- Human Serum Albumin-Delivered [Au(PEt3)]+ Is a Potent Inhibitor of T Cell Proliferation
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Using a modular library format in conjunction with cell viability (MTS) and flow cytometry assays, 90 cationic complexes [AuPL]n+ (P = phosphine ligand; L = thiourea derivative or chloride) were studied for their antiproliferative activity in CD8+ T lymphocyte cells. The activity of the compounds correlates with the steric bulk of the phosphine ligands. Thiourea serves as a leaving group that is readily replaced by cysteine thiol (NMR, ESI-MS). Taking advantage of selective thiourea ligand exchange, the fragments [Au(PEt3)]+ and [Au(JohnPhos)]+ (JohnPhos = 1,1′-biphenyl-2-yl)di-tert-butylphosphine) in compounds 1 and 2 were transferred to recombinant human serum albumin (rHSA). PEt3 promoted efficient modification of Cys34 in HSA (HSA-1), whereas use of bulky JohnPhos as a carrier ligand led to serum protein nonspecifically modified with multiple gold adducts (HSA-2) (Ellman’s test, ESI-TOF MS). HSA-1, but not HSA-2, strongly inhibits T cell proliferation at nanomolar doses. The potential role of HSA as a delivery vehicle in gold-based autoimmune disease treatment is discussed.
- Dean, Tyler C.,Yang, Mu,Liu, Mingyong,Grayson, Jason M.,DeMartino, Anthony W.,Day, Cynthia S.,Lee, Jingyun,Furdui, Cristina M.,Bierbach, Ulrich
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supporting information
p. 572 - 576
(2017/05/17)
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- Synthesis of Substituted Quinolizidines via a Gold-Catalyzed Double Cyclization Cascade
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A novel synthesis of quinolizidines by a cationic gold-catalyzed double cyclization cascade has been developed. The reaction was initiated by the gold-catalyzed 6-exo-dig cyclization of ynamides, which was followed by a second cyclization of an enamide intermediate to provide the corresponding quinolizidine derivatives. The utility of this reaction was demonstrated by application to the synthesis of multi-substituted quinolizidines and by the total synthesis of a quinolizidine alkaloid, (±)-lupinine.
- Nonaka, Shiori,Sugimoto, Kenji,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 380 - 385
(2016/02/12)
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- Gold catalysis: Biarylphosphine ligands as key for the synthesis of dihydroisocoumarins
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Agold-catalyzed phenol synthesis was successfully used in the synthesis of dihydroisocoumarins for the first time.Alarge number of gold(I) complexes were prepared and tested; only complexes based on the biarylphosphine motif were successful. CSIRO 2014.
- Hashmi, A. Stephen K.,Bechem, Benjamin,Loos, Annette,Hamzic, Melissa,Rominger, Frank,Rabaa, Hassan
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p. 481 - 499
(2014/04/03)
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- Leveraging the micellar effect: Gold-catalyzed dehydrative cyclizations in water at room temperature
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The first examples of gold-catalyzed cyclizations of diols and triols to the corresponding hetero- or spirocycles in an aqueous medium are presented. These reactions take place within nanomicelles, where the hydrophobic effect is operating, thereby driving the dehydrations, notwithstanding the surrounding water. By the addition of simple salts such as sodium chloride, reaction times and catalyst loadings can be significantly decreased.
- Minkler, Stefan R. K.,Isley, Nicholas A.,Lippincott, Daniel J.,Krause, Norbert,Lipshutz, Bruce H.
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supporting information
p. 724 - 726
(2014/03/21)
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- Efficient general procedure to access a diversity of gold(0) particles and gold(I) phosphine complexes from a simple HAuCl4 source. Localization of homogeneous/heterogeneous system's interface and field-emission scanning electron microscopy study
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Soluble gold precatalysts, aimed for homogeneous catalysis, under certain conditions may form nanoparticles, which dramatically change the mechanism and initiate different chemistry. The present study addresses the question of designing gold catalysts, taking into account possible interconversions and contamination at the homogeneous/heterogeneous system's interface. It was revealed that accurate localization of boundary experimental conditions for formation of molecular gold complexes in solution versus nucleation and growth of gold particles opens new opportunities for well-known gold chemistry. Within the developed concept, a series of practical procedures was created for efficient synthesis of soluble gold complexes with various phosphine ligands (R3P)AuCl (90-99% yield) and for preparation of different types of gold materials. The effect of the ligand on the particles growth in solution has been observed and characterized with high-resolution field-emission scanning electron microscopy (FE-SEM) study. Two unique types of nanostructured gold materials were prepared: hierarchical agglomerates and gold mirror composed of ultrafine smoothly shaped particles.
- Zalesskiy, Sergey S.,Sedykh, Alexander E.,Kashin, Alexey S.,Ananikov, Valentine P.
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supporting information
p. 3550 - 3559
(2013/05/09)
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