- Lipase-catalyzed synthesis of 4-methoxy cinnamoyl glycerol
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Cinnamoyl esters are used as organic ultraviolet (UV) filters in sunscreens and cosmetic formulations. To avoid any possible harmful effects from chemically synthesized product, the enzymatic synthesis appears to be an excellent way to satisfy the present consumer demand for natural products. Enzymatic esterification of 4-methoxy cinnamic acid (4MCA) with glycerol was carried out in organic solvents using immobilized lipase B from Candida antarctica, in which the maximum conversion of 34% was found in isooctane at 70 °C after 24 h with 12% of enantiomeric excess. If the reaction continued for longer times (48 h) it leads to the formation of 16% of diester along with 56% of monoester. The results of enzymatic esterification were compared with reported chemical esterification and the present method was found to be superior in terms of conversion yields and priority to the formation of monoester. Synthesized monoester product was isolated and characterized by spectroscopic techniques.
- Patil, Dipak,Dev, Bappaditya,Nag, Ahindra
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Read Online
- One-Pot Biocatalytic In Vivo Methylation-Hydroamination of Bioderived Lignin Monomers to Generate a Key Precursor to L-DOPA
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Electron-rich phenolic substrates can be derived from the depolymerisation of lignin feedstocks. Direct biotransformations of the hydroxycinnamic acid monomers obtained can be exploited to produce high-value chemicals, such as α-amino acids, however the reaction is often hampered by the chemical autooxidation in alkaline or harsh reaction media. Regioselective O-methyltransferases (OMTs) are ubiquitous enzymes in natural secondary metabolic pathways utilising an expensive co-substrate S-adenosyl-l-methionine (SAM) as the methylating reagent altering the physicochemical properties of the hydroxycinnamic acids. In this study, we engineered an OMT to accept a variety of electron-rich phenolic substrates, modified a commercial E. coli strain BL21 (DE3) to regenerate SAM in vivo, and combined it with an engineered ammonia lyase to partake in a one-pot, two whole cell enzyme cascade to produce the l-DOPA precursor l-veratrylglycine from lignin-derived ferulic acid.
- Birmingham, William R.,Galman, James L.,Parmeggiani, Fabio,Seibt, Lisa,Turner, Nicholas J.
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- Synthesis, crystal structure, and catalytic activity of bridged-bis(N-heterocyclic carbene) palladium(II) complexes in selective Mizoroki-Heck cross-coupling reactions
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A series of three 1,3-propanediyl bridged bis(N-heterocyclic carbene)palladium(II) complexes (Pd-BNH1, Pd-BNH2, and Pd-BNH3), with + I effect order of the N-substituents of the ligand (isopropyl > benzyl > methoxyphenyl), was the subject of a spectroscopic, structural, computational and catalytic investigation. The bis(NHC)PdBr2 complexes were evaluated in Mizoroki-Heck coupling reactions of aryl bromides with styrene or acrylate derivatives and showed high catalytic efficiency to produce diarylethenes and cinnamic acid derivatives. The X-ray structure of the most active palladium complex Pd-BNH3 shows that the Pd(II) center is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromide ligands in cis position, resulting in a distorted square planar geometry. The NMR data of Pd-BNH3 are consistent with a single chair-boat rigid conformer in solution with no dynamic behavior of the 8-membered ring palladacycle in the temperature range 25–120 °C. The catalytic activities of three Pd-bridged bis(NHC) complexes in the Mizoroki-Heck cross-coupling reactions were not found to have a direct correlation with +I effect order of the N-substituents of the ligand. However, a direct correlation was found between the DFT calculated absolute softness of the three complexes with their respective catalytic activity. The highest calculated softness, in the case of Pd-BNH3, is expected to favor the coordination steps of both the soft aryl bromides and alkenes in the Heck catalytic cycle.
- El Ali, Bassam,Fettouhi, Mohammed,Iali, Wissam,Mansour, Waseem,Suleiman, Rami
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- Design, synthesis, and evaluation of different scaffold derivatives against NS2B-NS3 protease of dengue virus
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The number of deaths or critical health issues is a threat in the infection caused by Dengue virus, which complicates the situation, as only symptomatic treatment is the current solution. In this regard we have targeted the dengue protease NS2B-NS3 that is responsible for the replication. The series was designed with the help of molecular modeling approach using docking protocols. The series comprised of different scaffolds viz. cinnamic acid analogs (CA1–CA11), chalcone (C1–C10) and their molecular hybrids (Lik1–Lik10), analogs of benzimidazole (BZ1-BZ5), mercaptobenzimidazole (BS1-BS4), and phenylsulfanylmethylbenzimidazole (PS1-PS4). Virtual screening of various natural phytoconstituents was employed to determine the interactions of designed analogs with the residues of catalytic triad in the active site of NS2B-NS3. We have further synthesized the selected leads. The synthesized analogs were evaluated for the cytotoxicity and NS2B-NS3 protease inhibition activity and compared with known anti-dengue natural phytoconstituent quercetin as the standard. CA2, BZ1, and BS2 were found to be more potent and efficacious than the standard quercetin as evident from the protease inhibition assay.
- Ganji, Lata R.,Gandhi, Lekha,Musturi, Venkataramana,Kanyalkar, Meena A.
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p. 285 - 301
(2020/11/19)
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- Discovery of Novel Benzothiazepinones as Irreversible Covalent Glycogen Synthase Kinase 3β Inhibitors for the Treatment of Acute Promyelocytic Leukemia
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Recently, irreversible inhibitors have attracted great interest in antitumors due to their advantages of forming covalent bonds to target proteins. Herein, some benzothiazepinone compounds (BTZs) have been designed and synthesized as novel covalent GSK-3β inhibitors with high selectivity for the kinase panel. The irreversible covalent binding mode was identified by kinetics and mass spectrometry, and the main labeled residue was confirmed to be the unique Cys14 that exists only in GSK-3β. The candidate 4-3 (IC50 = 6.6 μM) showed good proliferation inhibition and apoptosis-inducing ability to leukemia cell lines, low cytotoxicity on normal cell lines, and no hERG inhibition, which hinted the potential efficacy and safety. Furthermore, 4-3 exhibited decent pharmacokinetic properties in vivo and remarkably inhibited tumor growth in the acute promyelocytic leukemia (APL) mouse model. All the results suggest that these newly irreversible BTZ compounds might be useful in the treatment of cancer such as APL.
