Alkaloids from Sophora flavescens Aition.

Although the quinolizidine alkaloids and flavonoids, the main active components of the traditional Chinese medicine Sophora flavescens, have been largely investigated, a new matrine alkaloid derivative 9alpha-hydroxy-7,11-dehydromatrine (1) and a rare 1,4-diazaindan-type alkaloid flavascensine (17), together with 15 known alkaloids, were isolated from S. flavescens. The structures were established on the basis of spectroscopic techniques.

2-(4-Methoxyphenoxy)-6-methyl-3-oxo-3,6-dihydro-2H-pyran-4-yl benzoate.

The title compound, C(20)H(18)O(6), has been synthesized from 4-methoxy-phenyl 3-O-benzo-yloxy-α-l-rhamnopyran-oside by oxidation on treatment with pyridinium dichromate in the presence of acetic anhydride. In the mol-ecule, the pyran ring adopts an envelope conformation with the O atom at the flap position. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.