Novel Thioether-Bridged 2,6-Disubstituted and 2,5,6-Trisubstituted Imidazothiadiazole Analogues: Synthesis, Antiproliferative Activity, ADME, and Molecular Docking Studies.

In this study, starting from 2-amino-1,3,4-thiadiazole derivatives (3-5), a new series of 2,6-disubstituted (compounds 7-15) and 2,5,6-trisubstituted (compounds 16-33) imidazo[2,1-b][1,3,4]-thiadiazole derivatives were synthesized using cyclization and Mannich reaction mechanisms, respectively. All synthesized compounds were characterized by 1 H-NMR, 13 C-NMR, FT-IR, elemental analysis, and mass spectroscopy techniques. Also, X-ray diffraction analysis were used for compounds 4, 7, 11, 17, and 19. The cytotoxic effects of the new compounds on the viability of colon cancer cells (DLD-1), lung cancer cells (A549), and liver cancer cells (HepG2) were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method in vitro. Compound 15 was found to be the most potent anticancer drug candidate in this series with an IC50 value of 3.63 µM against HepG2 for 48 h. Moreover, the absorption, distribution, metabolism, and excretion (ADME) parameters of the synthesized compounds were calculated and thus, their potential to be safe drugs was evaluated. Finally, to support the biological activity experiments, molecular docking studies of these compounds were carried out on three different target cancer protein structures (PDB IDs: 5ETY, 1M17, and 3GCW), and the amino acids that play key roles in the binding of the compounds to these proteins were determined.

1-{2-Benz-yloxy-2-[4-(morpholin-4-yl)phen-yl]eth-yl}-1H-benzimidazole.

In the title compound, C26H27N3O2, the morpholine ring adopts a chair conformation. The benzene and phenyl rings are inclined to the benzimidazole mean plane by 7.28 (6) and 61.45 (4)°, respectively. In the crystal, pairs of weak C-H⋯O hydrogen bonds link the mol-ecules into inversion dimers. These dimers are further connected via weak C-H⋯N hydrogen bonds. A weak C-H⋯π inter-action is also observed.

1-{2-(4-Chloro-benz-yloxy)-2-[4-(mor-pho-lin-4-yl)phen-yl]eth-yl}-1H-benzimidazole propan-2-ol monosolvate.

In the title compound, C26H26ClN3O2·C3H7OH, the benzimid-azole ring system is essentially planar [maximum deviation = -0.018 (2) Å] and its mean plane is oriented with respect to the two benzene rings at dihedral angles of 4.51 (6) and 56.16 (6)°, and the dihedral angle between the two benzene rings is 59.11 (7)°. The morpholine ring displays a chair conformation. The propan-2-ol solvent mol-ecule links with the benzimidazole ring via an O-H⋯N hydrogen bond. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into inversion dimers with an R 2 (2)(28) motif. π-π stacking occurs between the parallel chloro-benzene rings [centroid-centroid distance = 3.792 (1) Å]. Weak C-H⋯π inter-actions and short Cl⋯Cl [3.2037 (10) Å] contacts are also observed.

2-(1H-Benzotriazol-1-yl)-3-(2,6-dichloro-phen-yl)-1-phenyl-propan-1-ol.

The asymmetric unit of the title compound, C(21)H(17)Cl(2)N(3)O, contains two crystallographically independent mol-ecules with similar conformations. The benzotriazole ring is oriented at dihedral angles of 30.61 (5) and 43.36 (5)°, respectively, to the phenyl and dichloro-phenyl rings in one mol-ecule, and 32.25 (5) and 41.04 (5)° in the other. The dihedral angles between the phenyl and dichloro-phenyl rings are 66.38 (7) and 66.14 (6)° in the two mol-ecules. An intra-molecular O-H⋯N hydrogen bond links the benzotriazole ring and phenyl-propanol unit in each mol-ecule. In the crystal, weak inter-molecular C-H⋯N hydrogen bonds link the mol-ecules into chains along the a axis. π-π stacking between the dichloro-phenyl rings [centroid-centroid distances = 3.809 (1) and 3.735 (1) Å] may further stabilize the crystal structure.

A novel glycoside from Acanthus hirsutus (Acanthaceae).

A novel glycoside, hirsutusoide (1), characterized as 2-(o-hydroxyphenyl)-2-hydroxyethenyl-O-beta-glucopyranoside, was isolated from the endemic Acanthus hirsutus Boiss. In addition to compound 1, three known glycosides, luteolin-7-O-beta-D-glucuronide (2), beta-sitosterol-3-O-beta-D-glucopyranoside (3) and (2R)-2-O-beta-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (4), were also isolated. Compound 2 was the first report from this genus. Antimicrobial and antioxidant activity of the extracts and the novel compound were investigated by determining MIC (microg/mL) and IC50 (microg/mL) values, respectively.