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An original synthetic strategy is presented for the preparation of the sensitive 3‐amino‐4‐hydroxypyrrolidinone‐4‐acetic acid residue that is present in the structures of the microsclerodermin natural product family. The approach relies on the use of a linear γ‐amino acid surrogate, derived from asparagine, bearing a β‐dithiolanyl group. A protected dipeptide model system is used to demonstrate that selective removal of the dithioketal protection followed by cyclization gives the target structure in single diastereoisomer form and with little or no dehydration. [ABSTRACT FROM AUTHOR]

A precise, sensitive, specific and accurate stability indicating densitometric method was developed and validated for alpha-lipoic acid (ALA) in bulk and capsule dosage form. The study employed pre-coated silica gel 60F254 TLC plates as stationary phase and toluene: chloroform: methanol: formic acid (5:3:1:0.05; v/v/v/v) as mobile phase. The developed method furnished compact spots of alpha-lipoic acid (Rf 0.28 ± 0.05) after derivatization, offered good linearity in range 80–400 ng/spot with correlation coefficient of 0.998. The values for detection and quantitation were found 18.022 and 54.612 ng/spot respectively. ALA was subjected to stress degradation studies and total 13 degradation products were resolved. Thus, the proposed method offered good results according to ICH guidelines, and can be used for identification, routine quantitative determination as well as for monitoring the stability of ALA in bulk and in capsules. [ABSTRACT FROM AUTHOR]

A series of 3-substituted-spiro-(1,3-dithiolan-2,2′-thiazolidin)-4-ones(2) designed as antimicrobial agents and have been synthesized by the reaction between [1,3]dithiolan-2-ylidene-(substituted-phenyl)amine (1) and mercaptoacetic acid. The reaction between substituted anilines, sodium hydroxide and carbon disulfide followed by the reaction of 1, 2-dichloroethane gave quantitatively and analytically pure compound (1). The structure of synthesized compound (1) and (2) is based on spectral (IR, 1H NMR, 13C NMR) as well elemental analysis. These compounds have been screened for their antimicrobial and antitubercular activities. Some of them have showed significant inhibition on bacterial and fungal growth. Few of them showed moderate antitubercular profile. Docking studies of the some novel compounds were performed and results showed that these compounds have good binding energy and have better binding affinity towards the active pocket, thus they may be considered as good inhibitors for selective proteins. Furthermore, computational studies of some derivatives were also performed using Gaussian suite of program.

• Synthesis of new cyanoacetamidopyrimidine compounds and their utility as a starting material for the synthesis of more heterocyclic compounds bearing pyrimidine moiety. • The main objective of this work was to study cytotoxicity and antitumor evaluation of the new pyrimidine derivatives. • Study the structure-activity relationship (SAR) of the newly prepared pyrimidine derivatives. • Study the molecular docking of the newly prepared pyrimidine derivatives. The precursor cyanoacetamide derivatives (6) were achieved by the reaction of pyrimidine derivative 5 with cyanoacetic acid catalyzed by acetic anhydride. The reaction of cyanoacetamide derivative 6 with different reagents afforded many heterocyclic systems such as thioacetic acid (9) , dithiolane derivatives (11) and (12) , 1,8-naphthyridine (14) , quinoline derivatives (17) and (18) , pyridine derivatives 20, 22, 24, 26 , and 27 , pyridazine (30) , pyranopyrimidine (32) , and pyrazolopyrimidine (34). All the newly synthesized compounds were characterized with spectroscopic analyses. Compounds were tested for their anticancer activity against three human cancer cell lines: hepatocellular carcinoma (HepG-2), colon cancer (HCT-116), and mammary gland breast cancer (MCF-7). The studied compound's cytotoxic activity ranged from very strong to very weak. The most active compounds were 9, 10, 11, 27 , and 34. The binding disposition of the docked compounds, in particular 9, 10, 11, 27, and 34 , towards the binding site of AKT complexed with co-crystallized ligand was investigated using molecular docking (PDB = 4EJN). A new approach for the synthesis of some new heterocyclic compounds bearing pyrimidine rings as antitumor agents. [Display omitted] [ABSTRACT FROM AUTHOR]

