Isolation and characterisation of flavonoids from the leaves of medicinal plant Orthosiphon stamineus

Six flavonoid compounds were isolated from the leaves of the medicinal plant Orthosiphon stamineus. On the basis of chemical and spectral analyses their structures were elucidated as eupatorin, sinensetin, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone, salvigenin, 6-hydroxy-5,7,4′-trimethoxyflavone and 5,6,7,3′-tetramethoxy-4′-hydroxy-8-C-prenylflavone. The last compound was isolated from this plant for the first time.