- Zhang, Peng,Min, Zhihui,Gao, Yang,Bian, Jiang,Lin, Xin,He, Jie,Ye, Deyong,Li, Yilin,Peng, Chao,Cheng, Yunfeng,Chu, Yong
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p. 7341 - 7358
(2021/06/28)
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- Kinetics-Driven Drug Design Strategy for Next-Generation Acetylcholinesterase Inhibitors to Clinical Candidate
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The acetylcholinesterase (AChE) inhibitors remain key therapeutic drugs for the treatment of Alzheimer's disease (AD). However, the low-safety window limits their maximum therapeutic benefits. Here, a novel kinetics-driven drug design strategy was employed to discover new-generation AChE inhibitors that possess a longer drug-target residence time and exhibit a larger safety window. After detailed investigations, compound 12 was identified as a highly potent, highly selective, orally bioavailable, and brain preferentially distributed AChE inhibitor. Moreover, it significantly ameliorated cognitive impairments in different mouse models with a lower effective dose than donepezil. The X-ray structure of the cocrystal complex provided a precise binding mode between 12 and AChE. Besides, the data from the phase I trials demonstrated that 12 had good safety, tolerance, and pharmacokinetic profiles at all preset doses in healthy volunteers, providing a solid basis for its further investigation in phase II trials for the treatment of AD.
- Zhou, Yu,Fu, Yan,Yin, Wanchao,Li, Jian,Wang, Wei,Bai, Fang,Xu, Shengtao,Gong, Qi,Peng, Tao,Hong, Yu,Zhang, Dong,Zhang, Dan,Liu, Qiufeng,Xu, Yechun,Xu, H. Eric,Zhang, Haiyan,Jiang, Hualiang,Liu, Hong
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p. 1844 - 1855
(2021/03/01)
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- Chlorination Reaction of Aromatic Compounds and Unsaturated Carbon-Carbon Bonds with Chlorine on Demand
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Chlorination with chlorine is straightforward, highly reactive, and versatile, but it has significant limitations. In this Letter, we introduce a protocol that could combine the efficiency of electrochemical transformation and the high reactivity of chlorine. By utilizing Cl3CCN as the chloride source, donating up to all three chloride atom, the reaction could generate and consume the chlorine in situ on demand to achieve the chlorination of aromatic compounds and electrodeficient alkenes.
- Liu, Feng,Wu, Na,Cheng, Xu
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supporting information
p. 3015 - 3020
(2021/05/05)
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- In quest of small-molecules as potent non-competitive inhibitors against influenza
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A series of scaffolds namely aurones, 3-indolinones, 4-quinolones and cinnamic acid-piperazine hybrids, was designed, synthesized and investigated in vitro against influenza A/H1N1pdm09 virus. Designed molecules adopted different binding mode i.e., in 430-cavity of neuraminidase, unlike sialic acid and oseltamivir in molecular docking studies. All molecules reduced the viral titer and exhibited non-cytotoxicity along with cryo-protective property towards MDCK cells. Molecules (Z)-2-(3′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2f), (Z)-2-(4′-Chloro-benzylidene)-1,2-dihydro-indol-3-one (2g) and 2-(2′-Methoxy-phenyl)-1H-quinolin-4-one (3a) were the most interesting molecules identified in this research, endowed with robust potencies showing low-nanomolar EC50 values of 4.0 nM, 6.7 nM and 4.9 nM, respectively, compared to reference competitive and non-competitive inhibitors: oseltamivir (EC50 = 12.7 nM) and quercetin (EC50 = 0.56 μM), respectively. Besides, 2f, 2g and 3a exhibited good neuraminidase inhibitory activity in sub-micromolar range (IC50 = 0.52 μM, 3.5 μM, 1.3 μM respectively). Moreover, these molecules were determined as non-competitive inhibitors similar to reference non-competitive inhibitor quercetin unlike reference competitive inhibitor oseltamivir in kinetics studies.
- Malbari, Khushboo,Saha, Priyanka,Chawla-Sarkar, Mamta,Dutta, Shanta,Rai, Swita,Joshi, Mamata,Kanyalkar, Meena
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- Dual Nickel/Ruthenium Strategy for Photoinduced Decarboxylative Cross-Coupling of α,β-Unsaturated Carboxylic Acids with Cycloketone Oxime Esters
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Herein, a dual nickel/ruthenium strategy is developed for photoinduced decarboxylative cross-coupling between α,β-unsaturated carboxylic acids and cycloketone oxime esters. The reaction mechanism is distinct from previous photoinduced decarboxylation of α,β-unsaturated carboxylic acids. This reaction might proceed through a nickelacyclopropane intermediate. The C(sp2)-C(sp3) bond constructed by the aforementioned reaction provides an efficient approach to obtaining various cyanoalkyl alkenes, which are synthetically valuable organic skeletons in organic and medicinal chemistry, under mild reaction conditions. The protocol tolerates many critical functional groups and provides a route for the modification of complex organic molecules.
- Gao, Ang,Jiang, Run-Chuang,Liu, Chuang-Chuang,Liu, Qi-Le,Lu, Xiao-Yu,Xia, Ze-Jie
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supporting information
p. 8829 - 8842
(2021/06/30)
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- Catalytic δ-hydroxyalkynone rearrangement in the stereoselective total synthesis of centrolobine, engelheptanoxides A and C and analogues
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A catalytic stereoselective total synthesis of centrolobine and engelheptanoxides A and C has been completed via a metal-free catalytic δ-hydroxyalkynone rearrangement to 2,3-dihydro-4H-pyran-4-one and diastereoselective hydrogenation to the all syn-2,4,6-trisubstituted pyran strategy. The onliest required chirality was introduced by Jacobsen kinetic resolution, which further directed the diastereoselective hydrogenation. A first stereoselective synthesis of engelheptanoxide A is also accomplished. The analogues and derivatives of centrolobine and engelheptanoxides prepared were evaluated for antitubercular activity against M. tuberculosis H37Rv ATCC 27294.
- Ahmad, Mohammad N.,Chopra, Sidharth,Fernandes, Rodney A.,Kumar, Praveen
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- Photo-Promoted Decarboxylative Alkylation of α, β-Unsaturated Carboxylic Acids with ICH2CN for the Synthesis of β, γ-Unsaturated Nitriles
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An efficient, catalyst/photocatalyst-free, and cost-effective methodology for the decarboxylative alkylation of α,β-unsaturated carboxylic acids to synthesize β,γ-unsaturated nitriles has been developed. The reaction proceeded in an environmentally benign atmosphere of blue light-emitting diode irradiation with K2CO3 and water at room temperature. The methodology worked for a wide range of substrates (22 examples) with up to 83% yield. The protocol is also compatible for gram-scale synthesis.
- Pan, Chunxiang,Yang, Chunhui,Li, Kangkui,Zhang, Keyang,Zhu, Yuanbin,Wu, Shiyuan,Zhou, Yongyun,Fan, Baomin
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supporting information
p. 7188 - 7193
(2021/10/01)
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- Meta-substituted piperlongumine derivatives attenuate inflammation in both RAW264.7 macrophages and a mouse model of colitis
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Piperlongumine (PL) has been showed to have multiple pharmacological activities. In this study, we reported the synthesis of three series of PL derivatives, and evaluation of their anti-inflammatory effects in both lipopolysaccharide (LPS)-induced Raw264.7 macrophages and a dextran sulfate sodium (DSS)-induced mouse model of colitis. Our results presented that two meta-substituent containing derivatives 1–3 and 1–6, in which γ-butyrolactam replaced α,β-unsaturated δ-valerolactam ring of PL, displayed low cytotoxicity and effective anti-inflammatory activity. Molecular docking also showed that the meta-substituted derivative, compared with the corresponding ortho- or para-substituted derivative, had significant interactions with the amino acid residues of CD14, which was the core receptors recognizing LPS. In vitro and in vivo studies, 1–3 and 1–6 could inhibit the expression of pro-inflammatory cytokines, and the excessive production of reactive nitrogen species and reactive oxygen species. Oral administration of 100 mg/kg/day of 1–3 or 1–6 alleviated the severity of clinical symptoms of colitis in mice, and significantly reduced the colonic tissue damage to protect the colonic tissue from the DSS-induced colitis. These results suggested that meta-substituted derivatives 1–3 and 1–6 were potential anti-inflammatory agents, which may lead to future pharmaceutical development.