First examples with the unknown tricyclic 4,8b-dihydro-3aHindeno[ 1,2-d][1,3]dithiole ring system have been prepared. Also, imidazoles linked in ring position 5 to a ketene dithioacetal and 1,3-dithiane derivatives with an exocyclic cyano- and imidazole-substituted C-C double bond are completely new. All these compounds are either conformationally locked, C-linked or six-ring analogues of the antifungal agent luliconazole. Synthesis and fungicidal activity of these sterol biosynthesis inhibitors are reported. [ABSTRACT FROM AUTHOR]

The synthesis of acyclic precursors to epothilone D analogs has been explored. Optimal conditions have been found for enolization of (1R)-1-(1,3-dithiolan-2-yl)-1-(methoxymethoxy)-2,2-dimethylpentan-3-one and its aldol condensation with C6‒C21 and C6‒C9 aldehydes. [ABSTRACT FROM AUTHOR]

The reaction of 3,3-bis(trifluoromethyl)-5-alkoxy-1,2-dithiolanes (RO= OEt or OBu-n) proceeds through thiophilic attack of BuLi leading to the formation of ring-opened product BuSCH(OR)CH 2 C(CF 3 ) 2 SLi, which can be converted into the corresponding thiols or sulfides by the reaction with H + or alkyl halide. Interaction of 3,3-bis(trifluoromethyl)-5-n-butoxy-1,2-dithiolane with CF 3 Si(CH 3 ) 3 resulted in unusual reaction leading to the formation of CF 3 SCH(OBu)CH 2 C(CF 3 )=CF 2 ( 7 ). The treatment of 7 with CsF in the presence pentafluoropyridine led to equimolar mixture of 2-n-butoxy-1,1-bis(trifluoromethyl)cyclopropane and 4-(trifluoromethylthio)tetrafluoropyridine (as a result of interception of liberated in this process CF 3 S- anion by pentafluoropyridine). [ABSTRACT FROM AUTHOR]

Abstract: Metal‐free regioselective [3+2]‐cycloaddition of 2‐aryl/alkylthiiranes with isothiocyanates, isoselenocyanates and carbodiimides is developed using BF2OTf⋅OEt2 to produce 2‐imino‐dithiolane/‐thiaselenolane/‐thiazolidine frameworks at room temperature. The selectivity, substrate scope and scale up are the important practical features. [ABSTRACT FROM AUTHOR]

The ring opening copolymerization of trimethylene carbonate (TMC) and dithiolane trimethylene carbonate (DTC) using acidic and basic organocatalysts, i.e., diphenyl phosphate (DPP) and triazabicyclo[4.4.0]dec-5-ene (TBD), was systemically investigated. Interestingly, DPP and TBD gave rise to completely different polymerization kinetics and copolymer sequences. The copolymerization of TMC and DTC using methoxy poly(ethylene glycol) (mPEG–OH) as an initiator and DPP as a catalyst proceeded in a first-order manner and to near completion in 72 h for both monomers, yielding well-controlled copolymers with random sequences, predictable molar mass, and low dispersity (Mw/Mn = 1.09–1.19). By contrast, TBD brought about much faster copolymerization of TMC and DTC under similar conditions (high monomer conversion achieved in 2–4 h), to furnish copolymers with controlled molar mass and moderate dispersity (Mw/Mn = 1.27–1.80). Moreover, polymerization kinetics revealed that DTC was preferentially polymerized followed by first-order polymerization of TMC, leading to blocky copolymers. These results signify that type of organocatalysts has a critical influence on polymerization kinetics of cyclic carbonates, copolymer sequence, and molar mass control. [ABSTRACT FROM AUTHOR]

An efficient transition-metal-free regioselective C–H/S–H cross-coupling of indolizines with thiols has been developed for the first time to describe a workable route to indolizine thioethers. This finding provides a new method and more straightforward pathway for controllable synthesis of mono- or dithiolation indolizines that are otherwise difficult to obtain by the literature methods. The reaction exhibits good functional group tolerance and high efficiency and affords the products in good to excellent yields. [ABSTRACT FROM AUTHOR]

