Dimethoxy Groups Research Articles

A functionalized phosphorous tetrabenzotriazacorrole dye as a novel passivating agent of high-performance planar perovskite solar cells

Surface passivation is a crucial strategy to manage the film characteristics of solution-processed perovskite absorber layers, which greatly impact the photovoltaic properties of perovskite solar cells (PSCs). However, designing and synthesizing suitable passivating agents with required functional groups and solution-processability is challenging due to their complex molecular structure. In this study, we demonstrate a facile passivation technique using a functionalized phosphorous tetrabenzotriazacorrole dye (PTBC) for p-i-n PSCs. The tetrabenzotriazacorrole dye has amines and ether linkages that can closely interact with the undercoordinated Pb2+ with halogen vacancies through Lewis acid-base interactions, leading to a pinhole-free perovskite absorber layer with reduced trap density. Moreover, the central phosphorus of PTBC is functionalized with dimethoxy groups, which can provide a more hydrophobic surface in the perovskite absorber layer. Consequently, high-quality perovskite films (CsFAPbI3) prepared with PTBC exhibit improved optical, electrical, and morphological properties, as well as superior carrier transportation/recombination kinetics, boosting the power conversion efficiency of PSCs from 17.64 % to 20.08 %, with over 75 % of initial efficiency preserved after 1000 h of aging under ambient conditions. These results highlight PTBC as an effective surface passivation agent for perovskite absorber layers and emphasize the importance of suitable passivating agents in optimizing PSC performance.

Antiproliferative Activity of Novel Imatinib Analogue as Potential Anticancer Agents, Synthesis and in vitro Screening

Abstract: Background: A series of N-(2,5-dimethylphenyl)-4-pyridin-3-ylpyrimidin-2-amine derivatives were synthesized as Imatinib derivatives, bearing 2-chloroquinoline as a heteroaryl motif. Materials and Methods: The compounds were synthesized by reducing in situ prepared azomethine intermediate using NaBH4 as a reducing agent in methanol as a solvent. Fourier transformation-IR, proton-NMR along with mass spectrometry were used to determine the structures of the compounds. The antiproliferative activity of the compounds against cell lines A549 and MCF7 was evaluated in vitro using the MTT assay protocol. Results: The compounds showed moderate cell growth inhibition at a concentration of 10 μM. Among the test compounds, the compound with a dimethoxy group at the 6 and 8 positions of the 2-chloroquinoline ring displayed the highest antiproliferative activity. Conclusion: The synthesized Imatinib derivatives exhibited moderate antiproliferative activity against A549 and MCF7 cell lines, and the compound with a dimethoxy group at the 6 and 8 positions of the 2-chloroquinoline ring showed the highest activity. These findings suggest that further studies can be performed to optimize the antiproliferative activity of these compounds. Keywords: Imatinib derivatives, Quinoline, Reducing amination, Antiproliferative activity.

The Synergistic Effects of Aminosilane Coupling Agent on the Adhesion Performance of Silane Primer for Silicone Resin Thermal Protection Coating.

As a bridge between the coating and the substrate, the primer has a direct impact on the adhesion performance of silicone resin thermal protection coating. In this paper, the synergistic effects of an aminosilane coupling agent on the adhesion performance of silane primer were investigated. The results show that silane primer containing N-aminoethyl-3-aminopropylmethyl-dimethoxysilane (HD-103) formed a continuous and uniform film on the surface of the substrate. Two amino groups of HD-103 were conducive to moderate and uniform hydrolysis of the silane primer system, and the introduction of dimethoxy groups was more conducive to the improvement of interfacial layer density and the formation of the planar surface structure, thus enhancing the bond strength at the interface. When the content was 13 wt%, it exhibited excellent synergistic effects on adhesive properties, and the adhesive strength reached 1.53 MPa. The possible morphology and composition of the silane primer layer were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A thermogravimetric infrared spectrometer (TGA-IR) was used to analyze the thermal decomposition of the silane primer layer. The results showed that the alkoxy groups in the silane primer were first hydrolyzed to form Si-OH, and then the dehydration and condensation reactions between Si-OH and the substrate formed a firm network structure.

