Methoxy Group In Position Research Articles

Self-hydrogen transfer hydrogenolysis of β-O-4 bonds in lignin model compounds over NiCu/Al2O3 catalyst

Hydrogenolysis of β-O-4 linkages in lignin to produce aromatic compounds is attractive but challenging. Currently, external hydrogen source like hydrogen gas or hydrogen-donor solvent is necessary during hydrogenolysis, leading to high cost and low selectivity of products. Herein, a NiCu/Al2O3 catalyst was prepared for self-hydrogen transfer hydrogenolysis (SHTH) of Cβ-O bond using inherent CαH-OH structure as H-source. A β-O-4 model compound, 2-phenoxy-1-phenethanol, was completely transformed into acetophenone and phenol at 220 ℃ under 1 MPa N2 for 2h. The SHTH reaction proceeded through a dehydrogenation reaction followed by a hydrogenolysis reaction. Hydrogen radicals released from CαH-OH group generated a “hydrogen pool” on the catalyst surface, which inserted into the formed β-O-4 ketone intermediate to cleave the Cβ-O bond. The catalyst presented outstanding reusability and universality during the SHTH reaction. Moreover, the methoxy groups at aryl positions impeded the SHTH process, and the steric effect was related to the amount and position of methoxy groups. This study realizes the utilization of structural hydrogen from lignin model compounds for its Cβ-O bond cleavage, providing an economical and sustainable method toward lignin valorization.

Tuning the linear optical properties and two-photon absorption on the cinnamylideneacetophenone derivatives: The effect of methoxy group by a experimental and theoretical point of view

The present work studied the effect of the methoxy group position in two cinnamylideneacetophenone (CA) derivatives on both one-photon (1PA) and two-photon absorption (2PA) processes. Our outcomes exhibit a dependence on the methoxy group position spectrally and in magnitude for both. A decrease in the lower energy 1PA band of 0.23eV was observed when the methoxy group was moved to the more conjugated part of the cinnamaldehyde molecule. The opposite was also observed for the next higher absorption band. The Quantum Chemical Calculations (QCCs), besides a good agreement between the experimental and simulated 1PA spectra, except for the magnitude of the high energy absorption band, showed that the effect behind the observed experimental red-shift of the lower absorption band is caused by the higher charge transfer when the methoxy group is bounded to the longer conjugated part of the cinnamaldehyde derivative. For experimental 2PA spectra, the higher energy band is strongly affected by the presence of the methoxy group, pointing out an increase of about 56 % in the values of the two-photon absorption cross-section (2PACS). Furthermore, the phenomenological Sum-Over-Essential States (SOS) approach and QCCs were performed for further clarification in the 2PACS experimental results. Hence, our findings demonstrate that changing the methoxy position on opposite sides of the CA may open up a novel insight for designing new organic molecules, particularly when seeking to enhance the values of 2PACS significantly of CA derivatives.

New 2-pyridone-based donor-acceptor dyes: the effect of the donor group position, type of π-linker and acid-base characteristics of the medium on the photophysical properties.

A series of novel donor-acceptor pyrid-2-ones was synthesized. The influence of the donor group on the photophysical properties of chromophores in solution was shown by varying the methoxy group position in the electron-rich aromatic ring. The effect of the π-linker was also demonstrated by the comparison of the D-π-A pyridone with its spacer-free analogue (D-A) and with the chromophore bearing an additional thiophene bridge (D-π-π-A). It was found that the presence of a π-linker plays a crucial role in the implementation of an intramolecular charge transfer (ICT) from the donor aryl moiety to the pyridone acceptor. Thus, for the synthesized D-A, D-π-A and D-π-π-A derivatives, the photoluminescence quantum yield in DMSO solution decreases from 56.8 to 4.3 and 3.5%, respectively, along with a strong bathochromic shift both for absorption (66 nm) and emission (162 nm) bands. Also, the possibility of shifting the equilibrium in DMSO solution towards either the pyridone form or the anionic form by the addition of a strong acid (TFA) and base (DBN) respectively was shown. Drastic changes in the photoluminescence of the solutions showed prospects for the application of the synthesized donor-acceptor pyridone derivatives as naked-eye acid-base indicators in organic media.

