Synthesis of Novel Aryloxyethylamine Derivatives and Evaluation of Their in Vitro and in Vivo Neuroprotective Activities

A series of aryloxyethylamine derivatives were designed, synthesized and evaluated for their biological activity. Their structures were confirmed by ¹H‐NMR, ¹³C‐NMR, FT‐IR and HR‐ESI‐MS. The preliminary screening of neuroprotection of compounds in vitro was detected by MTT, and the anti‐ischemic activity in vivo was tested using bilateral common carotid artery occlusion in mice. Most of these compounds showed potential neuroprotective effects against the glutamate‐induced cell death in differentiated rat pheochromocytoma cells (PC12 cells), especially for (4‐fluorophenyl){1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}methanone, {1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}(4‐methoxyphenyl)methanone, (4‐bromophenyl){1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}methanone, {1‐[2‐(4‐chlorophenoxy)ethyl]piperidin‐4‐yl}(4‐chlorophenyl)methanone, (4‐chlorophenyl)(1‐{2‐[(naphthalen‐2‐yl)oxy]ethyl}piperidin‐4‐yl)methanone, (4‐chlorophenyl){1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}methanone and {1‐[2‐(4‐bromophenoxy)ethyl]piperidin‐4‐yl}(4‐chlorophenyl)methanone, which exhibited potent protection of PC12 cells at three doses (0.1, 1.0, 10 μM). Compounds (4‐fluorophenyl){1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}methanone, (4‐fluorophenyl){1‐[2‐(naphthalen‐2‐yloxy)ethyl]piperidin‐4‐yl}methanone, {1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}(4‐methoxyphenyl)methanone and {1‐[2‐(4‐chlorophenoxy)ethyl]piperidin‐4‐yl}(4‐chlorophenyl)methanone possessed the significant prolongation of the survival time of mice subjected to acute cerebral ischemia and decreased the mortality rate at all five doses tested (200, 100, 50, 25, 12.5 mg/kg) and had significant neuroprotective activity. In addition, (4‐fluorophenyl){1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}methanone, {1‐[2‐(4‐methoxyphenoxy)ethyl]piperidin‐4‐yl}(4‐methoxyphenyl)methanone and {1‐[2‐(4‐chlorophenoxy)ethyl]piperidin‐4‐yl}(4‐chlorophenyl)methanone possessed outstanding neuroprotection in vitro and in vivo. These compounds can be used as a promising neuroprotective agents for future development of new anti‐ischemic stroke agents. Basic structure–activity relationships are also presented.     

Synthesis and Properties of a Novel Pyridineoxazoline Containing Optically Active Helical Polymer as a Catalyst Ligand for Asymmetric Diels–Alder Reaction

A novel pyridineoxazoline (PyOx) containing helical polymer, poly{(–)‐(S)‐4‐tert‐butyl‐2‐[5‐(4‐tert‐butylphenyl)‐3‐vinylpyridin‐2‐yl]‐oxazoline} ( PA ), was designed and synthesized to approach the effect of chain conformation on the catalytic property. Its complex with Cu(OTf)₂, i.e., Cu(II)-PA , was employed to catalyze the homogeneous Diels–Alder (D–A) reaction of alkenoyl pyridine N‐oxides with cyclopentadiene in tetrahydrofuran. Compared with the previously reported copper complex, Cu(II)-P1 (RSC Advances, 2015, 5 , 2882), which was derived from a nonhelical poly[(–)‐(S)‐4‐tert‐butyl‐2‐(3‐vinylpyridin‐2‐yl)‐oxazoline], Cu(II)-PA exhibited a remarkably enhanced enantioselectivity and reaction rate. However, its enantioselectivity was lower than the Cu(II) complex of (–)‐(S)‐4‐tert‐butyl‐2‐[5‐(4‐tert‐butylphenyl)‐3‐vinylpyridin‐2‐yl]‐oxazoline ( Cu(II)-A ), a low molar mass model compound. Chirality 27:523–531, 2015. © 2015 Wiley Periodicals, Inc.     