Ligand Conformation Fixation Strategy for Expanding the Structural Diversity of Copper-Tricarboxylate Frameworks and C2H2 Purification Performance Studies.

Structural and functional expansion of metal-organic frameworks (MOFs) is fundamentally important because it not only enriches the structural chemistry of MOFs but also facilitates the full exploration of their application potentials. In this work, by employing a dual-site functionalization strategy to lock the ligand conformation, we designed and synthesized a pair of biphenyl tricarboxylate ligands bearing dimethyl and dimethoxy groups and fabricated their corresponding framework compounds through coordination with copper(II) ions. Compared to the monofunctionalized version, introduction of two side groups can significantly fix the ligand conformation, and as a result, the dual-methoxy compound exhibited a different network structure from the mono-methoxy counterpart. Although only one almost orthogonal conformation was observed for the two ligands, their coordination framework compounds displayed distinct topological structures probably due to different solvothermal conditions. Significantly, with a hierarchical cage-type structure and good hydrostability, the dimethyl compound exhibited promising practical application value for industrially important C2H2 separation and purification, which was comprehensively demonstrated by equilibrium/dynamic adsorption measurements and the corresponding Clausius-Clapeyron/IAST/DFT theoretical analyses.

The structural differences between mushroom and human tyrosinase cleared by investigating the inhibitory activities of stilbenes

Tyrosinase (TYR: EC 1.14.18.1) is a copper-containing protein that catalyzes phenolic oxidation. The enzyme plays a critical role in melanin production and is widely distributed from microorganisms to humans. To date, many kinds of TYR inhibitors have been discovered for medical, cosmetic, and agricultural uses. In various TYRs, mushroom (Agaricus bisporus) tyrosinase (AbTYR) is widely used to search for inhibitors of TYRs because the enzyme is easy to handle and cheaper than other sources. However, some inhibitors behave in different ways for hTYR and AbTYR because the two enzymes share only about 23% of their sequences. Therefore, it is important to reveal the difference in the structure of the active pocket of both TYRs. To date, naturally-derived inhibitors, such as stilbenes, flavonoids, and coumarins, have been preferred for the ingredients of cosmetics and food preservatives. In this study, we compared the inhibitory activities of 6 stilbenes for Ab and hTYR. The A ring of these stilbenes has a 3,5-dihydroxy or dimethoxy group and the B ring of these stilbenes has several patterns in position and number of hydroxyl group, including no hydroxylation. As a result, compounds that did not have an active hydroxyl group in the A ring were not effective for AbTYR but effective for hTYR. The absence of hydroxyl groups in the B ring made the inhibitory activity weak for hTYR but effective for AbTYR. These results indicate that the A and B rings on stilbene can only enter into the active pocket of the AbTYR and hTYR, respectively. These results were then supported by the molecular docking of oxyresveratrol, which is the most potent inhibitor of Ab and hTYR (IC50 = 3.0 and 0.7, respectively). Molecular docking also revealed that the common feature and difference in the active pocket in the two enzymes. These results exploit the importance of the selection of biological resources according to the objective use.