Synthesis, Biological Evaluation, in silico ADMET and Molecular Docking of new 1,4‐Dihydropyridine Derivatives Bearing Ether Substitution as Calcium Channel Blockers

AbstractA set of 1,4‐dihydropyridine derivatives were synthesized, possessing methyl or ethyl esters at positions 3 and 5, an aliphatic or aromatic ether group at position 2, and a thienyl ring at position 4. The calcium channel blocking activity of these derivatives was investigated using K+‐induced contraction on the longitudinal smooth muscles of guinea pig ileum (GPILSM). Our findings showed that the derivatives had IC50 ranging from 0.5 to 5.2 μM. Among the synthesized compounds, compound including methoxy group in position 2 and ethyl acetate in positions 3 and 5, with IC50=0.55±0.58 μM was almost comparable to that of nifedipine (IC50=0.27±1.23 μM). The results of docking studies and biological evaluation of synthetic compounds were consistent. According to the physicochemical and drug‐likeness parameters, it is predicted that the synthesized compounds can be a suitable candidate for calcium channel blocking.

Isomer engineering to adjusting full width at half maximum and emission wavelength for efficient solution-processed red OLEDs

Given the great effect of red dyes with high color purity on ultrahigh-definition displays, exploring new red fluorophores remains urgent. In this work, two novel boron dipyrromethene derivatives (BODIPYs), named o-OMB and p-OMB, were designed and synthesized by adjusting the substitution position of methoxy group. The introduction of tert-butylbenzene units increases steric hindrance and adjacent distance between the host and guest to inhibit adverse Dexter energy transfer. Regioisomerization of methoxy group has a certain impact on photophysical properties, including the distribution of frontier molecular orbitals and recombination energy. The recombination energy of p-OMB is much smaller than that of o-OMB, and the Eg of the former is 1.94 eV less than that of the latter 2.02 eV. Compared with o-OMB, p-OMB with para-substituent has narrower emission spectrum with a FWHM of 37 nm and red-shifted emission wavelength of 634 nm. The solution-processed based-p-OMB OLEDs show a maximum EQE of 1.3% and standard red emission with CIE coordinates of (0.67, 0.33) when using PhCz-4CzTPN as a sensitizer.

Synthesis, Characterization, and Antiproliferative Properties of New Bio-Inspired Xanthylium Derivatives.

Xanthylium derivatives are curcumin analogs showing photochromic properties. Similarly, to anthocyanins, they follow the same multistate network of chemical species that are reversibly interconverted by external stimuli. In the present work, two new asymmetric monocarbonyl analogues of curcumin, 4-(4-hydroxy-3-metoxybenzylidene)-1,2,3,4-tetrahydroxanthylium chloride (compound 3) and 4-(4-hydroxybenzylidene)-6-methoxy-1,2,3,4-tetrahydroxanthylium chloride (compound 4) were synthesized, and their photochromic and biological properties were investigated. The UV-Vis spectroscopy and the direct and reverse pH-jumps studies confirmed the halochromic properties and the existence of different molecular species. A network of chemical reactions of these species was proposed. Furthermore, the antiproliferative properties of both compounds were evaluated using P19 murine embryocarcinoma cells and compared with each other. The results demonstrate that both new xanthylium derivatives modify the progression through the cell cycle of P19 cells, which translates into a significant antiproliferative effect. The effect of the methoxy group position is discussed and several checkpoint proteins are advanced as putative targets.

