野生和栽培银丝菇子实体抗氧化活性比较

为进一步开发利用银丝菇,以野生和栽培银丝菇子实体为试材,研究了不同浓度乙醇提取液对DPPH自由基的清除作用和对铁氰化钾的还原能力。结果表明：随着乙醇提取物浓度的提高,银丝菇子实体乙醇提取液对DPPH自由基清除能力和对铁氰化钾的还原能力不断增强,且栽培银丝菇高于野生银丝菇和香菇。当子实体生药浓度为3mg·mL-1时,野生银丝菇和栽培银丝菇对DPPH自由基清除率最高,分别为22．51％和17．54％。在提取物浓度为10mg·mL-1时,野生银丝菇、栽培银丝菇和香菇的还原力分别为0．416、0．475和0．513。     

铁观音与荆芥提取物协同抗氧化作用研究

为研究铁观音提取物和荆芥提取物联用在抗氧化方面的协同作用,采用水浸提法分别萃取铁观音和荆芥得其抗氧化活性成分。以芦丁为标准品检测两种提取物类黄酮含量,其中铁观音提取物为15.13 mg/g,荆芥提取物为0.87 mg/g;以没食子酸为标准品检测两种提取物的总酚含量,其中铁观音水提物为50.87μg/mg,荆芥水提物为47.40μg/mg。用2,2-二苯基-1-苦基肼(DPPH)和2,2'-二氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)法评估两种提取物联合应用时的抗氧化活性,结果表明,在较低浓度时,铁观音与荆芥提取物联用具有协同增强抗氧化作用。     

Antioxidant flavonoids from the seed of Oroxylum indicum

Three new flavonoid glycosides (1-3) and nineteen known compounds (4-22) were isolated from the aqueous ethanolic extract of the seed of Oroxylum indicum. The structures of 1-3 were elucidated on the basis of spectroscopic analysis. Antioxidant activities of all the isolated compounds were evaluated using a DPPH and an ORAC assay. Compounds 3, 5-7, 9 and 12 exhibited potent antioxidant activity in the DPPH assay, while compounds 3-15 showed potent antioxidant capacity in the ORAC assay, and seven antioxidant flavonoids (4-6, 8, 9, 11, 12) were detected as the main ingredients in the methanolic extract of seed of O. indicum using an HPLC analysis.     

一些野生果树鲜叶提取物清除自由基活性研究

本研究用二苯基苦基苯肼自由基酶标仪法,对亚热带常见的70余种果树鲜叶的自由基清除活性进行了比较,发现石榴、板栗、尖嘴林檎和黄山栎鲜叶的80％甲醇提取物有很强的自由基清除活性,其次是杨梅、麻栎、茅栗、短柄苞栎、木瓜、湖北海棠、南酸枣、三花悬钩子和黄山花楸,它们在相当于鲜叶浓度为0.5mp·mL~(-1) ,在37℃下孵育20min时的自由基清除率分别可达93.5％、89.3％、85.0％、82.9％、79.1％、77.6％、75.5％、74.3％、70.7、64.5％、63.7％、63.4％和61.3％,显示这些树种有较大的开发潜力。     

Anti-inflammatory, antioxidant and antifungal furanosesquiterpenoids isolated from Commiphora erythraea (Ehrenb.) Engl. resin

The topical anti-inflammatory, free radical scavenging and antifungal activities of essential oils and extracts of Commiphora erythraea (Ehrenb.) Engl. resin were investigated. The hexane extract significantly inhibited oedema when applied topically in Croton oil-induced ear oedema assay in mice. The same extract showed antioxidant activity in DPPH radical scavenging assay. A bioguided separation of the hexane extract led to the isolation of furanosesquiterpenoids 1 and 2 that showed a weak antifungal activity, while compounds 3-5 resulted to be antioxidant (EC₅₀ 4.28, 2.56 and 1.08 mg/mL, respectively) and anti-inflammatory (30, 26 and 32% oedema reduction, respectively).     

