James E. Hines, Curtistine J. Deere, Frank R. Fronczek, Rao M. Uppu
, differs in its degree of planarity from the 3-nitro isomer and also in its hydrogen-bonding pattern. Its NH group forms an intra-molecular hydrogen bond to a nitro oxygen atom, and its OH group forms an inter-molecular hydrogen bond to an amide oxygen atom, generating [10] chains in the crystal.
S.A. Babu, Michelle O. Claville, Frank R. Fronczek, Rao M. Uppu
The study of the oxidation of various proteins necessitates scrutiny of the amino acid sequence. Since methionine (Met) and tyrosine (Tyr) are easily oxidized, peptides that contain these amino acids are frequently studied using a variety of oxidation methods, including, but not limited to, pulse ra...
Rao M. Uppu, Frank R. Fronczek
, the acetamide substituent is twisted out of the phenyl plane, forming a dihedral angle of 58.61 (7)°. In the extended structure, each mol-ecule donates two hydrogen bonds [N-H⋯O(carbon-yl) and O-H⋯O(carbon-yl)] and thus also accepts two such hydrogen bonds. The chlorine atom is not involved in the...
James E. Hines, Curtistine J. Deere, Poornasai Vaddi, Ranjeeth R. Kondati et al.
, the three substituents vary in the degree of lack of planarity with the central phenyl ring. The meth-oxy group is nearest to being coplanar, with a C-C-O-C torsion angle of 6.1 (5)°. The nitro group is less coplanar, with a 12.8 (5)° twist about the C-N bond and the acetamido group is considerabl...
Rao M. Uppu, Ogad A. Agu, Patrick Mensah, Guoqiang Li et al.
The redetermined structure of the title compound, C 12 H 12 N 2 S, was refined from low-temperature (100 K) single-crystal X-ray diffraction data. Although achiral, the compound crystallizes in Sohncke space group P 2 1 2 1 2 1 in a chiral conformation distorted from idealized C 2 symmetry and the d...
Rao M. Uppu, Frank R. Fronczek
, the four substituents lie out of the phenyl plane by varying degrees. The methyl C atom lies 0.019 (3) Å out of plane, while the meth-oxy O and C atoms lie 0.067 (2) and 0.042 (3) Å out of plane, respectively, with the C-C-O-C torsion angle being 3.3 (2)°. The plane of the nitro group is twisted o...
Tashonda Vaughn, Saneei Soheil, Olalekan M. Ogundele, Frank R. Fronczek et al.
The title compound, C 5 H 2 Cl 3 NO, is almost planar. In the crystal, the molecules form centrosymmetric hydrogen-bonded dimers through pairwise O—H...N interactions to generate R 2 2 (8) loops.
S.A. Babu, Frank R. Fronczek, Rao M. Uppu, Michelle O. Claville
The oxidation of methionyl peptides can contribute to increased biological (oxidative) stress and development of various inflammatory diseases. The conformation of peptides has an important role in the mechanism of oxidation and the intermediates formed in the reaction. Herein, the crystal structure...
Rao M. Uppu, S.A. Babu, Frank R. Fronczek
At room temperature, the title salt, C 7 H 10 NO + ·Cl − , is orthorhombic, space group Pbca with Z ′ = 1, as previously reported [Zhao (2009). Acta Cryst. E 65 , o2378]. Between 250 and 200 K, there is a solid-state phase transition to a twinned monoclinic P 2 1 / c structure with Z ′ = 2. We repor...
Sree Vandana Yerramsetty, Frank R. Fronczek, Rao M. Uppu
The title compound, C 12 H 15 NO 3 , crystallizes with Z ′ = 2 in space group Pca 2 1 with the two independent molecules having almost the same conformation, differing mostly at the end of the butanamide chain. A local inversion center near 1/8, 3/4, z relates the two molecules, as is common for str...
James E. Hines, Ogad A. Agu, Curtistine J. Deere, Frank R. Fronczek et al.
, crystallizes with a disordered nitro group in twinned crystals. Both the meth-oxy group and the acetamide groups are nearly coplanar with the phenyl ring, and the C-N-C-O torsion angle [0.2 (4)°] is also insignificantly different from zero. Overall, the 12-atom meth-oxy-phenyl-acetamide group is n...
James E. Hines, Zechariah Myles, Garrick Breaux, Frank R. Fronczek et al.
, the mol-ecule is in an extended conformation as illustrated by the C-O-C-C torsion angle [170.14 (15)°] in the eth-oxy group and the subsequent C-N-C-C [-177.24 (16)°], N-C-C-C [170.08 (15)°] and C-C-C-C [171.41 (15)°] torsion angles in the butanamide chain. In the crystal, the O-H group donates a...
Rao M. Uppu, Frank R. Fronczek
The structure of the title compound, C 10 H 6 N 4 O 2 , reported by Smalley et al. [(2021). Cryst. Growth Des. 22 , 524–534] from powder diffraction data and 15 N NMR spectroscopy, is confirmed using low-temperature data from a twinned crystal. The tautomer in the solid state is alloxazine (1 H -ben...