Search for biologically active compounds in the series of indazole derivatives

Indazole compounds are intensively used in the synthesis of new active substances for pharmacological purposes. The present work includes methods of modification and preparation of new indazole compounds, determination of their biological activity (antibacterial properties, antiprotozoal and fungistatic activity). Modification methods were used: the recyclization reaction; acetylation of the amino group; acylation and others. We have synthesized indazole derivatives containing an aryl substituent with a 2-aminoethyl fragment by recyclization of 1-(2-chloroaryl)-3,4-dihydroioquinolines under the influence of hydrazine. The starting structures for the synthesis of indazoles (compounds 5, 6, 7) possess negligible activity toward Colpoda steinii, are practically inactive toward Penicillium italicum but retard the growth of E. coli and Staphylococcus aureus (retard zone 7-9 mm); compounds with dimethoxy groups in the benzene ring (compounds 5 and 6) are active toward E. coli whereas structure 7 has no activity without dimethoxy groups. The recycling reaction leading to indazole structures considerably increases the activity of all compounds (1-4, 8-14). Compounds with a primary amino group (structures 1, 2, and 9) possess marked antiprotozoan activity, the best results in this respect being demonstrated by compound 9 which does not contain dimethoxy groups in the benzene ring (15.6 ?g/ml). Acylation of the amino group in compound 2 allows a 4-fold increase in antiprotozoic activity and a slight fungistatic activity (compound 3). At the same time, acylation with a bulkier and more lipophilic benzoyl group (compound 4) practically suppresses antiprotozoic and fungistatic activities. It should be noted that conversion of the primary amino group of compounds 1 and 9 to the tertiary amino group (compounds 13 and 14) allows a dramatic increase in antiprotozoal activity (31.25 µg/ml for compound 1 and 3.9 µg/ml for compound 13; 15.6 µg/ml for compound 9 and 3.9 µg/ml for compound 14). In addition, these same compounds 13 and 14, unlike compounds 1 and 9, are active against all cultures studied. The best results are shown by compounds 11 and 12 in which the amino group is part of the urea structure.

In vitro photoinactivation of S. aureus and photocatalytic degradation of tetracycline by novel phthalocyanine-graphene quantum dots nano-assemblies

A novel asymmetrical zinc (II) phthalocyanine (Pc) 4 bearing three dimethoxy groups and one carboxyl group was linked to glutathione capped graphene quantum dots (GQDs) by the reaction of carboxylic acid substituent on Pc 4 with the amino group on the GQDs. On the other side, the symmetrical Pc analog 3 was linked to the same nanoparticles through π-π interactions. The as-formed nano-photosensitizers were fully characterized by spectroscopic methods and their photophysicochemical properties were investigated as well. Photodynamic antimicrobial chemotherapy was performed on the planktonic cells of S. aureus strain. And the results show that these nano assemblies were able to completely inhibit the metabolic activity of the resistant bacteria strain S. aureus with a 10.26 log reduction in the viable count. Again, asymmetrical Pc showed higher photocatalytic activity compared to the symmetrical complex with higher kobs and fast initial rates for the former. The photocatalysis obeyed the Langmuir-Hinshelwood kinetic model. The target conjugates showed all the advantages of two different groups existing on a single entity.

Synthesis & Anticancer Evaluation of New Substituted 2-(3,4- Dimethoxyphenyl)benzazoles.

The benzazole nucleus is found in many promising small molecules such as anticancer and antibacterial agents. Bendamustine (Alkylating agent), Nocodazole (Mitotic inhibitor), Veliparib (PARP inhibitor), and Glasdegib (SMO inhibitor) are being clinically used as anticancer therapeutic which bear benzimidazole moiety. Based on the principle of bioisosterism, in the present work, 23 compounds belonging to 2-(3,4-dimethoxyphenyl)benzazoles and imidazopyridine series were synthesized and evaluated for their anticancer and antimicrobial activities. A series of new 2-(3,4-dimethoxyphenyl)-1H-benz(or pyrido)azoles were synthesized and evaluated for their anticancer and antimicrobial activities. N-(5-chloro-2-hdroxyphenyl)-3,4-dimethoxybenzamide 1, was obtained by the amidation of 2-hydroxy-5-chloroaniline with 3,4-dimethoxybenzoic acid by using 1,1'-carbonyldiimidazole. Cyclization of 1 to benzoxazole derivative 2, was achieved by p-toluenesulfonic acid. Other 1H-benz(or pyrido)azoles were prepared by the reaction between 2-aminothiophenol, ophenylenediamine, o-pyridinediamine with sodium metabisulfite adduct of 3,4-dimethoxybenzaldehyde. The NMR assignments of the dimethoxy groups were established by the NOESY spectra. Compound 12, bearing two chlorine atoms at the 5(4) and 7(6) positions of the benzene moiety of benzimidazole was found the most potent analogue against A549 cells with the GI50 value of 1.5 μg/mL. Moreover, 24 showed remarkable cell growth inhibition against MCF-7 and HeLa cells with the GI50 values of 7 and 5.5 μg/mL, respectively. The synthesized compounds have no important antibacterial and antifungal activities. It could be concluded that the introduction of di-chloro atoms at the phenyl ring of 2-(3,4-dimethoxyphenyl)-1H-benzimidazoles increases significant cytotoxicity to selected human tumor cell lines in comparison to other all benzazoles synthesized. Unsubstituted 2-(3,4- dimethoxyphenyl)-imidazopyridines also gave good inhibitory profile against A549 and HeLa cells.

