- The adsorption and bonding of ω-mercaptoalkanols on HNO3 etched copper
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ω-Mercaptoalkanols (HO(CH2)nSH, n = 2, 6, 10) could cleave and were chemisorbed in trans and gauche conformation on HNO3 etched copper foils to form self-assembled monolayers. The orientation of the molecules in the film was characterized by Fourier transform surface enhanced Raman scattering spectroscopy (FT-SERS). In the liquid state the above compounds tend to be in the gauche conformation, however, in the adsorption state they inclined to be in the trans conformation. In the adsorption state the ratio of trans to gauche conformation increased with the chain length.
- Li, Fengting,Lu, Yun,Xue, Gi,Cao, Qing
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- Substrate hydrolysis triggered formation of fluorescent gold nanoclusters-a new platform for the sensing of enzyme activity
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Substrate hydrolysis was utilized to trigger a "top-down" etching process for the generation of fluorescent gold nanoclusters, and the changes in emission intensity of the assay solution provide a facile way for the sensing of enzyme activity.
- Chen, Yang,Zhou, Huipeng,Wang, Yan,Li, Wenying,Chen, Jian,Lin, Quan,Yu, Cong
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- Synthesis and in vitro photobiological studies of porphyrin capped gold nanoparticles
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Abstract: We describe the synthesis and characterization of a thiol-functionalized porphyrin derivative 2 and its gold nanoparticle conjugates. The porphyrin 2 exhibited its characteristic intense Soret absorption at 420?nm with a molar extinction coefficient value of 3.6×105M-1cm-1 and good fluorescence in the region of 650–660?nm. The porphyrin-capped gold nanoparticles (POPNPs) were synthesized from the citrate-capped gold nanoparticles by the ligand exchange method and characterized by spectroscopic and morphological analyses (UV–Vis, DLS and TEM). The broadening of the absorption spectrum and quenching of the fluorescence intensity for the porphyrin gold nanoconjugates suggest efficient incorporation of the porphyrin moiety onto the gold surface. The results of DLS and TEM analyses indicate that the nanoconjugate POPNPs are uniformly spherical in shape with a size of ca. 25±5nm and exhibits a negative zeta potential value of -16.0±2mV. The singlet oxygen generation efficiency of the porphyrin 2 and POPNPs was calculated and are found to be ca. 0.53 ± 0.02 and 0.43 ± 0.03 , respectively. The in vitro photobiological studies revealed that POPNPs exhibited enhanced photodynamic activity compared to their parent porphyrin derivative 2 with an IC 50 value of 5μM in MDA MB 231 cell lines. The mechanism of the cell destruction was studied by Annexin-FITC and confirmed through TMRM assay. We observed the increase in the percentage of cell population corresponding to the late apoptotic stage ca. 37.7% and 51.2% for 5 and 10μM of POPNPs, respectively, thereby demonstrating their apoptotic-mediated cell destruction and use in PDT applications. Graphical Abstract: Synopsis We synthesized a thiol-functionalized porphyrin-based sensitizer 2 and its gold nanoparticles (POPNPs) and have investigated their photophysical properties, singlet oxygen generation and in vitro photobiological efficacy. Our results demonstrate that the incorporation of the sensitizer onto the surface of nanoparticles not only improved its solubility in the aqueous medium, photophysical and photobiological properties but also its potential as a novel sensitizer for photodynamic therapeutical applications. [Figure not available: see fulltext.].
- Paul, Albish K,Jayaram, Dhanya T,Babu, P S Saneesh,Adarsh, Nagappanpillai,Thurakkal, Shameel,Nair, Asha S,Ramaiah, Danaboyina
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- Template effects of vesicles in dynamic covalent chemistry
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Vesicle lipid bilayers have been employed as templates to modulate the product distribution in a dynamic covalent library of Michael adducts formed by mixing a Michael acceptor with thiols. In methanol solution, all possible Michael adducts were obtained in similar amounts. Addition of vesicles to the dynamic covalent library led to the formation of a single major product. The equilibrium constants for formation of the Michael adducts are similar for all of the thiols used in this experiment, and the effect of the vesicles on the composition of the library is attributed to the differential partitioning of the library members between the lipid bilayer and the aqueous solution. The results provide a quantitative approach for exploiting dynamic covalent chemistry within lipid bilayers. This journal is
- Bravin, Carlo,Hunter, Christopher A.
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p. 9122 - 9125
(2020/09/17)
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- Compounds for the protection of sulfur containing linkers in nucleic acid synthesis
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Aromatic and alkyl thiocarbonates with and without a neighboring group that participates in the hydrolysis of a thiocarbonate are described. The aromatic or alkyl thiocarbonates can be used for the protection of sulfur during oligonucleotide synthesis. Th
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Page/Page column 14
(2014/03/26)
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- Rational size control of gold nanoparticles employing an organometallic precursor [Au-C≡C-t-Bu]4 and tunable thiolate-functionalized ionic liquids in organic medium
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Gold nanoparticles (Au NPs) stabilized with six different thiolate-functionalized ionic liquids (TFILs) were synthesized in an organic solvent. The size and optical properties of the TFIL-stabilized Au NPs can be rationally controlled by altering the N-alkyl chain length and (or) the counteranion of the TFIL-stabilizing ligand. Au NPs were prepared from the reduction of a gold precursor (HAuCl4 or [Au-C≡C-t-Bu] 4) employing NaBH4 in the presence of the different disulfide precursors. A model, based on Israelachvili theory, is proposed to account for the dependence of NP size on the N-alkyl chain length and the counteranion of the surfactantlike TFIL stabilizers.