- Gong, Zhaotang,Liu, Guoyun,Mu, Wenwen,Wang, Ziqing,Yang, Jie
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- Monosubstituted 3,3-Difluorocyclopropenes as Bench-Stable Reagents: Scope and Limitations
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A general approach to gem-difluorocyclopropenes synthesis based on the reaction of alkynes with Ruppert-Prakash reagent is reported. The proposed method is evaluated for the synthesis of a wide difluorocyclopropenes scope based on their bench lifespan and hydrolytic stability. The tolerance of the method for common functional groups was shown. Previously unavailable difluorocyclopropenes substituted with aliphatic were prepared using the proposed procedure. The retain of stability was proven by the multigram scale synthesis and further storage in the temperature interval ?78 to ?4 °C over a year. This makes them attractive building blocks and intermediates for organic synthesis. The reasons for dropping stability were defined. The relations between the structure of the substituents and the stability of the difluorocyclopropene ring were determined and discussed.
- Nosik, Pavel S.,Pashko, Mykola O.,Poturai, Andrii S.,Kvasha, Denys A.,Pashenko, Alexander E.,Rozhenko, Alexander B.,Suikov, Sergiy,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.,Yagupolskii, Yurii L.
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p. 6604 - 6615
(2021/12/08)
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- Water-initiated hydrocarboxylation of terminal alkynes with CO2and hydrosilane
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This work discloses a Cu(ii)-Ni(ii) catalyzed tandem hydrocarboxylation of alkynes with polysilylformate formed from CO2and polymethylhydrosiloxane that affords α,β-unsaturated carboxylic acids with up to 93% yield. Mechanistic studies indicate that polysilylformate functions as a source of CO and polysilanol. Besides, a catalytic amount of water is found to be critical to the reaction, which hydrolyzes polysilylformate to formic acid that induces the formation of Ni-H active species, thereby initiating the catalytic cycle.
- Wang, Meng-Meng,Lu, Sheng-Mei,Paridala, Kumaraswamy,Li, Can
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supporting information
p. 1230 - 1233
(2021/02/09)
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- Synthesis and in vitro evaluation of antimycobacterial and cytotoxic activity of new α,β-unsaturated amide, oxazoline and oxazole derivatives from L-serine
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The synthesis of 19 compounds derived from L-serine and analogs of p-substituted cinnamic acid is reported. Oxazolines 9 and oxazoles 10 have high antitubercular activity with Minimum Inhibitory Concentration (MIC) of 0.7812–25.0 μg/mL (3.21–100.3 μM), against two strains of Mycobacterium tuberculosis sensitive to first-line drugs Isoniazid (INH), Rifampicin (RIF), Ethambutol (EMB), Pyrazinamide (PZE) (H37Rv) and a clinical isolate resistant to INH, RIF and EMB (G122). The cytotoxic evaluation shows that oxazoles have low activity, finding viability>96% against the VERO cell line. The results show these compounds could be considered as future alternatives for antitubercular treatment.
- Aguirre-Rentería, Saúl A.,Arredondo-Espinoza, Eder,Avalos-Alanís, Francisco G.,Carrizales-Castillo, Juan J. J.,Garza-González, Elvira,Hernández-Fernández, Eugenio,Rivas-Galindo, Verónica M.,del Rayo Camacho Corona, María
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supporting information
(2020/03/13)
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- Knoevenagel-Doebner condensation promoted by chitosan as a reusable solid base catalyst
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The development of green and sustainable processes using naturally occurring biopolymers is becoming one of the suitable remedies to replace the conventional catalytic systems that generate large amount of byproducts with high risk factors. In this context, although Knoevenagel-Doebner condensation reaction has been reported with many organocatalysts including proline, no attempts were made to develop heterogeneous catalysts with environmental concerns. Considering these factors in mind, the title reaction is studied with chitosan as a heterogeneous solid base catalyst for the synthesis of α,β-unsaturated carboxylic acids through the condensation followed by decarboxylation reactions. Chitosan offers many advantages including high stability as evidenced by leaching, reusability tests, wide substrate scope and providing higher yields of the desired products with high purity. Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and elemental analysis revealed that there are no major changes in the structural integrity and morphology of chitosan before and after catalysis under the optimized reaction conditions.
- Anbu, Nagaraj,Hariharan, Surendran,Dhakshinamoorthy, Amarajothi
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- Photocatalytic decarboxylative alkenylation of α-amino and α-hydroxy acid-derived redox active esters by NaI/PPh3 catalysis
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Herein, we report the photocatalytic decarboxylative alkenylation reactions of N-(acyloxy)phthalimide derived from α-amino and α-hydroxy acids with 1,1-diarylethene, and with cinnamic acid derivatives through double decarboxylation, using sodium iodide and triphenylphosphine as redox catalysts. The reaction proceeds under mild irradiation conditions with visible blue light (440 nm or 456 nm) in an acetone solvent without recourse to transition-metal or organic dye based photoredox catalysts. The reaction proceeds via photoactivation of a transiently self-assembled chromophore from N-(acyloxy)phthalimide and NaI/PPh3. Solvation plays a crucial role in the reactivity.
- Fu, Ming-Chen,Fu, Yao,Shang, Rui,Wang, Ya-Ting,Zhao, Bin
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supporting information
p. 2495 - 2498
(2020/03/06)
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- Introducing of potent cytotoxic novel 2-(aroylamino)cinnamamide derivatives against colon cancer mediated by dual apoptotic signal activation and oxidative stress
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Curcumin and trans-cinnamaldehyde are acrolein-based Michael acceptor compounds that are commonly found in domestic condiments, and known to cause cancer cell death via redox mechanisms. Based on the structural features of these compounds we designed and synthesized several 2-cinnamamido-N-substituted-cinnamamide (bis-cinnamamide) compounds. One of the derivatives, (Z)-2-[(E)-cinnamamido]-3-phenyl-N-propylacrylamide 8 showed a moderate antiproliferative potency (HCT-116 cell line inhibition of 32.0 μM), no inhibition of normal cell lines C-166, and proven cellular activities leading to apoptosis. SAR studies led to more than 10-fold increase in activity. Our most promising compound, [(Z)-3-(1H-indol-3-yl)-N-propyl-2-[(E)-3-(thien-2-yl)propenamido)propenamide] 45 killed colon cancer cells at IC50 = 0.89 μM (Caco-2), 2.85 μM (HCT-116) and 1.65 μM (HT-29), while exhibiting much weaker potency on C-166 and BHK normal cell lines (IC50 = 71 μM and 77.6 μM, respectively). Cellular studies towards identifying the compounds mechanism of cytotoxic activities revealed that apoptotic induction occurs in part as a result of oxidative stress. Importantly, the compounds showed inhibition of cancer stem cells that are critical for maintaining the potential for self-renewal and stemness. The results presented here show discovery of covalently acting Michael addition compounds that potently kill cancer cells by a defined mechanism, with prominent selectivity profile over non-cancerous cell lines.
