Abstract C18H18O3S, orthorhombic, Cmc21 (no. 36), a = 14.463(3) Å, b = 9.780(5) Å, c = 10.848(4) Å, V = 1534.4(10) Å3, Z = 4, Rgt(F) = 0.0416, wRref(F2) = 0.1132, T = 293(2) K.

/pdf/crystal-structure-of-9-5-methylthiophen-2-yl-3-4-5-6-7-9-2y786gcp6b.pdf

Crystal structure of 9-(5-methylthiophen-2-yl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, C18H18O3S

The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as `a CIF') containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

/pdf/crystal-structure-refinement-with-shelxl-1jual428j8.pdf

Crystal structure refinement with SHELXL

New software, OLEX2, has been developed for the determination, visualization and analysis of molecular crystal structures. The software has a portable mouse-driven workflow-oriented and fully comprehensive graphical user interface for structure solution, refinement and report generation, as well as novel tools for structure analysis. OLEX2 seamlessly links all aspects of the structure solution, refinement and publication process and presents them in a single workflow-driven package, with the ultimate goal of producing an application which will be useful to both chemists and crystallographers.

OLEX2: a complete structure solution, refinement and analysis program

Synthesis and pharmacological activity of 2-oxo-(2H) 1-benzopyran-3-carboxamide derivatives

Background/Aims: Dairy cows with ketosis are characterized by oxidative stress and hepatic damage. The aim of this study was to investigate hepatic oxidative stress and the apoptotic status of ketotic cows, as well as the underlying apoptosis pathway. Methods: The blood aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (GGT) activities and the haptoglobin (HP), serum amyloid A (SAA) and serum apoptotic cytokeratin 18 neo-epitope M30 (CK18 M30) concentrations were determined by commercially available kits and ELISA kits, respectively. Liver histology, TUNEL and Oil red O staining were performed in liver tissue samples. TG contents were measured using an enzymatic kit; Caspase 3 assays were carried out using the Caspase 3 activity assay kit; oxidation and antioxidant markers were measured using biochemical kits; apoptosis pathway were determined by qRT-PCR and western blot. Results: Ketotic cows displayed hepatic fat accumulation. The hepatic malondialdehyde (MDA) content was significantly increased, but the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were markedly decreased in ketotic cows compared with control cows, indicating that ketotic cows displayed severe oxidative stress. Significantly higher serum levels of the hepatic damage markers AST, ALT, GGT and GLDH were observed in ketotic cows than in control cows. The blood concentration of the apoptotic marker CK18 M30 and the number of TUNEL-positive cells in the liver of ketotic cows were 1.19- and 2.61-fold, respectively, higher than the values observed in control cows. Besides, Caspase 3 activity was significantly increased in the liver of ketosis cows. Importantly, the levels of phosphorylated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK) were significantly increased but the level of phosphorylated extracellular signal-regulated kinase1/2 (ERK1/2) was markedly decreased, which further promoted tumor protein 53 (p53) expression and inhibited nuclear factor E2-related factor 2 (Nrf2) expression. The apoptosis-related molecules p21, MDM2, Caspase 3, Caspase 9 and Bax were expressed at significantly higher levels in ketotic cows than in healthy cows, whereas the anti-apoptosis molecule Bcl-2 was expressed at significantly lower levels. Conclusions: Based on these results, ketotic cows display severe hepatic oxidative stress. The hepatic MAPK-p53-Nrf2 apoptotic pathway is over induced and partially mediated apoptotic damage in the liver.

/pdf/elevated-apoptosis-in-the-liver-of-dairy-cows-with-ketosis-39f30bm1rk.pdf

Elevated Apoptosis in the Liver of Dairy Cows with Ketosis.

In the title compound, C23H24N2O7, the central 4H-pyran ring adopts a flattened boat conformation, whereas both cyclo­hexenone rings adopt envelope conformations, the C atom bearing the dimethyl substituent being the flap atom in each case. The mean and maximum deviation of the pyran ring are 0.0379 (4) and 0.0605 (3) A. The mean plane of the pyran ring and the dinitro­benzene ring make a dihedral angle of 85.88 (2)°.

https://journals.iucr.org/e/issues/2013/02/00/im2418/im2418.pdf

Crystal structure of 9-(5-methylthiophen-2-yl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, C18H18O3S

References

Crystal structure refinement with SHELXL

OLEX2: a complete structure solution, refinement and analysis program

Synthesis and pharmacological activity of 2-oxo-(2H) 1-benzopyran-3-carboxamide derivatives

Elevated Apoptosis in the Liver of Dairy Cows with Ketosis.

9-(2,4-Dinitrophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione

Crystal structure of 9-(5-methylthiophen-2-yl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione, C18H18O3S

References

Crystal structure refinement with SHELXL

OLEX2: a complete structure solution, refinement and analysis program

Synthesis and pharmacological activity of 2-oxo-(2H) 1-benzopyran-3-carboxamide derivatives

Elevated Apoptosis in the Liver of Dairy Cows with Ketosis.

9-(2,4-Dinitro­phen­yl)-3,3,6,6-tetra­methyl-3,4,5,6,7,9-hexa­hydro-1H-xanthene-1,8(2H)-dione

9-(2,4-Dinitrophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione