(20S,2′′S)-20-[4′-(3′′-Hydroxy-2′′-methyl­prop­yl)-3′-methylisoxazol-5-yl]-5β-preg­nan-3β,16β-diol

The title steroidal compound, C29H47NO4, was prepared in a one-pot reaction starting from a sarsasapogenin derivative of known configuration. The isoxazole heterocycle is oriented towards the α face of the steroid nucleus and, although fully functionalized on C atoms, does not provoke steric hindrance with the adjacent D ring. The absolute configuration observed for chiral centers is as expected, and shows that no epimerization occurred in the precursors. In the crystal, the three OH groups serve as donors for hydrogen bonding with O and N atoms. The isoxazole N atom is involved in O—H⋯N hydrogen bonds, forming chains along [100]. These chains are further connected via O—H⋯O and weak C—H⋯O contacts, giving rise to a three-dimensional supra­molecular network

The zwitterion (23′E)-(23R,25S)-23-[1-(oxidoiminio)eth­yl]-5β-spiro­stan-3β-yl acetate

The title steroidal compound, C31H49NO5, resulted from the selective oximation of (23R)-23-acetyl­sarsasapogenin acetate. One- and two-dimensional 1H and 13C NMR spectra, as well as IR data, are in agreement with the presence of a ketoxime group at C-23. However, recrystallization in slightly acidic media affords the title compound in the rare zwitterionic oxime form, as a consequence of migration of the hydr­oxy H atom to the N atom in the oxime group. This H atom is clearly detected and its position was refined from X-ray data. The geometry for the C=N+(H)—O− group features long C=N and short N—O bond lengths compared to non-zwitterionic oximes. The ketoxime is stabilized with the E configuration, avoiding steric hindrance between the oxime O atom and H atom at C-23. The sum of the angles around the oxime N atom is 359.6°, giving a planar configuration for that atom, as expected for sp 2 hybridization

(R)-1-Phenyl­ethyl­ammonium trifluoro­acetate

In the crystal structure of the title salt, C8H12N+·C2F3O2 −, all of the ammonium H atoms serve as donors for hydrogen bonds to carboxyl­ate O atoms, forming an R 4 3(10) ring motif based on two cations and two anions. Since both cations and anions act as inter-ion bridging groups, R(10) rings aggregate in a one-dimensional supra­molecular network by sharing the strongest N—H⋯O bond. Edge-sharing motifs lie on the twofold screw axis parallel to [010], and anti­parallel packing of these 21-column structural units results in the crystal structure. This arrangement is one of the most commonly occurring in conglomerates of chiral 1-phenyl­ethyl­amine with achiral monocarboxylic acids, confirming that these ionic salts are particularly robust supra­molecular heterosynthons useful in crystal engineering

(E)-(25S)-23-Acetyl-5β-furost-22-ene-3β,26-diol

The title steroid, C29H46O4, is a furostene derivative with a C=C double-bond length of 1.353 (3) Å and an E configuration. The side chain is oriented toward the α face of the A–E steroidal nucleus and presents a disordered terminal CH2—OH group [occupancies for resolved sites are 0.591 (9) and 0.409 (9)]. The methyl group at C20 attached to ring E is also oriented toward the α face, avoiding steric hindrance with the carbonyl O atom of the acetyl group. The furostene and acetyl functionalities form an α,β-unsaturated ketone system, with an s-cis configuration. All hydr­oxy and carbonyl groups are involved in weak inter­molecular hydrogen bonds. The absolute configuration was assigned from the synthesis

Retos actuales de la farmacia

Retos actuales de la farmacia es un proyecto que está coordinado por Leobargo Manuel Gómez Oliván y un equipo de investigadores que forman parte del claustro de la Facultad de Química en el área de posgrado, ellos han incentivado el espíritu investigador y científico de los estudiantes adscritos al programa para adentrarse en el ámbito farmacéutico. Los capítulos que conforman esta edición son el reflejo de la actividad académica desarrollada en este posgrado en las diferentes áreas de acentuación que lo conforman: farmacia molecular, farmacia social y tecnología farmacéutica

Mis casos clínicos de especialidades odontológicas

Libro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasLibro que muestra la atención de casos clínicos particulares referente a las diferentes especialidades odontológicasUniversidad Autónoma de Campeche Universidad Autónoma del Estado de Hidalgo Universidad Autónoma del Estado de Méxic

Intervención psicoeducativa: una propuesta para fomentar la asertividad en adolescentes de 1er. grado de secundaria

Licenciatura en Psicología Educativ