1164-16-5Relevant articles and documents
Synthesis of 6-Dimethylamino-9-[3'-(O-Methyl) (2S)-[UL-14C]Tyrosinylamino)-3'-Deoxy-β-D- ribofuranosyl] purine
Mehrotra, Amit P.,Ryan, Martin D.,Gani, David
, p. 623 - 634 (2000)
In order to investigate and further refine the mechanism of the unique cleavage activity of the 18 amino acid 2A region of the foot-and-mouth-disease virus (FMDV), the synthesis of 14C-labelled puromycin is required. Puromycin is an inhibitor of protein synthesis and is an analogue of the terminal aminoacyl-adenosine portion of aminoacyl-tRNA. A short and expedient four step synthesis of 6-dimethylamino-9-[3'-(O-methyl) (2S)-[UL-14C]tyrosinylamino)-3'-deoxy-β-D-ribofuranos purine (14C-labelled puromycin) starting from (2S)-[UL-14C]-tyrosine is therefore described.
Self-Assembled Nanomicelles as MRI Blood-Pool Contrast Agent
Babi?, Andrej,Vorobiev, Vassily,Xayaphoummine, Céline,Lapicorey, Ga?lle,Chauvin, Anne-Sophie,Helm, Lothar,Allémann, Eric
, p. 1348 - 1357 (2018)
Gadolinium-loaded nanomicelles show promise as future magnetic resonance imaging (MRI) contrast agents (CAs). Their increased size and high gadolinium (Gd) loading gives them an edge in proton relaxivity over smaller molecular Gd-complexes. Their size and stealth properties are fundamental for their long blood residence time, opening the possibility for use as blood-pool contrast agents. Using l-tyrosine as a three-functional scaffold we synthesized a nanostructure building block 8. The double C18 aliphatic chain on one side, Gd-1,4,7,10-tetraazacyclododecane-1-4-7-triacetic acid (Gd-DO3A) with access to bulk water in the center and 2 kDa PEG on the hydrophilic side gave the amphiphilic properties required for the core–shell nanomicellar architecture. The self-assembly into Gd-loaded monodispersed 10–20 nm nanomicelles occurred spontaneously in water. These nanomicelles (Tyr-MRI) display very high relaxivity at 29 mm?1 s?1 at low field strength and low cytotoxicity. Good contrast enhancement of the blood vessels and the heart together with prolonged circulation time in vivo, makes Tyr-MRI an excellent candidate for a new supramolecular blood-pool MRI CA.
Synthesis of Water-Soluble Chiral DOTA Lanthanide Complexes with Predominantly Twisted Square Antiprism Isomers and Circularly Polarized Luminescence
Dai, Lixiong,Zhang, Junhui,Chen, Yuqing,Mackenzie, Lewis E.,Pal, Robert,Law, Ga-Lai
supporting information, p. 12506 - 12510 (2019/10/02)
One-step cyclization of a tetraazamacrocycle 5 with 70% yield in a 25-g scale was performed. Its chiral DOTA derivatives, L4, has ?93% of TSAP coordination isomer in its Eu(III) and Yb(III) complexes in aqueous solution. [GdL4]5- exhibits a high relaxivity, making it a promising and efficient MRI contrast agent. High luminescence dissymmetry factor (glum) values of 0.285 (ΔJ = 1) for [TbL3]- and 0.241 (ΔJ = 1) for [TbL4]5- in buffer solutions were recorded.
α-Amino Diphenyl Phosphonates as Novel Inhibitors of Escherichia coli ClpP Protease
Moreno-Cinos, Carlos,Sassetti, Elisa,Salado, Irene G.,Witt, Gesa,Benramdane, Siham,Reinhardt, Laura,Cruz, Cristina D.,Joossens, Jurgen,Van Der Veken, Pieter,Br?tz-Oesterhelt, Heike,Tammela, P?ivi,Winterhalter, Mathias,Gribbon, Philip,Windshügel, Bj?rn,Augustyns, Koen
, p. 774 - 797 (2019/01/30)
Increased Gram-negative bacteria resistance to antibiotics is becoming a global problem, and new classes of antibiotics with novel mechanisms of action are required. The caseinolytic protease subunit P (ClpP) is a serine protease conserved among bacteria that is considered as an interesting drug target. ClpP function is involved in protein turnover and homeostasis, stress response, and virulence among other processes. The focus of this study was to identify new inhibitors of Escherichia coli ClpP and to understand their mode of action. A focused library of serine protease inhibitors based on diaryl phosphonate warheads was tested for ClpP inhibition, and a chemical exploration around the hit compounds was conducted. Altogether, 14 new potent inhibitors of E. coli ClpP were identified. Compounds 85 and 92 emerged as most interesting compounds from this study due to their potency and, respectively, to its moderate but consistent antibacterial properties as well as the favorable cytotoxicity profile.
CHIRAL CYCLEN COMPOUNDS AND THEIR USES
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Paragraph 0091; 0193, (2018/04/13)
The present invention relates to the preparation of a series of chiral DOTA, D03A, D02A, DO1A, cyclen and their metal complexes, which display properties superior to those of previous DOTA- based compounds, and hence are potentially valuable as a platform for diagnostic applications. The chiral DOTAs reveal a high abundance of twisted square antiprism (TSA) geometry favoring them to be used as potential MRI contrast agents, whereas their rapid labelling properties at mild conditions make them excellent candidates for use as radiometal chelators.