Synthesis and characterization of proton exchange poly (phenylenebenzophenone)s membranes grafted with propane sulfonic acid on pendant phenyl groups

A series of poly(phenylenebenzophenone)s with sulfonic acid groups via long alkyl side chains, SPPBPs, were successfully prepared as proton exchange membranes for fuel cells. The new monomer, 1,4-dichloro-2,5 diphenylenemethoxybenzophenone (PMBP) was synthesized by the Friedel–Crafts reaction of tetrachloroterephthalate with anisole and copolymerized with 1,4-dichloro-2,5-diphenylenebenzophenone (PBP) to prepare poly(phenylenebenzophenone)s copolymers containing dimethoxy groups (sPPMBP). After converting the methoxy group to the reactive hydroxyl group, the resulting side-chain-type sulfonated copolymers (SPPBP) were obtained by a sulfopropylation reaction. These SPPBP series membranes showed high proton conductivity in the range of 98.4–162.1 mS/cm 80 °C under 90% hydrated conditions. SPPBP-40 (IEC = 2.45 meq./g) showed comparable higher proton conductivity (162.1 mS/cm) than Nafion 211 (130.2 mS/cm) in the 90% hydrated state. The membranes were studied by 1H NMR spectroscopy, thermo-gravimetric analysis, ionic exchange capacity, water uptake, and proton conductivity. Also surface morphologies were assessed by atomic force microscope (AFM).

Effect of Aminosilane Compounds as External Donors on Isospecific Polymerizations of 1-Butene with MgCl2/TiCl4/DIBP Catalyst

Four aminosilane compounds were synthesized and employed as external electron donors for 1-butene polymerization with MgCl2 supported Ziegler-Natta catalyst. The four aminosilane compounds are di(piperidinyl)dimethoxysilane (DPPDMS), di(piperidinyl)- diethoxysilane (DPPDES), di(pyrrolidinyl)dimethoxysilane (DPRDMS) and di(pyrrolidinyl)- diethoxysilane (DPRDES). A detailed study has been performed on the effects of the chemical structure of different external electron donors on the catalytic efficiency, isotacticity, melting temperature and molecular weight distribution of obtained poly(1-butene). Poly(1-butene) products have been characterized with gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) analysis. The results indicated that: first, aminosilane compounds with dimethoxy groups showed higher catalytic efficiency and polymers isospecificity than those of with diethoxy groups. Conversely, the aminosilane compounds with diethoxy groups were conductive to obtaining polymers with broader molecular weight distribution than those of with dimethoxy groups. Second, compared with single DPPDMS or TEOS (tetraethyl orthosilicate), DPPDMS/TEOS complex in a proper molar ratio would not only increase the catalytic efficiency and isotacticity of obtained polymers, but also broaden the molecular weight distribution of polymers. Third, the effects of other factors on catalytic efficiency and isotacticity of polymers product were also studied, including different amount of hydrogen, concentration of external donor and cocatalyst. Di(piperidinyl)dimethoxysilane (DPPDMS) was synthesized and employed as external electron donors for 1-butene polymerization with MgCl2 supported Ziegler-Natta catalyst. Compared with single DPPDMS or TEOS (tetraethyl orthosilicate), DPPDMS/TEOS complex in a proper molar ratio would not only increase the catalytic efficiency and isotacticity of obtained polymers, but also broaden the molecular weight distribution of polymers. The selection of molar ratio should depend on the requirements to the polymer.