- Abdel-Bakky, Mohamed S.,Abdelghany, Tamer M.,Ahmed, Hany E. A.,Ahmed, Mostafa H.,Boothello, Rio,El-Araby, Moustafa E.,Elhaggar, Radwan S.,Malebari, Azizah M.,Omar, Abdelsattar M.,Patel, Bhaumik B,Safo, Martin K.
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- New coumarin/sulfocoumarin linked phenylacrylamides as selective transmembrane carbonic anhydrase inhibitors: Synthesis and in-vitro biological evaluation
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Two novel series of phenylacrylamide linked coumarins and sulfocoumarins (6a-p, 8a-i, and 14a-g) were synthesized and evaluated against four physiologically relevant human carbonic anhydrases (hCAs, EC 4.2.1.1), isoforms hCA I, hCA II, hCA IX and hCA XII for their inhibitory action. All new compounds when screened for carbonic anhydrase inhibitory activity have shown selective inhibition towards the tumor associated isoforms hCA IX and XII over CA I and II, with inhibition constants in the submicromolar to low nanomolar range. Compound 6b and 14g exhibited significant inhibition with low nanomolar potency against hCA IX, whereas 6k was effective against hCA XII. Compounds 6b, 14g and 6k may be considered as lead molecules for future development of cancer therapeutics based on a novel mechanism of action.
- Angeli, Andrea,Arifuddin, Mohammed,Singh, Priti,Supuran, Claudiu T.,Swain, Baijayantimala
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- Radical-Cation Vinylcyclopropane Rearrangements by TiO2Photocatalysis
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Radical cation vinylcyclopropane rearrangements by TiO2 photocatalysis in lithium perchlorate/nitromethane solution are described. The reactions are triggered by oxidative single electron transfer, which is followed by immediate ring-opening of the cyclopropanes to generate distonic radical cations as unique reactive intermediates. This approach can also be applied to vinylcyclobutane, leading to the construction of six-membered rings. A stepwise mechanism via distonic radical cations is proposed based on preliminary mechanistic studies, which is supported by density functional theory calculations.
- Maeta, Naoya,Kamiya, Hidehiro,Okada, Yohei
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supporting information
p. 6551 - 6566
(2020/07/14)
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- Toward a Scalable Synthesis and Process for EMA401, Part II: Development and Scale-Up of a Pyridine- A nd Piperidine-Free Knoevenagel-Doebner Condensation
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During route scouting for EMA401 (1), an angiotensin II type 2 antagonist, we identified the synthesis of key amino acid intermediate 2 via its cinnamic acid derivative 3 as a streamlined option. In general, cinnamic acids can be synthesized from the corresponding aldehydes by a Knoevenagel-Doebner condensation in pyridine with piperidine as an organocatalyst. We aimed to replace both of these reagents and found novel conditions involving toluene as the solvent and morpholine as the organocatalyst. Scale-up of the process allowed the production of 25 kg of cinnamic acid 3 that was of the quality required for process development of the subsequent phenylalanine ammonia lyase-catalyzed step. The modified conditions were found to be widely applicable to alternative aldehydes and thus are of relevance to practitioners of chemical scale-up.
- Hardegger, Leo A.,Humair, Roger,Sidler, Eric
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p. 1756 - 1762
(2020/10/26)
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- CO2-Folded Single-Chain Nanoparticles as Recyclable, Improved Carboxylase Mimics
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Emulating the function of natural carboxylases to convert CO2 under atmospheric condition is a great challenge. Herein we report a class of CO2-folded single-chain nanoparticles (SCNPs) that can function as recyclable, function-intensified carboxylase mimics. Lewis pair polymers containing bulky Lewis acidic and basic groups as the precursor, can bind CO2 to drive an intramolecular folding into SCNPs, in which CO2 as the folded nodes can form gas-bridged bonds. Such bridging linkages highly activate CO2, which endows the SCNPs with extraordinary catalytic ability that can not only catalyze CO2-insertion of C(sp3)-H for imitating the natural enzyme's function, it can also act on non-natural carboxylation pathways for C(sp2 and sp)-H substrates. The nanocatalysts are of highly catalytic efficiency and recyclability, and can work at room temperature and near ambient CO2 condition, inspiring a new approach to sustainable C1 utilization.
- Chen, Liang,Yan, Qiang,Zeng, Rongjin
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supporting information
p. 18418 - 18422
(2020/08/21)
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- Method for preparing P-methoxycinnamic acid
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The invention relates to a method for preparing p-methoxycinnamic acid. The method comprises the following steps: a salt forming reaction: reacting acrylic acid with an alkaline inorganic salt to obtain acrylate; and a coupling reaction: reacting 4-methoxyhalobenzene and acrylate, and carrying out acidifying to obtain p-methoxycinnamic acid. According to the method, an organic phase reaction system is changed into a water phase reaction system; a brand-new, efficient and low-cost catalyst is adopted for catalysis; so high-quality p-methoxycinnamic acid is prepared at low cost, and the preparedp-methoxycinnamic acid has HPLC content of no less than 99.5%, single impurity content of no more than 0.2% and total impurity content of no more than 0.5%.
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Paragraph 0068-0097
(2019/12/25)
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- Engineered mesoporous ionic-modified γ-Fe2O3@hydroxyapatite decorated with palladium nanoparticles and its catalytic properties in water
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A new mesoporous organic–inorganic nanocomposite was formulated and then used as stabilizer and support for the preparation of palladium nanoparticles (Pd NPs). The properties and structure of Pd NPs immobilized on prepared 1,4-diazabicyclo[2.2.2]octane (DABCO) chemically tagged on mesoporous γ-Fe2O3@hydroxyapatite (ionic modified (IM)-MHA) were investigated using various techniques. The synergistic effects of the combined properties of MHA, DABCO and Pd NPs, and catalytic activity of γ-Fe2O3@hydroxyapatite-DABCO-Pd (IM-MHA-Pd) were investigated for the Heck cross-coupling reaction in aqueous media. The appropriate surface area and pore size of mesoporous IM-MHA nanocomposite can provide a favourable hard template for immobilization of Pd NPs. The loading level of Pd in the nanocatalyst was 0.51?mmol?g?1. DABCO bonded to the MHA surface acts as a Pd NP stabilizer and can also lead to colloidal stability of the nanocomposite in aqueous solution. The results reveal that IM-MHA-Pd is highly efficient for coupling reactions of a wide range of aryl halides with olefins under green conditions. The superparamagnetic nature of the nanocomposite means that the catalyst to be easily separated from solution through magnetic decantation, and the catalytic activity of the recycled IM-MHA-Pd showed almost no appreciable loss even after six consecutive runs.
