To overcome these limitations, several studies have reported optimized extraction and stabilization procedures. In this review, the major pigments found in fruits and their extraction and stabilization techniques for uses as food additives will be looked over.Aim To explore the biological functions and clinicopathologic significance of the long noncoding RNA KTN1-AS1 in head and neck squamous cell carcinoma (HNSCC). Materials & methods We assessed the effects of KTN1-AS1 and identified the target miRNA by bioinformatics analysis, luciferase reporter, RNA pull-down and RNA immunoprecipitation assays. The clinicopathologic features of KTN1-AS1 and its target miRNA were analyzed in HNSCC. Results KTN1-AS1, a competing endogenous RNA, promoted cell proliferation, migration, invasion and epithelial-mesenchymal transition by sponging miR-153-3p in HNSCC. Dysregulation of SNAI1 and ZEB2 mediated the effect of KTN1-AS1 due to miR-153-3p exhaustion. The KTN1-AS1 and miR-153-3p combination can accurately diagnose HNSCC. Conclusion The KTN1-AS1 and miR-153-3p combination could be a valuable diagnostic and prognostic predictor for HNSCC.Charge-enhanced Brønsted acid organocatalysts with electron-withdrawing substituents were synthesized, and their relative acidities were characterized by computations, 11 binding equilibrium constants (K11) with a UV-vis active sensor, 31P NMR shifts upon coordination with triethylphosphine oxide, and in one case by infrared spectroscopy. Pseudo-first-order rate constants were determined for the Friedel-Crafts alkylations of N-methylindole with trans-β-nitrostyrene and 2,2,2-trifluoroacetophenone and the Diels-Alder reaction of cyclopentadiene with methyl vinyl ketone. These results along with kinetic isotope effect determinations revealed that the rate-determining step in the Friedel-Crafts transformations can shift from carbon-carbon bond formation to proton transfer to the catalyst’s conjugate base. This leads to an inverted parabolic reaction rate profile and slower reactions with more acidic catalysts in some cases. Electron-withdrawing groups placed on the N-vinyl and N-aryl substituents of hydroxypyridinium ion salts lead to enhanced acidities, more acidic catalysts than trifluoroacetic acid, and a linear correlation between the logarithms of the Diels-Alder rate constants and measured K11 values.Palladium-catalyzed dearomative [2+2+1] annulations of aryl ethers with alkynes are reported via para-selective C-H functionalization, providing highly functionalized spirocyclohexadienones in moderate to excellent yields under mild reaction conditions. Importantly, mechanistic investigation indicated an unusual C-O bond cleavage was involved. Moreover, polyarylated naphthalenes could be obtained via oxidative [2+2+2] annulation by tuning aryl ethers from monomethoxybenzenes to polymethoxybenzenes under an identical catalytic system.A Pd(II)-catalyzed C(sp3)-H/C(sp2)-H coupling/annulation of anilides and α-dicarbonyl compounds for the synthesis of diverse N-acyl indoles is described. The reaction is achieved by cascade C-H activation, coupling, and intramolecular cyclization. This protocol provides a variety of indoles with high functional group tolerance and excellent regioselectivity. The utility of this protocol is demonstrated by transforming the synthesized compound into diversely functionalized analogues.iClick reactions between Au(I) acetylides PPh3Au-C≡CR where R = nitrophenyl (PhNO2), phenyl (Ph), thiophene (Th), bithiophene (biTh), and dimethyl aniline (PhNMe2) with Au(I)-azide PPh3AuN3 provide digold complexes of the general formula R-1,5-bis-triphenylphosphinegold(I) 1,2,3-triazolate (Au2-R). Within the digold triazolate complexes the Au(I) atoms are held in close proximity but beyond the distance typically observed for aurophilic bonding. Though no bond exists in the ground state, time-dependent density functional theory interrogation of the complexes reveals excited states with significant aurophilic bonding. The series of complexes allows for tuning of the excited state “turn-on” of aurophilicity, where ligand to metal charge transfer (LMCT) induces the aurophilic bonding. Complexes containing lig-and localized excited states however, do not exhibit aurophilicity in the excited state. As a control experiment, monogold complexes were synthesized. Computed excited states of monogold species exhibit LMCT to the gold ion as in the dinuclear cases, but without a partnering gold ion only a distinct N-Au-P bending occurs revealing a potential mechanism for the excited state turn-on of aurophilic bonding. Analysis of the steady-state electronic spectra indicate that LMCT states are achievable for compounds with sufficiently strong electron donating ligands, and in digold com-plexes this is associated with enhanced fluorescence, suggestive of an aurophilic interaction.The singlet fission (SF) process is generally defined as the conversion of one singlet exciton (S1) into two triplet excitons (2·T1), which has the potential to overcome thermalization losses in the field of photovoltaic devices. Among the applicable compounds for SF-based photovoltaic devices, perylene bisimide (PBI) is one of the best candidates because of its electronic tunability and photostability. However, the strategy for efficient SF in PBIs remains ambiguous because of numerous competing relaxation pathways in PBI-based molecular materials. In this regard, for the first time, we observed the SF mechanism in PBI dimers by controlling the intrinsic factor (exciton coupling) and the external environment (solvent polarity and viscosity). Time-resolved spectroscopic measurements and quantum chemical simulations reveal that efficient SF occurs through the charge-transfer-assisted mechanism, entailing a large structural fluctuation. Our findings not only highlight the SF mechanism in PBI dimers but also suggest the factors responsible for an efficient SF process, which are important considerations in the design of molecular materials for photovoltaic devices.We investigate the structure and dissociation pathways of the deprotonated amphoteric peptide arginylglycylasparic acid, [RGD-H]-. read more We model the pertinent gas-phase structures and fragmentation chemistry of the precursor anions and predominant sequence-informative bond cleavages (b2+H2O, c2, and z1 peaks) and compare these predictions to our tandem mass spectra and infrared spectroscopy experiments. Formation of the b2+H2O anions requires rate-limiting intramolecular back biting to cleave the second amide bond and generate an anhydride structure. Facile cleavage of the newly formed ester bond with concerted expulsion of a cyclic anhydride neutral generates the product structure. IR spectroscopy supports this b2+H2O anion having structures that are essentially identical to C-terminally deprotonated arginylglycine, [RG-H]-. Formation of the c2 anion is predicted to require concerted expulsion of CO2 from the aspartyl side chain carboxylate and cleavage of the N-Calpha bond to produce a proton-bound dimer of arginylglycinamide and acrylate.