白及花与块茎石油醚部位成分分析及其生物活性的比较研究

Comparative Research of Bioactivity and Analysis of Petroleum Ether Components in Flower and Tuber of Bletilla Striata

关键词:  白及  花  块茎  石油醚部位成分  气相色谱-质谱联用  生物活性

Key words:  Bletilla striata  flower  tuber  petroleum ether components  GC-MS  biological activity

摘要:

目的 分析白及花和块茎石油醚部位成分及生物活性。方法 以石油醚（60~90℃）为提取溶剂，采用索氏提取法提取白及花和块茎脂溶性成分，采用GC-MS分析其化学成分，通过滤纸片扩散法、CCK8法和分光光度法分别对其进行抑菌、抗肿瘤和α-淀粉酶抑制作用研究，通过检测DPPH自由基、ABTS自由基和羟自由基的清除率考察其体外抗氧化活性。结果 白及花和块茎中共鉴定出20种石油醚部位成分，其中花11种，块茎19种，共有成分10种，α-乙酰基-γ-丁内酯（15.20%，21.84%）和苄醇（12.07%，24.10%）为主要成分。白及花中石油醚部位成分的抑菌活性高于块茎，对枯草芽孢杆菌效果最好，最小抑菌浓度和最小杀菌浓度分别为0.41，0.51 g·L^-1和0.53，0.66 g·L^-1。当质量浓度为5.0 mg·mL^-1时，白及块茎石油醚部位成分对A₅₄₉细胞的抑制率为29.451%，高于花中石油醚部位成分27.621%的抑制率，前者对α-淀粉酶的IC₅₀为1.819 mg·mL^-1，后者的IC₅₀为2.028 mg·mL^-1。两者对DPPH自由基、ABTS自由基和羟自由基的清除率均随质量浓度的增大而增大，当浓度达到1.0 mg·mL^-1时，前者对ABTS自由基和羟自由基的清除率分别为99.67%和92.22%，高于后者90.07%和38.11%的清除率，后者对DPPH自由基的清除率为31.23%，高于前者18.94%的清除率，两者均低于Vc的清除率。结论 白及花和块茎中石油醚部位成分主要为酯类和醇类，2种石油醚部位成分均具有一定的生物活性，具有潜在的药用价值，并可为白及花的资源开发提供参考。

Abstract:

OBJECTIVE To analyze the petroleum ether components in flower and tuber of Bletilla striata and compare their biological activity. METHODS Petroleum ether (60-90℃) was used to the extraction solvent of soxhlet extraction method to extract petroleum ether components in flower and tuber of B. striata. The chemical compositions of petroleum ether components in flower and tuber of B. striata were analyzed by GC-MS, and they were also evaluated for antimicrobial activity by paper disc diffusion method, and antitumor activity by CCK8 method, while their antioxidant activity in vitro were evaluated by removal ability of DPPH and ABTS and OH free radicals. And their inhibitory effects on alpha amylase were determined by spectrophotometric method. RESULTS Twenty kinds of petroleum ether components were identified from flower and tuber of B. striata. Flower had 11 kinds of them, and tuber had 19 and there were 10 in common. 2-Acetylbutyrolactone (15.20%, 21.84%) and benzyl alcohol (12.07%, 24.10%) were in the majority. The bacteriostatic activity of petroleum ether components in flower was higher than the petroleum ether components in tuber, especially for Bacillus subtilis, the minimal inhibitory concentration and minimal bactericidal concentrations were 0.41, 0.51 g·L^-1 and 0.53, 0.66 g·L^-1 respectively. Inhibition rate of petroleum ether components in tuber on A549 cells was 29.451% and was higher than the petroleum ether components in flower which was 27.621%, when the mass concentration reached 5.0 mg·mL^-1. The IC₅₀ of the former on alpha amylase was 1.819 mg·mL^-1 and the latter was 2.028 mg·mL^-1. The scavenging rate of DPPH free radicals, ABTS free radicals and hydroxyl radical increased with the increase of mass concentration. When the mass concentration reached 1.0 mg·mL^-1, the scavenging rates of former on ABTS free radicals and hydroxyl free radical were 99.67% and 92.22% respectively, and were higher than the latter which were 90.07%, 38.11% respectively, while the scavenging rate of latter on DPPH free radicals was 31.23%, and was higher than the former which was 18.94%. But both of them in scavenging rates of DPPH free radicals, ABTS free radicals and hydroxyl radical were lower than Vc. CONCLUSION Lipids and alcohols are in the majority in petroleum ether components in flower and tuber of B. striata. Both of them have significant biological activity. Therefore they have potential medicinal value, and can provide reference for exploiting resources of B. striata.