Abstract: Elevated reactive oxygen species and antioxidant defense systems have been recognized as one of the hallmarks of cancer cells. As a major regulator of the cellular redox homeostasis, the selenoprotein thioredoxin reductase (TrxR) is increasingly considered as a promising target for anticancer drug development. The current approach to inhibit TrxR predominantly relies on the modification of the selenocysteine residue in the C‐terminal active site of the enzyme, in which it is hard to avoid the off‐target effects. By conjugating the anticancer drug gemcitabine with a 1,2‐dithiolane scaffold, an unprecedented prodrug strategy is disclosed that achieves a specific release of gemcitabine by TrxR in cells. As overexpression of TrxR is frequently found in different types of tumors, the TrxR‐dependent prodrugs are promising for further development as cancer chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Novel imidazole-based ketene dithioacetals show impressive in planta activity against the economically important plant pathogens Alternaria solani , Botryotinia fuckeliana , Erysiphe necator and Zymoseptoria tritici . Especially derivatives of the topical antifungal lanoconazole, which bear an alkynyloxy or a heteroaryl group in the para -position of the phenyl ring, exhibit excellent control of the mentioned phytopathogens. These compounds inhibit 14α -demethylase in the sterol biosynthesis pathway of the fungi. Synthesis routes starting from either benzaldehydes or acetophenones as well as structure-activity relationships are discussed in detail. [ABSTRACT FROM AUTHOR]

Dodecanoyl isothiocyanate 1 was utilized for the construction of thioureido, 2-thioxo-2,3-dihydroquinazolin-4(1H)-one, benzo[d]-1,3-thiazin-4(H)-one and 3-amino quinazolin-4(3H)-one derivatives 2, 3, 4, and 5 respectively. However, N′-(2-cyanoacetyl) dodecanehydrazide 6 was also used as a key starting material for the construction of a variety of new pyrazolone, pyrazole, thiadiazole, pyridazine, chromeno[2,3-c]pyrazole, and dithiolane derivatives 7, 9, 12, 15, 18, and 20, respectively. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, 1H NMR, and mass spectra). Some of the newly synthesized compounds bearing heterocyclic moieties were tested for antioxidant activity as reflected in their ability to inhibit oxidation in rat brain and kidney homogenates using 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) inhibition. Also, in vitro anticancer activity was examined using the standard (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) (MTT) method against a panel of two human tumor cell lines namely; hepatocellular carcinoma HepG2 and mammary gland breast cancer MCF-7. Compounds 12 and 16b exhibited the highest activities as antioxidant and antitumor agents. Meanwhile, compounds 7 and 20 showed moderate activities and the rest of the tested compounds showed weak activities. [ABSTRACT FROM AUTHOR]

The conformational analysis of 2-methyl-1,3-dithiolane using quantum chemical calculations at some levels of theory yielded only one stable conformer with envelope geometry. However, other levels of theory indicated two envelope conformers. Analysis of the microwave spectrum recorded using two molecular jet Fourier transform microwave spectrometers covering the frequency range from 2 to 40 GHz confirms that only one conformer exists under jet conditions. The experimental spectrum was reproduced using a rigid-rotor model with centrifugal distortion correction within the measurement accuracy of 1.5 kHz, and molecular parameters were determined with very high accuracy. The gas phase structure of the title molecule is compared with the structures of other related molecules studied under the same experimental conditions. [ABSTRACT FROM AUTHOR]

Abstract: A rotaxane scaffold incorporating two dithiolane anchoring units for the modification of gold surfaces has been functionalized with multiple copies of a redox unit, namely ferrocene. Surface modification has been first assessed at the single molecule level by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) imaging, while tip enhanced Raman spectroscopy (TERS) provided the local vibrational signature of the ferrocenyl subunits of the rotaxanes grafted onto the gold surface. Finally, oxidation of the redox moieties within a rotaxane scaffold grafted onto gold microelectrodes has been investigated by ultrafast cyclic voltammetry. Intramolecular electron hopping is indeed extremely fast in this system. Moreover, the kinetics of charge injection depends on the molecular coverage due to the influence of intermolecular contacts on molecular motions. [ABSTRACT FROM AUTHOR]

Template-free fabrication of non-spherical polymeric nanoparticles is desirable for various applications, but has had limited success owing to thermodynamic favorability of sphere formation. Herein we present a simple way to prepare cubic nanoparticles of block copolymers by self-assembly from aqueous solutions at room temperature. Nanocubes with edges of 40-200 nm are formed spontaneously on different surfaces upon water evaporation from micellar solutions of triblock copolymers containing a central poly(ethylene oxide) block and terminal trimethylene carbonate/dithiolane blocks. These polymers self-assemble into 28±5 nm micelles in water. Upon drying, micelle aggregation and a kinetically controlled crystallization of central blocks evidently induce solid cubic particle formation. An approach for preserving the structures of these cubes in water by thiol- or photo-induced crosslinking was developed. The ability to solubilize a model hydrophobic drug, curcumin, was also explored. [ABSTRACT FROM AUTHOR]

