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Phenytoin is an anticonvulsant drug that suffers from low aqueous solubility. The formation of phenytoin salts is a strategy employed to address this issue. A phenytoin–piperidine salt (PPD–PNT) was synthesized by solvent-assisted grinding and characterized by infrared (IR) spectroscopy, 1H and 13C Nuclear Magnetic Resonance (NMR), and powder and single crystal X-ray diffraction. The IR and NMR spectra obtained differed from those of the starting compounds, showing shifts in the N-H and C=O group signals, as well as the appearance of NH+ signals, indicating proton transfer and salt formation. Powder X-ray diffraction confirmed the formation of a new solid phase corresponding to the salt. Single crystal X-ray diffraction showed the molecular structure of the PPD–PNT salt.

This work reports the crystallographic study of two benzenesulfonamides, 1 ((E)-N-benzyl-3-((benzylimino)methyl)-4-hydroxybenzenesulfonamide) and 2 (N-benzyl-3-(3-(N-benzylsulfamoyl)-2-oxo-2H-chromene-6-sulfonamide). These compounds share structural features with belinostat, an FDA-approved histone deacetylase (HDAC) inhibitor used in the treatment of peripheral T-cell lymphoma. Compound 1 contains one sulfonamide group, meanwhile compound 2 contains two sulfonamide moieties and presents four independent molecules in its unit cell. The crystal packing of 1 and 2 is mainly governed by N–H···O=S hydrogen bonding interactions. π → π* and n → π* stacking interactions also contribute to the molecular assembly. Hirshfeld surface (HS) analysis was carried out to further examine the intermolecular interactions of compounds 1 and 2, revealing that N–H∙∙∙O and C–H∙∙∙O hydrogen bonding interactions, along with O∙∙∙H/H∙∙∙O interactions, are the strongest contributors to the individual surfaces. Interaction energy analysis was also performed to evaluate the relative strength and nature of the intermolecular contacts. Additionally, molecular docking studies of compounds 1 and 2 were performed on the crystal structure of the enzyme HDAC2, an enzyme overexpressed in several cancers, particularly breast cancer. The results revealed that both compounds exhibit a binding mode and binding energies similar to those of belinostat, suggesting their potential as novel therapeutic agents.

This work reports the synthesis of aminoazobenzene compounds derived from 3,5-dimethylaniline (1a–1f) via a diazo-coupling reaction with aromatic amines. These aminoazobenzenes were acylated with maleic anhydride to obtain the corresponding maleimides (2a–2f). The maleimides were then used as dienophiles in a Dies–Alder cycloaddition reaction with furan as the diene, yielding the adducts (3a–3f). All synthesized compounds were characterized using FTIR, 1H, and 13C NMR spectroscopy. Additionally, electrochemical studies using cyclic voltammetry were conducted to determine the oxidation–reduction reactions present in the compounds.

A series of three 1,3-phenylene bis-oxamides 3a–c, structurally related to the GPR35 receptor-agonist drug lodoxamide, has been synthesized by reacting the 1,3-phenylene bis-oxalamates 2a and 2b with amines. The obtained compounds were characterized by 1H and 13C NMR, and IR spectroscopy, they showed characteristic signals for the aromatic, N―H, and C=O groups. Molecular structure was determined using single-crystal X-ray diffraction. The supramolecular architecture is driven by N―H···O=C, N―H···N, C—H···π, and O=C···O=C interactions depicting a supramolecular helix (3a) and tapes (3b–c). Intermolecular interactions were studied using Hirshfeld surface analysis, where N―H∙∙∙X (X = N, O) hydrogen bonding represents 30.2% to the surface of 3a and 17.8–18.8% to the surface of 3b–c. The most energetic interactions involve the amide N—H∙∙∙O hydrogen bonding, contributing in the −113.9 to −97.0 kJ mol−1 range to the crystal energy, being more dispersive than electrostatic in nature. The molecular docking study was performed to evaluate the binding ability of 3a–c compounds to the GPR35 receptor, showing a favorable binding in a similar way to lodoxamide.

Isoniazid is used as anti-tuberculosis drug which possesses functional groups capable of forming hydrogen bonds. A series of cocrystals of isoniazid (INH) with polyphenolic coformers such as catechol (CAT), orcinol (ORC), 2-methylresorcinol (MER), pyrogallol (PYR), and phloroglucinol (PLG) were prepared by solvent-assisted grinding. Powder cocrystals were characterized by infrared (IR) spectroscopy and X-ray powder diffraction. The crystal structure of the cocrystals revealed the unexpected hydration of the INH-MER cocrystal and the preference of the (phenol) O–H∙∙∙N (pyridine) and (terminal) N-H∙∙∙O (phenol) heterosynthons in the stabilization of the structures. The supramolecular architecture of the cocrystals is affected by the conformation and the substitution pattern of the hydroxyl groups of the polyphenols.