The combination of quinazoline and chalcone moieties leads to novel potent heterodimeric modulators of breast cancer resistance protein (BCRP/ABCG2)

During the last decade it has been found that chalcones and quinazolines are promising inhibitors of ABCG2. The combination of these two scaffolds offers a new class of heterocyclic compounds with potentially high inhibitory activity against ABCG2. For this purpose we investigated 22 different heterodimeric derivatives. In this series only methoxy groups were used as substituents as these had been proven superior for inhibitory activity of chalcones. All compounds were tested for their inhibitory activity, specificity and cytotoxicity. The most potent ABCG2 inhibitor in this series showed an IC50 value of 0.19 μM. It possesses low cytotoxicity (GI50 = 93 μM), the ability to reverse MDR and is nearly selective toward ABCG2. Most compounds containing dimethoxy groups showed slight activity against ABCB1 too. Among these three compounds (17, 19 and 24) showed even higher activity toward ABCB1 than ABCG2. All inhibitors were further screened for their effect on basal ATPase activity. Although the basal ATPase activity was partially stimulated, the compounds were not transported by ABCG2. Thus, quinazoline-chalcones are a new class of effective ABCG2 inhibitors.

Optimization of permethyl ningalin B analogs as P-glycoprotein inhibitors

In the present study, a total of 9 novel permethyl ningalin B analogs have been synthesized and evaluated for their P-gp modulating activity in a P-gp overexpressed breast cancer cell line LCC6MDR. Among these derivatives, compound 12 with dimethoxy groups at rings A and B and tri-substitution at ring C with ortho-methoxyethylmorpholine, meta-bromo and para-benzyloxy groups displays the most potent P-gp modulating activity with EC50 of 423nM to reverse paclitaxel resistance. It is non-toxic towards L929 fibroblast with IC50 greater than 100μM and with selective index greater than 236. Its mechanism to reverse P-gp mediated drug resistance is by virtue of inhibiting transport activity of P-gp, restoring intracellular drug accumulation and eventually chemosensitizing the cancer cells to anticancer drug again. Moreover, compound 12 showed better solubility (405ng/mL) than hit compound 1 in phosphate buffer (pH 4.0). In summary, our study demonstrates that permethyl ningalin B derivative 12 is non-toxic and efficient P-gp inhibitor that is a potential candidate to be used clinically to reverse P-gp mediated cancer drug resistance.

Photoracemization of Blestriarene C and Its Analogs.

Two analogs of blestriarene C (4,4'-dimethoxy-1,1'-biphenanthrene-2,2',7,7'-tetraol) bearing no 7,7'-dihydroxy (3) and 4,4'-dimethoxy groups were prepared. Unlike blestriarene C (1), compounds and , as well as 1,1'-biphenanthrene-2,2'-diol (5), do not racemize under fluorescent lamp illumination. Cyclic voltammetry analysis reveals that compound has a lower half-wave potential (E(1/2)) than compounds , suggesting that a redox cycle is involved in the racemization. Compound racemizes by absorbing UV light corresponding to the (1) L(b) band. During the reaction, no side products are observed. The racemization is significantly inhibited under nitrogen. Based on these observations, we propose a feasible mechanism for the easy racemization of compound , which is mediated by a cation radical generated in situ by a reversible photo-induced oxygen oxidation.