- Pashaei, Mokhtar,Mehdipour, Ebrahim,Azaroon, Maedeh
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- Structure-aided drug development of potential neuraminidase inhibitors against pandemic H1N1 exploring alternate binding mechanism
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Abstract: The rate of mutability of pathogenic H1N1 influenza virus is a threat. The emergence of drug resistance to the current competitive inhibitors of neuraminidase, such as oseltamivir and zanamivir, attributes to a need for an alternative approach. The design and synthesis of new analogues with alternate approach are particularly important to identify the potential neuraminidase inhibitors which may not only have better anti-influenza activity but also can withstand challenge of resistance. Five series of scaffolds, namely aurones (1a–1e), pyrimidine analogues (2a–2b), cinnamic acid analogues (3a–3k), chalcones (4a–4h) and cinnamic acid linkages (5a–5c), were designed based on virtual screening against pandemic H1N1 virus. Molecular modelling studies revealed that the designed analogues occupied 430-loop cavity of neuraminidase. Docking of sialic acid in the active site preoccupied with the docked analogues, i.e. in 430-loop cavity, resulted in displacement of sialic acid from its native pose in the catalytic cavity. The favourable analogues were synthesized and evaluated for the cytotoxicity and cytopathic effect inhibition by pandemic H1N1 virus. All the designed analogues resulting in displacement of sialic acid suggested alternate binding mechanism. Overall results indicated that aurones can be measured best among all as potential neuraminidase inhibitor against pandemic H1N1 virus. Graphical abstract: [Figure not available: see fulltext.].
- Malbari, Khushboo D.,Chintakrindi, Anand S.,Ganji, Lata R.,Gohil, Devanshi J.,Kothari, Sweta T.,Joshi, Mamata V.,Kanyalkar, Meena A.
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p. 927 - 951
(2019/02/07)
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- Pyridazinone derivative, and preparation method and medical application thereof
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The invention provides a pyridazinone derivative, and a preparation method and a medical application thereof. O-formylbenzoic acid used as a raw material reacts with dimethyl phosphite to obtain dimethyl (3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate, the dimethyl (3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate reacts with 3-cyano-4-fluorobenzaldehyde in the presence of triethylamine to prepare (Z,E)-2-fluoro-5-[(3-oxoisobenzofuran-1(3H)-ylidene)methyl]benzonitrile, and the (Z,E)-2-fluoro-5-[(3-oxoisobenzofuran-1(3H)-ylidene)methyl]benzonitrile is reduced by hydrazine hydrate to prepare 2-fluoro-5-[(4-oxo-3,4-dihydropyridazin-1-yl)methyl]benzoic acid; and benzaldehyde or substituted aromatic formaldehyde or furfural used as a raw material and malonic acid undergo a Knoevenagel reaction to obtain cinnamic acid or substituted cinnamic acid or furan-2-acrylic acid, the cinnamic acid or substituted cinnamic acid or furan-2-acrylic acid and 1-tert-butoxycarbonylpiperazine undergo an amidation reaction, a tert-butoxycarbonyl group is removed from the obtained amidation product in the presence of trifluoroacetic acid, and the obtained product and the 2-fluoro-5-[(4-oxo-3,4-dihydropyridazin-1-yl)methyl]benzoic acid undergo the amidation reaction to obtain a series of (E)-4-{3-[4-[(3-substituted aryl)acryloyl]piperazin-1-carbonyl]-4-fluorobenzyl}-2H-pyridazin-1-one derivatives. Results of preliminary pharmacological activity screening show that the compound represented by a general formula shown in the present invention has a certain in-vitro PARP-1 inhibition ability and a certain in-vitro tumor cell proliferation resisting activity. The structural general formula of compound is shown in the description; and in the general formula, Ar is selected from two formulas also shown in the description, and R1, R2, R3, R3, R4 and R5 can be the hydrogen atom, the fluorine atom, the chlorine atom, the bromine atom, a methyl group, a methoxy group, a tetrafluoromethyl group and a nitro group.
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Paragraph 0078-0082
(2019/10/07)
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- Substituted styrene preparation method
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The invention belongs to the technical field of synthesis of chemical and medical intermediates, and relates to a substituted styrene preparation method, in particular to a method for preparing substituted styrene by using an ionic solution. In the method, the ionic solution is used as a solvent, and the reaction catalyzing efficiency is high. The ionic solution can be repeatedly used, industrialproduction cost is saved, and environment problems caused by a traditional solvent are solved favorably.
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Paragraph 0038-0040
(2019/02/26)
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- Method for preparing styrene derivative from ionic liquid
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The invention belongs to the technical field of chemical engineering and pharmaceutical intermediate synthesis and relates to a method for preparing a styrene derivative from ionic liquid. The methodhas advantages that by adoption of the ionic liquid as a solvent, high reaction catalyzing efficiency is achieved; due to reusability of the ionic liquid, industrial production cost is saved, and theenvironment problem caused by traditional solvents can be solved helpfully.
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Paragraph 0038-0040
(2019/04/06)
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- A method for the preparation of substituted styrene ion solution method
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The invention belongs to chemical and pharmaceutical intermediate synthesis technology field, relates to a process for preparing a substituted styrene ion solution method. The method takes the ionic liquid as solvent, reaction of high catalytic efficiency. The ionic liquid can be used repeatedly, save the industrialized production cost, and to facilitate the solution of the environmental problem of traditional solvent.
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Paragraph 0038; 0039; 0040
(2019/04/02)
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- Synthesis, preliminarily biological evaluation and molecular docking study of new Olaparib analogues as multifunctional PARP-1 and cholinesterase inhibitors
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A series of new Olaparib derivatives was designed and synthesized, and their inhibitory activities against poly (ADP-ribose) polymerases-1 (PARP-1) enzyme and cancer cell line MDA-MB-436 in vitro were evaluated. The results showed that compound 5l exhibited the most potent inhibitory effects on PARP-1 enzyme (16.10 ± 1.25 nM) and MDA-MB-436 cancer cell (11.62 ± 2.15 μM), which was close to that of Olaparib. As a PARP-1 inhibitor had been reported to be viable to neuroprotection, in order to search for new multitarget-directed ligands (MTDLs) for the treatment of Alzheimer’s disease (AD), the inhibitory activities of the synthesized compounds against the enzymes AChE (from electric eel) and BChE (from equine serum) were also tested. Compound 5l displayed moderate BChE inhibitory activity (9.16 ± 0.91 μM) which was stronger than neostigmine (12.01 ± 0.45 μM) and exhibited selectivity for BChE over AChE to some degree. Molecular docking studies indicated that 5l could bind simultaneously to the catalytic active of PARP-1, but it could not interact well with huBChE. For pursuit of PARP-1 and BChE dual-targeted inhibitors against AD, small and flexible non-polar groups introduced to the compound seemed to be conducive to improving its inhibitory potency on huBChE, while keeping phthalazine-1-one moiety unchanged which was mainly responsible for PARP-1 inhibitory activity. Our research gave a clue to search for new agents based on AChE and PARP-1 dual-inhibited activities to treat Alzheimer’s disease.