Pharmaceutical cocrystallization offers the possibility to modify the physicochemical and biopharmaceutical properties of active pharmaceutical ingredients. The mechanochemical synthesis and spectroscopic characterization of the catechol-theophylline (CAT-TEO) cocrystal is reported. The cocrystal was prepared by the solvent-assisted grinding method. The ATR-IR spectroscopy study allowed to determine the formation of the cocrystal because the O-H and C=O stretching bands in the CAT-TEO cocrystal were shifted with respect to the starting materials, suggesting the formation of the C=O···H-O hydrogen bond interaction. Infrared spectroscopy also allowed to discard hydration of the cocrystal, and polymorphic transitions of the starting products as a consequence of the mechanochemical grinding. The X-ray powder diffraction and thermal studies confirmed the formation of a new solid phase. In the solid state 13C NMR spectra of the cocrystal, the signals were shifted with respect to the starting products. The 13C NMR chemical shifts of the CAT-TEO cocrystal were simulated by using the gauge including the atomic orbital (GIAO) method. These results showed a good correlation between the experimental and calculated 13C NMR results. Theoretical calculations and natural bonding orbital analysis (NBO) at a B3LYP/6-31G(d,p) level of theory were performed to obtain structural information of the cocrystal.

The crystal structure and the supramolecular architectures of the antiallergic compounds N,N′-(4,4′-methanediyl-di-phenyl)-bis-diethyl dioxalamate (1); N′,N′-(4,4′-oxydi-p-phenylene)-bis-diethyl dioxalamate (2); N,N′-(4,4′-biphenylene)-bis- diethyl dioxalamate (3) are reported. The supramolecular self-assembly in 1-3 is driven by N-H···O=C hydrogen bonds and reinforced by C-H···O=C, C-H···π and C=O···C=O interactions. The three compounds preferred to form cross-linked supramolecular architectures. Intermolecular interactions also were studied by the Hirshfeld surface analysis, revealing that the H···H, O···H, and C···H are the more dominant contacts in the three compounds. The knowledge of crystal structure will allow us to perform theoretical studies to evaluate the antiallergic activity of compounds 1-3.

Molecular complexation is a strategy used to modify the physicochemical or biopharmaceutical properties of an active pharmaceutical ingredient. Solvent assisted grinding is a common method used to obtain solid complexes in the form of cocrystals. Lidocaine is a drug used as an anesthetic and for the treatment of chronic pain, which bears in its chemical structure an amide functional group able to form hydrogen bonds. Polyphenols are used as cocrystal coformers due to their ability to form O–H···X (X = O, N) hydrogen bond interactions. The objective of this study was to exploit the ability of phloroglucinol to form molecular complexes with lidocaine by liquid assisted grinding. The formation of the complex was confirmed by the shift of the O–H and C=O stretching bands in the IR spectra of the polycrystalline ground powders, suggesting the formation of O–H···O=C hydrogen bonds. Hydration of the complexes also was confirmed by IR spectroscopy and by powder X-ray diffraction. The molecular structure was determined by single crystal X-ray diffraction.

The jump squat is one of the exercises most frequently used to improve lower body power production, which influences sports performance. However, the traditional determination of the specific workload at which power production is maximized (i.e., optimum power load) is time-consuming and requires one-repetition maximum tests. Therefore, the aim of this study was to verify whether elite athletes from different sports would produce maximum mean propulsive power values at a narrow range of mean propulsive velocities, resulting in similar jump heights. One hundred and nine elite athletes from several individual/team sport disciplines underwent repetitions at maximal velocity with progressive loads, starting at 40% of their body mass with increments of 10% to determine the individual optimum power zone. Results indicated that regardless of sport discipline, the athletes' optimum mean propulsive power was achieved at a mean propulsive velocity close to 1.0 m.s(-1) (1.01 ± 0.07 m.s(-1)) and at a jump height close to 20 cm (20.47 ± 1.42 cm). Data were narrowly scattered around these values. Therefore, jump squat optimum power load can be determined simply by means of mean propulsive velocity or jump height determination in training/testing settings, allowing it to be implemented quickly in strength/power training.

The article discusses the importance of accurately distinguishing HER2-low from HER2-negative breast cancer, as novel ADCs have demonstrated activity in a large population of patients with HER2-low-expressing BC. While current guidelines recommend a dichotomous classification of HER2 as either positive or negative, the emergence of the HER2-low concept calls for standardization of HER2 testing in breast cancer, using currently available assays to better discriminate HER2 levels. This review covers the evolution and latest updates of the ASCO/CAP guidelines relevant to this important biomarker in breast cancer, including still-evolving concepts such as HER2 low, HER2 heterogeneity, and HER2 evolution. Our group presents the latest Mexican recommendations for HER2 status evaluation in breast cancer, considering the ASCO/CAP guidelines and introducing the HER2-low concept. In the era of personalized medicine, accurate HER2 status assessment remains one of the most important biomarkers in breast cancer, and the commitment of Mexican pathologists to theragnostic biomarker quality is crucial for providing the most efficient care in oncology.