Synthesis and Cytotoxic Properties of New Substituted Glycosides-Indole Conjugates as Apoptosis Inducers in Cancer Cells.

BACKGROUND & OBJECTIVE: Glycosyl heterocycles, being as nucleoside analogs with modified glycon and hybrid heterocycle motifs, are of considerable interest, and thus, the targeted compounds were synthesized via a convenient and efficient approach. METHODS: New indolyl-thiadiazolyl thioglycosides scaffolds were synthesized, starting with the reaction of indole-3-carbaldehyde with 2-aminothiadiazole-5-thiole followed by glycosylation and deprotection. Likewise, new molecular hybrids comprising indole, thiadiazole, triazole and glycosyl moieties were synthesized utilizing click chemistry strategy. The cytotoxic activities of the newly synthesized compounds were studied on colon carcinoma HCT116, breast carcinoma MCF-7, lung carcinoma A549 and hepatocellular carcinoma HepG2 cell lines using Sulphorhodamine-B (SRB) assay. RESULTS: The 1,3,4-thiadiazole thioglycoside and the 1,2,3-triazole N1-glycoside possessing xylose moiety, compounds 8 and 15 revealed the most potent bio-activity among the new chemical entities; therefore, they undertook for further analysis of apoptosis. CONCLUSION: IC50s of Compound 8 were 38, 36, 33 and 158µg/ml, while they were 41, 44, 32 and 25µg/ml for compound 15 on HepG2, MCF7, HCT116 and A549 cell lines, respectively; furthermore, the total apoptosis rate (%) for control untreated cells were 9.63, 28.4, 25.4 (%), compounds 8 and 15 respectively, they produced a significant increase in total and early apoptosis rate (%) compared to control (P=0.0001). At the same time, no significant difference was detected in the late apoptosis rate (%), which means that both derivatives have the potential to be developed into potent anticancer agents.

New benzenesulfonamide scaffold-based cytotoxic agents: Design, synthesis, cell viability, apoptotic activity and radioactive tracing studies.

A new series of thiazolidinone (5a-g), thiazinone (9a-g) and dithiazepinone (9a-g) heterocycles bearing a benzenesulfonamide scaffold was synthesized. Cytotoxicity of these derivatives was assessed against MCF-7, HepG2, HCT-116 and A549 cancer cell lines and activity was compared to the known cytotoxic agents doxorubicin and 5-FU where the most active compounds displayed better to nearly similar IC50 values to the reference compounds. For assessing selectivity, the most active derivatives against MCF-7, 5b, 5c and 5e, were also assessed against the normal breast cell line MCF-10 A where they demonstrated high selective cytotoxicity to cancerous cells over that to normal cells. Further, the effect of the most active compounds 5b-e on MCF-7 and HepG2 cell cycle phase distribution was assessed and the tested sulfonamide derivatives were found to induce accumulation of cells in the <2n phase. To further confirm apoptosis induction, caspase 8 and 9 levels in MCF-7 and HepG2 were evaluated before and after treatment with compounds 5b-e and were found to be significantly higher after exposure to the test agents. Since 5c was the most active, its effect on the cell cycle regulation was confirmed where it showed inhibition of the CDK2/cyclin E1. Finally, in vivo biodistribution study using radioiodinated-5c revealed a significant uptake and targeting ability into solid tumor in a xenograft mouse model.