Proanthocyanidins From The Plant Urceola Huaitingii And Their Preliminary Anticancer Effects In Combination With Chemotherapeutics

Urceola huaitingii(Chun & Tsiang), belonging to the family of Apocynaceae, is widely distributed in the southern and southwest regions of China. It has been usually used as folk medicine for treatment of hemiplegy and paralysis in Guangxi.In this paper, twelve proanthocyanidins(1-12) were obtained from the plant Urceola huaitingii by using various chromatographic methods including Diaion HP-20 macroporous adsorption resin, ODS, Toyopear HW-40 C column chromatographies and reversed phase high performance liquid chromatography(RP-HPLC) methods. The chemical structures of nine of them(1-9), including a new compound(9), were determined by combination of IR, UV,(HR)-ESI-MS, 1D-, 2D-NMR, and CD spectroscopic method with chemical derivatization. In addition, the absolute configuration of proanthocyanidins were discussed, which suggested that positive(35)? values at 245 nm in the CD spectrum can be applied to determine the absolute configuration of them. In order to study the relationship between the degrees of polymerization of proanthocyanidins and their bioactivity, the proanthocyanidin fraction from Urceola huaitingii was degradated by H2SO3 in acidic conditions. The anticancer activity of proanthocyanidins, including the crude extract, proanthocyanidinfraction, and pure compounds, were evaluated in combination with chemotherapeutics(Doxorubicin and Cisplatin). The results showed that some proanthocyanidin compounds exhibited synergistic anticancer effects with Doxorubicin and Cisplatin. These findings will be helpful to discovery of novel and less toxic strategies for cancer therapy.