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Qianli Chu, Andrew J E Duncan, Giannis S Papaefstathiou, Tamara D Hamilton, Manza B J Atkinson, S V Santhana Mariappan, Leonard R MacGillivray
Enlargement of a self-assembled metal-organic rhomboid is achieved via the organic solid state. The solid-state synthesis of an elongated organic ligand was achieved by a template directed [2+2] photodimerization in a cocrystal. Initial cocrystals obtained of resorcinol template and reactant alkene afforded a 1:2 cocrystal with the alkene in a stacked yet photostable geometry. Cocrystallization performed in the presence of excess template resulted in 6:4 cocrystal composed of novel discrete 10-component hydrogen-bonded 'super-assemblies' wherein the alkenes undergo a head-to-head [2+2] photodimerization...
March 15, 2018: Journal of the American Chemical Society
Shobhana Krishnaswamy, Mysore Srikantiah Shashidhar
Intermolecular acyl transfer reactivity in several molecular crystals was studied and the outcome of the reactivity was analysed in the light of structural information obtained from the crystals of the reactants. Minor changes in the molecular structure resulted in significant variations in the non-covalent interactions and packing of molecules in the crystal lattice, which drastically affected the facility of the intermolecular acyl transfer reactivity in these crystals. Analysis of the reactivity Vs. crystal structure data revealed dependence of the reactivity on electrophile...
March 14, 2018: Journal of Organic Chemistry
Takashi Otaki, Yuta Tanabe, Takashi Kojima, Masaru Miura, Yukihiro Ikeda, Tatsuo Koide, Toshiro Fukami
In recent years, to guarantee a quality-by-design approach to the development of pharmaceutical products, it is important to identify properties of raw materials and excipients in order to determine critical process parameters and critical quality attributes. Feedback obtained from real-time analyses using various process analytical technology (PAT) tools has been actively investigated. In this study, in situ monitoring using low-frequency (LF) Raman spectroscopy (10-200cm-1 ), which may have higher discriminative ability among polymorphs than near-infrared spectroscopy and conventional Raman spectroscopy (200-1800 cm-1 ), was investigated as a possible application to PAT...
March 7, 2018: International Journal of Pharmaceutics
Stanislav O Fedechkin, Natasha L George, Jacob T Wolff, Lawrence M Kauvar, Rebecca M DuBois
Respiratory syncytial virus (RSV) is a top cause of severe lower respiratory tract disease and mortality in young children and the elderly. The viral envelope G glycoprotein contributes to pathogenesis through its roles in host cell attachment and modulation of host immunity. Although the G glycoprotein is a target of protective RSV-neutralizing antibodies, its development as a vaccine antigen has been hindered by its heterogeneous glycosylation and sequence variability outside a conserved central domain (CCD)...
March 9, 2018: Science Immunology
Goudappagouda- -, Murali- Gedda, Giridhar U Kulkarni, Santhosh Babu Sukumaran
One-dimensional (1D) nanostructures of -conjugated molecules exhibiting excellent charge carrier mobilities have found much interest in organic electronic devices. Even though it is tedious to form such structures, the availability of highly delocalized electron and hole carriers in these donor (D)-acceptor (A) co-assemblies realize ambipolar charge transport. Here we report the successful demonstration of a simple solution casting method to create ambipolar donor-acceptor single crystalline assembly. 1D assemblies of 5,10,15,20-tetraphenylporphyrins (H2TPP, ZnTPP) and fullerene (C60) exhibit high ambipolar mobility in the range of 0...
March 9, 2018: Chemistry: a European Journal
Zeeshan Fatima, Dipti Srivastava, Chanchal Deep Kaur
Cocrystallization is a technique for modifying the physicochemical and pharmacokinetic properties of an active pharmaceutical ingredient (API) embodying the concept of supramolecular synthon. Most of the examples cited in the literature are of cocrystals formed between an API and a coformer chosen from the generally recognized as safe (GRAS) substance list, however, few examples exist where a cocrystal consists of two or more APIs. These cocrystals are commonly known as multi API, multi drug or drug- drug cocrystals...
March 5, 2018: Mini Reviews in Medicinal Chemistry
John W Patrick, Christopher D Boone, Wen Liu, Gloria M Conover, Yang Liu, Xiao Cong, Arthur Laganowsky
Membrane proteins interact with a myriad of lipid species in the biological membrane, leading to a bewildering number of possible protein-lipid assemblies. Despite this inherent complexity, the identification of specific protein-lipid interactions and the crucial role of lipids in the folding, structure, and function of membrane proteins is emerging from an increasing number of reports. Fundamental questions remain, however, regarding the ability of specific lipid binding events to membrane proteins to alter remote binding sites for lipids of a different type, a property referred to as allostery [Monod J, Wyman J, Changeux JP (1965) J Mol Biol 12:88-118]...
