Phthalimido thioureas with high antimicrobial performance as stabilizers for enhancement of the thermal stability of poly(vinyl chloride) loaded with multi‐walled carbon nanotubes

Design and synthesis of novel multi-target tetrabromophthalimides as CBS and Topo-II inhibitors and DNA intercalators

Microtubules are highly dynamic structures and constitute a crucial component of the cellular cytoskeleton. Besides, topoisomerases (Topo) play a fundamental role in maintaining the appropriate structure and organization of DNA. On the other hand, dual mechanism drug candidates for cancer treatment primarily aim to enhance the efficacy of cancer treatment and potentially overcome drug resistance. Hence, this work was tailored to design and synthesize new multi-target tetrabromophthalimide derivatives (2a-2k) that are capable of inhibiting the colchicine binding site (CBS) and topoisomerase II (Topo-II). The conducted in vitro studies showed that compound 2f showed the lowest IC50 value (6.7 μg mL-1) against the MDA-MB-468 cancer cell line. Additionally, compound 2f prompted upregulation of pro-apoptotic markers (caspases 3, 7, 8, and 9, Bax and p53). Moreover, some anti-apoptotic proteins (MMP2, MMP9, and BCL-2) were downregulated by compound 2f treatment. Besides, the colchicine binding assay showed that compounds 2f and 2k displayed promising inhibitory potential with IC50 values of 1.92 and 4.84 μg mL-1, respectively, in comparison with colchicine (1.55 μg mL-1). Furthermore, the Topo-II inhibition assay displayed the prominent inhibitory potential of compound 2f with an IC50 value of 15.75 μg mL-1, surpassing the IC50 of etoposide (20.82 μg mL-1). Cell cycle analysis revealed that compound 2f induced cell cycle arrest at both the G0-G1 and G2-M phases. The new candidates were docked against both the CBS (PDB ID: 5XIW) and Topo-II (PDB ID: 5CDP) targets to investigate their binding interactions and affinities as well. Accordingly, the synthesized compounds could serve as promising multi-target anticancer candidates with eligible apoptotic activity.

Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the β-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

Synthesis, characterization, anti-inflammatory and anti-Helicobacter pylori activities of novel benzophenone tetracarboxylimide benzoyl thiourea cross-linked chitosan hydrogels

Chitosan (Cs) was cross-linked with four various quantities of 4,4'-(5,5'‑carbonylbis(1,3-dioxoisoindoline-5,2-diyl))dibenzoyl isothiocyanate. Elemental analysis, FTIR and ¹H NMR spectroscopy assured that the amino groups of chitosan reacted with the isothiocyanate groups of the cross-linker producing four new hydrogels namely as BBTU-Cs-1, BBTU-Cs-2, BBTU-Cs-3, and BBTU-Cs-4 according to the increment of their cross-linking content, respectively. SEM showed their porous structures and XRD indicated their amorphous nature. Their swell ability increased with decreasing the medium pH value and with increasing cross-linking density. In comparison with the popular COX inhibitor Celecoxib, these hydrogels showed an inhibition activity towards COX enzymes with selective inhibition towards COX-2. Their inhibition activity could be arranged as follows: Celecoxib > BBTU-Cs-4 > BBTU-Cs-3 > BBTU-Cs-2 > BBTU-Cs-1. BBTU-CS-4 hydrogel exhibited a potent inhibition against COX-2 (IC₅₀ 0.42 μg/ml) compared with that observed for the standard Celecoxib (IC₅₀ 0.26 μg/ml). BBTU-Cs-4 is more potent against H. pylori compared to the other hydrogels. BBTU-Cs-4 at a concentration of 7.81 μg/ml is able to kill 100% of the H. pylori and exhibits a preferential ability to inhibit 89.35% of COX-2 than COX-1 (0%). These findings make BBTU-Cs-4 a promising anti-H. pylori and selective anti-inflammatory agent.