Synthesis, stereochemical and biological studies of some N-cyclohexylcarbamoyl -2,6-diarylpiperidin-4-ones

Design, synthesis, pharmacological evaluation, and in silico studies of the activity of novel spiro pyrrolo[3,4-d]pyrimidine derivatives

In the present study, spiro compounds are shown to have distinctive characteristics because of their interesting conformations and their structural impacts on biological systems. A new family of functionalized spiro pyrrolo[3,4-d]pyrimidines is prepared via the one-pot condensation reaction of amino cyclohexane derivatives with benzaldehyde to prepare fused azaspiroundecanedione and azaspirodecenone/thione derivatives. A series of synthesized spiro compounds were scanned against DPPH and evaluated for their ability to inhibit COX-1 and COX-2. All compounds exhibit significant antiinflammatory activity, and they inhibited both COX-1 and COX-2 enzymes with a selectivity index higher than celecoxib as a reference drug. The most powerful and selective COX-2 inhibitor compounds were 11 and 6, with selectivity indices of 175 and 129.21 in comparison to 31.52 of the standard celecoxib. However, candidate 14 showed a very promising antiinflammatory activity with an IC50 of 6.00, while celecoxib had an IC50 of 14.50. Our findings are promising in the area of medicinal chemistry for further optimization of the newly designed and synthesized compounds regarding the discussed structure-activity relationship study (SAR), in order to obtain a superior antioxidant lead compound in the near future. All chemical structures of the novel synthesized candidates were unequivocally elucidated and confirmed utilizing spectroscopic and elemental investigations.

Synthesis, pharmacological evaluation, DFT calculation, and theoretical investigation of spirocyclohexane derivatives

Polycyclic structures fused at a central carbon are of great interest due to their appealing conformational features and their structural implications in biological systems. Although progress in the development of synthetic methodologies toward such structures has been impressive, the stereo selective construction of such quaternary stereo centers remains a significant challenge in the total synthesis of natural products. From the computational calculations by Density Functional Theory along with the B3LYP as basis set, It is obvious that the all studied compounds are soft molecules and η varied from 0.069 for compound (10) to 0.087 for compound (15), while the compound (14) is treated as hard molecule, the value of η is 0.102, also the electronic transition within the soft compounds is easy as indicated from the △E, the compound (10) is absolute soft according to the (σ = 14.49 eV), while the compound (14) is treated as hard compounds (σ = 9.804 eV). The newly formed compounds exhibited both anti-inflammatory and antioxidant activities on HRBC homolytic and membrane stabilization and DPPH scavenging percent, respectively.

Synthesis, crystal structure, DFT and molecular docking studies of N-acetyl-2,4-[diaryl-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4'-acetyl-2'-(acetylamino)-4',9-dihydro-[1',3',4']-thiadiazoles: A potential SARS-nCoV-2 Mpro (COVID-19) inhibitor

In this paper, we describe the synthesis and crystal structure analysis of N-acetyl-2,4-[diphenyl-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4′-acetyl-2′-(acetylamino)-4′,9-dihydro-[1′,3′,4′]-thiadiazole (3a) and N-acetyl- 2,4-[bis(p-methoxyphenyl)-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4′-acetyl-2′-(acetylamino)-4′,9-dihydro-[1′,3′,4′]-thiadiazole (3b). The title compounds 3a and 3b are characterized by 1D NMR and single crystal x-ray diffraction analysis. Non-covalent interactions in a molecule were identified by Hirshfeld surface (d_norm contacts and 2D fingerprint plot) analysis. In addition, the existence of chalcogen bond (S•••O bond) in the molecular structures (3a and 3b) are described by NCI-RDG and QTAIM analysis. NBO analysis is employed to describe the orbital interactions and electron transfer between sulfur and oxygen atoms. Molecular docking is carried out for compounds 3a and 3b with COVID-19 viral protein SARS-nCoV-2 M^pro (PDB ID: 6LU7).