Relationship between cellulolytic enzyme lignin structural and lignin nanoparticle-polyvinyl alcohol membrane property: Insights from monolignols and molecular dynamics simulations

Lignin is an abundant and sustainable biopolymer that presence great potential in the production of biofuels and biomaterials. In this work, cellulolytic enzyme lignin (CEL) was obtained from eucalyptus, pine, bamboo, and pennisetum in order to investigate the relationship between their structural and utilization in the production of lignin nanoparticle-polyvinyl alcohol (LNP-PVA) composite film. Results showed that CELs obtained from softwood contained the larger amount of G-type lignin, while CELs obtained from hardwood had more S-type lignin. The particle size of the LNPs was in the order of CEL-PI > CEL-PE > CEL-BB > CEL-EP. In addition, the existence of phenolic hydroxyl group in LNP was beneficial to the improvement of the UV shielding performance of LNP-PVA composite film. The higher content of H-type lignin in LNPs was, the better UV shielding performance of LNP-PVA composite film could be observed. The hydrophobicity of the composite films enhanced in the presence of LNPs with the order of BB-PVA > PE-PVA > PI-PVA > EP-PVA. Moreover, the higher amount of S-type lignin in LNPs was, the better mechanical properties of LNP-PVA composite film could be obtained. EP-PVA showed the best elongation with the respect to breakage and tensile strain performances. Molecular dynamic simulation indicated that the interaction between lignin monomers and PVA is mainly van der Waals force, and the position of methoxy group will affect their interaction strength. This study provided a new strategy for high-value utilization of lignocellulose.

Exceptional structure flexibility and adaptive catalytic desulfurization of a cyclic decanuclear polyoxoalkoxyvanadate (Ⅲ)

Removal of notorious organic sulfur-containing compounds to produce low-sulfur-content diesel is of great significance in developing modern industry and addressing environmental protection, but the key challenge is to seek recyclable heterogeneous catalysts with high efficiency. Herein, an intelligent regulation structural polyoxometalate-based hybrid compound with a ten-membered ring cluster has been synthesized via facile solvothermal method, formulated as [VIII10(μ2-OCH3)20(CH3CO2)10] (V10). Single crystal diffraction shows that every two adjacent vanadium ions in V10 are connected by methoxides and acetate group to construct a ten-membered wheel ring. It is noteworthy that the center of the ring can exhibit different opening and closing states through the disordered methoxy groups with rotational/oscillatory flexibility without disrupting the main structure of the ring, being analogous to IRIS stop of an optical camera. Notably, sulfur oxidation experiments indicated that V10 as heterogeneous catalyst displayed excellent catalytic activity, selectivity and stability for the catalytic oxidation of dibenzothiophene (DBT) at mild condition, which outperforms most of reported vanadium oxygen clusters. Benefiting from the multi-modal transformation of the inner ring structure, the catalyst can adaptively adjust the position of methoxy groups to make the sulfides more accessible to the active site, thus facilitating the conversion of DBT up to >99% in 40 ​°C. This study affords a novel perspective for the development of polyoxovanadates with better performance.

The effect of the position of the trimethoxy groups as distant substituents on the spectral and acid sensing properties of phthalocyanines

In this study, alpha and beta substituted phthalonitrile derivatives were obtained by using 3,4,5-trimethoxyphenol and 2,4,6-trimethoxyphenol, and metal-free and Co2+ phthalocyanine molecules were synthesized using these starting compounds. After the phthalocyanine compounds were purified and characterized by classical methods, their detailed solubility, UV–Vis and FT-IR spectroscopy studies were performed and it was revealed how the positions of methoxy groups changed the spectroscopic properties of phthalocyanines. In addition, during detailed UV–Vis studies of Pcs, it was determined that alpha-substituted Pcs gave an extra peak in 1 × 10−5 M dichloromethane solution. It was determined that this peak was caused by acid impurities in dichloromethane in trace amounts and UV–Vis spectra in DCM solutions with different trifluoroacetic acid(TFA) concentrations for alpha substituted Pcs (5–8) were studied and their protonation behaviour was examined. It was determined that H2Pc(6) was sensitive to acid even at 1.8 × 10−3 mM concentration. Thus, acid sensor device can be developed by using this Pc molecule, if desired.

