Selenyl Derivatives of Polysaccharide from Tithonia diversifolia (Hemsley) A. Gray and their Cytotoxicity

Abstract

In this work, a polysaccharide from Tithonia diversifolia (TDP) was extracted and selenized to obtain Se-TDPs derivatives. Structural properties of TDP and Se-TDPs were characterized using HPLC, NMR, AAS, GPC, FT-IR, and ESI-MS. TDP was determined to be a pectic polysaccharide with branched arabinan in the side chains. The FT-IR and MS spectra indicated new peaks on the Se-TDPs spectra in comparison to that of TDP. Moreover, MS spectra suggested that selenyl groups were substituted on the backbone of TDP molecules instead of the side chains. Selenized-TDP (Se-TDP) samples exhibited significant cytotoxicity on human gastric cancer cells MKN7, and increasing selenium content enhanced the cytotoxicity of TDP. Therefore, Se-TDP derivatives can be regarded as a potential source of bioactive compounds for pharmaceutical applications.