Photoinduced electron transfer-promoted debenzylation of phenylalanine and tyrosine derivatives using dicyanoarene
Yamawaki, Mugen,Okita, Yoshiki,Yamamoto, Takashi,Morita, Toshio,Yoshimi, Yasuharu
, p. 7239 - 7244 (2017/11/20)
Photoinduced debenzylations of phenylalanine and tyrosine derivatives with dicyanoarenes afford glycine derivatives by the generation of radical cations. Despite the limited substrate scope, the radical cation of phenylalanine and tyrosine derivatives bearing both a carbamate (without an aromatic group) at the N-terminal and an amide at the C-terminal could promote the breaking C–C bond at the benzylic position by a photoinduced electron transfer. It is important to understand the chemical behavior of the radical cations of phenylalanine and tyrosine in enzymes involving electron transfer.
LAT1 activity of carboxylic acid bioisosteres: Evaluation of hydroxamic acids as substrates
Zur, Arik A.,Chien, Huan-Chieh,Augustyn, Evan,Flint, Andrew,Heeren, Nathan,Finke, Karissa,Hernandez, Christopher,Hansen, Logan,Miller, Sydney,Lin, Lawrence,Giacomini, Kathleen M.,Colas, Claire,Schlessinger, Avner,Thomas, Allen A.
supporting information, p. 5000 - 5006 (2016/10/05)
Large neutral amino acid transporter 1 (LAT1) is a solute carrier protein located primarily in the blood–brain barrier (BBB) that offers the potential to deliver drugs to the brain. It is also up-regulated in cancer cells, as part of a tumor's increased metabolic demands. Previously, amino acid prodrugs have been shown to be transported by LAT1. Carboxylic acid bioisosteres may afford prodrugs with an altered physicochemical and pharmacokinetic profile than those derived from natural amino acids, allowing for higher brain or tumor levels of drug and/or lower toxicity. The effect of replacing phenylalanine's carboxylic acid with a tetrazole, acylsulfonamide and hydroxamic acid (HA) bioisostere was examined. Compounds were tested for their ability to be LAT1 substrates using both cis-inhibition and trans-stimulation cell assays. As HA-Phe demonstrated weak substrate activity, its structure–activity relationship (SAR) was further explored by synthesis and testing of HA derivatives of other LAT1 amino acid substrates (i.e., Tyr, Leu, Ile, and Met). The potential for a false positive in the trans-stimulation assay caused by parent amino acid was evaluated by conducting compound stability experiments for both HA-Leu and the corresponding methyl ester derivative. We concluded that HA's are transported by LAT1. In addition, our results lend support to a recent account that amino acid esters are LAT1 substrates, and that hydrogen bonding may be as important as charge for interaction with the transporter binding site.
Synthesis of N -acyl- N, O -acetals mediated by titanium ethoxide
Li, Min,Luo, Bingling,Liu, Qi,Hu, Yumin,Ganesan,Huang, Peng,Wen, Shijun
supporting information, p. 10 - 13 (2014/01/23)
N-Acyl-N,O-acetals are present in a number of bioactive natural products, and this unusual functional group can act as a synthetic precursor to unstable reactive N-acylimines. In this paper, a variety of N-acyl-O-ethyl-N,O-acetals was concisely prepared under mild conditions mediated by titanium ethoxide (Ti(OEt)4). The method also offers a new strategy to make other O-alkyl-N,O-acetals. Furthermore, this strategy was extended to the synthesis of an analogue of the natural product turtschamide.
One-step C-terminal deprotection and activation of peptides with peptide amidase from stenotrophomonas maltophilia in neat organic solvent
Arif, Muhammad I.,Toplak, Ana,Szymanski, Wiktor,Feringa, Ben L.,Nuijens, Timo,Quaedflieg, Peter J. L. M.,Wu, Bian,Janssen, Dick B.
, p. 2197 - 2202 (2014/07/21)
Chemoenzymatic peptide synthesis is a rapidly developing technology for cost effective peptide production on a large scale. As an alternative to the traditional C→N strategy, which employs expensive N-protected building blocks in each step, we have investigated an N→C extension route that is based on activation of a peptide C-terminal amide protecting group to the corresponding methyl ester. We found that this conversion is efficiently catalysed by Stenotrophomonas maltophilia peptide amidase in neat organic media. The system excludes the possibility of internal peptide cleavage as the enzyme lacks intrinsic protease activity. The produced peptide methyl ester was used for peptide chain extension in a kinetically controlled reaction by a thermostable protease.
An efficient synthesis of l-3,4,5-trioxygenated phenylalanine compounds from l-tyrosine
Chen, Ruijiao,Liu, Hao,Liu, Xiubing,Chen, Xiaochuan
, p. 3565 - 3570 (2013/04/24)
A new strategy for the synthesis of l-3,4,5-trioxygenated phenylalanine derivatives from l-tyrosine is developed for the first time. The approach, featuring the transformation of aryl diiodide to bis-phenol via a one-pot procedure including lithiation, boronation, and oxidation, is highly practical. By this robust protocol, N-protected l-3,5-bis(tert-butyldimethylsilyloxy)-4- methoxy-phenylalanine and l-3,4,5-trimethoxy-phenylalanine derivatives were obtained from l-tyrosine in 9 steps with 36-40% overall yields.