Imine-based Zwitterion: Synthesis, single-crystal characterization, and computational investigation

The 2‑hydroxy-1-naphthaldehyde based Schiff base zwitterions: (E)-1-(((4-methoxyphenyl)-iminio)methyl)naphthalen-2-olate (3a) and (E)-1-(((2‑methoxy-4-nitrophenyl)iminio)methyl)-naphthalen-2-olate (3b) have been obtained from the condensation reaction of 2‑hydroxy-1-naphthaldehyde and substituted aniline. The structures of these Schiff base zwitterions have been verified unambiguously by the single-crystal X-ray diffraction analysis. The SC-XRD (single crystal X-ray diffraction) exploration revealed that both compounds have same crystal system, i.e., monoclinic, and same space group, i.e., P21/c. Also, there are intermolecular attractive forces that are responsible for the stabilization of these organic frameworks. Additionally, these structures have been thoroughly explored by the density functional theory (DFT) calculations. The optimized geometries were found to be close to the experimental structures. The analysis of frontier molecular orbitals (FMOs) suggested that 3a would be more stable towards redox reactions than 3b. Therefore, modifying the imine-zwitterion structure with the nitro group and changing the position of methoxy group would increase the reactivity of the resulting species. This is further supported by the computed global reactivity parameters (GRPs): both compounds should be considered as noticeably stable, both from thermodynamic and kinetic points of view, with 3a showing even higher stability. The compound 3b was shown to be more reactive in redox processes, being more prone to be reduced rather than oxidized. The higher stability of 3a was further supported by the NBO analysis results.

Unsymmetrical Trifluoromethyl Methoxyphenyl β-Diketones: Effect of the Position of Methoxy Group and Coordination at Cu(II) on Biological Activity.

Copper(II) complexes with 1,1,1-trifluoro-4-(4-methoxyphenyl)butan-2,4-dione (HL1) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single crystal X-ray diffraction. The biological properties of HL1 and cis-[Cu(L1)2(DMSO)] (3) were examined against Gram-positive and Gram-negative bacteria and opportunistic unicellular fungi. The cytotoxicity was estimated towards the HeLa and Vero cell lines. Complex 3 demonstrated antibacterial activity towards S. aureus comparable to that of streptomycin, lower antifungal activity than the ligand HL1 and moderate cytotoxicity. The bioactivity was compared with the activity of compounds of similar structures. The effect of changing the position of the methoxy group at the aromatic ring in the ligand moiety of the complexes on their antimicrobial and cytotoxic activity was explored. We propose that complex 3 has lower bioavailability and reduced bioactivity than expected due to strong intermolecular contacts. In addition, molecular docking studies provided theoretical information on the interactions of tested compounds with ribonucleotide reductase subunit R2, as well as the chaperones Hsp70 and Hsp90, which are important biomolecular targets for antitumor and antimicrobial drug search and design. The obtained results revealed that the complexes displayed enhanced affinity over organic ligands. Taken together, the copper(II) complexes with the trifluoromethyl methoxyphenyl-substituted β-diketones could be considered as promising anticancer agents with antibacterial properties.

Design and synthesis of naphthylchalcones as novel anti-leukaemia agents

A series of new hydroxylated chalcone derivatives with different substitution patterns on a phenyl ring A and B, were prepared by Claisen–Schmidt condensation in an aqueous alkaline base. The antiproliferative activity of the studied compounds was evaluated against the human leukaemia cell line U-937. The structure–activity relationship of these naphthylchalcones was investigated by the introduction of one methoxy or two methyl groups on the A ring, the introduction of a methoxy group on the naphthyl ring or by varying the position of the methoxy group on the A ring. The results revealed that the naphthylchalcone containing a methoxy group in position 6́ of the A ring was the most cytotoxic compound, with an IC50 value of 4.7 ± 0.5 μM against U-937 cells. This synthetic chalcone induced S and G2-M cell cycle arrest, a time-dependent increase in sub-G1 ratio and annexin-V positive cells, caspase activation and poly(ADP-ribose) polymerase cleavage. Apoptosis induction was blocked by a pan-caspase inhibitor and by the selective caspase-3/7 inhibitor and attenuated by the inhibition of c-jun N-terminal kinases / stress-activated protein kinases (JNK/SAPK) and phosphoinositide 3-kinase. The structure–activity relationship of naphthylchalcones against human leukaemia cells reveals that the major determining in cytotoxicity is the presence of a methoxy group in position 6́ of the A ring that suggest the potential of this compound or derivatives in the development of new anti-leukaemia drugs.

