Synthesis of Novel Anticancer Drugs Derived from 4‐nitrobenzaldehyde, and Investigation of Responsive Drug Delivery Systems Based on Carbon Quantum Dots

The present work describes the synthesis two novel derivatives of 4‐nitrobenzaldehyde through a single pot microwave assisted green synthetic method and the characterization of the synthesized drugs using UV, IR,1HNMR, Mass spectra and CHN analysis. The structure optimization of the synthesized anticancer agents was carried out using Gaussian 9. Also carbon quantum dots (CQDs) derived from amino acid precursors were synthesized (Cystine and threonine) by microwave assisted method, followed by the integration of CQDS together with 4‐nitrobenzaldehyde and its novel derivatives. The drugs were subjected to targeted drug delivery applications in cancer cell lines (PC3) The MTT assay results revealed that the CQDs conjugated with 4‐nitrobenzaldehye (D1) and one of the derivatives (D3) exhibited greater cytotoxic effects on PC3 cells compared to L929 cells. The outcomes demonstrated that this novel derivative could kill cancer cells as effectively as 4‐nitrobenzaldehyde conjugated with CQDs. Also, the potential cytotoxicity of drugs D1 and D3 were further confirmed by the apoptosis assay using flow cytometry, which also explains that apoptosis is the mechanism underlying cell death in PC3 cancer cells. The autofluorescence test were also carried out in PC3 cells lines and the drugs D1 and D3 showed significant autofluorescence in PE−A (29.9 % and 34.7 %), in Alexa Fluor‐488 (32.6 % and61.1 %) and in Bv510‐A (16.6 % and 23.2 %) respectively. Thus, the synergistic effect of CQDs together with 4‐nitrobenzaldehyde and its derivative drug D3 are indeed a promising medication towards the localized drug delivery applications in prostate cancer cells as well as the autofluorescence results will explore novel arenas in bioimaging applications. The present work involved the synthesis of two novel anti‐cancer drugs derived from a known anticancer drug 4‐nitrobenzaldehyde and a novel drug delivery system based on Carbon quantum dots derived from amino acids, which are hydrophilic and less cytotoxic. The MTT assay results revealed that the CQDs integrated 4‐ nitro benzaldehye (D1) and one of the derivatives (D3) exhibited greater cytotoxic effects on PC3 cells compared to L929 cells and the novel derivative D3 was able to kill the cancer cells as effectively as 4‐nitrobenzaldehyde conjugated with CQDs. The mechanism leading to cell death was identified to be apoptosis in PC3 cancer cell line and the drugs D1 and D3 conjugated with carbon quantum dots were identified as promi