Synthesis, characterization and inhibitory effects of crocetin derivative compounds in cancer and inflammation

Abstract Crocetin is a natural product possessing extraordinary therapeutic effects for various diseases. However, its extremely low solubility limits its application greatly. Conjugation of organic compounds containing heteroatoms such as N to poor soluble molecules can help the synthesized derivative to form stable hydrogen bonds by lowering the salvation energy, which will improve the solubility of the synthesized compounds. Herein, crocetin was modified by conjugating with piperidyl, diethylin and benzylamine to improve their solubility and bioactivities. In the present study, the conjugation of crocetin with piperidyl, diethylin and benzylamine and their influence on the solubility and the pharmacological effects of crocetin were investigated. With the described strategy, crocetin derivatives were synthesized and their structures were elucidated by 1 H NMR, 13 C NMR and UPLC-MS spectroscopic analysis. The solubility of crocetin and its derivatives were identified. Upon that, the pharmacological effects of the crocetin derivatives on the tumor and inflammation treatment were investigated. It was shown that, in contrast to crocetin, of which, the solubility and pharmacological effects were low and limited, the synthesized compounds have significantly higher solubility and possess broad spectrum of anticancer effects in multiple tumor cell lines, including B16F10, MCF-7, A549 and SKOV3, as well as enhanced anti-inflammation efficacy in macrophage (RAW264.7) without causing cells damage. Conjugation of piperidyl, diethylin and benzylamine with the crocetin was demonstrated to be a highly efficient strategy to improve the solubility of crocetin. The synthesized crocetin derivatives were shown the promising therapeutics for the tumor and inflammation treatment with high safety.