Separation of flavonoids with significant biological activity from Acacia mearnsii leaves.

Acacia mearnsii leaves, which are a rich source of flavonoids, were used to separate and purify myricitrin (W3) and myricetin-3-O-glucoside (W1). Further, the antioxidant and hypoglycemic activities of the two purified flavonoids were evaluated. The flavonoids were separated using solvent partition, macroporous adsorbent resin column, and Sephadex column chromatography, and purified using preparative reverse-phase high-performance liquid chromatography (HPLC). The purified flavonoids were characterized using HPLC, mass spectrometry, and nuclear magnetic resonance methods. A high yield (7.3 mg g-1 of crude extract) of W3 was obtained, with a high purity of 98.4%. Furthermore, the purity of W1 was over 95%. W1 and W3 showed strong antioxidant activity and significantly inhibited α-glucosidase. W3 also demonstrated substantial α-amylase inhibitory capacity. This study indicated that A. mearnsii leaves, which are discarded in significant amounts, can be used as a source of myricitrin, thus providing more adequate material for the production of antioxidants and type II diabetes inhibitors. Hence, A. mearnsii leaves have the potential to create great market economic value and environmental benefits.

[Value of nitrite in exhaled breath condensate in estimating the severity of asthma].

OBJECTIVE: To explore the relationship between nitrite levels in the exhaled breath condensates (EBC) and the severity of asthma. METHODS: Sixty asthmatic patients with exacerbation (including 23 with mild, 21 with moderate, and 16 with severe asthma) and 23 healthy nonsmokers were enrolled in this study. The lung function tests were performed and nitrite levels measured in the EBC by the spectrophotometry and nitric oxide assay kit in these subjects. The percentage of eosinophils was also measured in induced sputum by Wright staining. RESULTS: The concentrations of nitrites in the EBC and the percentage of eosinophils in induced sputum in the asthmatic patients were significantly higher than those of the healthy subjects (P<0.01), and showed positive correlations to the disease severity. A significant positive correlation was found between nitrites in the EBC and percentage of eosinophils in induced sputum (r=0.706, P<0.01). The concentration of exhaled nitrites was inversely correlated to MEF50% (r=-0.806, P<0.01) and FEV1% (r=-0.724, P<0.01). CONCLUSION: Nitrite level in the EBC may serve as useful indicators for estimating the severity of asthma.