Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

• Rémi Martinent,
• Javier López-Andarias,
• Dimitri Moreau,
• Yangyang Cheng,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

• depolymerization as soon as they reach the cytosol, and their endosomal capture is minimal because they enter cells by thiol-mediated uptake (Figure 4) [38][39][40][41][42][43][44][45][46][47][48]. This mechanism operates by dynamic covalent disulfide exchange on the cell surface and on the way into the cell

• for the thiol-mediated uptake, beginning with a dynamic covalent disulfide exchange with exofacial thiols, followed by either endocytosis or the direct crossing of membranes into cytosols through successive thiolate–disulfide exchange reactions or micellar pores (Figure 5b) [61]. Anionic glutamate was

• and cyclic peptides with Schmuck cations for gene transfection. Evolution from CPPs to CPDs and COCs. Structure of a) the trifunctional transporter 23 and c) the HaloTag reporter 26. b) Schematic mechanism of the thiol-mediated uptake of COCs with dynamic covalent disulfide exchange with exofacial

A dynamic combinatorial library for biomimetic recognition of dipeptides in water

• Florian Klepel and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2020, 16, 1588–1595, doi:10.3762/bjoc.16.131

• ), while AA binds significantly weaker (K ≈ 65–71 M−1). Keywords: artificial receptor; dynamic combinatorial chemistry; dynamic covalent chemistry; molecular recognition; thiolate–disulfide exchange; Introduction Peptides are one of the most abundant and structurally versatile motifs in nature. Thus

• cysteines are converted quantitively to disulfides by oxidation with oxygen. Until fully oxidized library members can exchange building blocks in a thiol–disulfide exchange reaction. While a closed monomer can be observed in the beginning (Figure S1, Supporting Information File 1), exclusively cyclic

• library to be under thermodynamic control. Therefore, the equilibrium responds to stimuli such as addition of a template, which would stabilize a suitable receptor and thus amplifies its formation. This strategy has led to the discovery of many artificial receptors [7][8][9][10], with thiolate disulfide

Understanding the unexpected effect of frequency on the kinetics of a covalent reaction under ball-milling conditions

• Ana M. Belenguer,
• Adam A. L. Michalchuk,
• Giulio I. Lampronti and
• Jeremy K. M. Sanders

Beilstein J. Org. Chem. 2019, 15, 1226–1235, doi:10.3762/bjoc.15.120

• Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK 10.3762/bjoc.15.120 Abstract We here explore how ball-mill-grinding frequency affects the kinetics of a disulfide exchange reaction. Our kinetic data show that the reaction progress is similar at all the frequencies studied (15–30 Hz

• ) conditions with 50 μL of acetonitrile added to 200 mg of powder. The kinetic points prepared for this study are all single point experiments. The reaction under study is a base-catalyzed disulfide exchange reaction starting from equimolar amounts of homodimers using DBU as the base catalyst to result in the

• , reported as mol % and documented in Supporting Information File 1. The solid product was dissolved in MeCN + 0.2% trifluoroacetic acid (TFA) at a concentration of 1 mg/mL and injected in the HPLC system. TFA was added to the sample for HPLC analysis to neutralize the base DBU and to quench the disulfide

Synthesis of a tubugi-1-toxin conjugate by a modulizable disulfide linker system with a neuropeptide Y analogue showing selectivity for hY1R-overexpressing tumor cells

• Rainer Kufka,
• Robert Rennert,
• Goran N. Kaluđerović,
• Lutz Weber,
• Wolfgang Richter and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2019, 15, 96–105, doi:10.3762/bjoc.15.11

• all nucleophilic thiolates (bound to various target peptides) by directed disulfide exchange. Compound 4 is accessible by reaction of the commercially available substances cysteamine (5) and 2,2'-dithiodipyridine (6). In practice, the synthesis of tubugi-1-SSPy from the published methyl ester

Stimuli-responsive oligonucleotides in prodrug-based approaches for gene silencing

• Françoise Debart,
• Christelle Dupouy and
• Jean-Jacques Vasseur

Beilstein J. Org. Chem. 2018, 14, 436–469, doi:10.3762/bjoc.14.32

• ’-O-acetylthiomethyl-containing RNA, produces various 2’-O-alkyldithiomethyl (RSSM)-modified RNAs bearing lipophilic or polar groups through a thiol disulfide exchange reaction with alkyldisulfanyl-pyridine derivatives (Scheme 3). In a preliminary evaluation, the RSSM modifications were shown to

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• disulfide exchange reactions in vivo [42][43]. All of these compounds were synthesized by (sometimes troublesome) chemical protocols requiring accurate control of the reaction conditions and several protection/deprotection steps. This is avoided using a biocatalyzed approach, as it has been shown exploiting

Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

• Christian Dollendorf,
• Martin Hetzer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 1652–1662, doi:10.3762/bjoc.9.189

• circulation and extracellular milieus, but are prone to cleavage in a reductive environment through dithiol–disulfide exchange reactions forming two corresponding thiol end-group bearing moieties [27][28]. The cleavage reaction is relatively fast and can take place within minutes to hours. This is

Multistep organic synthesis of modular photosystems

• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2012, 8, 897–904, doi:10.3762/bjoc.8.102

• new method introduced to secure facile access to complex architectures. Chemoorthogonal to the ring-opening disulfide exchange used for SOSIP, hydrazone exchange is then introduced to achieve stack exchange, which is a “switching” technology invented to drill giant holes into SOSIP architectures and

• fill them with functional π-stacks of free choice. Keywords: asparagusic acid; charge-transfer cascades; chromophores; disulfide exchange; hydrazone exchange; molecular switches; naphthalenediimides; π-stacks; surface-initiated polymerization; Introduction The architecture of photosystem 1 is rather

• surface of monolayer 48 were removed with DTT to afford free thiols on the surface of monolayer 49. For SOSIP [18][19], the concentration of propagators had to be optimized to a critical SOSIP concentration, cSOSIP. Below cSOSIP, ring-opening disulfide-exchange polymerization [27] does not occur, whereas