【作者】 孙长霞；

【导师】 张柏林； 苏印泉；

【作者基本信息】 北京林业大学 ， 植物学， 2012， 博士

【摘要】 松萝是子囊地衣纲茶渍目松萝科松萝属植物,富含松萝酸和松萝多糖等活性物质,具有显著的生物学功效。本文以采自西藏色季拉山和黑龙江伊春市带岭凉水林场的长松萝(Usnea longissima)、黑龙江伊春市带岭凉水林场的环裂松萝(U.diffracta)、陕西秦岭火地塘林场的粗皮松萝(U.montis-fuji)、新疆阿勒泰喀纳斯国家级自然保护区的亚花松萝(U.subfloridana)为试验材料,优化了松萝酸和松萝多糖的提取工艺,评价了松萝酸粗提物、松萝粗多糖、纯化物及松萝纯化多糖的抗氧化能力和抑菌效果,推测了松萝活性物质的结构与活性机理,为松萝资源的综合利用奠定了理论与实践基础。主要研究结果如下：(1)松萝酸含量与活性研究1)研究表明,薄层层析-分光光度法(TLC-UV)适宜于松萝中松萝酸的定量分析,加标回收率均在94.85%以上,相对标准偏差RSD为3.86%。进一步分析表明,松萝中松萝酸含量与产地相关,其中松萝酸含量依次是长松萝(黑龙江)>长松萝(西藏)>亚花松萝>环裂松萝>粗皮松萝。2)松萝酸粗提物(ULXCUA)的最佳提取条件是：提取温度75.00℃,提取时间4.50h,乙醇浓度85.00%和液/料比29.00：2.00,松萝酸提取率达到8.05mg/g,试验误差不超过5%。对ULXCUA活性研究表明,五种松萝的松萝酸粗提物具有清除DPPH的能力,其清除能力强弱依次是：粗皮松萝>长松萝(西藏)>长松萝(黑龙江)>亚花松萝>环裂松萝。进一步研究表明,ULXCUA对供试菌种表现出很好的抑菌作用,为松萝中主要的抑菌成分,特别是在含脂肪较高食品中防腐效果明显。3)ULXCUA中分离纯化得到五种物质,其结构分别是：Compound-1的分子式为C11H1404,M=210.25；Compound-2的分子式为C19H2007,M=360.36；Compound-3的分子式C18H1607,M=344.32；Compound-4分子式为C8H1002,M=138.16；Compound-5的分子式为C18H3202,M=280.45.获得的5种纯化物都表现出良好的抗氧化物活性及抑菌能力,其活性与纯化物的分子结构有关。(2)松萝多糖与活性研究1)研究表明,松萝中松萝多糖含量与产地相关,松萝多糖含量依次是：粗皮松萝>长松萝(西藏)>亚花松萝>长松萝(黑龙江)>环裂松萝。进一步研究表明,松萝多糖(UMCP)提取的最佳工艺条件是：提取温度80.00℃,提取时间3.00h,液/料比40.00：1.00,松萝多糖提取率达到80.16mg/g,试验误差不超过5%。2)松萝粗多糖具有清除DPPH的能力,其能力大小依次是：粗皮松萝>长松萝(黑龙江)>亚花松萝>环裂松萝>长松萝(西藏)。亚花松萝纯化多糖的分子量均高于其他四种松萝的纯化多糖,其清除DPPH的能力也明显优于其它松萝纯化多糖,纯化多糖对DPPH的清除能力优于粗多糖,且多糖分子量越大清除能力越强。综上所述,松萝酸和松萝多糖是松萝中含量丰富的活性成分,这两类化合物随产地变化而变化,具有一定的抗氧化和抑菌活性,这些资料有利于松萝资源在食品领域的深加工和利用。更多还原