- Gao, Cheng-Zhi,Dong, Wei,Cui, Zhi-Wen,Yuan, Qiong,Hu, Xia-Min,Wu, Qing-Ming,Han, Xianlin,Xu, Yao,Min, Zhen-Li
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p. 150 - 162
(2018/11/30)
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- Novel morpholine containing cinnamoyl amides as potent tyrosinase inhibitors
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Tyrosinase enzyme plays a crucial role in melanin biosynthesis and enzymatic browning process of vegetables and fruits. Hence, tyrosinase inhibitors are important in the fields of medicine, cosmetics and agriculture. In this study, novel N-(2-morpholinoethyl)cinnamamide derivatives bearing different substituents on phenyl ring were designed, synthesized and evaluated for their tyrosinase diphenolase inhibitory activity. The compounds were found to be better tyrosinase inhibitors (IC50s were in micro molar range) than cinnamic acid. (E)-3-(3-chlorophenyl)-N-(2-morpholinoethyl)acrylamide (B6) exhibited the highest inhibition with IC50 value of 15.2 ± 0.6 μM which was comparable to that of kojic acid. The inhibition kinetic analysis of B6 indicated that the compound was a mixed-type tyrosinase inhibitor. In silico ADME prediction indicated that B6 might show more skin penetration than kojic acid. Molecular docking analysis confirmed that the active inhibitors well accommodated in the mushroom tyrosinase active site and it was also revealed that B6 formed the most stable drug-receptor complex with the target protein. Therefore, cinnamamide B6 could be introduced as a potent tyrosinase inhibitor that might be a promising lead in cosmetics, medicine and food industry.
- Ghafari, Shahrzad,Ranjbar, Sara,Larijani, Bagher,Amini, Mohsen,Biglar, Mahmood,Mahdavi, Mohammad,Bakhshaei, Maryam,Khoshneviszadeh, Mahsima,Sakhteman, Amirhossein,Khoshneviszadeh, Mehdi
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p. 978 - 985
(2019/06/13)
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- Pd-Catalyzed decarboxylative cross-coupling reactions of epoxides with α,β-unsaturated carboxylic acids
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A Pd-catalyzed decarboxylative cross-coupling of α,β-unsaturated carboxylic acids with cyclic and acyclic epoxides has been developed. Both β-monosubstituted and β-disubstituted unsaturated carboxylic acids, as well as conjugated diene unsaturated carboxylic acids are suitable reaction substrates. Substituted homoallylic alcohols were obtained in moderate to good yields. The product was obtained as a mixture of diastereomers favoring the anti diastereomer of the cyclic epoxides. This work provides a method for the modification of complex organic molecules containing α,β-unsaturated carboxylic acids.
- Lu, Xiao-Yu,Li, Jin-Song,Wang, Shi-Qun,Zhu, Yu-Jing,Li, Yue-Ming,Yan, Lu-Yu,Li, Jia-Mei,Wang, Jin-Yu,Zhou, Hai-Pin,Ge, Xiu-Tao
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supporting information
p. 11123 - 11126
(2019/09/20)
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- Synthesis and biological evaluation of 4-arylcoumarins as potential anti-Alzheimer's disease agents
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Alzheimer's disease (AD) is a progressive neurological degenerative disease that has complex pathogenesis. A variety of studies in humans indicate that several enzymes inhibitors can be useful in the treatment of AD, including acetylcholinesterase (AchE), butyrylcholinesterase (BuChE) and monoamine oxidase (MAO). Various substituted 4-arylcoumarin derivatives were synthesised, and their activity in vitro were investigated, including AChE/BuChE inhibitory activity, MAO inhibitory activity, and antioxidant activity. Most of the compounds were found to exhibit high inhibitory activity, and individual compounds have extremely excellent activities. Therefore 4-arylcoumarins provides an idea for drugs design for the development of therapeutic or preventive agents for AD.
- Miao, Yuhang,Sun, Jie,Wang, Xiaojing,Yang, Jie,Yun, Yinling
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- Imidazole oxime ester compound, preparation method, composition and use thereof (by machine translation)
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The invention relates to novel imidazole oxime ester compound, preparation method, composition and in photoinitiators, photosensitizers, the light absorbent, or sensitizers of the application. The invention imidazole oxime ester compound, at the same time with imidazole kind of light initiator (for example BCIM) and oxime mere initiator (for example 0 XE - 1) structural features. In one aspect, the compounds of the invention has improved the imidazole kind of light will produce sludge to the shortcoming of the initiator. On the other hand, compound of the present invention improved the thermal stability of the oxime [...] initiator problem not good, and increasing the operating convenience. (by machine translation)
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Paragraph 0063-0066
(2019/05/11)
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- An efficient and new protocol for the Heck reaction using palladium nanoparticle-engineered dibenzo-18-crown-6-ether/MCM-41 nanocomposite in water
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Palladium nanoparticle-incorporated mesoporous organosilica (MCM-41-Crown.Pd) was synthesized via the grafting of dibenzo-18-crown-6-ether moieties on the MCM-41 surface, followed by reaction of the nanocomposite with palladium acetate and then its reduction in ethanol. The cavity of the immobilized dibenzo-18-crown-6 as host material can stabilize the palladium nanoparticles effectively and prevent their aggregation and separation from the surface. The structure of the nanocomposite was characterized using various techniques. The catalytic properties of the nanocomposite in the Heck coupling reaction, one of the most useful transformations in organic synthesis, between aryl halides and olefins in water were also explored. The main advantages of the method are low cost, high yields, easy work-up and short reaction time. The nanocatalyst can be easily separated from a reaction mixture and was successfully examined for seven runs, with a slight loss of catalytic activity.
- Azaroon, Maedeh,Kiasat, Ali Reza
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- METHOD FOR THE SYNTHESIS AND PRODUCTION OF ALKENYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing an efficient alkenyl compound conveniently and inexpensively. SOLUTION: A first compound represented by formula (1) reacts with a second compound represented by formula (3), in the presence of amino acid, in solvent containing amine, in a range of 50-200°C, to produce an alkenyl compound represented by formula (A) [where R1 is hydrogen or an optionally substituted C1-C30 alkyl group, R2 is a carboxyl group or the like, R3 and R4 are hydrogen, an optionally substituted C1-C30 alkyl group or the like]. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0081; 0082
(2018/09/20)
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- SOLID-SUPPORTED PALLADIUM(II) COMPLEX FOR CATALYZING MIZOROKI-HECK COUPLING REACTIONS AND A METHOD THEREOF
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A solid-supported palladium(II) complex which catalyzes the Mizoroki-Heck coupling reaction efficiently and a method of employing the solid-supported palladium(II) complex to synthesize cinnamic acid and derivatives thereof. The solid-supported palladium(II) complex is also stable and can be recycled without significantly losing catalytic activity.