March 5, 2018: Proceedings of the National Academy of Sciences of the United States of America
Matthew D Ward, Haw-Tyng Huang, Li Zhu, Arani Biswas, Dmitry Popov, John V Badding, Timothy A Strobel
The 1 : 1 acetylene-benzene cocrystal, C2 H2 ·C6 H6 , was synthesized under pressure in a diamond anvil cell (DAC) and its evolution under pressure was studied with single-crystal X-ray diffraction and Raman spectroscopy. C2 H2 ·C6 H6 is stable up to 30 GPa, nearly 10× the observed polymerization pressure for molecular acetylene to polyacetylene. Upon mild heating at 30 GPa, the cocrystal was observed to undergo an irreversible transition to a mixture of amorphous hydrocarbon and a crystalline phase with similar diffraction to i-carbon, a nanodiamond polymorph currently lacking a definitive structure...
February 27, 2018: Physical Chemistry Chemical Physics: PCCP
Ilma Nugrahani, Dwi Utami, Slamet Ibrahim, Yuda Prasetya Nugraha, Hidehiro Uekusa
No abstract text is available yet for this article.
February 20, 2018: European Journal of Pharmaceutical Sciences
Kunti Abhishek Shah, Vijay Parmar
Cocrystals of active pharmaceutical ingredient have been of interest in the field of pharmaceutical research due to their potential for tailoring the physicochemical properties of pharmaceutical molecules. The increase in the number of cocrystals screening experiments being reported for numerous drug substances having less favorable physicochemical properties and simultaneously the draft guidelines issued from regulatory bodies on pharmaceutical cocrystals provide the evidence of the acceptance of cocrystals in the drug development...
February 21, 2018: Recent Patents on Nanotechnology
Jae Eun Cheong, Anil Ekkati, Lijun Sun
Indoleamine 2,3-dioxygenase 1 (IDO1) is overexpressed by cancer cells and the antigen presenting dendritic cells in the tumor microenvironment (TME). Activation of IDO1 depletes tryptophan and produces kynurenine, which induces T cell anergy and suppresses tumor control by the immune system. When combined with an immune checkpoint inhibitor, IDO1 inhibitors have shown promising anticancer activity in preclinical tumor models as well as in early stage clinical trials. Areas covered: IDO1 inhibitors disclosed in the patent literature from 2013-2017 are categorized, when applicable, according to their structural similarity to the clinical development candidates indoximod and PF-06840003, navoximod, epacadostat, KHK2455 and aryl-1,2-diamines, and BMS-986205 among others, respectively...
February 23, 2018: Expert Opinion on Therapeutic Patents
Battini Swapna, M K Chaitanya Mannava, Ashwini Nangia
The classic FDC of four TB drugs, namely Rifampicin (RIF), Isoniazid (INH), Pyrazinamide (PZA) and Ethambutol Dihydrochloride (EDH) has the twin issues of physical stability and rifampicin cross-reaction in the 4FDC. The major reason for these quality issues is the interaction between RIF and INH to yield isonicotinyl hydrazone (HYD) in drug tablets. Pharmaceutical cocrystals of INH with caffeic acid (PZA + EDH + RIF + INH-CFA cocrystal) and vanillic acid (PZA + EDH + RIF + INH-VLA cocrystal) are able to stabilize the FDC formulation compared to the reference batch (PZA + EDH + RIF + INH)...
February 17, 2018: Journal of Pharmaceutical Sciences
Barbara Zheng, Stanley V D'Andrea, Li-Qiang Sun, Alan Xiangdong Wang, Yan Chen, Peter Hrnciar, Jacques Friborg, Paul Falk, Dennis Hernandez, Fei Yu, Amy K Sheaffer, Jay O Knipe, Kathy Mosure, Ramkumar Rajamani, Andrew C Good, Kevin Kish, Jeffrey Tredup, Herbert E Klei, Manjula Paruchuri, Alicia Ng, Qi Gao, Richard A Rampulla, Arvind Mathur, Nicholas A Meanwell, Fiona McPhee, Paul M Scola
The design and synthesis of potent, tripeptidic acylsulfonamide inhibitors of HCV NS3 protease that contain a difluoromethyl cyclopropyl amino acid at P1 are described. A cocrystal structure of 18 with a NS3/4A protease complex suggests the presence of a H-bond between the polarized C-H of the CHF2 moiety and the backbone carbonyl of Leu135 of the enzyme. Structure-activity relationship studies indicate that this H-bond enhances enzyme inhibitory potency by 13- and 17-fold compared to the CH3 and CF3 analogues, respectively, providing insight into the deployment of this unique amino acid...
