30 research outputs found
DIMERIC MOLECULAR AGGREGATION MOTIF IN CRYSTAL OF 2,7-DIETHOXY-1-(4-NITROBENZOYL)NAPHTHALENE: CORRELATION OF SINGLE MOLECULAR STRUCTURE, MOLECULAR ACCUMULATION STRUCTURE AND NON-COVALENT-BONDING INTERACTIONS
Crystal structure of 2,7-diethoxy-1-(4-nitrobenzoyl)naphthalene, C21H19NO5, is reported and discussed on the characteristics of the spatial organization of single molecule and molecular aggregation as contrasted with a homologous compound. The molecular structures of these compounds differ only in the kind of alkoxy group of 2,7-positions of naphthalene rings, i.e., ethoxy groups for title compound and methoxy ones for homologue. In single molecular crystal structure, the 4-nitrobenzoyl groups of these molecules are attached non-coplanarly to the naphthalene ring. The congested situation makes bonds connecting naphthalene ring and carbonyl group fixed to turn stereogenetic, which allow the independent existence of atrope stereoisomers of (R)- and (S)-enantiomeric conformer molecules, contrary to their solute state where the fast interconversion disturbs the distinction of the enantiomeric molecules. The two pairs of the enantiomeric molecules are related by two-fold helical axis in the asymmetric unit of P21/n space group for title compound and P21/c for homologous compound, exhibiting the number of molecules (Z) is four for both compounds. In crystal of title compound, (R)- and (S)-enantiomers are connected to each other by pi…pi stacking interaction and two types of C–H…O=N non-classical hydrogen bonds, (sp2)C–H…O=N and (sp3)C–H…O=N non-classical hydrogen bonds along b-axis, forming centrosymmetric dimeric molecular aggregates. The dimeric units are stacked into columnar structure by (sp2)C–H…O=C non-classical hydrogen bonds between molecular unit of identical enantiomeric configuration along a-axis. The columns are also connected by (sp2)C–H…OEt non-classical hydrogen bonds between molecular unit of identical enantiomeric configuration along c-axis to give sheet-like aggregate composed of molecules of same enantiomeric configuration spreading on ac-plane. The sheets are piled up through (sp3)C–H…pi non-classical hydrogen bonds between opposite enantiomeric molecular units of next dimeric aggregates along b-axis. In crystal of the homologous compound, 2,7-dimethoxy-1-(4-nitrobenzoyl)naphthalene, centrosymmetric dimeric aggregate resulted from the association of (R)- and (S)-enantiomers via pi…pi stacking interactions are also observed. The centrosymmetric dimeric aggregates are unidirectionally lined by two kinds of non-classical hydrogen bonds between molecular unit of identical enantiomeric configuration, (sp3)C–H…O=C and (sp3)C–H…pi non-classical hydrogen bonds, giving columnar structure. The columns are accumulated giving a wavy sheet structure composed of stripes of respective enantiomeric configuration oriented alternatively and anti-parallelly through weak (sp2)C–H…pi non-classical hydrogen bonds. The difference of higher ordered structure between title compound and homologue is plausibly explained according to one CH2 margin in 2,7-dialkoxy groups, i.e., elongation of the least length in alkyl group of title compound compared to homologue brings about the sterically significant hindrance among dimeric aggregates that makes rather anisotropic intermolecular non-covalent bonding interactions resulting in accumulating sheet structure. For 1-monoaroylnaphthalene compounds, the most stabilized single molecular structure on condition that the sufficiently effective intermolecular interaction is absent is proposed the perpendicular alignment of naphthalene and benzene rings to prevent the steric repulsion of two aromatic rings. The smaller spatial volume of methyl group in homologue molecule is plausibly able to be merged without large alternation in the single molecular structure most stabilized. Contrarily, the additional methylene unit at 2,7-alkoxy group probably requires the rather large perturbation from the supposed structure most stabilized
Asthma-COPD overlap : prevalence and features
Background Asthma-COPD overlap (ACO) is a disease that shares clinical features of both asthma and COPD. The purpose of this study is to investigate the prevalence and clinical features of ACO. Methods We retrospectively reviewed data for 170 patients with persistent airflow limitation and diagnosed them according to “The Japanese Respiratory Society Guidelines for the Management of ACO 2018”. Results Of the 170 patients, 111 were diagnosed as follows : COPD (74 patients, 66.6%), ACO (34 patients, 30.6%), and asthma (3 patients, 2.8%). There was no significant difference in clinical features between ACO and COPD patients. The following pulmonary function tests were significantly lower in ACO than in COPD patients : forced expiratory volume in 1 second/forced vital capacity, peak expiratory flow, maximal mid-expiratory flow, and the maximum expiratory flow at 50% and 75%. The following respiratory impedance parameters were significantly higher in ACO than in COPD patients : respiratory resistance (Rrs) at 5 Hz (R5), Rrsat 20 Hz (R20), R5-R20, and low-frequency reactance area. Conclusions About 30% of patients with persistent airflow limitation were diagnosed with ACO. ACO patients had lower lung function and higher respiratory impedance compared with COPD patients