Enzymatic Hydrolysis of Esters Containing a Tetrazole Ring

The lipase‐catalyzed enantioselective hydrolysis of acetates containing tetrazole moiety was studied. Among all tested lipases, Novozyme SP 435 allowed to obtain optically active 4‐(5‐aryl‐2H‐tetrazol‐2yl)butan‐2‐ol and 1‐(5‐aryl‐2H‐tetrazol‐2yl)‐propan‐2‐ol and their acetates with the highest optical purities (ee = 95%‐99%) and excellent enantioselectivity (E>100). Some of the synthesized tetrazole derivatives were screened for their antifungal activity. Racemic mixtures of 4‐[5‐(4‐chlorophenyl)‐2H‐tetrazol‐2‐yl)butan‐2‐ol as well as pure enantiomers of this compound showed promising antifungal activity against F. sambucinum, F. oxysporum, C. coccodes, and A. niger. Chirality 26: 811–816, 2014. © 2014 Wiley Periodicals, Inc.     

Photoactive Blend Morphology Engineering through Systematically Tuning Aggregation in All‐Polymer Solar Cells

Polymer aggregation plays a critical role in the miscibility of materials and the performance of all‐polymer solar cells (APSCs). However, many aspects of how polymer texturing and aggregation affect photoactive blend film microstructure and photovoltaic performance are poorly understood. Here the effects of aggregation in donor–acceptor blends are studied, in which the number‐average molecular weights (M_ns) of both an amorphous donor polymer, poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)] ( PBDTT‐FTTE ) and a semicrystalline acceptor polymer, poly{[N,N′‐bis(2‐octyldodecyl)naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} ( P(NDI2OD‐T2) ) are systematically varied. The photovoltaic performance is correlated with active layer microstructural and optoelectronic data acquired by in‐depth transmission electron microscopy, grazing incidence wide‐angle X‐ray scattering, thermal analysis, and optical spectroscopic measurements. Coarse‐grained modeling provides insight into the effects of polymer aggregation on the blend morphology. Notably, the computed average distance between the donor and the acceptor polymers correlates well with solar cell photovoltaic metrics such as short‐circuit current density (J_sc) and represents a useful index for understanding/predicting active layer blend material intermixing trends. Importantly, these results demonstrate that for polymers with different texturing tendencies (amorphous/semicrystalline), the key for optimal APSC performance, photovoltaic blend morphology can be controlled via both donor and acceptor polymer aggregation.     

A Small Molecule Non‐fullerene Electron Acceptor for Organic Solar Cells

Organic bulk heterojunction photovoltaic devices predominantly use the fullerene derivatives [C60]PCBM and [C70]PCBM as the electron accepting component. This report presents a new organic electron accepting small molecule 2‐[{7‐(9,9‐di‐n‐propyl‐9H‐fluoren‐2‐yl)benzo[c][1,2,5]thiadiazol‐4‐yl}methylene]malononitrile (K12) for organic solar cell applications. It can be processed by evaporation under vacuum or by solution processing to give amorphous thin films and can be annealed at a modest temperature to give films with much greater order and enhanced charge transport properties. The molecule can efficiently quench the photoluminescence of the donor polymer poly(3‐n‐hexylthiophene‐2,5‐diyl) (P3HT) and time resolved microwave conductivity measurements show that mobile charges are generated indicating that a truly charge separated state is formed. The power conversion efficiencies of the photovoltaic devices are found to depend strongly on the acceptor packing. Optimized K12:P3HT bulk heterojunction devices have efficiencies of 0.73±0.01% under AM1.5G simulated sunlight. The efficiencies of the devices are limited by the level of crystallinity and nanoscale morphology that was achievable in the blend with P3HT.     