广玉兰叶片抗氧化活性评价

用乙酸乙酯从广玉兰(Magnolia grandiflora)叶片中萃取出的活性物质,在进行主要成分理化检识鉴定后,以人工抗氧化剂PG(没食子酸丙酯)和天然抗氧化剂PA(植酸)为对照,测定了其体外抗氧化活性,并用两种体系DPPH·(二苯代苦味酰基自由基)和卵磷脂进行评价.结果表明,提取物含有黄酮类化合物和酚类化合物.提取物稀释10倍(92.00 mg·mL-1)时,对过氧化氢的清除率达最大,为29.41%,在稀释20倍(46.00 mg·mL-1)时,抑制活性氧活性达最大,达500活力单位,稀释50倍(18.40 mg·mL-1)时,非酶体系的总抗氧化能力达最大,为270活力单位.DPPH·体系和卵磷脂体系评价结果表明,在提取物稀释50倍时(18.40 mg·mL-1),对DPPH·的清除率为92.69%,比PG强,对脂质过氧化的抑制作用达最大,达56.67%,与PA相当,因此,抗氧化效果最好.     

响应面法优化红茶茶多酚清除DPPH能力的研究

本试验以日照红茶为材料,在单因素试验基础上,采用Box-Behnken响应面设计法对茶多酚超声波辅助提取清除DPPH的工艺进行优化,建立了乙醇体积分数、超声时间、超声温度、乙酸乙酯萃取静置时间4因素与DPPH清除率之间的回归优化模型,确定了最佳提取工艺为:乙醇体积分数86.54%,超声时间69.61min,超声温度60℃,静置萃取时间82.26min,在优化后的最佳工艺参数下,红茶茶多酚对DPPH的清除率最高可达74.84%,研究表明红茶茶多酚具有较强的清除DPPH的能力。     

Total phenols,flavonoids, and procyanidins levels and total antioxidant activity of different Korean pine(Pinus koraiensis) varieties

Total phenols,flavonoids,procyanidins,and total antioxidant capacity,measured with ferric reducing antioxidant power,radical scavenging capacity,and oxygen radical absorption capacity assays were first evaluated in the extracts of the shells,skins and kernels of 10 varieties of Pinus koraiensis.Results indicate that these varieties had strong radical scavenging capacities,ferric reducing antioxidant power and oxygen radical absorption capacities.Phenolic,flavonoid and procyanidin values ranged from 138.6(#3 kernel)to 518.6(#10 shell)mg GAE/g,from 23.3(#2 kernel)to 70.8(#5 skin)mg RE/g,from 2.5(#2 kernel)to 142.1(#7 skin)mg CE/g,respectively.Radical scavenging capacity and ferric reducing antioxidant power values were positively correlated to the polyphenol contents which play a major role in antioxidant properties.The varieties may be divided into two groups by cluster analysis and the variables being measured.These results will be useful for breeding varieties and guiding their production.     

米糠蛋白抗氧化肽的制备及初步分离

试验以米糠蛋白为原料,制备米糠蛋白抗氧化肽。以DPPH自由基清除率为指标,采用正交试验,优化碱性蛋白酶酶解米糠蛋白制备抗氧化肽的工艺条件;采用超滤、SephadesG-25柱层析分离纯化米糠蛋白抗氧化肽。试验结果表明,制备米糠蛋白抗氧化肽的最优工艺条件为：酶解温度45℃,pH9．0,时间60rain,米糠蛋白底物浓度3％,碱性蛋白酶加酶量3000U·g-1。在米糠蛋白酶解产物中,Mrs〈5KDa组分的抗氧化活性最强,其对DPPH自由基清除率为68．7％。通过SephadexG-25凝胶层析柱进一步分离得到4个混合组分,混合组分Ⅱ活性最强,其DPPH自由基清除率为75．83％。     

紫甘薯乳酸发酵醪体外抗氧化性研究

测定5种乳酸发酵醪和紫甘薯醋的总抗氧化能力和对二苯代苦味酰基(DPPH)自由基清除率,结果表明紫:甘薯乳酸发酵后抗氧化能力轻微增强,总抗氧化能力达200.18mg/mL,添加量为100μL时对DPPH自由基清除率达96.99%,与紫甘薯醋抗氧化能力相当。5种乳酸发酵醪中,紫甘薯乳酸发酵醪抗氧化能力最强。