative 2. Our study has shown that cryptolepine (1) and its 2-bromo-derivative 2 are dual inhibitors of acetylcholinesterase and butyrylcholinesterase, the enzymes which are involved in blocking the process of neurotransmission. Cryptolepine inhibits Electrophorus electricus acetylcholinesterase, recombinant human acetylcholinesterase and equine serum butyrylcholinesterase with IC50 values of 267, 485 and 699 nM, respectively. The 2-bromo-derivative of cryptolepine also showed inhibition of these enzymes, with IC50 values of 415, 868 and 770 nM, respectively. The kinetic studies revealed that cryptolepine inhibits human acetylcholinesterase in a non-competitive manner, with ki value of 0.88 μM. Additionally, these alkaloids were also tested against two other important pathological events of Alzheimer's disease viz. stopping the formation of toxic amyloid-β oligomers (via inhibition of BACE-1), and increasing the amyloid-β clearance (via P-gp induction). Cryptolepine displayed potent P-gp induction activity at 100 nM, in P-gp overexpressing adenocarcinoma LS-180 cells and excellent toxicity window in LS-180 as well as in human neuroblastoma SH-SY5Y cell line. The molecular modeling studies with AChE and BChE have shown that both alkaloids were tightly packed inside the active site gorge (site 1) via multiple π-π and cation-π interactions. Both inhibitors have shown interaction with the allosteric “peripheral anionic site” via hydrophobic interactions. The ADME properties including the BBB permeability were computed for these alkaloids, and were found within the acceptable range.
Orally Effective Aminoalkyl 10H-Indolo[3,2-b]quinoline-11-carboxamide Kills the Malaria Parasite by Inhibiting Host Hemoglobin Uptake
Mudududdla, Ramesh,Mohanakrishnan, Dinesh,Bharate, Sonali S.,Vishwakarma, Ram A.,Sahal, Dinkar,Bharate, Sandip B.
, p. 2581 - 2598 (2018/11/23)
A series of indolo[3,2-b]quinoline-C11-carboxamides were synthesized by incorporation of aminoalkyl side chains into the core of indolo[3,2-b]quinoline-C11-carboxylic acid. Their in vitro antiplasmodial evaluation against Plasmodium falciparum led to the identification of a 2-(piperidin-1-yl)ethanamine-linked analogue {2-bromo-N-[2-(piperidin-1-yl)ethyl]-10H-indolo[3,2-b]quinoline-11-carboxamide (3 g)} (IC50=1.3 μm) as the most promising compound exhibiting good selectivity indices against mammalian cell lines. The kill kinetics on erythrocytic-stage parasites revealed that 3 g caused complete killing of only the trophozoite-stage parasites. Mechanistic studies showed that 3 g targets the food vacuole of the parasite and inhibits hemoglobin uptake, β-hematin formation, and the basic endocytic processes of the parasite. Analogue 3 g was found to be orally bioavailable, and its curative antimalarial studies at 50 mg per kg p.o. against a Plasmodium berghei (ANKA)-infected mouse model revealed that mice treated with 3 g showed 27–35 % suppression of parasitemia with an increase in life span relative to untreated, control mice. Thus, the present work demonstrated a proof of concept for the oral efficacy of indolo[3,2-b]quinoline-C11-carboxamides.
The "gatekeeper" Residue Influences the Mode of Binding of Acetyl Indoles to Bromodomains
Unzue, Andrea,Zhao, Hongtao,Lolli, Graziano,Dong, Jing,Zhu, Jian,Zechner, Melanie,Dolbois, Aymeric,Caflisch, Amedeo,Nevado, Cristina
, p. 3087 - 3097 (2016/05/19)
Small-molecule hits for the bromodomains of CREBBP and BAZ2B have been identified by scaffold hopping followed by docking of a set of ～200 compounds containing the acetyl indole scaffold. Chemical synthesis of nearly 30 derivatives has resulted in ligands of representatives of three subfamilies of human bromodomains with favorable ligand efficiency. The X-ray crystal structures of three different bromodomains (CREBBP, BAZ2B, and BRPF1b) in complex with acetyl indole derivatives reveal the influence of the gatekeeper residue on the orientation of small-molecule ligands in the acetyl lysine binding site.
Indoloquinoline compounds as calcium channel blockers
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Page/Page column 8, (2008/06/13)
Various calcium channel blockers and pharmaceutical compositions containing these compounds are disclosed. Calcium channel blockers are compounds capable of inhibiting calcium ion channels. Methods for preparing calcium channel blockers and their use as c
A concise synthesis of the DNA-intercalating and antimalarial alkaloid cryptolepine and its fluorescence behaviour in solvents of different polarities
Lai, Tapan Kumar,Chatterjee, Asima,Banerji, Julie,Sarkar, Deboleena,Chattopadhyay, Nitin
experimental part, p. 1975 - 1983 (2009/02/07)
A microwave-induced rapid and facile synthesis of the DNA-intercalating and antimalarial drug cryptolepine is described. The key step in this synthesis involves the aqueous-phase base-catalyzed condensation of isatin and 1-acetyl-1H-indol-3-yl acetate which has been simplified and expedited by dielectric heating, employing an ordinary domestic microwave oven. The method transforms the synthesis of an important drug molecule from a prohibitively lengthy process to a matter of a few minutes with a much improved yield. Dual absorption and fluorescence is observed from the molecular system in solvents of different polarity thus providing valuable insight into its binding modes toward protein or DNA.
Synthesis of some cryptolepine analogues, assessment of their antimalarial and cytotoxic activities, and consideration of their antimalarial mode of action
Onyeibor, Onyeka,Croft, Simon L.,Dodson, Hilary I.,Feiz-Haddad, Mohammad,Kendrick, Howard,Millington, Nicola J.,Parapini, Silvia,Phillips, Roger M.,Seville, Scott,Shnyder, Steven D.,Taramelli, Donatella,Wright, Colin W.
, p. 2701 - 2709 (2007/10/03)
A series of analogues of cryptolepine (1) have been synthesized and evaluated for their in vitro antiplasmodial and cytotoxic properties. The IC50 values of several compounds (11a, 11k-m, 11o, 13) against Plasmodium falciparum (strain K1) were 90% at doses of 25 mg kg-1 day -1 with no apparent toxicity to the mice. 2,7-Dibromocryptolepine (15) was evaluated at several dose levels, and a dose-dependent suppression of parasitemia was seen (ED90 = 21.6 mg kg-1 day -1). The antimalarial mode of action of 1 appears to be similar to that of chloroquine and involves the inhibition of hemozoin formation. A number of analogues were assessed for their effects on the inhibition of β-hematin (hemozoin) formation, and the results were compared with their antiplasmodial activities having taken account of their predicted accumulation into the acidic parasite food vacuole. No correlation was seen (r2 = 0.0781) suggesting that the potent antimalarial activity of compounds such as 15 involves other mechanisms in addition to the inhibition of hemozoin formation.