Toxicity of Thiophenes from Echinops transiliensis (Asteraceae) against Aedes aegypti (Diptera: Culicidae) Larvae

Structure? activity relationships of nine thiophenes, 2,2′: 5′,2″‐terthiophene ( 1 ), 2‐chloro‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐1‐yl acetate ( 2 ), 4‐(2,2′‐bithiophen‐5‐yl)but‐3‐yne‐1,2‐diyl diacetate ( 3 ), 4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yne‐1,2‐diyl diacetate ( 4 ), 4‐(2,2′‐bithiophen‐5‐yl)‐2‐hydroxybut‐3‐yn‐1‐yl acetate ( 5 ), 2‐hydroxy‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐1‐yl acetate ( 6 ), 1‐hydroxy‐4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yn‐2‐yl acetate ( 7 ), 4‐(2,2′‐bithiophen‐5‐yl)but‐3‐yne‐1,2‐diol ( 8 ), and 4‐[5‐(penta‐1,3‐diyn‐1‐yl)thiophen‐2‐yl]but‐3‐yne‐1,2‐diol ( 9 ), isolated from the roots of Echinops transiliensis, were studied as larvicides against Aedes aegypti. Structural differences among compounds 3, 5 , and 8 consisted in differing AcO and OH groups attached to C(3″) and C(4″), and resulted in variations in efficacy. Terthiophene 1 showed the highest activity (LC₅₀, 0.16 μg/ml) among compounds 1 – 9 , followed by bithiophene compounds 3 (LC₅₀, 4.22 μg/ml), 5 (LC₅₀, 7.45 μg/ml), and 8 (LC₅₀, 9.89 μg/ml), and monothiophene compounds 9 (LC₅₀, 12.45 μg/ml), 2 (LC₅₀, 14.71 μg/ml), 4 (LC₅₀, 17.95 μg/ml), 6 (LC₅₀, 18.55 μg/ml), and 7 (LC₅₀, 19.97 μg/ml). These data indicated that A. aegypti larvicidal activities of thiophenes increase with increasing number of thiophene rings, and the most important active site in the structure of thiophenes could be the tetrahydro‐thiophene moiety. In bithiophenes, 3, 5 , and 8 , A. aegypti larvicidal activity increased with increasing number of AcO groups attached to C(3″) or C(4″), indicating that AcO groups may play an important role in the larvicidal activity.     

Synthesis,Characterization, and Biological Activities of Pendant Arm‐Pyridyltetrazole Copper(II) Complexes: DNA Binding/Cleavage Activity and Cytotoxic Studies

2‐(1H‐Tetrazol‐5‐yl)pyridine ( L ) has been reacted separately with Me₂NCH₂CH₂Cl?HCl and ClCH₂CH₂OH to yield two regioisomers in each case, N,N‐dimethyl‐2‐[5‐(pyridin‐2‐yl)‐1H‐tetrazol‐1‐yl]ethanamine ( L1 )/N,N‐dimethyl‐2‐[5‐(pyridin‐2‐yl)‐2H‐tetrazol‐2‐yl]ethanamine ( L2 ) and 2‐[5‐(pyridin‐2‐yl)‐1H‐tetrazol‐1‐yl]ethanol ( L3 )/2‐[5‐(pyridin‐2‐yl)‐2H‐tetrazol‐2‐yl]ethanol ( L4 ), respectively. These ligands, L1 – L4 , have been coordinated with CuCl₂?H₂O in 1 : 1 composition to furnish the corresponding complexes 1 – 4 . EPR Spectra of Cu complexes 1 and 3 were characteristic of square planar geometry, with nuclear hyperfine spin 3/2. Single X‐ray crystallographic studies of 3 revealed that the Cu center has a square planar structure. DNA binding studies were carried out by UV/VIS absorption; viscosity and thermal denaturation studies revealed that each of these complexes are avid binders of calf thymus DNA. Investigation of nucleolytic cleavage activities of the complexes was carried out on double‐stranded pBR322 circular plasmid DNA by using a gel electrophoresis experiment under various conditions, where cleavage of DNA takes place by oxidative free‐radical mechanism (OH ^? ). In vitro anticancer activities of the complexes against MCF‐7 (human breast adenocarcinoma) cells revealed that the complexes inhibit the growth of cancer cells. The IC₅₀ values of the complexes showed that Cu complexes exhibit comparable cytotoxic activities compared to the standard drug cisplatin.     