February 8, 2018: ACS Medicinal Chemistry Letters
Qiuping Xiang, Chao Wang, Yan Zhang, Xiaoqian Xue, Ming Song, Cheng Zhang, Chenchang Li, Chun Wu, Kuai Li, Xiaoyan Hui, Yulai Zhou, Jeff B Smaill, Adam V Patterson, Donghai Wu, Ke Ding, Yong Xu
The CREB (cAMP responsive element binding protein) binding protein (CBP) and its homolog EP300 have emerged as new therapeutic targets for the treatment of cancer and inflammatory diseases. Here we report the identification, optimization and evaluation of 1-(1H-indol-1-yl)ethanone derivatives as CBP/EP300 inhibitors starting from fragment-based virtual screening (FBVS). A cocrystal structure of the inhibitor (22e) in complex with CBP provides a solid structural basis for further optimization. The most potent compound 32h binds to the CBP bromodomain and has an IC 50 value of 0...
February 6, 2018: European Journal of Medicinal Chemistry
Christopher R Taylor, Graeme M Day
We present a periodic density functional theory study of the stability of 350 organic cocrystals relative to their pure single-component structures, the largest study of cocrystals yet performed with high-level computational methods. Our calculations demonstrate that cocrystals are on average 8 kJ mol -1 more stable than their constituent single-component structures and are very rarely (<5% of cases) less stable; cocrystallization is almost always a thermodynamically favorable process. We consider the variation in stability between different categories of systems-hydrogen-bonded, halogen-bonded, and weakly bound cocrystals-finding that, contrary to chemical intuition, the presence of hydrogen or halogen bond interactions is not necessarily a good predictor of stability...
February 7, 2018: Crystal Growth & Design
Wenping Hu, Yu Wang, Weigang Zhu, Wenna Du, Xinfeng Liu, Xiaotao Zhang, Huanli Dong
Herein, a cocrystal strategy with simple preparation process is developed to fabricate novel materials for Near-infrared photothermal (PT) conversion and imaging. Dibenzotetrathiafulvalene (DBTTF) and tetracyanobenzene (TCNB) are selected as electron-donor and electron-acceptor, which self-assemble into new cocrystals through non-covalent interactions. The strong interaction between the donors and acceptors leads to a narrow bandgap with near-infrared (NIR) absorption and that both the ground state and lowest-lying excited state are CT state...
February 14, 2018: Angewandte Chemie
Silvério Ferreira Silva Filho, Andreia Cardoso Pereira, Jorge M G Sarraguça, Mafalda C Sarraguça, João Lopes, Pedro Freitas Filho, Adenilson Oliveira Dos Santos, Paulo Roberto da Silva Ribeiro
A cocrystal of glibenclamide (GLB), an antidiabetic drug classified as type II compound according to the Biopharmaceutics Classification System (BCS), has been synthesised using tromethamine (TRIS) as coformer in 1:1 molar ratio, by slow solvent evaporation cocrystalization. The cocrystal obtained was characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Raman, mid infrared (MIR), and near-infrared (NIR) spectroscopy. The results consistently show the formation of a cocrystal between API and conformer with the synthons corresponding to hydrogen bonding between hydrogen in amines of tromethamine and carbonyl and sulfonyl groups in glibenclamide...
February 9, 2018: Journal of Pharmaceutical Sciences
Vikas D Ghule, Ayushi Nirwan, Alka Devi
The application of average atomic volumes to predict the crystal densities of benzene-derived energetic compounds of general formula C a H b N c O d is presented, along with the reliability of this method. The densities of 119 neutral nitrobenzenes, energetic salts, and cocrystals with diverse compositions were estimated and compared with experimental data. Of the 74 nitrobenzenes for which direct comparisons could be made, the % error in the estimated density was within 0-3% for 54 compounds, 3-5% for 12 compounds, and 5-8% for the remaining 8 compounds...
February 9, 2018: Journal of Molecular Modeling
Zengnan Wu, Mashooq Khan, Sifeng Mao, Ling Lin, Jin-Ming Lin
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a fast analysis tool for the detection of a wide range of analytes. However, heterogeneous distribution of matrix/analyte cocrystal, variation in signal intensity and poor experimental reproducibility at different locations of the same spot means difficulty in quantitative analysis. In this work, carbon nanotubes (CNTs) were employed as adsorbent for analyte cum matrix on a conductive porous membrane as a novel mass target plate. The sample pretreatment step was achieved by enrichment and dead-end filtration and dried by a solid-liquid separation...
May 1, 2018: Talanta
Wenwei Lin, Taosheng Chen
Time-resolved fluorescence resonance energy transfer (TR-FRET) protein-protein interaction assays, especially in the format of receptor coregulator (coactivator and corepressor) recruitment/repression assays, have been widely used in nuclear receptor research to characterize the modes of action, efficacies, and binding affinities of ligands (including their properties as agonists, antagonists, and inverse agonists). However, there has been only limited progress in using this assay format for pregnane X receptor (PXR)...
2018: Advances in Protein Chemistry and Structural Biology
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