- Luska, Kylie L.,Moores, Audrey
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scheme or table
p. 145 - 152
(2012/03/07)
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- Efficient Swern oxidation and Corey-Kim oxidation with ion-supported methyl sulfoxides and methyl sulfides
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The Swern oxidation of various benzylic and allylic alcohols, primary alcohols, and secondary alcohols with two ion-supported methyl sulfoxides A-1 (C6) and B-1 (C10), and oxalyl chloride in the presence of triethylamine in dichloromethane, followed by simple diethyl ether extraction of the reaction mixture, gave the corresponding aldehydes and ketones, respectively, in good yields with high purity. Similarly, the Corey-Kim oxidation of various benzylic and allylic alcohols, primary alcohols, and secondary alcohols with two ion-supported methyl sulfides A-2 (C6) and B-2 (C10), and N-chlorosuccinimide in the presence of triethylamine in dichloromethane, followed by simple diethyl ether extraction of the reaction mixture, furnished the corresponding aldehydes and ketones, respectively, in good yields with high purity. Both reactions did not produce any unpleasant odor at all. In the Swern oxidation, ion-supported methyl sulfides were recovered in high yields and could be re-oxidized to produce ion-supported methyl sulfoxides A-1 (C6) and B-1 (C10), for reuse in the same oxidation. In the Corey-Kim oxidation, ion-supported methyl sulfides A-2 (C6) and B-2 (C10) were recovered in high yields and could be also reused for the same oxidation.
- Tsuchiya, Daisuke,Tabata, Masayuki,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 6849 - 6855
(2012/08/28)
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- Swern oxidation of alcohols with ion-supported methyl sulfoxide and oxalyl chloride
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The oxidation of primary and secondary alcohols with ion-supported methyl sulfoxide and oxalyl chloride in the presence of triethylamine in dichloromethane efficiently proceeded to give the corresponding aldehydes and ketones, respectively, in good yields with high purity. Isolation of the product was achieved very easily by simple diethyl ether extraction of the reaction mixture and subsequent removal of solvent from the extract. The reaction did not produce any unpleasant odor. Furthermore, ion-supported methyl sulfide was recovered in good yield and could be re-oxidized to ion-supported methyl sulfoxide for reuse in the same oxidation. Georg Thieme Verlag Stuttgart · New York.
- Tsuchiya, Daisuke,Moriyama, Katsuhiko,Togo, Hideo
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supporting information; experimental part
p. 2701 - 2704
(2012/01/03)
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- Chemically-defined non-polymeric valency platform molecules and conjugates thereof
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Chemically-defined, non-polymeric valency platform molecules and conjugates comprising chemically-defined valency platform molecules and biological or chemical molecules including polynucleotide duplexes of at least 20 base pairs that have significant bin
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- Microwave assisted synthesis of S-trityl and S-acylmercaptoalkanols, nucleosides and their deprotection
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Simple and high yielding methods for the synthesis and deprotection of S-trityl and S-acylhexanols and appropriately protected 2'-deoxynucleosides in solvent and dry media conditions are described which occur under mild conditions using microwave irradiation.
- Kumar,Gupta
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p. 635 - 636
(2007/10/03)
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- Sulfoboration of Cyclic Ethers - A Preparative Route to Mercaptoalkanols and Bis(hydroxyalkyl) Sulfides
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Bis(1,5-cyclooctanediylboryl) sulfide (1) reacts slowly with the cyclic ethers A-D to give O,S-bis(9-BBN)mercaptoalkanols 2a-d in excellent yields.From oxetane (E) and 1, however, 2e is obtained rapidly, which further reacts with E to yield the bis(9-BBN-oxypropyl) sulfide 3ee. 2a and c react with E to form the mixed thioethers 3ae and 3ce, respectively.The methanolysis of 2a-e leads to the O-(9-BBN)mercaptoalkanols 4a-e.The compounds 2 and 3 react with acetylacetone or with 2-aminoethanol to yield the mercaptoalkanols 7a-c, e and the bis(hydroxyalkyl) sulfides 8ae, 8ce and 8ee, resp., in high yields beside the 9-BBN-chelates 5 or 6.Key Words: Ethers, cyclic, cleavage of / Sulfoborations / Mercaptoethanols, 9-BBN derivatives of / Sulfides, bis(hydroxyalkyl), 9-BBN derivatives of
- Koester, Roland,Kucznierz, Ralf
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p. 835 - 842
(2007/10/02)
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- THE CHEMISTRY OF α,ω-MERCAPTOALCOHOLS IN THE PRESENCE OF DIETHOXYTRIPHENYLPHOSPHORANE. TEMEPERATURE DEPENDENCE OF CYCLODEHYDRATIONS AND S-ETHYLATIONS
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Diethoxytriphenylphosphorane (DTPP) is easily prepared by oxidative addition of triphenylphosphine with diethyl peroxide.DTPP converts a variety of mercaptoalcohols to cyclic sulfides as well as hydroxythioethers.The temperature dependence (+25 --> -25 deg C) of the product distribution has synthetic petential.
- Robinson, Philip L.,Kelly, Jeffery W.,Slayton, A. Evans
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- Chemical synthesis
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This invention relates to pharmacologically active compounds of the formula: STR1 wherein Z is trans--CH=CH, C C; or CH2 --CH2 ; M is H or lower alkyl; n is an integer of from 2 to 5; X is alkyl; W is H or OR, wherein R is H, acyl, or alkyl; each Y is H, OH or alkoxy; and to novel intermediates and processes useful in the production thereof.
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- Chemical synthesis
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This invention relates to pharmacologically active compounds of the formula: STR1 wherein Z is trans-CH=CH, C C; or CH2 -CH2 ; M is H or lower alkyl; n is an integer of from 2 to 5; X is alkyl; W is H or OR, wherein R is H, acyl, or alkyl; and Each Y is H, OH or alkoxy; And to novel intermediates and processes useful in the production thereof.
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