Plasmonic Back Reflectors: A Small Molecule Non‐fullerene Electron Acceptor for Organic Solar Cells

Organic bulk heterojunction photovoltaic devices predominantly use the fullerene derivatives [C60]PCBM and [C70]PCBM as the electron accepting component. This report presents a new organic electron accepting small molecule 2‐[{7‐(9,9‐di‐n‐propyl‐9H‐fluoren‐2‐yl)benzo[c][1,2,5]thiadiazol‐4‐yl}methylene]malononitrile (K12) for organic solar cell applications. It can be processed by evaporation under vacuum or by solution processing to give amorphous thin films and can be annealed at a modest temperature to give films with much greater order and enhanced charge transport properties. The molecule can efficiently quench the photoluminescence of the donor polymer poly(3‐n‐hexylthiophene‐2,5‐diyl) (P3HT) and time resolved microwave conductivity measurements show that mobile charges are generated indicating that a truly charge separated state is formed. The power conversion efficiencies of the photovoltaic devices are found to depend strongly on the acceptor packing. Optimized K12:P3HT bulk heterojunction devices have efficiencies of 0.73±0.01% under AM1.5G simulated sunlight. The efficiencies of the devices are limited by the level of crystallinity and nanoscale morphology that was achievable in the blend with P3HT.     

Structural characterization of a new N‐substituted pantothenamide bound to pantothenate kinases from Klebsiella pneumoniae and Staphylococcus aureus

Pantothenate kinase (PanK) is the rate‐limiting enzyme in Coenzyme A biosynthesis, catalyzing the ATP‐dependent phosphorylation of pantothenate. We solved the co‐crystal structures of PanKs from Staphylococcus aureus (SaPanK) and Klebsiella pneumonia (KpPanK) with N‐[2‐(1,3‐benzodioxol‐5‐yl)ethyl] pantothenamide (N354‐Pan). Two different N354‐Pan conformers interact with polar/nonpolar mixed residues in SaPanK and aromatic residues in KpPanK. Additionally, phosphorylated N354‐Pan is found at the closed active site of SaPanK but not at the open active site of KpPanK, suggesting an exchange of the phosphorylated product with a new N354‐Pan only in KpPanK. Together, pantothenamides conformational flexibility and binding pocket are two key considerations for selective compound design. Proteins 2014; 82:1542–1548. © 2014 Wiley Periodicals, Inc.     

Balancing High Open Circuit Voltage over 1.0 V and High Short Circuit Current in Benzodithiophene‐Based Polymer Solar Cells with Low Energy Loss: A Synergistic Effect of Fluorination and Alkylthiolation

Based on the most recently significant progress within the last one year in organic photovoltaic research from either alkylthiolation or fluorination on benzo[1,2‐b:4,5‐b′]dithiophene moiety for high efficiency polymer solar cells (PSCs), two novel simultaneously fluorinated and alkylthiolated benzo[1,2‐b:4,5‐b′] dithiophene (BDT)‐based donor–acceptor (D–A) polymers, poly(4,8‐bis(5′‐((2″‐ethylhexyl)thio)‐4′‐fluorothiophen‐2′‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl)‐alt‐2′‐ethylhexyl‐3‐fluorothieno[3,4‐b]thiophene‐2‐carboxylate (PBDTT‐SF‐TT) and poly(4,8‐bis(5′‐((2″‐ethylhexyl)thio)‐4′‐fluorothiophen‐2′‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl)‐alt‐1,3‐bis(thiophen‐2‐yl)‐5,7‐bis(2‐ethylhexyl)benzo[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione (PBDTT‐SF‐BDD), namely, via an advantageous and synthetically economic route for the key monomer are reported herein. Synergistic effects of fluorination and alkylthiolation on BDT moieties are discussed in detail, which is based on the superior balance between high V_oc and large J_sc when PBDTT‐SF‐TT/PC₇₁BM and PBDTT‐SF‐BDD/PC₇₁BM solar cells present their high V_oc as 1.00 and 0.97 V (associated with their deep highest occupied molecular orbital level of ?5.54 and ?5.61 eV), a moderately high J_sc of 14.79 and 14.70 mA cm^?2, and thus result a high power conversion efficiency of 9.07% and 9.72%, respectively. Meanwhile, for PBDTT‐SF‐TT, a very low energy loss of 0.59 eV is pronounced, leading to the promisingly high voltage, and furthermore performance study and morphological results declare an additive‐free PSC from PBDTT‐SF‐TT, which is beneficial to practical applications.     