Discovery of polymethoxyflavones as potential cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) and phosphodiesterase 4B (PDE4B) inhibitors

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely prescribed to treat inflammatory-related diseases, pain and fever. However, the prolong use of traditional NSAIDs leads to undesirable side effects such as gastric, ulceration, and renal toxicity due to lack of selectivity toward respective targets for COX-2, 5-LOX, and PDE4B. Thus, targeting multiple sites can reduce these adverse effects of the drugs and increase its potency. A series of methoxyflavones (F1–F5) were synthesized and investigated for their anti-inflammatory properties through molecular docking and inhibition assays. Among these flavones, only F2 exhibited selectivity toward COX-2 (Selectivity Index, SI: 3.90, COX-2 inhibition: 98.96 ± 1.47%) in comparison with celecoxib (SI: 7.54, COX-2 inhibition: 98.20 ± 2.55%). For PDEs, F3 possessed better selectivity to PDE4B (SI: 4.67) than rolipram (SI: 0.78). F5 had the best 5-LOX inhibitory activity among the flavones (33.65 ± 4.74%) but less than zileuton (90.81 ± 0.19%). Docking analysis indicated that the position of methoxy group and the substitution of halogen play role in determining the bioactivities of flavones. Interestingly, F1–F5 displayed favorable pharmacokinetic profiles and acceptable range of toxicity (IC50>70 µM) in cell lines with the exception for F1 (IC50: 16.02 ± 1.165 µM). This study generated valuable insight in designing new anti-inflammatory drug based on flavone scaffold. The newly synthesized flavones can be further developed as future therapeutic agents against inflammation.

Guiding synthetic targets of anodically coloring electrochromes through density functional theory.

Electrochromic devices offer many technological applications, including flexible displays, dimmable mirrors, and energy-efficient windows. Additionally, adsorbing electrochromic molecular assemblies onto mesoporous metal-oxide surfaces facilitates commercial and manufacturing potential (i.e., screen-printing and/or roll-to-roll processing). These systems also demonstrate synthetic versatility, thus making a wide array of colors accessible. In this work, using Time-Dependent Density Functional Theory (TD-DFT), we investigated ten different bi-aryl type molecules of 3,4-ethylendioxythiophene (EDOT) conjugated to various phenyl derivatives as potential anodically coloring electrochromes (ACEs). The non-substituted phenylene, hexylthiol-EDOT-phenyl-phosphonic acid, PA1, was synthesized and characterized as a means of model validity. PA1 absorbs in the UV region in its neutral state and upon oxidation absorbs within the visible, hence showcasing its potential as an ACE chromophore. The properties of PA1 inspired the designs of the other nine structural derivatives where the number and position of methoxy groups on the phenylene were varied. Using our DFT treatment, we assessed the impact of these modifications on the electronic structures, geometries, and excited-state properties. In particular, we examined stabilization intermolecular interactions (S-O and O-H) as they aid in molecule planarization, thus facilitating charge transport properties in devices. Additionally, destabilizing O-O forces were observed, thereby making some chromophores less desirable. A detailed excited state analysis was performed, which linked the simulated UV-Vis spectra to the dominant excited state transitions and their corresponding molecular orbitals. Based on these results, the nine chromophores were ranked ergo providing an ordered list of synthetic targets.

Crystal Structures of Dimethoxyanthracens: A Clue to a Rational Design of Packing Structures of π-Conjugated Molecules.