Novel 2-cyano-N-[1-(naphtha-2-yl)ethylidene] acetohydrazide1was utilized as key intermediate for the synthesis of some new dithiolane, thiophene, coumarin, 2-pyridone, and other related products containing a hydrazide moiety. Newly synthesized compounds were characterized by elemental analyses and spectral data (IR,1H NMR and mass spectra). The antimicrobial activity of the synthesized compounds was evaluated. [ABSTRACT FROM AUTHOR]

The parent compound 1,3-dithiolane L1 reacts with CuI providing the 2D coordination polymer (CP) [{Cu(μ-I)Cu}(μ- L1)] ( CP1). The Cu⋯Cu distance within the Cu(μ-I)Cu rhomboid is temperature-dependent and shrinks from 2.9081(7) (294 K) to 2.8743(5) (100 K). The 1D polymeric compound [{Cu(μ-Br)}(μ- L1)] ( CP2) was isolated upon treatment of CuBr with L1 in MeCN solution. Likewise, treatment of L1 with CuCl in a 1:1 ratio results in formation of the unusual 1D CP [{Cu(μ-Cl)}(μ- L1)] ( CP3). In contrast to CP1 incorporating dinuclear Cu(μ-I)Cu units as connection nodes, the isolated Cu atoms of CP2 and CP3 are bridged by a single μ-Br or μ-Cl ligand giving rise to infinite [Cu(μ-X)Cu] ribbons. Reaction of ferrocenecarbaldehyde with 1,2-ethanedithiol affords the crystallographically characterized ferrocenyl-dithiolane Fc-C(H)SCH ( L2). L2 was used as organometallic dithioether ligand to assemble, upon treatment with CuI, the original luminescent 1D CP [{Cu(μ-I)(μ-I)}(μ- L2)] ( CP4), in which both S atoms of one L2 molecule span two copper centers of a meander-shaped infinite (CuI) ribbon. Upon reaction of L2 with CuBr in a 1:2 ratio, the discrete tetranuclear cluster [{Cu(μ-Br)(μ-Br)}(μ- L2)(MeCN)] ( CL1) is formed. [ABSTRACT FROM AUTHOR]

The use of dithiolane-containing polymers to construct responsive and dynamic networks is an attractive strategy in material design. Here, we provide a detailed mechanistic study on the self-assembly and gelation behavior of a class of ABA triblock copolymers containing a central poly(ethylene oxide) block and terminal polycarbonate blocks with pendant 1,2-dithiolane functionalities. In aqueous solution, these amphiphilic block copolymers self-assemble into bridged flower micelles at high concentrations. The addition of a thiol initiates the reversible ring-opening polymerizations of dithiolanes in the micellar cores to induce the cross-linking and gelation of the micellar network. The properties of the resulting hydrogels depend sensitively on the structures of 1,2-dithiolanes. While the methyl asparagusic acid-derived hydrogels are highly dynamic, adaptable, and self-healing, those derived from lipoic acid are rigid, resilient, and brittle. The thermodynamics and kinetics of ring-opening polymerization of the two dithiolanes were investigated to provide important insights on the dramatically different properties of the hydrogels derived from the two different dithiolanes. The incorporation of both dithiolane monomers into the block copolymers provides a facile way to tailor the properties of these hydrogels. [ABSTRACT FROM AUTHOR]

A new series of spiro[[1,3]dithiolane-2,3′-indolines]-2′-one derivatives was synthesized using Michael addition reaction of spiro[[1,3]dithiolane-2,3′-indolin]-2′-one to various α,β-unsaturated esters as well as direct alkylation of this compound with alkyl dihalides. Michael reaction of spiro[[1,3]dithiolane-2,3′-indolin]-2′-one and α,β-unsaturated esters produced related Michael adduct in the presence of tetrabutylammonium bromide and base 1,4-diazabicyclo[2.2.2]octane in good to excellent yields at 80°C under solvent-free conditions. Also, direct alkylation of spiro[[1,3]dithiolane-2,3′-indolin]-2′-one by dihaloalkanes in the presence of base K2CO3afforded the corresponding products in good yields under the same conditions. [ABSTRACT FROM PUBLISHER]