Design and Synthesis of Novel Thiazolo[5,4‐d]pyrimidine Derivatives as Potential Angiogenesis Inhibitors

Vascular endothelial growth factor receptor‐2 (VEGFR‐2) plays an important role in both vasculogenesis and angiogenesis. Inhibition of VEGFR‐2 has been demonstrated as a key method against tumor‐associated angiogenesis. Thiazolopyrimidine is an important analog of the purine ring, and we choose the thiazolopyrimidine scaffold as the mother nucleus. Two series of thiazolo[5,4‐d]pyrimidine derivatives were synthesized and evaluated for their antiproliferative activity. In HUVEC inhibition assay, compounds 3l (=1‐(5‐{[2‐(4‐chlorophenyl)‐5‐methyl[1,3]thiazolo[5,4‐d]pyrimidin‐7‐yl]amino}pyridin‐2‐yl)‐3‐(3,4‐dimethylphenyl)urea) and 3m (=1‐(5‐{[2‐(4‐chlorophenyl)‐5‐methyl[1,3]thiazolo[5,4‐d]pyrimidin‐7‐yl]amino}pyridin‐2‐yl)‐3‐(4‐methoxyphenyl)urea) exhibited the most potent inhibitory effect (IC₅₀=1.65 and 3.52 μm , respectively). Compound 3l also showed the best potency against VEGFR‐2 at 50 μm (98.5 %). These results suggest that further investigation of compound 3l might provide potential angiogenesis inhibitors.     

Identification of N‐octylnortadalafil and its Stereoisomers in Dietary Supplements with Chiral Liquid Chromatography–Circular Dichroism

A direct chiral liquid chromatography–circular dichroism (LC‐CD) method was developed for the simple and rapid identification of N‐octylnortadalafil [(6R, 12aR)‐6‐(1,3‐benzodioxol‐5‐yl)‐2‐octyl‐2,3,6,7,12,12a‐hexahydropyrazino[1’,2’:1,6]pyrido[3,4‐b]indole‐1,4‐dione; RR‐OTDF] and its stereoisomers in dietary supplements. Samples were extracted with methanol. Compounds were then separated by chiral LC‐CD using Chiralcel OD‐RH (4.6 × 1 50 mm, 5 µm) with 5 mM ammonium formate (pH 3)/0.1% formic acid in acetonitrile (95:5, v/v) mixture solution (mobile phase A) and 0.1% formic acid in acetonitrile (mobile phase B). The isocratic elution used was mobile phase A / mobile phase B (3:7, v/v) at a flow rate of 1 ml/min. The column temperature was held at 30°C. RR‐OTDF and its stereoisomers were separated within 20 min with the resolution factors being over 2.0. Using this method, RR‐OTDF and (6R, 12aS)‐6‐(1,3‐benzodioxol‐5‐yl)‐2‐octyl‐2,3,6,7,12,12a‐hexahydropyrazino[1’,2’:1,6]pyrido[3,4‐b]indole‐1,4‐dione were detected in a dietary supplement. Chirality 28:204–208, 2016. © 2016 Wiley Periodicals, Inc.     

