29329-03-1Relevant articles and documents
A short, efficient route of 1-hydroxylated vitamin D ring A fragments
Mascarenas,Garcia,Castedo,Mourino
, p. 4365 - 4368 (1992)
The bis-exocyclic conjugated diene system of vitamin D ring A synthons is efficiently constructed by means of a palladium-catalyzed intramolecular cyclization of the (Z)-iodoalkene resulting from the stereoselective hydrometallation-iodinolysis of proparg
Dual delivery of nucleic acids and PEGylated-bisphosphonates via calcium phosphate nanoparticles
Bisso, Sofia,Mura, Simona,Castagner, Bastien,Couvreur, Patrick,Leroux, Jean-Christophe
, p. 142 - 152 (2019)
Despite many years of research and a few success stories with gene therapeutics, efficient and safe DNA delivery remains a major bottleneck for the clinical translation of gene-based therapies. Gene transfection with calcium phosphate (CaP) nanoparticles brings the advantages of low toxicity, high DNA entrapment efficiency and good endosomal escape properties. The macroscale aggregation of CaP nanoparticles can be easily prevented through surface coating with bisphosphonate conjugates. Bisphosphonates, such as alendronate, recently showed promising anticancer effects. However, their poor cellular permeability and preferential bone accumulation hamper their full application in chemotherapy. Here, we investigated the dual delivery of plasmid DNA and alendronate using CaP nanoparticles, with the goal to facilitate cellular internalization of both compounds and potentially achieve a combined pharmacological effect on the same or different cell lines. A pH-sensitive poly(ethylene glycol)-alendronate conjugate was synthetized and used to formulate stable plasmid DNA-loaded CaP nanoparticles. These particles displayed good transfection efficiency in cancer cells and a strong cytotoxic effect on macrophages. The in vivo transfection efficiency, however, remained low, calling for an improvement of the system, possibly with respect to the extent of particle uptake and their physical stability.
Nickel-catalyzed intramolecular [3 + 2 + 2] cycloadditions of alkylidenecyclopropanes. A straightforward entry to fused 6,7,5-tricyclic systems
Saya, Luca,Fernndez, Israel,Lpez, Fernando,Mascareas, Jos L.
, p. 5008 - 5011 (2014)
A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloadd
Palladium-catalyzed intramolecular iodine-transfer reactions in the presence of β-hydrogen atoms
Monks, Brendan M.,Cook, Silas P.
, p. 14214 - 14218 (2013)
Atom economy: A palladium-catalyzed atom-transfer reaction of secondary alkyl iodides is described. An intramolecular double insertion of an alkyne and olefin provides access to primary iodides possessing β-hydrogen atoms. The process delivers these complex bicyclic homoallylic iodides with tetrasubstituted olefins from easily accessible aliphatic iodides. Different functional groups, including common heterocycles, are tolerated. Copyright
Click-Connected 2-(Hydroxyimino)aldehydes for the Design of UV-Responsive Functional Molecules
Carbonaro, Linda,Cort, Antonella Dalla,D'Acunzo, Francesca,Di Sabato, Antonio,Filippini, Dario,Gentili, Patrizia,Leonelli, Francesca,Mancini, Laura
, p. 289 - 294 (2021)
Click chemistry is used to functionalize simple lipophilic and water-soluble molecules, a complex PEGylated phospholipid (DSPE-PEG2000), and two benzylic substrates with the 2-(hydroxyimino)aldehyde (HIA) group. To this end, two terminal alkynes bearing the HIA moiety were synthesized and coupled to different azides through copper(I)-catalyzed azide alkyne cycloaddition (CuAAC). Norrish–Yang photoisomerization (λ= 365 nm, LED source) is successfully obtained, with no interference by the triazole linker, except when the forbidden n-π* carbonyl transition is screened by a remote substituent such as salicylaldehyde. UV-Vis spectrometry suggests a specific interaction of HIAs with Cu(II), whereas no such evidence is found with Cu(I). We thereby show that the CuAAC methodology can be used successfully to obtain HIA-based UV-responsive hydrophilic or lipophilic ligands, phospholipidic components for the construction of liposomes, and macrocycle precursors.
Polymer supported cobalt carbonyl complexes as novel traceless alkyne linkers for solid-phase synthesis
Comely, Alex C.,Gibson, Susan E.,Hales, Neil J.
