Synthesis of Thieno[2,3-b]thiophene Containing Bis-Heterocycles-Novel Pharmacophores

Thioenethiophene derivatives represent an important class of compounds with diverse biological activities. We describe here the synthesis of a new series of thieno[2,3-b]thiophene containing bis-heterocyclic compounds 3–7. All the compounds were evaluated for their in vitro antioxidant potential, α-glucosidase and β-glucuronidase inhibiton and anticancer activity against PC-3 cell lines. Compounds 2b (IC(50) = 1.3 ± 0.2 μM), 5a (IC(50) = 2.3 ± 0.4 μM) and 5b (IC(50) = 8.7 ± 0.1 μM) showed a potent inhibition of β-glucuronidase enzyme, more active than the standard d-saccharic acid 1,4-lactone (IC(50) = 45.8 ± 2.5 μM). Compounds 5a (IC(50) = 22.0 ± 0.3 μM) and 5b (IC(50) = 58.4 ± 1.2 μM) were also found to be potent α-glucosidase inhibitors as compared to standard drug (acarbose, IC(50) = 841 ± 1.7 μM).