Further Thymol Derivatives from Ageratina cylindrica

From the leaves of Ageratina cylindrica, in addition to the described [(2S)‐2‐{4‐formyl‐5‐hydroxy‐2‐[(2‐methylpropanoyl)oxy]phenyl}oxiran‐2‐yl]methyl benzoate (cylindrinol A, 8 ), seven new thymol derivatives were isolated and named cylindrinols B – H ( 1 – 7 ). The structures of these compounds were established as (2‐{4‐(hydroxymethyl)‐2‐[(2‐methylpropanoyl)oxy]phenyl}oxiran‐2‐yl)methyl benzoate ( 1 ), (2‐{4‐formyl‐2‐[(2‐methylpropanoyl)oxy]phenyl}oxiran‐2‐yl)methyl benzoate ( 2 ), (2‐{4‐[(acetyloxy)methyl]‐2‐[(2‐methylpropanoyl)oxy]phenyl}oxiran‐2‐yl)methyl benzoate ( 3 ), [2‐(2‐[(2‐methylpropanoyl)oxy]‐4‐{[(2‐methylpropanoyl)oxy]methyl}phenyl)oxiran‐2‐yl]methyl benzoate ( 4 ), [2‐(5‐hydroxy‐2‐[(2‐methylpropanoyl)oxy]‐4‐{[(2‐methylpropanoyl)oxy]methyl}phenyl)oxiran‐2‐yl]methyl benzoate ( 5 ), 2‐{4‐(hydroxymethyl)‐2‐[(2‐methylpropanoyl)oxy]phenyl}prop‐2‐en‐1‐yl benzoate ( 6 ), and 2‐hydroxy‐2‐[2‐hydroxy‐4‐(hydroxymethyl)‐phenyl]‐3‐[(2‐methylpropanoyl)oxy]propyl benzoate ( 7 ), by spectroscopic means. Compounds 1 showed moderate antiprotozoal activity on both protozoa. Compounds 4 and 5 showed selectivity on Giardia lamblia trophozoites. All isolated compounds were less active than two antiprotozoal drugs, metronidazole and emetine, used as positive controls. Compound 5 exhibited a high inhibitory effect on hyperpropulsive movement of the small intestine in rats; its effect was best than loperamide, antidiarrheal drug used as a positive control.     

Antiproliferative Evaluation of Some 2‐[2‐(2‐Phenylethenyl)‐cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles: DFT and Molecular Docking Study

The 2‐[2‐(2‐phenylethenyl)cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles were synthesized from the reactions of 7‐benzylidenebicyclo[3.2.0]hept‐2‐en‐6‐ones with 2‐aminobenzenethiol. The antiproliferative activities of 2‐[2‐(2‐phenylethenyl)cyclopent‐3‐en‐1‐yl]‐1,3‐benzothiazoles were determined against C6 (rat brain tumor) and HeLa (human cervical carcinoma cells) cell lines using BrdU cell proliferation ELISA assay. Cisplatin and 5‐fluorouracil (5‐FU) were used as standards. The most active compound was 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against C6 cell lines with IC₅₀=5.89 μm value (cisplatin, IC₅₀=14.46 μm and 5‐FU, IC₅₀=76.74 μm ). Furthermore, the most active compound was 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against HeLa cell lines with IC₅₀=3.98 μm (cisplatin, IC₅₀=37.95 μm and 5‐FU, IC₅₀=46.32 μm ). Additionally, computational studies of related molecules were performed by using B3LYP/6‐31G+(d,p) level in the gas phase. Experimental IR and NMR data were compared with the calculated results and were found to be compatible with each other. Molecular electrostatic potential (MEP) maps of the most active 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against HeLa and the most active 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole against C6 were investigated, aiming to determine the region that the molecule is biologically active. Biological activities of mentioned molecules were investigated with molecular docking analyses. The appropriate target protein (PDB codes: 1 M17 for the HeLa cells and 1JQH for the C6 cells) was used for 2‐{(1S,2S)‐2‐[(E)‐2‐(2‐methoxyphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole and 2‐{(1S,2S)‐2‐[(E)‐2‐(4‐methylphenyl)ethenyl]cyclopent‐3‐en‐1‐yl}‐1,3‐benzothiazole molecules exhibiting the highest biological activity against HeLa and C6 cells in the docking studies. As a result, it was determined that these molecules are the best candidates for the anticancer drug.     