, p. 2075 - 2076 (1999)
The immobilisation of functionalised alkynes onto 'polymer-bound triphenylphosphine', their chemical manipulation and subsequent release has been demonstrated for the first time, thus illustrating that cobalt carbonyl complexes can be used as 'traceless' π-alkyne linkers.
Harnessing Redox Cross-Reactivity to Profile Distinct Cysteine Modifications
Majmudar, Jaimeen D.,Konopko, Aaron M.,Labby, Kristin J.,Tom, Christopher T. M. B.,Crellin, John E.,Prakash, Ashesh,Martin, Brent R.
, p. 1852 - 1859 (2016)
Cysteine S-nitrosation and S-sulfination are naturally occurring post-translational modifications (PTMs) on proteins induced by physiological signals and redox stress. Here we demonstrate that sulfinic acids and nitrosothiols react to form a stable thiosulfonate bond, and leverage this reactivity using sulfinate-linked probes to enrich and annotate hundreds of endogenous S-nitrosated proteins. In physiological buffers, sulfinic acids do not react with iodoacetamide or disulfides, enabling selective alkylation of free thiols and site-specific analysis of S-nitrosation. In parallel, S-nitrosothiol-linked probes enable enrichment and detection of endogenous S-sulfinated proteins, confirming that a single sulfinic acid can react with a nitrosothiol to form a thiosulfonate linkage. Using this approach, we find that hydrogen peroxide addition increases S-sulfination of human DJ-1 (PARK7) at Cys106, whereas Cys46 and Cys53 are fully oxidized to sulfonic acids. Comparative gel-based analysis of different mouse tissues reveals distinct profiles for both S-nitrosation and S-sulfination. Quantitative proteomic analysis demonstrates that both S-nitrosation and S-sulfination are widespread, yet exhibit enhanced occupancy on select proteins, including thioredoxin, peroxiredoxins, and other validated redox active proteins. Overall, we present a direct, bidirectional method to profile select redox cysteine modifications based on the unique nucleophilicity of sulfinic acids.
A Ring Closing Metathesis Approach to the Formal Synthesis of (+)-Callyspongiolide
Ko, Kwang-Yoon,Wilson, Zoe E.,Furkert, Daniel P.,Brimble, Margaret A.
, p. 5759 - 5771 (2020)
An enantioselective synthesis of macrocyclic core of (+)-callyspongiolide is described, constituting a formal synthesis of this natural product. The synthetic strategy constructs the 14-membered macrocyclic domain via Yamaguchi esterification followed by a challenging ring-closing metathesis (RCM) to effect the final formation of the macrolactone.
Synthesis of the C1-C27 Fragment of Stambomycin D Validates Modular Polyketide Synthase-Based Stereochemical Assignments
Anderson, Edward A.,Bernasconi, Alice,Blanco, Araceli,Challis, Gregory L.,Chintalapudi, Venkaiah,Gudmundsson, Haraldur G.,Lim, Jieyan,Song, Lijiang,Tran, Minh
supporting information, p. 7439 - 7444 (2021/10/01)
The stambomycins are a family of bioactive macrolides isolated from Streptomyces ambofaciens. Aside from two stereocenters installed through cytochrome P450 oxidations, their stereochemistry has been predicted by sequence analysis of the polyketide synthase. We report a synthesis of the C1-C27 fragment of stambomycin D, the spectroscopic data of which correlates well with that of the natural product, further validating predictive sequence analysis as a powerful tool for stereochemical assignment of complex polyketide natural products.
Synthesis of α,β-unsaturated epoxy ketones utilizing a bifunctional sulfonium/phosphonium ylide
Eskandari, Roozbeh,Hess, Jeremy P.,Tochtrop, Gregory P.
supporting information, p. 7136 - 7139 (2021/07/28)
Herein, a new protocol for rapid synthesis of α,β-unsaturated epoxy ketones utilizing a bifunctional sulfonium/phosphonium ylide is described. This approach comprises two sequential chemoselective reactions between sulfonium and phosphonium ylides and two distinct aldehydes, which allows for the rapid construction of a variety of unsymmetric α,β-unsaturated epoxy ketones. This methodology allows the rapid construction of the core reactive functionality of a family of lipid peroxidation products, the epoxyketooctadecenoic acids, but can be further broadly utilized as a useful synthon for the synthesis of natural products, particularly those derived from oxidized fatty acids. Accordingly, a protocol utilizing this approach to synthesize the epoxyketooctadecenoic acid family of molecules is described.
