- Enhancing cellular sulfane sulfur through β-glycosidase-activated persulfide donors: mechanistic insights and oxidative stress mitigation
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Sulfane sulfur species such as persulfides and polysulfides along with hydrogen sulfide protect cells from oxidative stress and are key members of the cellular antioxidant pool. Here, we report perthiocarbamate-based prodrugs that are cleaved by β-glycosidases to produce persulfide and relatively innocuous byproducts. The β-glucosidase-activated persulfide donor enhances cellular sulfane sulfur and protects cells against lethality induced by elevated reactive oxygen species (ROS).
- Bora, Prerona,Sathian, Manjima B.,Chakrapani, Harinath
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p. 2987 - 2990
(2022/03/15)
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- COMPOUNDS COMPRISING CLEAVABLE LINKER AND USES THEREOF
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Provided are a compound including a cleavable linker, a use thereof, and an intermediate compound for preparing the same, and more particularly, the compound including a cleavable linker of the present invention may include an active agent (for example, a drug, a toxin, a ligand, a probe for detection, etc.) having a specific function or activity, a -S(=0)(=N-)- functional group which is capable of selectively releasing the active agent, and a functional group which triggers a chemical reaction, a physicochemical reaction and/or a biological reaction by external stimulation, and may further include a ligand (for example, oligopeptide, polypeptide, antibody, etc.) having binding specificity for a desired target receptor.
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- O-Glycosidation reactions promoted by in situ generated silver N-heterocyclic carbenes in ionic liquids
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We herein report O-glycosidation reactions promoted via silver N-heterocyclic carbene complexes formed in situ in ionic liquids. Seven different room temperature ionic liquids were screened for the glycosidation reaction of 4-nitrophenol with tetra-O-acetyl-α-d-galactopyranosyl bromide. Good to excellent yields were obtained using Ag-NHC complexes derived from imidazolium halide salts to promote the glycosidation reaction, whereas yields considered moderate to low were obtained without use of the silver carbene complex. Anion metathesis of the ionic liquids with inexpensive alkylammonium halides also resulted in silver N-heterocyclic carbene formation and subsequent O-glycosidation in the presence of silver carbonate. Effective utility of this methodology has been demonstrated with biologically relevant acceptors (including flavones and steroids) where O-β-glycoside products were obtained selectively in moderate to good yields. We have also demonstrated that the Ag-NHC complex is a superior promoter to traditionally used silver carbonate for the glycosidation of polyphenolic acceptors. The ionic liquids used in the study could be recycled three times without apparent loss in activity.
- Talisman, Ian Jamie,Kumar, Vineet,Razzaghy, Jacqueline,Malhotra, Sanjay V.
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experimental part
p. 883 - 890
(2011/06/20)
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- Application of halide molten salts as novel reaction media for O-glycosidic bond formation
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In this study we have explored the application of halide molten salts as reaction media for O-glycosidic bond formation under basic conditions and mild heating. Eighteen different room-temperature ionic liquids and molten salts, representing four different classes of cations (i.e. imidazolium, pyridinium, pyrrolidinium and ammonium), were screened in the glycosidation reaction of p-nitrophenol with aceto-bromo-α-D-galactose. 1-Butyl-4-methylimidazolium chloride (BMIM·Cl) gave the best results and was applied in the reactions of other phenolic substrates to give the products with up to 80% yields. All the reactions were highly selective to give the β-anomers, and the molten salt BMIM·Cl could easily be reused with no apparent loss in activity.
- Kumar, Vineet,Talisman, Ian Jamie,Malhotra, Sanjay V.
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supporting information; experimental part
p. 3377 - 3381
(2010/08/19)
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- Aryl O- and S-galactosides and lactosides as specific inhibitors of human galectins-1 and -3: Role of electrostatic potential at O-3
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Phase transfer catalyzed reaction was used for the high yielding synthesis of aryl 1-thio-β-d-galacto- and lacto-pyranosides carrying a panel of substituents on the phenyl groups. Best galectin-1 inhibitors were simple p-nitrophenyl thiogalactoside 5a for
- Giguere, Denis,Sato, Sachiko,St-Pierre, Christian,Sirois, Suzanne,Roy, Rene
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p. 1668 - 1672
(2007/10/03)
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- Sol-Gel Polycondensation of Tetraethyl Orthosilicate (TEOS) in Sugar-Based Porphyrin Organogels: Inorganic Conversion of a Sugar-Directed Porphyrinic Fiber Library through Sol-Gel Transcription Processes
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Sugar-appended porphyrins (1a-e) with monosaccharide groups at their periphery have been rationally designed for a new class of gelating reagents. A few of these compounds have the tendancy to form one-dimensional aggregates stable enough to show successful gelation ability for DMF-alcohol mixed solvents. The aggregation mode in the specific columnar super structures has been evaluated in detail by UV-visible spectrometry (UV/Vis), circular dichroism (CD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). All UV-visible spectra of sugar-appended porphyrinic gels obtained from la-c exhibit Soret band absorptions, which shift to lower wave-length and are significantly broadened. This phenomenon indicates that these porphyrin cores strongly interact with each other in an H-aggregate fashion, which drives the generation of a one-dimensional porphyrin-stacking array. The CD spectra of the organogels from 1a and 1b, which are in anomers, exhibit an almost symmetric pattern, whereas the gel from 1c gives a completely different pattern. This implies that the gel fibrils wind themselves in a right- or left-handed fashion; this reflects chirality in the specific molecular structure of the gelators. The results from SEM for the gel fibrils are in good agreement with the CD patterns. The gel fibrils in la possess left-handed helicity, whereas those in lb wind themselves right-handedly. Macroscopic helical morphology reflects the microscopic structure well at a molecular level, which gives structural variety of the gel fibrils, which can be defined by the sugar library. Inorganic conversion of the organic helical fibrils by a sol-gel transcription process successfully gives the helical-silica structures, which finely inherit the organic morphology. A striking observation is that a unimolecular porphyrin-stacking array is also transcribed into silica fibers when the optimized sol-gel reaction conditions are selected. A sugar-based organic-fiber library in porphyrinic gels thus provides a variety of inorganic materials through the sol-gel transcription process.
- Kawano, Shin-Ichiro,Tamaru, Shun-Ichi,Fujita, Norifumi,Shinkai, Seiji
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p. 343 - 351
(2007/10/03)
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