First Synthesis of Double Headed 1,3,4‐Oxadiazino[6,5‐b]indole Acyclo C‐Nucleosides

Condensation of 1,3‐dihydro‐2,3‐dioxo‐2H‐indoles (1a–c) with galactaric acid bis hydrazide (2) gave the corresponding galactaric acid bis[2‐(1,2‐dihydro‐2‐oxo‐3H‐indol‐3‐ylidene)hydrazides] (3a–c). Acetylation of the latter compounds with acetic anhydride in the presence of pyridine at ambient temperature gave the 2,3,4,5‐tetra‐O‐acetylgalactaric acid bis[2‐(1,2‐dihydro‐2‐oxo‐1‐substituted‐3H‐indol‐3‐ylidene)hydrazides] (4b–d). Heterocyclization of the tetra‐O‐acetates 4b–d by heating with thionyl chloride afforded the double headed acyclo C‐nucleosides: 1,2,3,4‐tetra‐O‐acetyl‐1,4‐bis{9‐substituted‐1,3,4‐oxadiazino[6,5‐b]indol‐2‐yl‐1‐ium}‐galacto‐tetritol dichlorides (5b–d). Structures of the prepared compounds were elucidated from their spectral properties.     

Harmonious Compatibility Dominates Influence of Side‐Chain Engineering on Morphology and Performance of Ternary Solar Cells

A growing number of recent studies have demonstrated the substantial impact of the alkyl side chains on the device performance of organic semiconductors. However, detailed investigation of the effect of side‐chain engineering on the blend morphology and performance of ternary organic solar cells (OSCs) has not yet been undertaken. In this study, the performance of ternary OSCs is investigated in a given poly(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)):[6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PTB7‐Th:PC₇₁BM) host set by introducing various small molecule donors (SMDs) with different terminal side‐chain lengths. As expected, the performance of binary OSCs with SMDs depends greatly on the side‐chain length. In contrast, it is observed that all SMD‐based ternary OSCs exhibit almost identical and high power‐conversion efficiencies of 12.0–12.2%. This minor performance variation is attributed to good molecular compatibility between the two donor components, as evidenced by in‐depth electrical and morphological investigations. These results highlight that the alloy‐like structure formed due to the high compatibility of the donor molecules has a more significant effect on the overall performance than the side‐chain length, offering a new guideline for pairing donor components for achieving high‐performance ternary OSCs.     

Chemoenzymatic Approach to Optically Active 4‐Hydroxy‐5‐alkylcyclopent‐2‐en‐1‐one Derivatives: An Application of a Combined Circular Dichroism Spectroscopy and DFT Calculations to Assignment of Absolute Configuration

A series of representative optically active derivatives of 4‐hydroxy‐5‐alkylcyclopent‐2‐en‐1‐one were prepared from the respective 2‐furyl methyl carbinols via the Piancatelli rearrangement followed by the enzymatic kinetic resolution of racemates. Applicability of chiroptical methods (experimental and calculated electronic circular dichroism [ECD] and vibrational circular dichroism [VCD] spectra) to determine the absolute configuration of both stereogenic centers in 4‐hydroxy‐5‐methylcyclopent‐2‐en‐1‐one was demonstrated. It was also demonstrated that the concurrent application of ECD and VCD spectroscopy can be used for the determination of the configuration of two stereogenic centers. Chirality 26:300–306, 2014. © 2014 Wiley Periodicals, Inc.     

