- Near-Infrared Fluorescent Micelles from Poly(norbornene) Brush Triblock Copolymers for Nanotheranostics
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This contribution describes the design and synthesis of multifunctional micelles based on amphiphilic brush block copolymers (BBCPs) for imaging and selective drug delivery of natural anticancer compounds. Well-defined BBCPs were synthesized via one-pot multi-step sequential grafting-through ring-opening metathesis polymerization (ROMP) of norbornene-based macroinitiators. The norbornenes employed contain a poly(ethylene glycol) methyl ether chain, an alkyl bromide chain, and/or a near-infrared (NIR) fluorescent cyanine dye. After block copolymerization, post-polymerization transformations using bromide-azide substitution, followed by the strain-promoted azide-alkyne cycloaddition (SPAAC) allowed for the functionalization of the BBCPs with the piplartine (PPT) moiety, a natural product with well-documented cytotoxicity against cancer cell lines, via an ester linker between the drug and the polymer side chain. The amphiphilic BBCPs self-assembled in aqueous media into nano-sized spherical micelles with neutral surface charges, as confirmed by dynamic light scattering analysis and transmission electron microscopy. During self-assembly, paclitaxel (PTX) could be effectively encapsulated into the hydrophobic core to form stable PTX-loaded micelles with high loading capacities and encapsulation efficiencies. The NIR fluorescent dye-containing micelles exhibited remarkable photophysical properties, excellent colloidal stability under physiological conditions, and a pH-induced disassembly under slightly acidic conditions, allowing for the release of the drug in a controlled manner. The in vitro studies demonstrated that the micelles without the drug (blank micelles) are biocompatible at concentrations of up to 1 mg mL-1 and present a high cellular internalization capacity toward MCF-7 cancer cells. The drug-functionalized micelles showed in vitro cytotoxicity comparable to free PPT and PTX against MCF-7 and PC3 cancer cells, confirming efficient drug release into the tumor environment upon cellular internalization. Furthermore, the drug-functionalized micelles exhibited higher selectivity than the pristine drugs and preferential cellular uptake in human cancer cell lines (MCF-7 and PC3) when compared to the normal breast cell line (MCF10A). This study provides an efficient strategy for the development of versatile polymeric nanosystems for drug delivery and image-guided diagnostics. Notably, the easy functionalization of BBCP side chains via SPAAC opens up the possibility for the preparation of a library of multifunctional systems containing other drugs or functionalities, such as target groups for recognition.
- Braga, Carolyne B.,Pilli, Ronaldo A.,Ornelas, Catia,Weck, Marcus
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p. 5290 - 5306
(2021/11/30)
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- Efficient Syntheses of Diverse, Medicinally Relevant Targets Planned by Computer and Executed in the Laboratory
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The Chematica program was used to autonomously design synthetic pathways to eight structurally diverse targets, including seven commercially valuable bioactive substances and one natural product. All of these computer-planned routes were successfully executed in the laboratory and offer significant yield improvements and cost savings over previous approaches, provide alternatives to patented routes, or produce targets that were not synthesized previously. Although computers have demonstrated the ability to challenge humans in various games of strategy, their use in the automated planning of organic syntheses remains unprecedented. As a result of the impact that such a tool could have on the synthetic community, the past half century has seen numerous attempts to create in silico chemical intelligence. However, there has not been a successful demonstration of a synthetic route designed by machine and then executed in the laboratory. Here, we describe an experiment where the software program Chematica designed syntheses leading to eight commercially valuable and/or medicinally relevant targets; in each case tested, Chematica significantly improved on previous approaches or identified efficient routes to targets for which previous synthetic attempts had failed. These results indicate that now and in the future, chemists can finally benefit from having an “in silico colleague” that constantly learns, never forgets, and will never retire. Multistep synthetic routes to eight structurally diverse and medicinally relevant targets were planned autonomously by the Chematica computer program, which combines expert chemical knowledge with network-search and artificial-intelligence algorithms. All of the proposed syntheses were successfully executed in the laboratory and offer substantial yield improvements and cost savings over previous approaches or provide the first documented route to a given target. These results provide the long-awaited validation of a computer program in practically relevant synthetic design.
- Klucznik, Tomasz,Mikulak-Klucznik, Barbara,McCormack, Michael P.,Lima, Heather,Szymku?, Sara,Bhowmick, Manishabrata,Molga, Karol,Zhou, Yubai,Rickershauser, Lindsey,Gajewska, Ewa P.,Toutchkine, Alexei,Dittwald, Piotr,Startek, Micha? P.,Kirkovits, Gregory J.,Roszak, Rafa?,Adamski, Ariel,Sieredzińska, Bianka,Mrksich, Milan,Trice, Sarah L.J.,Grzybowski, Bartosz A.
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supporting information
p. 522 - 532
(2018/03/21)
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- A Robust, Recyclable Resin for Decagram Scale Resolution of (±)-Mefloquine and Other Chiral N-Heterocycles
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Decagram quantities of enantiopure (+)-mefloquine have been produced via kinetic resolution of racemic mefloquine using a ROMP-gel supported chiral acyl hydroxamic acid resolving agent. The requisite monomer was prepared in a few synthetic steps without chromatography and polymerization was safely performed on a >30 gram scale under ambient conditions. The reagent was readily regenerated and reused multiple times for the resolution of 150 grams of (±)-mefloquine and other chiral N-heterocylces.
- Kreituss, Imants,Chen, Kuang-Yen,Eitel, Simon H.,Adam, Jean-Michel,Wuitschik, Georg,Fettes, Alec,Bode, Jeffrey W.
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supporting information
p. 1553 - 1556
(2016/02/12)
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- AMIDOALKYLPIPERAZINYL DERIVATIVES FOR THE TREATMENT OF CENTRAL NERVOUS SYSTEM DISEASES
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The invention relates to novel amidoalkylpiperazinyl derivatives of tricyclic heterocyclic systems of general formula (I), wherein Z represents -NH- and X represents -S-, or Z represents -S- and X represents >C=C1 represents H or -CH3, R6 and R7 both represent H, n is an integer from 0 to 4 inclusive, G represents a cyclic amide or imide moiety, and optical isomers, geometric isomers, and pharmaceutically acceptable salts thereof. The compounds may be useful for the treatment and/or prevention of the central nervous system disorders.
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Page/Page column 28; 29
(2013/03/26)
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- CYCLOALKANE DERIVATIVE
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The present invention relates to a novel cycloalkane derivative which has a useful psychotropic action with less side effect.
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Page/Page column 6-7
(2011/06/19)
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- Synthesis and anxiolytic activity of N-substituted cyclic imides (1R*,2S*3R*,4S*)-N-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-2,3-b icyclo[2.2.1]heptanedicarboxime (Tandospirone) and related compounds
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A series of cyclic imides bearing a ω-(4-aryl and 4-heteroaryl-1-piperazinyl)alkyl moieties was synthesized and tested in vivo for anxiolytic activity. The in vitro binding affinities of these compounds were also examined for 5-HT(1A) receptor sites. Structure-activity relationships within these series are discussed. One of these compounds, (1R*,2S*,3R*,4S*)-N-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-2,3- bicyclo[2.2.1]heptanedicarboximide (1: tandospirone), was found to be equipotent with buspirone in its anxiolytic activity and more anxio-selective than buspirone and diazepam. Tandospirone (1) is currently undergoing clinical evaluation as a selective anxiolytic agent.
- Ishizumi,Kojima,Antoku
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p. 2288 - 2300
(2007/10/02)
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