We carried out a systematic investigation of packing structures of a series of dimethoxyanthracenes, i. e., 1,4- (1), 1,8- (2), 1,5- (3), 2,6- (4), and 2,7-derivatives (5). The packing structures of the dimethoxyanthracenes are classified into two types, a rubrene-like pitched π-stack (1-3) and a typical herringbone packing (4 and 5), which evidently show that the position of methoxy groups is crucial to determine the packing structure of dimethoxyanthracenes. Effects of the substitution position on intermolecular interactions are analyzed by the noncovalent intermolecular interaction (NCI) method, Hirshfeld surface analysis, and symmetry-adapted perturbation theory (SAPT) method, thus clarifying active roles of the methoxy groups in the formation of rubrene-like pitched π-stack. The present results shed light on a molecular design strategy to realize the rubrene-like pitched π-stack in the solid state, which had been regarded as a packing structure limited for rubrene and its closely related derivatives.

Vapor phase GC-IR identification of regioisomeric N-methoxybenzyl-4-substituted-2,5-dimethoxyphenethylamines (NBOMe)

The common NBOMe drugs of abuse, N-(2-methoxybenzyl)-4-iodo-2,5-dimethoxyphenethylamine (25I-NBOMe) and N-(2-methoxybenzyl)-4-bromo-2,5-dimethoxyphenethylamine (25B-NBOMe), can be differentiated from their corresponding 3- and 4-methoxybenzyl isomers by gas chromatography with vapor phase infrared spectroscopy. The mass spectra for these regioisomeric compounds are essentially identical providing only the identity of the halogen but no specific ions to identify the methoxy group position on the benzyl aromatic ring. The bands from single ring model compounds 2C-B, 2C-I, and all three positional methoxy substituted benzylamines were used to assign each vapor phase absorption band to either the halogenated 2,5 dimethoxybenzene ring or the methoxybenzylamine ring.A pair of aromatic ring stretching bands reflect the position of methoxy group substitution on the benzyl aromatic ring. The 1608 cm−1 band is specific for the two regioisomeric 4-methoxy-benzylamine isomers and this band occurs at 1593 cm−1 for the 2-methoxy isomer in both the 25I and 25B series and shifts to1597/1598 cm−1 for 3-methoxybenzyl 25I and 25B. Asymmetric aryl-O stretching frequencies shift with a change in methoxy substitution around the benzyl aromatic ring (Ring 2) and occur at 1237/1238 cm−1 for ortho, 1261 cm−1 for meta, and 1246 cm−1 for the para isomers. The overall shape and relative intensities of numerous bands in the vapor phase spectra provide clear identification for the individual methoxybenzyl isomers for the 25I-NBOMe and 25B-NBOMe series.

Cytotoxic Activity of Methoxy-4’amino Chalcone Derivatives Against Leukemia Cell Lines

Background: Chemotherapy is a common treatment for leukemia as well as in other cancer treatment. The lack of tumor selectivity and development of multi-drug resistance by chemotherapy caused the development of new strategy in cancer treatment become a pressing need. This study was performed to evaluate the anticancer activity and selectivity of seven derivatives of chalcones against K562 and HL-60 leukemia cell lines. Materials and Methods: The cytotoxicity of chalcone’s seven derivatives (compound 1-7) was tested by using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxyme-thoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) method. The percentage of cell mortality data was calculated then the IC50 was analyzed using probit analysis (SPSS 17). The selectivity index (SI) then calculated from IC50 ratio of normal lymphocyte cells and cancerous cells line (HL-60 and K562).Results: The IC50 of almost all seven tested compounds were lower in HL-60 cell lines than K562 cell lines, except for Compound 7. The number and position of methoxy groups in chalcone derivatives influenced the anticancer and cancer selectivity of chalcone derivatives.Conclusion: The results revealed that the number and position of methoxy groups in chalcone derivatives influenced the anticancer and cancer selectivity of chalcone derivatives.Keywords: anticancer, chalcone derivatives, methoxy-4’-amino chalcone, leukemia, cytotoxic, selectivity