The radical-initiated reaction of (Me 3 Si) 3 SiH with a variety of sulfoxides has been investigated. The reactivity varies significantly with the nature of the starting materials. The reactions of diaryl sulfoxides provide the corresponding sulfides in high yields while the related reactions with dialkyl sulfoxides occur more slowly and in moderate yields. The rate constant for the addition of (Me 3 Si) 3 Si radical with dibutyl sulfoxide is in the range 10 3 –10 4 M −1 s −1 at 80 °C. The reactivity of (Me 3 Si) 3 SiH with 1,3-dithiolane derivatives has also been investigated in a comparative study. The 2,2-dimethyl-1,3-dithiolane and the corresponding 1,1-dioxide give very smooth reaction with (Me 3 Si) 3 Si radical attack at sulfur followed by the ring opening at S–CMe 2 bond and subsequent H-abstraction from the silane in very high yield, whereas the 2,2-dimethyl-1,3-dithiolane-1-oxide behaves quite differently and unexpectedly. [ABSTRACT FROM AUTHOR]

A reproducible electro-assisted method was proposed for the fast and well-controlled formation of mixed binary 1,2-dithiolane-based self-assembled monolayers (SAMs) on a gold electrode from micromolar adsorbate solution concentrations. This was made possible by the combined use of 1,2-dithiolane derivatives having comparable surface binding affinities and the application of a moderate cathodic potential to the electrode until an equilibrium binary SAM coverage was reached. Dithiolane derivatives containing distinct redox-active ferrocenyl groups were synthesized and used for simultaneous and quantitative electrochemical monitoring of the formation of the binary SAMs. The corresponding separate electrochemical responses of each component in the mixed layer allowed for the determination of the adsorbate ratio, which afforded the overall and the individual chemisorption kinetics. Regardless of the different adsorption kinetics, the resulting adsorbate ratios at equilibrium in the SAM were found to be the same as those in solution. Upon reporting the equilibrium surface concentration of the adsorbate as a function of its mole fraction in solution, a clear-cut linear relationship was obtained, which makes this method particularly useful for controlling and predicting the chemical composition of functional binary SAMs on gold surfaces. [ABSTRACT FROM AUTHOR]

Pancreatic adenocarcinoma has a 5 year survival of approximately 3% and median survival of 6 months and is among the most dismal of prognoses in all of medicine. This poor prognosis is largely due to delayed diagnosis where patients remain asymptomatic until advanced disease is present. Therefore, techniques to allow early detection of pancreatic adenocarcinoma are desperately needed. Imaging of pancreatic tissue is notoriously difficult, and the development of new imaging techniques would impact our understanding of organ physiology and pathology with applications in disease diagnosis, staging, and longitudinal response to therapy in vivo. Magnetic resonance imaging (MRI) provides numerous advantages for these types of investigations; however, it is unable to delineate the pancreas due to low inherent contrast within this tissue type. To overcome this limitation, we have prepared a new Gd(III) contrast agent that accumulates in the pancreas and provides significant contrast enhancement by MR imaging. We describe the synthesis and characterization of a new dithiolane-Gd(III) complex and a straightforward and scalable approach for conjugation to a gold nanoparticle. We present data that show the nanoconjugates exhibit very high per particle values of r1 relaxivity at both low and high magnetic field strengths due to the high Gd(III) payload. We provide evidence of pancreatic tissue labeling that includes MR images, post-mortem biodistribution analysis, and pancreatic tissue evaluation of particle localization. Significant contrast enhancement was observed allowing clear identification of the pancreas with contrast-to-noise ratios exceeding 35:1. [ABSTRACT FROM AUTHOR]

Cross-linked poly(N-bromoacrylamide) (PNBA) and poly(N- bromosuccinimide) as the mild and efficient heterogeneous polymeric catalysts were applied for selective deprotection of 1,3-dithianes and 1,3-dithiolanes to their corresponding carbonyl compounds. They were also effective as a reagent in aqueous media. These methods are very simple and the polymer catalysts could be recycled several times. Deprotection of thioacetal and thioketal without enolizable hydrogens proceeded very well to give only the corresponding aldehyde and ketone in high to excellent yield. Nevertheless, in the case of thioketals carrying enolizable hydrogens, deprotection accompanied with the formation of a minor ring-expanded product is observed. However, using the PNBA/H2O system, ring expansion of these thiolketals with enolizable hydrogen was not detected. These methods provide advantages, such as chemoselectivity, easy preparation, simple work up, excellent yields, and the ability to recycle the catalyst, which makes this method more useful compared to other known methodologies. [ABSTRACT FROM PUBLISHER]