GC–MS and GC-IRD studies on the six ring regioisomeric dimethoxybenzoylpiperazines (DMBzPs)

The dimethoxybenzoylpiperazines show mass spectra characteristic for this set of six regioisomeric substances and the position of ring substitution for the dimethoxy groups can be determined by vapor phase infrared methods. The dimethoxybenzoylpiperazines are characterized by several fragment ions unique to the mass spectra for this set of regioisomeric compounds. Ions at m/z 165 and 182 indicate the presence of the dimethoxybenzoyl and dimethoxybenzamide groups while low mass ions at m/z 56, 69 and 85 are characteristic of the piperazine ring in these isomeric compounds. The mass spectra for these regioisomeric dimethoxybenzoylpiperazines are almost identical and this method alone does not provide for the confirmation of identity of any one of the isomers to the exclusion of the other compounds.The perfluoroacyl derivatives of the six regioisomers were resolved by gas chromatography and their mass spectra showed some differences in relative abundance of fragment ions without the appearance of any unique fragments for specific confirmation of structure. Gas chromatography with infrared detection (GC-IRD) provides direct confirmatory data for the differentiation between the regioisomeric underivatized dimethoxybenzoylpiperazines.

Solution Processed Green Phosphorescent Organic Light-Emitting Diodes Based on Phenylpyridine Derivatives Using Small Molecule Host

A novel cyclometalated ligand 2-(2,4-dimethoxyphenyl)-5-trifluoromethylpyridine (MeO2CF3ppy), and its complexes bis[2-(2,4-dimethoxy-phenyl)-5-trifluoromethyl pyridinato-N,C2′]iridium acetylacetonate (MeO2CF3ppy)2Ir(acac) and bis[2-(2,4-Dimethoxy-phenyl)-5-trifluoromethyl pyridinato-N,C2′]iridium pyrazolate (MeO2CF3ppy)2Ir(prz) were synthesized, respectively. Trifluoromethyl (CF3) and dimethoxy group (MeO2) were introduced into main ligand for color tuning. The green emitting PhOLEDs, based on ITO/PEDOT:PSS (40 nm)/TCTA:TPBi:Ir(III) complex (80 nm)/Bphen (20 nm)/LiF (0.7 nm)/ Al (120 nm) were fabricated. The solution-processed PhOLEDs based on (MeO2CF3ppy)2Ir(acac) exhibited a maximum quantum efficiency of 3.40% and luminance efficiency 8.32 cd/A with CIE coordinate of (0.33, 0.63).

Synthesis and an Evaluation of Molecular Conformation and Crystal Packing in Two Substituted 4-Phenylquinolines

The title compounds, namely Methyl 2-methyl-4 -phenylquinoline-3-carboxylate (I), C18H15NO2, and (2E)-3-(3,4-dimethoxyphenyl)-1-(2-methyl-4 -phenylquinolin-3-yl)prop-2-en-1-one (II), C27H23NO3, comprising of the phenyl ring, exhibit differences in conformational behaviour with respect to the plane of the quinoline fragment. (I) contains the methyl ester moiety whereas (II) contains the chalcone fragment, consisting of a double bond and phenyl group containing dimethoxy groups as substituents. The dihedral angles between the phenyl group and the quinoline ring is 82.77 (7)° in (I), and 79.02 (8)° in (II) respectively. It is the weak C–H···O=C H-bond and C–H···π interactions which dictate packing of molecules in (I). In (II), it is C–H···N and C–H···π, involving the dimethoxy ring, which controls packing of molecules in the crystal lattice. In addition, π···π aromatic stacking interactions involving the quinoline fragment is present in all the molecules. The title compounds, namely methyl-2-methyl-4 -phenylquinoline-3-carboxylate (I), C18H15NO2, and (2E)-3-(3,4-dimethoxyphenyl)-1-(2-methyl-4 -phenylquinolin-3-yl)prop-2-en-1-one (II), C27H23NO3, comprising of the phenyl ring, exhibit differences in conformational behaviour with respect to the plane of the quinoline fragment. (I) contains the methyl ester moiety whereas (III) contains the chalcone fragment, consisting of a double bond and phenyl group containing dimethoxy groups as substituents. The dihedral angles between the phenyl group and the quinoline ring is 82.77 (7)° in (I), and 79.02 (8)° in (II) respectively. It is the weak C–H···O=C H-bond and C–H···π interactions which dictate packing of molecules in (I). In (II), it is C–H···N and C–H···π, involving the dimethoxy ring, which controls packing of molecules in the crystal lattice. In addition, π···π aromatic stacking interactions involving the quinoline fragment is present in all the molecules.

