Abstract:

The uniform design method was applied to optimize the extraction of flavonoids from blackberry leaves and
the composition of flavonoids in blackberry leaf extracts was analyzed by HPLC. The optimum extraction conditions for
ethanol concentration, temperature, solid-to-solvent ratio and number of repeated extractions were 65%, 85 ℃, 1:30 and 3,
respectively. The extraction yield of flavonoids under the optimized conditions was 8.091%. The resulting blackberry leaf
extract contained 3.519 mg/g rutin, 17.342 mg/g scutellarin, 1.276 mg/g luteolin, 1.566 mg/g quercitrin, 0.928 mg/g apigenin
and 1.160 mg/g kaempferol. This study suggests that blackberry leaves contain a variety of abundant flavonoids and thus
deserves intensive research and development.

Key words: blackberry leaves, flavonoids, extraction, composition