Methoxy‐Substituted Difluoroboron Benzoylacetonate Complexes with Color‐Tunable Phosphorescence

AbstractDifluoroboron β‐diketonates (BF2bdks) exhibit fluorescence (F) and room‐temperature phosphorescence (RTP) in a poly(lactic acid) (PLA) matrix. Fluorescence color tuning has been achieved by dye loading or bdk ligand modification, namely substituent effects or extended conjugation. In this study, color‐tunable RTP (450–570 nm) is achieved with 1‐benzoylacetonate derivatives by varying the number and position of methoxy groups on the benzene ring. The methoxy groups can be used to alter the energy levels of the dye or induce geometry changes (e. g. twisting) to disrupt π‐conjugation. The dyes were evaluated theoretically with density functional theory (DFT) and spectroscopy (absorbance and fluorescence) in CH2Cl2 solution and dilute PLA blends. These findings inform future boron‐based lighting devices and oxygen‐sensing bioprobe designs.

Interactions of phenethylamine-derived psychoactive substances of the 2C-series with human monoamine oxidases.

Psychoactive substances of the 2C-series (2Cs) are phenethylamine-derived designer drugs that can induce psychostimulant and hallucinogenic effects. Chemically, the classic 2Cs contain two methoxy groups in positions 2 and 5 of the phenyl ring, whereas substances of the so-called FLY series contain rigidified methoxy groups integrated in a 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran core. One of the pharmacological features that has not been investigated in detail is the inhibition of monoamine oxidase (MAO). Inhibition of this enzyme can cause elevated monoamine levels that have been associated with adverse events such as agitation, nausea, vomiting, tachycardia, hypertension, or seizures. The aim of this study was to extend the knowledge surrounding the potential of MAO inhibition for 17 test drugs, which consisted of 12 2Cs (2C-B, 2C-D, 2C-E, 2C-H, 2C-I, 2C-N, 2C-P, 2C-T-2, 2C-T-7, 2C-T-21, bk-2C-B, and bk-2C-I) and five FLY analogs (2C-B-FLY, 2C-E-FLY, 2C-EF-FLY, 2C-I-FLY, and 2C-T-7-FLY). The extent of MAO inhibition was assessed using an established in vitro procedure based on heterologously expressed enzymes and analysis by hydrophilic interaction liquid chromatography-high resolution tandem mass spectrometry. Thirteen test drugs showed inhibition potential for MAO-A and 11 showed inhibition of MAO-B. In cases where MAO-A IC50 values were determined, values ranged from 10 to 125μM (7 drugs) and from 1.7 to 180μM for MAO-B (9 drugs). In the absence of detailed clinical information on most test drugs, it is concluded that a pharmacological contribution of MAO inhibition cannot be excluded and that further studies are warranted.

Effect of methoxy group on NLOphoric properties of fluorescent 7-arylstyryl-2-methoxyphenylimidazo[1,2-a]pyridine - Solvatochromic and computational method

Extensively conjugated donor-π-acceptor-donor (D-π-A-π-D) type fluorescent styryl dyes bearing imidazo[1,2-a]pyridine units have been investigated for their nonlinear optical properties (NLO). Enhanced Stokes shift (2486–2843 cm−1) brought about by replacing methoxy group by diethyl, dimethyl, cyclohexylamino substituents at C-2 and C-7 positions of imidazo[1,2-a]pyridine core in styryl dyes have been understood in elucidating the electronic structures. The position of methoxy group acting as auxiliary donor largely influences the nonlinear optical (NLO) properties of imidazo[1,2-a]pyridine derivatives. Polarizabilities and hyperpolarizabilies were estimated by solvatochromic and DFT method using BHandHLYP and CAM-B3LYP functionals with the 6-311 + G(d,p) basis set. Imidazo[1,2-a]pyridine derivatives showed minimum ten-fold higher NLO parameters compared to reminiscent of charge transfer contribution of donor groups. The dyes have two-photon cross-section values 66–189 GM and comparable with commercial two photon absorbing styryl dyes.