Concise Synthesis of 5-Methoxy-6-hydroxy-2-methyichromone-7-O- and 5-Hydroxy-2-methyichromone-7-O-rutinosides. Investigation of Their Cytotoxic Activities against Several Human Tumor Cell Lines

The synthesis of two novel 2-methylchromone-7-O-rutinosides is reported, and the in vitro biological activities of these compounds and their synthetic precursors have been investigated on the basis of their cytotoxicity against several human tumor cell lines. The synthesis features early stage assembly of the acidic labile glycosidic bond between sugar and 2-methylchromone aglycon under phase transfer catalyzed glycosidation conditions, whereas all the other standard glycosylation conditions specific to a wide array of rutinosyl donors bearing different anomeric leaving groups (e.g., SPh, OC(NH)CCl3, Br, OH groups) failed to furnish any detectable products.