Crystal engineering of exemestane to obtain a co-crystal with enhanced urease inhibition activity

Co-crystallization is a phenomenon widely employed to enhance the physio-chemical and biological properties of active pharmaceutical ingredients (APIs). Exemestane, or 6-methylideneandrosta-1,4-diene-3,17-dione, is an anabolic steroid used as an irreversible steroidal aromatase inhibitor, which is in clinical use to treat breast cancer. The present study deals with the synthesis of co-crystals of exemestane with thiourea by liquid-assisted grinding. The purity and homogeneity of the exemestane–thiourea (1:1) co-crystal were confirmed by single-crystal X-ray diffraction followed by thermal stability analysis on the basis of differential scanning calorimetry and thermogravimetric analysis. Detailed geometric analysis of the co-crystal demonstrated that a 1:1 co-crystal stoichiometry is sustained by N—H...O hydrogen bonding between the amine (NH2) groups of thiourea and the carbonyl group of exemestane. The synthesized co-crystal exhibited potent urease inhibition activity in vitro (IC50 = 3.86 ± 0.31 µg ml−1) compared with the API (exemestane), which was found to be inactive, and the co-former (thiourea) (IC50 = 21.0 ± 1.25 µg ml−1), which is also an established tested standard for urease inhibition assays in vitro. The promising results of the present study highlight the significance of co-crystallization as a crystal engineering tool to improve the efficacy of pharmaceutical ingredients. Furthermore, the role of various hydrogen bonds in the crystal stability is successfully analysed quantitatively using Hirshfeld surface analysis.

Symmetrical Heterocyclic Cage Skeleton: Synthesis, Urease Inhibition Activity, Kinetic Mechanistic Insight, and Molecular Docking Analyses

The present study focuses on the design and synthesis of a cage-like organic skeleton containing two triazole rings jointed via imine linkage. These molecules can act as urease inhibitors. The in-vitro urease inhibition screening results showed that the combination of the two triazole skeleton in the cage-like morphology exhibited comparable urease inhibition activity to that of the reference thiourea while the metallic complexation, especially with copper, nickel, and palladium, showed excellent activity results with IC50 values of 0.94 ± 0.13, 3.71 ± 0.61, and 7.64 ± 1.21 (3a–c), and 1.20 ± 0.52, 3.93 ± 0.45, and 12.87 ± 2.11 µM (4a–c). However, the rest of compounds among the targeted series exhibited a low to moderate enzyme inhibition potential. To better understand the compounds’ underlying mechanisms of the inhibitory effect (3a and 4a) and their most active metal complexes (3b and 4b), we performed an enzymatic kinetic analysis using the Lineweaver–Burk plot in the presence of different concentrations of inhibitors to represent the non-competitive inhibition nature of the compounds, 3a, 4a, and 4b, while mixed type inhibition was represented by the compound, 3b. Moreover, molecular docking confirmed the binding interactive behavior of 3a within the active site of the target protein.

New bioactive triaryl triglyceride esters: Synthesis, characterization and biological activities

<p class="Abstract">Four new bioactive aryl triester derivatives of glycerol and benzoic acids were synthesized. The synthetic compounds were studied for their antimicrobial and urease inhibition activities. Esterification was carried out by using carbonyldiimidazole to enhance the acyl elimination addition reaction with benzoic acid derivatives. The structure of triglycerides were studied by EI-MS, ¹H, ¹³C-NMR, FT-IR and elemental analysis. All synthetic compounds showed urease inhibition activity with highest value of IC₅₀value 22.4 ± 0.45 μM which is nearest to standard thiourea IC₅₀value (21.6 ± 0.12 μM). Except compound (3d), all other compounds exhibited antimicrobial activity against <em>Streptococcus pneumoniae, Staphylococcus epidermidis, Bacillus pumilus, Escherichia coli, Pseudomonas aeruginosa</em> and <em>Candida albican</em>.</p><p><strong>Video Clip of Methodology:</strong></p><p>7 min 59 sec <a href="https://youtube.com/v/PvGTYUxO7-4">Full Screen</a> <a href="https://youtube.com/watch?v=PvGTYUxO7-4">Alternate</a> </p>

Smart urea ionic co-crystals with enhanced urease inhibition activity for improved nitrogen cycle management

A smart ionic co-crystal of urea with KCl and ZnCl2, obtainedviamechanochemical and solution methods has been proven to be a very efficient urease inhibitor and to provide soil nutrients to complement N supply.

Synthesis, spectroscopic characterization and pharmacological evaluation of oxazolone derivatives

A series of 4-aryl methylidene-2-phenyl/methyl-5-(4H)-oxazolone derivatives (2-7) have been synthesized using the reported method by condensation of aldehydes with N-benzoyl / N-acetyl glycine in the presence of zinc oxide as a catalyst and acetic anhydride at room temperature in ethanol. The compounds (2-6) are new derivatives. The structures of compounds were evaluated on the basis of 1H-NMR, 13C-NMR, EIMS, FT-IR and elemental analysis. All the compounds were screened for their antibacterial and urease inhibition activity. Antibacterial activity was tested by agar well diffusion method using Mueller Hinton Agar medium. Compound (2) showed excellent activity against S. aureus which has 16 mm (80%) inhibition and above 24 mm (70%) against S. typhi. The most active compound against E. coli was compound (6) having 20 mm (80%) inhibition followed by compound (5) having above 18 mm (70%) inhibition. Urease inhibition activity of all the compounds was determined by indophenol method. Compounds (3, 6) and (7) showed significant inhibition against Jacks bean urease.