【Abstract】 Usnea, belonging to the usnea genera of Ascus lichens Lecanoromycetes families, contains usnic acid and usnic polysaccharide that have bioactivitiy substances.4 usnea, i.e., Usnea longissima (Tibet Autonomous Region and Hei Long-jiang province), U.diffracta (Hei Long-jiang province), U.montis-fuji (Shan Xi province) and U.subfloridanu (Xin Jiang Uygur Autonomous Region) were selected for their characterizations and productions of bioactive compounds. The extraction, purification and partial physiolygical functions of the main components including polysaccharides and usnic acid from these usneas were investigated. The obectives of this study are to characterize the roles of usnic acids and usnic polysaccharides in health food production. The following are main results.1. Usnic acid content and activities1) TLC-UV was proved to be a good method for the determination of usnic acid from usneas due to good recovery as well as standard addition ranging above 94.85% and the relative standard deviation (RSD) less than3.86%. Moreover, the levels of usnic acid in usneas, depending on different producing areas, ranked firstly by Usnea longissima (Hei Long-jiang Province), followed by Usnea longissima (Tibet), U. suhfloridana, U. diffracta and U. monlis-fuji.2) Factors influencing the extraction of usnic acids from usnea included extract temperature, extract time, ethanol concentrations, and ratio of raw material to water (m/m). The optimum operating parameters for yielding usnic acids were 75℃of extract temperature,4.5h of extract time,85%of ethanol concentration, and ratio of raw material to water(m/m) 29.00:2.00. The yield of usnic acids crude extract was 8.05mg/g, with an experimental error less than 5%. Moreover, usnic-acid crude extracts from five usneas had a good ability to scavenge DPPH free radical. The highest DPPH free radical scavenging was produced by U.montis-fuji, followed by Usnea longissima (Tibet), Usnea longissima (Hei Long-jiang province), U.subfloridana, and U.diffracta. The crude extract of usnic acid (ULXCUA) from U.longissima (Tibet) showed antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus niger, Aspergillus flavus and Candida sp.. Usnic acids were suggested to be the major antibacterial compounds. The viability of spoiled bacteria was lower in fresh meat, bean curd and milk treated with ULXCUA, compared to the control. It means that ULXCUA should be a good preservator for extending the shelf-life of food products, especially food with high fat content.3) Five compounds were purified from crude extract of usnic acids in U.snea longissima (Tibet). The structures of these compounds were as follows:Compound-1 C11H14O4, M=210.25; Compound-2 C19H20O7, M=360.36; Compound-3 C18116O7, M=344.32; Compound-4 C8H10O2, M=138.16, Compound-5 C18H32O2, M=280.45.2. Usnic polysaccharides and their bio-activities1) The levels of usnic polysaccharide in usneas, depending on different producing areas, ranked firstly by U.montis-fuji, followed by Usnea longissima (Tibet), U. subfloridana, Usnea longissima (Ilei Long-jiang province), U. diffracfa. Further study showed that factors influencing the extraction of usnic polysaccharides from usnea included extract temperature, extract time, and ratio of raw material to water (m/m). The optimum operating parameters were 80℃of extracting temperature,3h of extracting time, and ratio of raw material to water (m/m) 40.00:1.00. The yield of usnic polysaccharides extracted reached 80.16 mg/g, with an experimental error less than 5%.2) Usnic polysaccharides extracted from usneas had a DPPH free radical scavenging ability. The highest DPPH free radical scavenging was produced by U.montis-fuji. followed by Usnea longissima (Hei Longjiang Province), U.subfloridana. U.diffracted and U. longissima (Tibet). The numbers average of molecular weight for each usnic polysaccharide purified from usneas extract ranged from 5.22×105Da to 8.81×106Da. The weight average of molecular weight for each purified polysaccharide varied between 8.49×105 Da and 1.62×107Da. The molecular weight of usnic polysaccharides purified from U.subfloridna was higher than that from other four usneas. Additionally, the more molecular weight was, the more total antioxidant capacity was. In conclusions, usnic acids and usnic polysaccharides were the major bioactive components in existing in usnea, and their yields, together with their antioxidant and antibacterial activities largely depended on producing areas. The present data favor the long-term utilizations of usneas resources.更多还原