Novel thienopyrimidine-aminothiazole hybrids: Design, synthesis, antimicrobial screening, anticancer activity, effects on cell cycle profile, caspase-3 mediated apoptosis and VEGFR-2 inhibition

A series of novel hybrid compounds of hexahydrobenzo[4,5]thieno[2,3-d]pyrimidine with aminothiazole scaffolds were synthesized. The synthesized compounds were evaluated for their cytotoxic activity against the NCI-60 human tumor cell line panel. Compounds 7c, 7d and 7e exhibited significant antiproliferative activities at 10^-5 M dose. Compound 7c exhibited excellent cytotoxic activity against CNS cancer cell lines including SNB-75 and SF-295 as well as renal cancer cell line CAKI-1 when compared with sorafenib as standard anticancer drug. In addition, compound 7d showed almost comparable anticancer activity to sorafenib against SNB-75 cell line and displayed moderate activity against SF-295 and CAKI-1 cell lines in comparison to sorafenib. Compound 7c inhibited the vascular endothelial growth factor receptor 2 (VEGFR-2) with IC₅₀ of 62.48 ± 3.7 nM and decreased both total VEGFR-2 and phosphorylated VEGFR-2 in treated SNB-75 cells suggesting its ability to down regulate cell proliferation, growth, and survival.. The flow cytometric analysis showed that 7c displayed its cytotoxic activity through the reduction of the cellular proliferation and induction of cell cycle arrest at the G2/M phase. Compound 7c clearly boosted the level of the apoptotic caspase-3. All the synthesized compounds were also screened for their antibacterial and antifungal activity against four pathogenic strains of both Gram-positive and Gram-negative as well as Candida albicans. Only compound 7d exhibited antifungal activity against Candida albicans compared to nystatin as the standard antifungal compound.

Synthesis of Novel Biocompatible Thienopyrimidine Chromophores with Aggregation-Induced Emission Sensitive to Molecular Aggregation

Biocompatible luminogens with aggregation-induced emission (AIE) have several applications in the biology field, such as in detecting biomacromolecules bioprobes and in bio-imaging. Due to their bioactivities and light-emitting properties, many heterocyclic compounds are good candidates for such applications. However, heterocyclic π-conjugated systems with AIE behavior remain rare as strong intermolecular π-π interactions usually quench their emission. In this work, new thienopyrimidine heterocyclic compounds were synthesized and their structures were verified by elemental analysis and Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (NMR), and 13C NMR spectra. The photophysical properties of some compounds were investigated in the solution and solid states. Density functional theory calculations were also performed to confirm the observed photophysical properties of the compounds. The studied dyes displayed AIE properties with spectral shapes related to the aggregate structure and a quantum yield up to 10.8%. The emission efficiency of the powder is attributed to the incorporation of multiply rotatable and twisted aryl groups to the fused heterocyclic moieties. The dyes also showed high thermal stability and potent antimicrobial activities against numerous bacterial and fungal strains. Additionally, the cytotoxicity of the new compounds was evaluated against the Caco-2 cell line, and molecular docking was used to investigate the binding conformation of the most effective compound with the MNK2 enzyme. Therefore, the presented structures may potentially be used for bioapplications.

Synthesis and Antibacterial Activities of Different Five-Membered Heterocyclic Rings Incorporated with Pyridothienopyrimidine

Certain pyridothienopyrimidine derivatives exhibit antiatheroscleorotic, antibacterial, antiviral, antidepressant, antidiabetic, antihypertensive, anticancer, antihistaminic, antiallergic, anti-inflammatory, spasmolytic, analgesic, and neurotropic activities. 4-Hydrazino-7,9-dimethylpyrido[3',2':4,5]thieno[3,2-d]pyrimidine (1) is a reported pyridothienopyrimidine derivative. In the current study, (1) has been reacted with different reagents to obtain 12 new pyridothienopyrimidine derivatives. The newly synthesized five-membered heterocyclic rings incorporated with pyridothienopyrimidines have been screened for their antibacterial activities. The results encourage further studies on other possible biological activities.