The determination of flavonoid contents in mulberry and their scavenging effects on superoxide radicals

摘要

Flavonoid content of mulberry leaves of 19 varieties of species, determined spectrophotometrically in terms of rutin equivalent, varied from 11.7 to 26.6 mmg g~(-1) in autumn leaves. Fresh leaves gave more extract than airdried or oven-dried ones. HPLC showed that mulberry leaves contain at least four flavonoids, two of which are rutin and quercetin. The percentage superoxide ion scavenged by extracts of mulberry leaves, mulberry tender leaves, mulberry branches and mulberry back were 46.5, 55.5, 67.5 and 85.5/100, respectively, at a concentration of 5 ug ml~(-1). The scavenging effects of most mulberry extracts were greater than those of rutin (52.0/100).