Efficient Vacuum‐Deposited Tandem Organic Solar Cells with Fill Factors Higher Than Single‐Junction Subcells

Efficient vacuum‐deposited tandem organic photovoltaic cells (TOPVs) composed of pristine fullerenes as the acceptors and two complementary absorbing donors, 2‐((2‐(5‐(4‐(diphenylamino)phenyl)thieno[3,2‐b]thiophen‐2‐yl)thiazol‐5‐yl)methylene)malononitrile for the visible absorption and 2‐((7‐(5‐(dip‐tolylamino)thiophen‐2‐yl)benzo[c]‐[1,2,5]thiadiazol‐4‐yl)methylene)malononitrile for the near‐infrared absorption, are reported. Two subcells are connected by the interconnection unit (ICU) composed of electron‐transporting layer/metal/p‐doped hole‐transporting layer. The p‐doped layer in the ICU enables increasing the short‐circuit current density (J _SC) of TOPVs by tuning the relative position of subcells in the tandem devices to have the maximum optical field distribution response, which is well matched with theoretical calculation. Moreover, the introduction of the doped layer benefits to the higher fill factor (FF) of the consisting subcells without losing open‐circuit voltage (V _OC) even with the thick active layers. As a result, power conversion efficiency of 9.2% is achieved with higher FF of 0.62 than that of single‐junction subcells (0.54, 0.57), J _SC of 8.7 mA cm^?2, and V _OC of 1.71 V using 80 nm thick active layers in both subcells.     

Synthesis and Fungicidal Activities of New 1,2,4‐Triazolo[1,5‐a]pyrimidines

A series of new acetohydrazone‐containing 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives were designed and synthesized for the purpose of searching for novel agrochemicals with higher fungicidal activity. Their in vitro fungicidal activities against Rhizoctonia solani were evaluated, and the most promising compound, 2‐[(5,7‐dimethyl[1,2,4]triazolo[1,5‐a]pyrimidin‐2‐yl)sulfanyl]‐2′‐[(2‐hydroxyphenyl)methylidene]acetohydrazide ( 2‐17 ), showed a lower EC₅₀ value (5.34 μg ml^?1) than that of commercial carbendazim (EC₅₀=7.62 μg ml^?1). Additionally, compound 2‐17 was also found to display broad‐spectrum fungicidal activities, and its EC₅₀ value (4.56 μg ml^?1) against Botrytis cinereapers was very similar to that of carbendazim. Qualitative structure–activity relationships (QSARs) of the synthesized compounds were also discussed.     

Study on the synthesis of sulfonamide derivatives and their interaction with bovine serum albumin

Three sulfonamide derivatives (SAD) were first synthesized from p‐hydroxybenzoic acid and sulfonamides (sulfadimidine, sulfamethoxazole and sulfachloropyridazine sodium) and were characterized by elemental analysis, ¹H NMR and MS. The interaction between bovine serum albumin (BSA) and SAD was studied using UV/vis absorption spectroscopy, fluorescence spectroscopy, time‐resolved fluorescence spectroscopy and circular dichroism spectra under imitated physiological conditions. The experimental results indicated that SAD effectively quenched the intrinsic fluorescence of BSA via a static quenching process. The thermodynamic parameters showed that hydrogen bonding and van der Waal's forces were the predominant intermolecular forces between BSA and two SADs [4‐((4‐(N‐(4,6‐dimethylpyrimidin‐2‐yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate and 4‐((4‐(N‐(5‐methylisoxazol‐3‐yl)sulfamoyl)phenyl)carbamoyl)phenyl acetate], but hydrophobic forces played a major role in the binding process of BSA and 4‐((4‐(N‐(6‐chloropyridazin‐3‐yl)sulfamoyl)phenyl) carbamoyl)phenyl acetate. In addition, the effect of SAD on the conformation of BSA was investigated using synchronous fluorescence spectroscopy and circular dichroism spectra. Molecular modeling results showed that SAD was situated in subdomain IIA of BSA. Copyright © 2014 John Wiley & Sons, Ltd.