Objective: The leaves of Citrus reticulata

a common traditional Chinese medicine

are mainly used for the treatment of various diseases

including acute mastitis

caked breast and hernia symptoms

owing to its effects of relieving the depressed liver

soothing the liver

regulating the circulation of Qi

alleviating pain

dissipating phlegm and resolving masses. Modern pharmacological studies have shown that the hot water extracts from the leaves of C. reticulata have inhibitory effects on mastitis in mice. This paper aims to study their chemical constituents and reveal the effective substances. Method: The coarse powder of C. reticulata leaves was extracted by methods of soaking and refluxing with 95% and 70% ethanol

respectively. Then the ethanol extracts were separated preliminarily by MCI column chromatography(CC).The compounds were isolated and purified by using various chromatographic techniques

including silica gel

MCI

ODS

polyamide and Sephadex LH-20 CC. Their structures were identified on the basis of their physical-chemical properties and spectroscopic techniques

including NMR and MS. Result: Twelve compounds were obtained and identified as nobiletin(1)

5-demethylnobile(2)

tangeretin(3)

5

7

8

4'-tetramethoxyflavone(4)

5-hydroxy-6

7

3'

4'-tetramethoxyflavone(5)

β-amyrin(6)

lupeol(7)

phytol(8)

stigmastane-5

22-dien-3β-ol(9)

β-sitosterol(10)

p-hy-droxybenzaldehyde(11) and vanillin(12)

respectively. Conclusion: Compounds 4-12 were isolated from the leaves of Citrus reticulata for the first time.