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The chemical investigation of the aerial part of Abrus canescens led to isolation of a new triterpenoid glycoside named Canescensoside ( 1 ) and four known compounds including longispinogenin-3- O - β -D-glucuronopyranoside ( 2 ), β -sitosterol-3- O - β -D-glucoside ( 3 ), apigenin-7- O - β -D-glucopyranoside ( 4 ) and apigenin-7- O -[ α -L-rhamnopyranosyl-(1→3)- β -D-glucopyranoside] ( 5 ). Structures of compounds were assigned by interpretation of their spectral data, mainly 1D and 2D NMR, HRESIMS, and by comparison with the reported data. The MeOH extract, EtOAc and n -BuOH fractions as well as isolated compounds were tested for their antibacterial activities against four bacteria strains among which, two Gram-negative ( Pseudomonas aeruginosa ATCC 76110 and Escherichia coli ATCC 8739) and two Gram-positive ( Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 25923) bacteria using the broth microdilution method. The MeOH extract and EtOAc fraction exhibited significant activities (MIC values ranging from 128 to 512  μ g/mL) against all the tested bacteria. Compounds 2 and 3 showed the lowest MIC values of 55.47 and 50.40  µ M, respectively.

Two new Cobalt(II) complexes 12 and 13 have been synthesized from 2-[(E)-(3-acetyl-4-hydroxyphenyl)diazenyl]-4-(2-hydroxyphenyl)thiophene-3-carboxylic acid (11) as a novel ligand. These three new compounds were characterized on the basis of their powder X-Ray Diffraction, UV-Vis, IR, NMR, elemental analysis and MS spectral data. DFT/B3LYP mode of calculations were carried out to determine some theorical parameters of the molecular structure of the ligand. The purity of the azoic ligand and the metal complexes were ascertained by TLC and melting points. The analysis of the IR spectra of the polyfunctionalized azo compound 11 and its metal complexes 12 and 13, reveals that the coordination patterns of the ligand are hexadentate and tetradentate respectively. Based on the UV-Vis electronic spectral data and relevant literature reports, the ligand and derived complexes were assigned the E (trans) isomer form. Likewise, octahedral and square-planar geometries were respectively assigned to the cobalt(II) complexes. The broth microdilution method was used for antibacterial assays through the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The ligand 11 displayed moderate antibacterial activity (MIC = 32-128 μg/mL) against Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa and Klebsiella pneumoniae 22. The octahedral cobalt(II) complex 12 showed moderate activity against Pseudomonas aeruginosa (MIC = 128 μg/mL) and Klebsiella pneumoniae 22 (MIC = 64 μg/mL) and none against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922, whereas the square-planar complex 13 displayed moderate activity only on Klebsiella pneumoniae 22 (MIC = 64 μg/mL)., (© 2024. The Author(s).)