Discovery and Pharmacophore Studies of Novel Pyrazole-Based Anti-Melanoma Agents

Development of benzaldehyde-pyrazoline hybrids for functionalization of polymers with fluorescent pendant moieties

Compounds with a pyrazoline scaffold are useful as sensors for fluorescence detection of different types of analytes. Recovery of a pyrazoline-based sensor with a view to use it recurrently would be more facile when the sensing molecule is attached to a solid support. A reaction sequence has been designed to synthesize two benzaldehyde-pyrazoline hybrids as examples of a hitherto unknown type of compounds to be employed for the potential derivatization of polymers containing primary amino groups through azomethine formation. All intermediates, including the fairly unstable N1 -unsubstituted pyrazolines, along with the target compounds have been structurally characterized, with an emphasis on their particular NMR features. Examination of the photophysical properties of these benzaldehyde-pyrazoline hybrids showed that, despite the shortening of the extended N1-N2-C3 conjugated system common to 1,3,5-triarylpyrazolines through the replacement of the aryl at N1 by an aryloxyacetyl moiety, the novel compounds exhibit emission maxima at approximately 350 nm. Moreover, the introduction of a moderately electron-withdrawing substituent such as chlorine in the phenyl at C3 of pyrazoline leads to an amplification of fluorescence intensity.

Challenges and Opportunities in the Crusade of BRAF Inhibitors: From 2002 to 2022

Serine/threonine-protein kinase B-Raf (BRAF; RAF = rapidly accelerated fibrosarcoma) plays an important role in the mitogen-activated protein kinase (MAPK) signaling cascade. Somatic mutations in the BRAF gene were first discovered in 2002 by Davies et al., which was a major breakthrough in cancer research. Subsequently, three different classes of BRAF mutants have been discovered. This class includes class I monomeric mutants (BRAFV600), class II BRAF homodimer mutants (non-V600), and class III BRAF heterodimers (non-V600). Cancers caused by these include melanoma, thyroid cancer, ovarian cancer, colorectal cancer, nonsmall cell lung cancer, and others. In this study, we have highlighted the major binding pockets in BRAF protein, their active and inactive conformations with inhibitors, and BRAF dimerization and its importance in paradoxical activation and BRAF mutation. We have discussed the first-, second-, and third-generation drugs approved by the Food and Drug Administration and drugs under clinical trials with all four different binding approaches with DFG-IN/OUT and αC-IN/OUT for BRAF protein. We have investigated particular aspects and difficulties with all three generations of inhibitors. Finally, this study has also covered recent developments in synthetic BRAF inhibitors (from their discovery in 2002 to 2022), their unique properties, and importance in inhibiting BRAF mutants.

Synthesis and fungicidal activity of novel pyrazole derivatives containing 5-Phenyl-2-Furan

Pyrazole constitutes an important heterocyclic family covering a broad range of synthetic as well as natural products that exhibit numerous chemical, biological, agrochemical and pharmacological properties. In order to explore compounds with good fungicidal activity, a series of new pyrazole derivatives containing 5-phenyl-2-furan were designed and synthesized. In vitro and in vivo fungicidal activities were evaluated and the compound ethyl-1-(5-phenylfuran-2-carbonyl)-5-propyl-1H-pyrazole-3-carboxylate (I8) displayed significant fungicidal activity against various fungi, especially against P. infestans. The structures of the novel pyrazole derivatives were confirmed by ¹H NMR, ¹³C NMR, MS, elemental analysis and X-ray single crystal diffraction. Further study showed that compound I8 might act on the synthesis of cell walls from morphological and ultrastructural studies by SEM and TEM. The results also revealed that compound I8 could block the nutritional transportation leading to cells senescence and death. These results suggested that the novel pyrazole derivatives proved to be promising lead compounds.

The crystal structure of 1-((5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-yl)methyl)-1,3-diphenylurea, C24H21ClN4O

C24H21ClN4O, monoclinic, P21/n (no. 14), a = 10.2630(11) Å, b = 17.8954(16) Å, c = 12.3517(14) Å, β = 102.510(11)°, V = 2214.7(4) Å3, Z = 4, R gt(F) = 0.0569, wR ref(F 2) = 0.1617, T = 293(2) K.

Simple assembly of polysubstituted pyrazoles and isoxazoles via ring closure–ring opening domino reaction of 3-acyl-4,5-dihydrofurans with hydrazines and hydroxylamine

A general approach to 2-(pyrazolyl-/isoxazolyl-)ethanols based on the Brønsted acid-initiated reaction of 3-acyl-4,5-dihydrofurans with hydrazines or hydroxylamine was developed.