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Paragraph 0137-0138
(2018/03/25)
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- Design, synthesis of N-phenethyl cinnamide derivatives and their biological activities for the treatment of Alzheimer's disease: Antioxidant, beta-amyloid disaggregating and rescue effects on memory loss
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Gx-50 is a bioactive compound for the treatment of Alzheimer's disease (AD) found in Sichuan pepper (Zanthoxylum bungeanum). In order to find a stronger anti-AD lead compound, 20 gx-50 (1-20) analogs have been designed and synthesized, and their molecular structures were determined based on nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis, as well as comparison with literature data. Compounds 1-20 were evaluated for their anti-AD potential by using DPPH radical scavenging assay for considering their anti-oxidant activity, thioflavin T (ThT) fluorescence assay for considering the inhibitory or disaggregate potency of Ab, and transgenic Drosophila model assay for evaluating their rescue effect on memory loss. Finally, compound 13 was determined as a promising anti-AD candidate.
- Chai, Tian,Zhao, Xiao-Bo,Wang, Wei-Feng,Qiang, Yin,Zhang, Xiao-Yun,Yang, Jun-Li
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- Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study
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The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.
- Yuan, Ning,Pascanu, Vlad,Huang, Zhehao,Valiente, Alejandro,Heidenreich, Niclas,Leubner, Sebastian,Inge, A. Ken,Gaar, Jakob,Stock, Norbert,Persson, Ingmar,Martín-Matute, Belén,Zou, Xiaodong
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supporting information
p. 8206 - 8217
(2018/06/22)
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- Mesogenic naphthyl derivatives
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Two new mesogenic homologous series of liquid crystalline naphthalene derivatives with different central linkages: 2- Naphthyl-4-n-alkoxybenzoates (I) and trans-2-Naphthyl -4-n –alkoxycinnamates(II), have been synthesized and characterized by a combination of elemental analysis and standard spectroscopic methods. Twelve compounds have been synthesized in both the series I and II. In series I, methoxy to n-pentyloxy derivatives are non mesogenic, n-hexyloxy to n-hexadecyloxy derivatives exhibit monotropic nematic mesophase. Smectic A mesophase commences from n-decyloxy derivatives as a monotropy and persist up to the last member synthesized. All the 12 compounds of series II exhibit mesomorphism. Methoxy to n-propyloxy derivatives exhibit monotropic nematic mesophse, and n-butyloxy to n-tetradecyloxy derivatives exhibit enantiotropic nematic mesophase. n-Hexayloxy to n-hexadecyloxy derivatives also exhibit enantiotropic smectic A mesophase. The mesomorphic properties of present series were compared with each other and with a structurally related mesogenic homologous series to evaluate the effects of central linkage on mesomorphism.
- Patel,Prajapati
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p. 106 - 115
(2017/03/08)
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- The effect of position of octadecyloxy tail on the formation of liquid crystal with chalconyl-ester and chalconyl-vinyl ester series: Comparison with corresponding linkage group
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Two series of chalconyl-based liquid crystals which differ from each other in the position of the first linking group have been synthesized and characterized by elemental analyses and spectroscopic techniques such as Fourier transform infrared and proton magnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and differential scanning calorimetry (DSC). We have synthesized two homologous series viz. 3-(3-(4-(Octadecyloxy) phenyl) acrylonyl) phenyl 3-(4-n-alkoxyphenyl) acrylate (series-1) and 3-(3-(4-(Octadecyloxy) phenyl) acryloyl) phenyl 4-n-alkoxy benzoate (series-2). Series-1 has chalconyl-ester central linkage group while in series-2 chalconyl-vinyl ester group is present and tail octadecyloxy side chain is common in both homologous series. All the homologous in present series display LC property in enantiotropical manner except first three homologous in both series.
- Solanki,Sharma, Vinay. S.,Patel
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p. 216 - 232
(2017/03/08)
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- Enantioselective Palladium-Catalyzed Oxidative Cascade Cyclization of Aliphatic Alkenyl Amides
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The catalyst system of Pd(TFA)2/(S,S)-diPh-pyrox is reported to promote the highly efficient enantioselective oxidative cascade cyclization of alkene-tethered aliphatic acrylamides under mild aerobic conditions. A series of pyrrolizidine derivatives have been synthesized in good yield and excellent enantioselectivity. Deuterium-labeling experiments have revealed that the reaction proceeded through an anti-aminopalladation (anti-AP) pathway with high selectivity. The transition states for the anti-AP step have been calculated to account for the observed enantioselectivity.
- Du, Wei,Gu, Qiangshuai,Li, Yang,Lin, Zhenyang,Yang, Dan
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p. 316 - 319
(2017/04/21)
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- A Simple and straightforward synthesis of cinnamic acids and ylidene malononitriles via knoevenagel condensation employing dabco as catalyst
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An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is developed via Knoevenagel condensation of aromatic aldehydes with malonic acid and malononitrile in the presence of catalytic amounts of DABCO. This method has many advantages, such as mild reaction conditions, excellent yields, short reaction times and no furthur purification required.
- Nagalakshmi,Diwakar,Govindh,Gopal Reddy,Venu,Bhargavi,Prasanna Devi,Murthy,Siddaiah
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p. 1561 - 1564
(2017/05/29)
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- Enantioselective Synthesis of N?H-Free 1,5-Benzothiazepines
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An enantioselective sulfa-Michael-cyclization reaction was developed for the synthesis of 1,5-benzothiazepines with versatile pharmacological activities. The reaction between 2-aminothiophenol and α,β-unsaturated pyrazoleamides gave direct access to N?H-free 1,5-benzothiazepines in the presence of a chiral N,N′-dioxide/Yb(OTf)3complex. Excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 %) were obtained for a broad range of substrates under mild reaction conditions. This method provided a facile approach to the antidepressant drug (R)-(?)-Thiazesim.
- Wang, Guojin,Tang, Yu,Zhang, Yu,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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supporting information
p. 554 - 557
(2017/01/18)
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- Structural elucidation and bioassays of newly synthesized pentavalent antimony complexes
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Antimony (V) organometallics (1–5) have been synthesized with general formula [SbR′3(O2CR)2], where R' = phenyl, p-tolyl and O2CR are substituted cinnamates. These complexes have been characterized by FT-IR analysis, multinuclear (1H, 13C) NMR spectroscopy and single crystal X-ray diffraction analysis. The crystal structures of [Sb(phenyl)3(4-ClC6H4C2H2O2C)2] (1) and [Sb(p-tol)3(4-OCH3C6H4C2H2O2C)2].CHCl3 (5) displayed distorted geometry between trigonal bipyramidal and square pyramidal with monomeric structure at a five coordinated Sb center. Starting reagents and complexes were evaluated for anticancer, antileishmanial, antibacterial and alpha amylase inhibition potentials. It was observed that complexes 3, 4 and 5 showed significant (p 0.05) antileishmanial and anticancer activities against Leishmania tropica KWH23 promastigotes and HepG2 cell lines respectively. Antibacterial activity of compound 3 was also significant against E. coli (MIC: 5.55 μg/mL), K. pneumoniae (MIC: 16.66 μg/mL), S. aureus (MIC: 5.55 μg/mL) and P. aeruginosa (MIC: 50 μg/mL). Hence, these new antimony complexes can act as good drug candidates.