Anti-inflammatory and morphologic effects of pitavastatin on carotid arteries and thoracic aorta evaluated by integrated backscatter trans-esophageal ultrasound and PET/CT: a prospective randomized comparative study with pravastatin (EPICENTRE study)
Applications of a Standardized Green Tea Catechin Preparation for Viral Warts and Human Papilloma Virus-Related and Unrelated Cancers
Most cell-based and animal experiments have shown that green tea catechins (GTC) exhibit various health benefits. In human experimental and epidemiological studies, there are conflicting results, and more precise investigations are required. One of the most effective ways to prove beneficial health effects in humans might be clinical intervention studies. Polyphenon®E was developed as a standardized GTC preparation, which was approved by Food and Drug Administration of US in 2006 as a medication to treat genital warts (Veregen® or sinecatechins). Positive efficacy of Polyphenon®E/sinecatechins/Veregen® (PSV) on anogenital warts has been demonstrated in several epidemiological studies and there have been several case reports to show the clinical effectiveness of PSV. In addition, several studies have provided evidence to suggest that PSV is effective in other human papillomavirus (HPV)-related diseases, although some studies failed to show such effects. Since (−)-epigallocatechin gallate (EGCG) is the major component of PSV, the mechanism of the action of PSV might be deduced from that of EGCG. The microarray analysis of the biopsy samples from the patients suggested that apoptosis induction and the downregulation of inflammation are involved in the mechanism of the action of PSV in the clearance of anogenital warts. Cell-based and animal experiments using PSV also demonstrated effects similar to those elicited by EGCG, explaining how PSV works to induce apoptosis and exert anti-inflammatory actions in HPV-related diseases. Future studies would clarify what kinds of diseases respond effectively to PSV, showing health benefits of GTC and EGCG in humans
Ambipolar-transporting coaxial nanotubes with a tailored molecular graphene–fullerene heterojunction
Despite a large steric bulk of C60, a molecular graphene with a covalently linked C60 pendant [hexabenzocoronene (HBC)–C60; 1] self-assembles into a coaxial nanotube whose wall consists of a graphite-like π-stacked HBC array, whereas the nanotube surface is fully covered by a molecular layer of clustering C60. Because of this explicit coaxial configuration, the nanotube exhibits an ambipolar character in the field-effect transistor output [hole mobility (μh) = 9.7 × 10−7 cm2 V−1 s−1; electron mobility (μe) = 1.1 × 10−5 cm2 V−1 s−1] and displays a photovoltaic response upon light illumination. Successful coassembly of 1 and an HBC derivative without C60 (2) allows for tailoring the p/n heterojunction in the nanotube, so that its ambipolar carrier transport property can be optimized for enhancing the open-circuit voltage in the photovoltaic output. As evaluated by an electrodeless method called flash-photolysis time-resolved microwave conductivity technique, the intratubular hole mobility (2.0 cm2 V−1 s−1) of a coassembled nanotube containing 10 mol % of HBC–C60 (1) is as large as the intersheet mobility in graphite. The homotropic nanotube of 2 blended with a soluble C60 derivative [(6,6)-phenyl C61 butyric acid methyl ester] displayed a photovoltaic response with a much different composition dependency, where the largest open-circuit voltage attained was obviously lower than that realized by the coassembly of 1 and 2
Highly Photoconducting π-Stacked Polymer Accommodated in Coordination Nanochannels
We report on the formation of single poly(<i>N</i>-vinylcarbazole)
(PVCz) chains in one-dimensional channels of [La(1,3,5-benzenetrisbenzoate)]<sub><i>n</i></sub>, where the side carbazolyl groups of the
confined PVCz are effectively π-stacked. This ideal conformation
of PVCz chains in the coordination nanochannels contributed to a drastic
increase in hole mobility, which was 5 orders of magnitude higher
than that in the bulk state. It is also noteworthy that PVCz isolated
from the nanchannels still had a high hole mobility