Here we report for the first time the use of dithiolane as a platform for reversible surface functionalization with switchable water and oil-wettability. That platform allows the preparation of switchable superhydrophobic/hydrophilic surfaces and oleophobic/oleophilic surfaces. Based on a poly(3,4-ethylenedioxythiophene) surface bearing dithiolane groups, this strategy allows the obtainment of reversible functionalization of surfaces with various thiol compounds. Interestingly, the use of fluorinated thiols also highly changes the surface morphology and porosity leading to superhydrophobic properties and highly oleophobic properties with water and oil reversibility. Dithiolane surfaces are the key platforms in order that switchable surfaces are prepared for a large range of applications. [ABSTRACT FROM AUTHOR]

The reaction of amines with dithiocyclohexylidenes is a general reaction for the synthesis of diaminomethylidene barbiturates. When diamines of the type H2N-(CH2)n-NH 2 are used as nucleophiles bicyclic compounds are the major reaction products, with yields increasing as n decreases, n = 2, 3, 4. When n = 6, macrocyclic compounds, novel 18 and 27 member rings, are obtained in very good yields. The ¹H and 13C NMR assignment for all products is discussed.

The new preparation of 2-(1,3-dithian-2-ylidene)-2-arylacetonitrile and 2-(1,3-dithiol-2-ylidene)-2-arylacetonitrile is described. The electrogenerated cyanomethyl base/anion obtained from the electroreduction of acetonitrile promotes reactions between arylacetonitrile, carbon disulfide and 1-bromo-3-chloropropane or 1,2-dibromoethane. Obtained products have been identified according to their spectroscopic data (IR and1H NMR and13C NMR) and elemental analysis. The possible antibacterial activities of some of these compounds were investigated. Promising results were found against few types of bacteria. [ABSTRACT FROM AUTHOR]

Controlled oxidation of various hexafluorothioacetone cycloadducts by m -chloroperoxybenzoic acid (MCPBA) at low temperature led to the formation of the corresponding cyclic sulfoxides in 56–82% yield. The oxidation of 5-ethoxy-3,3-bis(trifluoromethyl)-1,2-dithiolane proceeded selectively leading to trans -5-ethoxy-3,3-bis(trifluoromethyl)-1,2-dithiolane-1-oxide, which underwent selective isomerization into the cis -isomer at higher temperature. [ABSTRACT FROM AUTHOR]

Azafullerene (C59N) was functionalized using a Mannich-type reaction and then subsequently condensed with lipoic acid to yield dithiolane-modified C59N. In the following step, the extended dithiolane moiety from the C59N core was utilized to decorate the azafullerene sphere with gold nanoparticles (Au NPs). The latter were initially stabilized with dodecanothiol (DT ⋅Au) and then integrated on azafullerene through a ligand exchange reaction with the dithiolane-functionalized C59N to produce the C59N/DT ⋅Au nanohybrid. The nanohybrid was fully characterized by spectroscopy and microscopy, revealing the formation of spherical nanoparticles with a diameter in the range of 2-5 nm, as imaged by HR-TEM. In the electronic absorption spectrum of C59N/DT ⋅Au nanohybrid, the characteristic surface plasmon band (SPB) of Au NPs was observed, however, it was redshifted compared with that of DT ⋅Au. The redshift of the SPB is indicative of closer interparticle proximity of Au NPs, in accordance with the formation of aggregated NPs as observed by TEM, in C59N/DT ⋅Au nanohybrid. Excited-state interactions in C59N/DT ⋅Au were probed by photoluminescence assays. It was found that the weak emission of C59N at 819 nm was blueshifted by 14 nm in C59N/DT ⋅Au, but was stronger in intensity, thus suggesting energy transfer to C59N, within the organic-inorganic C59N/DT ⋅Au nanohybrid. Finally, with the aid of pump-probe measurements and transient absorption spectroscopy, the formation of the singlet excited state of C59N was identified. [ABSTRACT FROM AUTHOR]

The article discusses research which examines the importance of 1,2-dithiolane structure in a-lipoic acid for downregulating cell surface βl-integrin expression of human bladder cancer cells. It reports on inhibition of gene expression of cell surface protein βl-integrin, cell adhesion to fibronectin, migration, and invasion by α-lipoic acid. It also discusses on role of 1,2-dithiolane structure in determining the action of α-lipoic acid.