- Iftikhar, Tuba,Rauf, Muhammad Khawar,Sarwar, Sidra,Badshah, Amin,Waseem, Durdana,Tahir, Muhammad Nawaz,Khan, Amjad,Khan, Khalid Mohammad,Khan, Gul Majid
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- Synthesis and biological evaluation of novel neoflavonoid derivatives as potential antidiabetic agents
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Various substituted neoflavonoid derivatives were synthesized using sulfated montmorillonite K-10 as a catalyst. This method is environmental friendly, sustainable and economical, convenient in isolation and purification processes, with little byproducts, using earth-abundant catalysts and has relatively high yield. Those neoflavonoid derivatives were screened for antioxidant, a-glucosidase inhibitory, aldose reductase 2 (ALR2) inhibitory and advanced glycation end-product formation inhibitory effects. Most compounds exhibited significant antioxidant and advanced glycation end-product (AGE) formation inhibitory activities. It was interesting to note that out of thirty compounds, 8k and 8l were found to have greater ALR2 inhibitory activity than the standard drug quercetin. The pharmacological studies suggested neoflavonoid with adjacent 7,8-dihydroxy groups were more effective in inhibiting ALR2. Antidiabetic activity studies had shown that compounds 8l and 8m were equipotent to the standard drug glibenclamide in vivo. In summary, the target compound 8l provided a potential drug design concept for the development of therapeutic or prophylactic agents of diabetes and diabetes complications.
- Wang, Bing,Li, Na,Liu, Teng,Sun, Jie,Wang, Xiaojing
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p. 34448 - 34460
(2017/07/22)
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- Mesomorphism dependence on heterocyclic tail
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A novel homologous series of liquid crystal materials containing a heterocyclic ring was synthesized with a view to understanding and establishing the relation between liquid crystal (LC) properties and a molecular structure; and with a view to curing skin-related diseases following biological activity studies. The series consist of 13 (C1 to C18) members. All the members are liquid crystals. The C4 to C18 members are smectogenic of which C4 and C5 are monotropic and remaining members (C6 to C18) are enantiotropic in nature; whereas all C1 to C18 members are enantiotropically nematogenic. Hence the C1, C2, C3 members are only nematogenic and the rest of the homologues are smectogenic in addition to nematogenic. Transition temperatures were determined by an polarizing optical microscope equipped with heating stage. Analytical and spectral data confirmed the molecular structures of homologues. It is a middle ordered melting type series. LC properties of a series are compared with the structurally known series.
- Bhola,Bhoya
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- Study of mesomorphism and its relation to molecular structure with special reference to central bridges viz. -COO- and -CH=CH-COO- of the homologous series
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Two ester homologous series of mesogens, viz., Methyl-p-(p′-n-alkoxy benzoyloxy) cinnamates (X) and Methyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates (Y) being structurally similar are discussed. Both (X) and (Y) differ in respect of central bridges linking two phenyl rings. Only enantiotropic nematogenic character is observed without exhibition of any smectic character by all members of series (X) and (Y). Thermal stability of series (X) is relatively low as compared to (Y), but nematogenic mesophase lengths are of reverse order. Solid-nematic/solid-isotropic and nematic-isotropic transition curves in the phase diagrams behave in normal manner.
- Sharma,Solanki,Patel,Patel
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p. 137 - 145
(2016/03/01)
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- Mesomorphism and flexibility of alkyl chains in chalcone esters
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A novel homologous series of chalconyl ester liquid crystals (LCs): RO?C6H4–CH:CH–COO?C6H4–CO?CH:CH?C6H4–OC10H21 (n) (para) has been synthesized and studied with a view to understanding and establishing the relationship between molecular structure and LC properties with reference to flexibility of the terminal chain. The novel series consists of eleven homologs (C1–C16). The C1 and C2 homologs are nonliquid crystals and the rest of the homologs (C3–C16) are enantiotropic nematic without exhibition of smectic mesophase. Transition and melting temperatures were determined by an optical polarizing microscope equipped with a heating stage. Textures of nematic phases are threaded or Schlieren. Cr-N/I transition curve adopts a zigzag path in a normal manner with overall descending behaviors. The N-I transition curve exhibits a sharp and shorter odd-even effect from C3 to C6 and it diminishes from and beyond C6 for higher homologs of longer n-alkyl chain (R) in more or less or negligible deviating manner from normal descending tendency. Thermal stability for the nematic is 116.4°C and mesophase length ranges from 19°C to 67°C at the C3 and C12 homolog respectively. The LC properties of present novel series are compared with structurally similar analogous series to derive group efficiency order.
- Muniya,Patel
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- The effect of geometrical shape and molecular rigidity on mesomorphism
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A novel nonlinear homologous series RO?C6H4?CH?CH?COO?C6H4 (meta) ?CO?CH?CH?C6H4?OC12H25(n) (para) consisting of three phenyl rings, two central bridges ?CH?CH?COO? and ?CO?CH?CH? as well as ?OR and ?OC12H25(n) as flexible and constant terminal end groups respectively. The object in view is aimed to understand and establish the effect of molecular structure on LC properties of nonlinear inverted “V” shaped molecules. Novel homologous series consists of thirteen homologues. Transition temperatures and textures were determined by polarizing optical microscopy (POM) equipped with a heating stage. Textures of nematic phases are threaded or schlieren and that of a smectic phases are of the type-A or C. Transition curves of a phase diagram behaved in a normal manner. Sm-N and N-I transition curves exhibited odd-even effect. Analytical, Thermal and Spectral data confirms the molecular structure of homologues.
- Patel, Priya K.,Shah
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- Green synthesis of palladium nanoparticles via branched polymers: A bio-based nanocomposite for C-C coupling reactions
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Catalytic process is the key process for many chemical industries. In this study, a novel heterogeneous Pd (CMH-Pd(0)) has been prepared by the deposition of palladium nanoparticles (Pd NPs) onto the surface of carboxymethyl functionalized hemicelluloses using ethanol as solvent and in situ reducing agent. The as prepared catalyst was characterized by TEM, HR-TEM, XRD, FT-IR, TGA and XPS. The loading level of Pd in the CMH-Pd(0) catalyst was 0.38 mmol g-1. The catalyst showed high catalytic activity and versatility towards Heck coupling reactions under aerobic conditions and could be readily recovered and reused in at least five successive cycles without obvious loss in activity. The catalyst is promising for its renewability, environmental benefits, efficient catalytic activity, mild reaction conditions, simple product work-up and easy catalyst recovery.
- Wu, Changyan,Peng, Xinwen,Zhong, Linxin,Li, Xuehui,Sun, Runcang
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p. 32202 - 32211
(2016/04/26)
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