2-Aminothiazole-Oxadiazole Bearing N-Arylated Butanamides: Convergent Synthesis, Tyrosinase Inhibition, Kinetics, Structure-Activity Relationship, and Binding Conformations.

A multi-step synthesis of novel bi-heterocyclic N-arylated butanamides was consummated through a convergent strategy and the structures of these medicinal scaffolds, 7a-h, were corroborated using spectral techniques. The in vitro analysis of these hybrid molecules revealed their potent tyrosinase inhibition as compared to the standard used. The kinetics mechanism was investigated through Lineweaver-Burk plots which exposed that, 7f, inhibited tyrosinase enzyme non-competitively by forming the enzyme-inhibitor complex. The inhibition constants Ki calculated from Dixon plots for this compound was 0.025 µM. Their binding conformations were ascertained by in silico computational studies whereby these molecules disclosed good binding energy values (kcal/mol). So, it was anticipated from the current research that these bi-heterocyclic butanamides might be probed as imperative therapeutic agents for melanogenesis.

Synthesis of novel N-(1,3-thiazol-2-yl)benzamide clubbed oxadiazole scaffolds: Urease inhibition, Lipinski rule and molecular docking analyses.

Present work aimed to synthesize some unique bi-heterocyclic benzamides as lead compounds for the in vitro inhibition of urease enzyme, followed by in silico studies. These targeted benzamides were synthesized in good yields through a multi-step protocol and their structures were confirmed by IR, 1H NMR, 13C NMR, EI-MS and elemental analysis. The in vitro screening results showed that most of the ligands exhibited good inhibitory potentials against the urease. Chemo-informatics analysis envisaged that all these compounds obeyed the Lipinski's rule. Molecular docking results showed that 7h exhibited good binding energy value (-8.40 kcal/mol) and was bound within the active region of urease enzyme. From the present investigation, it was inferred that some of these potent urease inhibitors might serve as novel templates in drug designing.

Synthesis and exploration of a novel chlorobenzylated 2-aminothiazole-phenyltriazole hybrid as migratory inhibitor of B16F10 in melanoma cells.

In the study presented here, a novel chlorobenzylated bi-heterocyclic hybrid molecule (7) was synthesized and its structural confirmation was carried out by IR, 1H-NMR, 13C-NMR and CHN analysis data. This compound 7 was subjected to biological study with B16F10 mouse melanoma cells. The anti-proliferative results showed that 7 showed no significant toxicity at concentrations ranging of 0-44 µM. The treatment of B16F10 cells with 7 at aforementioned concentration range indicated that migration of cells was significantly lower than that of the control cells in a dose dependent manner. The possible migration inhibitory effect of these melanoma cells was further evaluated through gelatinolytic activity of MMP-2 and MMP-9 secreted from B16F10 cells. It was inferred from our results that 7 was not affecting the expression and activity of these enzymes. Some other zinc-dependent matrix metalloproteinases (MMPs) were involved in the inhibitory progression. Taken together, compound 7 inhibited migrations of B16F10 mouse melanoma cells. Therefore, it may deserve consideration as a potential agent for the treatment of cancer.

Structure determination of bioactive galloyl derivatives by NMR spectroscopy.

The investigation of the chemical constituents of Symplocos racemosa Roxb led to the isolation of two new glycosides, symcomoside A (1) and symcomoside B (2), together with one known glycoside, tortoside C (3), which is reported for the first time from this plant. The structures of the new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy, from chemical evidence and by comparison with published data for closely related compounds. Symcomoside B (2) showed potent inhibitory activity against alpha-glucosidase in a concentration-dependent fashion with an IC50 value of 0.733 +/- 0.033 mM whereas symcomoside A (1) showed very weak inhibitory activity against alpha-glucosidase (9.90% in 0.70 mM).