Objective: To investigate the dynamic changes of rutin

naringin

scutellarin

hesperidin

quercetin and kaempferol contents in three jujube leaves(‘Huizao’

‘Junzao’ and ‘Suanzao’) from Xinjiang within one growth cycle

determine their appropriate picking periods

and provide a scientific basisfor comprehensive development and utilization of jujube. Method: High performance liquid chromatography (HPLC) was used to determine the content and dynamic changes of 6 flavonoids in 3 jujube leaves

and the chromatographic separation was performed on cosmosil C18 column(4.6 mm×250 mm

5 μm) with acetonitrile-0.2% formic acid solution as the mobile phase for gradient elution

at a flow rate of 1.0 mL·min-1. The detection wavelength was set at 280 nm and column temperature was 25℃. Result: Six flavonoids components were well separated at baseline with good linearity(r≥0.999)

and their mass fraction range was as follows: rutin 1.33-11.59 mg · g-1

naringin 0.35-3.51 mg · g-1

scutellarin 0.61-1.74 mg · g-1

hesperidin 0.11-2.81 mg · g-1

quercetin 0.008-0.37 mg·g-1 and kaempferol 0.01-0.03 mg · g-1. Flavonoid contents were different in three kinds of jujube leaves

and their mass fraction was influenced significantly by ripening stages

which was higher in the germination period and flowering period

and was lowest at fruit-setting period. Conclusion: The established HPLC method is simple

accurate and repeatable for content determination. For the purpose of using flavonoids

jujube leaf bud can be collected at the beginning of April to get higher yield.