Anti-hyperlipidemic Activity of Thieno - [2, 3-d] - Pyrimidin-4-(3H)-ones

Aim: The present study was aimed to evaluate some newly synthesized thieno – [2, 3-d] - pyrimidin-4-(3H)-ones namely SR-C1 to SR-C12 for their anti-hyperlipidemic activity. Materials and Methods: Anti-hyperlipidemic activity was evaluated using Triton 1339-induced hyperlipedemia in rats as an experimental model. Plasma triglycerides, total cholesterol, HDL-C, LDL-C, atherogenic index (AI) and LDL-C/HDL-C ratio were determined to assess the anti-hyperlipidemic activity. Results: SR-C1,SR-C4, SR-C5, SR-C6, SR-C7, SR-C11 and SR-C12 have shown significant anti-hyperlipidemic activity by decreasing the total cholesterol and triglyceride, LDL-cholesterol, atherogenic index and LDL/HDL ratio (p < 0.001) and by increasing the HDL-Cholesterol (p < 0.001). Conclusion: The findings of the present study clearly demonstrates that methyl, methoxy, chloro, dimethylamino, dimethoxy and trimethoxy functional groups possess cholesterol-suppressive capacities and has an ability to attenuate the accelerated development of atherosclerosis in hypercholesterolemic models. However, hydroxyl and nitro derivatives did not show any hypolipidemic activity.

Synthesis and electrophosphorescent properties of iridium complexes based on phenylpyridine-based main ligand for organic light-emitting diodes

A novel cyclometalated ligand 2-(2,4-dimethoxyphenyl)-5-trifluoromethylpyridine (MeO 2CF 3ppy) and its complexes bis[2-(2,4-dimethoxy-phenyl)-5-trifluoromethyl pyridinato-N,C 2`]iridium 2-pyrazine carboxylic acid (MeO 2CF 3ppy) 2Ir(prz) and bis[2-(2,4-dimethoxy-phenyl)-5-trifluoromethyl pyridinato-N,C 2`]iridium 5-methyl-2-pyrazine carboxylic acid (MeO 2CF 3ppy) 2Ir(mprz) were synthesized. Trifluoromethyl and dimethoxy groups were introduced into main ligand for tuning the emission color. The phosphorescence organic light-emitting diodes (PhOLEDs) based on these complexes with the configuration of ITO/PEDOT:PSS (40 nm)/PVK:TCTA:OXD-7:Ir complex (50 nm)/BCP (20 nm)/Alq 3 (10 nm)/LiF (1 nm)/Al (100 nm) were fabricated. The solution-processed PhOLEDs based on (MeO 2CF 3ppy) 2Ir(mprz) exhibited a maximum quantum efficiency of 2.97% and luminance efficiency of 4.95 cd/A with CIE coordinate of (0.43, 0.53).

