荔枝核活性成分及其提取物抑菌活性分析

Analysis on active components and antibacterial and antifungal activities of extracts in litchi seeds

为给荔枝副产品的增值利用提供理论依据,对不同荔枝核样品采用香草醛-高氯酸比色法测定了荔枝核总皂苷含量,用硝酸铝-亚硝酸钠比色法测定了总黄酮含量,用蒽酮-硫酸法测定了多糖的含量,分别采用纸碟法和菌丝生长速率法测定了荔枝核提取物对细菌和真菌抑菌圈的大小,并采用混平板稀释法测定了其最小抑菌浓度。结果表明:不同荔枝核样品中总皂苷含量在1.30%～1.40%之间,总黄酮含量在5.78%～6.80%之间,多糖含量在2.85%～3.34%之间。不同品种荔枝核提取物具有不同抑菌活性。妃子笑荔枝核的抑菌活性强于其它品种,其甲醇提取物对细菌的最小抑菌浓度在1～2mg/mL之间。

In order to provide theoretical basis for value-added and utilization of by-product in Litchichinensis Sonn., taking seeds from different cultivars of litchi as materials, the content of total saponins was measured by vanillin and perchloric acid colorimetric method, the content of total flavonoids was measured by aluminum nitrate and sodium nitrite colorimetric method, and the content of polysaccharide was measured by anthrone-sulfate. The results showed that the contents of total saponins, total flavonoids and polysaccharide were 1.30%-1.40%, 5.78%-6.80% and 2.85%-3.34%, respectively. Bacterial and fungal inhibition circles of extracts in litchi seed were measured by paper-dish method and mycelium growth rate method. Minimal inhibitory concentration was measured by mixed plate dilution method. The results showed that antibacterial and antifungal activities of extracts from different cultivars of litchi were different, and that from L. Sonn. cv. Feizixiao was higher than that from the others. Minimal inhibitory concentration of methanol extract in seed from L. Sonn. cv. Feizixiao was 1.0-2.0 mg/mL.