Synthesis and Characterization of Plumbagin S-Allyl Cysteine Ester: Determination of Anticancer Activity In Silico and In Vitro

Abstract

In recent years, derivatives of natural compounds are synthesized to increase the bioavailability, pharmacology, and pharmacokinetics properties. The naphthoquinone, plumbagin (PLU), is well known for its anticancer activity. However, the clinical use of PLU is hindered due to its toxicity. Previous reports have shown that modification of PLU at 5'-hydroxyl group has reduced its toxicity towards normal cell line. In accordance, in the present study, 5'-hydroxyl group of PLU was esterified with S-allyl cysteine (SAC) to obtain PLU-SAC ester. The drug-likeness of PLU-SAC was understood by in silico ADME analysis. PLU-SAC was characterized by UV-visible spectroscopy, mass spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Molecular docking and dynamics simulation analysis revealed the interaction of PLU-SAC with proteins of interest in cancer therapy such as human estrogen receptor α, tumor protein p53 negative regulator mouse double minute 2, and cyclin-dependent kinase 2. MMGBSA calculation showed the favorable binding energy which in turn demonstrated the stable binding of PLU-SAC with these proteins. PLU-SAC showed apoptosis in breast cancer cell line (MCF-7) by inducing oxidative stress, disturbing mitochondrial function, arresting cells at G1 phase of cell cycle, and initiating DNA fragmentation. However, PLU-SAC did not show toxicity towards normal Vero cell line. PLU-SAC was synthesized and structurally characterized, and its anticancer activity was determined by in silico and in vitro analysis.