In Silico Quantitative Structure-Activity Relationship Studies on P-gp Modulators of Tetrahydroisoquinoline-Ethyl-Phenylamine Series

BackgroundMultidrug resistance (MDR) is a major obstacle in cancer chemotherapy. The drug efflux by a transport protein is the main reason for MDR. In humans, MDR mainly occurs when the ATP-binding cassette (ABC) family of proteins is overexpressed simultaneously. P-glycoprotein (P-gp) is most commonly associated with human MDR; it utilizes energy from adenosine triphosphate (ATP) to transport a number of substrates out of cells against concentration gradients. By the active transport of substrates against concentration gradients, intracellular concentrations of substrates are decreased. This leads to the cause of failure in cancer chemotherapy.ResultsHerein, we report Topomer CoMFA (Comparative Molecular Field Analysis) and HQSAR (Hologram Quantitative Structure Activity Relationship) models for third generation MDR modulators. The Topomer CoMFA model showed good correlation between the actual and predicted values for training set molecules. The developed model showed cross validated correlation coefficient (q2) = 0.536 and non-cross validated correlation coefficient (r2) = 0.975 with eight components. The best HQSAR model (q2 = 0.777, r2 = 0.956) with 5-8 atom counts was used to predict the activity of test set compounds. Both models were validated using test set compounds, and gave a good predictive values of 0.604 and 0.730.ConclusionsThe contour map near R1 indicates that substitution of a bulkier and polar group to the ortho position of the benzene ring enhances the inhibitory effect. This explains why compounds with a nitro group have good inhibitory potency. Molecular fragment analyses shed light on some essential structural and topological features of third generation MDR modulators. Fragments analysis showed that the presence of tertiary nitrogen, a central phenyl ring and an aromatic dimethoxy group contributed to the inhibitory effect. Based on contour map information and fragment information, five new molecules with variable R1 substituents were designed. The activity of these designed molecules was predicted by the Topomer CoMFA and HQSAR models. The novel compounds showed higher potency than existing compounds.

Structure−Function Relationships of Inhibition of Human Cytochromes P450 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 Flavonoid Derivatives

Structure-function relationships for the inhibition of human cytochrome P450s (P450s) 1A1, 1A2, 1B1, 2C9, and 3A4 by 33 flavonoid derivatives were studied. Thirty-two of the 33 flavonoids tested produced reverse type I binding spectra with P450 1B1, and the potencies of binding were correlated with the abilities to inhibit 7-ethoxyresorufin O-deethylation activity. The presence of a hydroxyl group in flavones, for example, 3-, 5-, and 7-monohydroxy- and 5,7-dihydroxyflavone, decreased the 50% inhibition concentration (IC50) of P450 1B1 from 0.6 μM to 0.09, 0.21, 0.25, and 0.27 μM, respectively, and 3,5,7-trihydroxyflavone (galangin) was the most potent, with an IC50 of 0.003 μM. The introduction of a 4'-methoxy- or 3',4'-dimethoxy group into 5,7-dihydroxyflavone yielded other active inhibitors of P450 1B1 with IC50 values of 0.014 and 0.019 μM, respectively. The above hydroxyl and/or methoxy groups in flavone molecules also increased the inhibition activity with P450 1A1 but not always toward P450 1A2, where 3-, 5-, or 7-hydroxyflavone and 4'-methoxy-5,7-dihydroxyflavone were less inhibitory than flavone itself. P450 2C9 was more inhibited by 7-hydroxy-, 5,7-dihydroxy-, and 3,5,7-trihydroxyflavones than by flavone but was weakly inhibited by 3- and 5-hydroxyflavone. Flavone and several other flavonoids produced type I binding spectra with P450 3A4, but such binding was not always related to the inhibitiory activities toward P450 3A4. These results indicate that there are different mechanisms of inhibition for P450s 1A1, 1A2, 1B1, 2C9, and 3A4 by various flavonoid derivatives and that the number and position of hydroxyl and/or methoxy groups highly influence the inhibitory actions of flavonoids toward these enzymes. Molecular docking studies suggest that there are different mechanisms involved in the interaction of various flavonoids with the active site of P450s, thus causing differences in inhibition of these P450 catalytic activities by flavonoids.