Rapid preparative isolation of cleistanthin A from the leaves of Cleistanthus collinus Using reverse-phase flash chromatography

Introduction: Cleistanthin A (CA) is an aryl naphthalene lignan, which has a potent anticancer activity by regulating the tumor microenvironment. The objective was to develop a new technique for the isolation of cleistanthin A from the acetone extract of Cleistanthus collinus utilizing reverse phase flash chromatography. Materials and Methods: Cleistanthus collinus leaves were shade dried, defatted using n-hexane and then macerated to obtain acetone extract which was further subjected to reverse phase flash chromatography for the isolation of cleistanthin A using the gradient mobile phase of 0.1% formic acid (v/v) in water and acetonitrile. Gradient elution of chromatographic run was performed for 80 min. The separated peaks that showed absorbance at λmax 254 nm were collected for the chemical characterization. Cell viability of the isolated cleistanthin A was studied on hepatocellular cancer cell line HePG2 and prostate cancer cell line PC3 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The chemical characteristics of the isolated compound cleistanthin A was further characterized using spectral techniques such as 1H and 13C nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), and electron spray ionization-tandem mass spectrometry (ESI-MS/MS). Cleistanthin A has decreased the cell viability of the HePG2 cell line to 52.25% at 32 μg/ml and PC3 cell line to 51.82% at 16 μg/ml in a dose-dependent manner. Conclusion: Cleistanthin A was successfully isolated from the natural source using reverse phase flash chromatography and the MTT assay has shown that cleistanthin A has decreased the cell viability in both the HePG2 and PC3 cell lines in a dose-dependent manner.