丹皮酚乙酸哌嗪盐的合成

目的:合成丹皮酚乙酸哌嗪并优化其合成工艺。方法:以丹皮酚溴乙酸为原料,合成中间体丹皮酚乙酸,再与哌嗪成盐,得到目标产物丹皮酚乙酸哌嗪。结果与结论:设计合成了丹皮酚乙酸哌嗪盐,产物的化学结构经IR、MS等确定。     

NO供体型丹皮酚衍生物的合成及其生物活性研究

以丹皮酚与溴乙酸为原料制备丹皮酚乙酸,利用其羧基与不同碳数的二溴烷烃反应得到相应的丹皮酚乙酸溴代烷基酯(3a~3e),再与硝酸银反应生成目标化合物NO供体型丹皮酚衍生物4a~4e。目标化合物的结构经过红外光谱、核磁共振氢谱和质谱确证。对合成的NO供体型丹皮酚衍生物进行体外抗血小板聚集及体内调血脂作用的生物活性测试,结果表明,目标化合物均具有一定的体外抗血小板聚集活性及较强的体内降脂作用,其中化合物4c的活性最强。     

常压SO_3微热爆技术在丹皮酚提取中的应用

采用常压SO_3微热爆技术对丹皮进行预处理,再经过水蒸气蒸馏提取丹皮酚,相比于仅水蒸气蒸馏提取丹皮酚的提取率提高了13%左右。利用元素分析和HNMR对提取的产物进行表征,证明该技术对丹皮酚的质量没有负效应;同时通过SEM对预处理前后的丹皮进行组织结构观察发现,微热爆技术使丹皮表皮结构脱落甚至内部的筛管破裂,从而有助于溶剂进入提取丹皮酚。对工艺参数进行优化得到最佳提取工艺:浸泡时间为1 h、颗粒粒径为0.85 mm、蒸馏时间为2.5 h,此时,丹皮酚提取产率达到近99%。     

丹皮酚缩脂肪胺Schiff碱的合成及生物活性研究

以丹皮酚和脂肪胺为主要原料,合成9种Schiff碱化合物,并对标题化合物进行表征。利用细菌作为生物指示,采用琼脂扩散法测定了目标产物的抑菌性能;通过DPPH.分析法,测定了目标产物的抗氧化性。结果表明:目标产物对所受试菌种都有一定的抑制作用,但其清除自由基能力比较弱。     

NO供体型丹皮酚氧异丁酸硝酸酯类衍生物的合成及降血脂活性研究

以丹皮酚为先导化合物,与α-溴代异丁酸通过Willamson合成法得到丹皮酚氧异丁酸,与不同碳数的二溴烷烃生成丹皮酚氧异丁酸溴代烷基酯中间体,再与硝酸银反应得到5个目标化合物。目标化合物结构经核磁共振氢谱、红外光谱和质谱确证。采用HepG2高血脂细胞实验、脂肪酶活性抑制和胆酸盐结合能力实验对所得化合物进行活性研究。实验结果表明目标化合物降血脂活性高于丹皮酚,其中丹皮酚氧异丁酸硝氧乙基酯活性最好,其升高HDL-C能力高于非诺贝特。当目标化合物浓度为5 mg/mL时,脂肪酶抑制率可达40%左右,对甘氨胆酸钠(SG)、牛黄胆酸钠(ST)的结合率可达80%左右。     

丹皮酚合成过程中抑菌活性的变化研究

研究了在丹皮酚的合成过程中,原料间苯二酚、中间产物2,4-二羟基苯乙酮及主产物丹皮酚对11种植物病原真菌的抑菌活性,并通过抑菌活性的变化来推测影响抑菌活性的主要官能团.结果表明:0.5g·L-1的2,4-二羟基苯乙酮对11种真菌的抑菌率大于或等于同浓度丹皮酚的抑菌率,两者均远远大于同浓度间苯二酚的抑菌率.由此可推测,酚类分子中乙酰基的引入对抑菌活性起到了非常重要的作用,而酚羟基的甲基化的作用却并不显著.该结论对寻求具有更高抑菌活性的酚类衍生物有着非常重要的意义.     

丹皮酚及其席夫碱衍生物的抑菌性研究

以丹皮酚为先导,合成了丹皮酚缩1,3-丙二胺、丹皮酚缩2-羟基-1,3-丙二胺和丹皮酚缩糠胺3种丹皮酚席夫碱衍生物。琼脂扩散抑菌试验表明,丹皮酚及其衍生物对受试4种革兰氏阴性菌、阳性菌皆有明显的抑制作用。     

丹皮酚吗啉杂合物的合成及抗血小板聚集活性

以丹皮酚为起始原料，在碱性条件下丹皮酚的2-位酚羟基与二溴烷烃经Williamson反应得到中间体丹皮酚溴代烷基醚2a～2e,化合物2a～2e与吗啉经N-烷基化反应得到丹皮酚吗啉杂合物3a～3e。目标化合物3a～3e经过核磁共振氢谱(¹H NMR)、红外(IR)和高分辨质谱(HRMS)表征。体外抗血小板聚集活性测试结果表明，所得目标化合物3a～3e对二磷酸腺苷(ADP)所诱导的血小板聚集均具有较强的抑制活性，优于阳性对照药阿司匹林。     

N-苄叉丹皮酚腙的合成及其抗菌活性研究

以中药有效成分丹皮酚 (2-羟基-4-甲氧基苯乙酮)为原料,与水合肼反应得到中间体丹皮酚腙,然后分别与各种取代苯甲醛反应合成了9个N-苄叉丹皮酚腙,产率为50.5%~91.9%。初步探索了合成条件,目标化合物的结构经FT-IR,1H NMR,13C NMR, LC-MS表征。初步探索了合成条件、测定抗菌活性;结果表明：测定结果表明,部分化合物具有良好的抗菌活性,尤其是化合物N-(4-氟苄叉基)丹皮酚腙 (3c) 对金黄色葡萄球菌的MIC为4μg/mL,化合物N-(2-氟苄叉基)丹皮酚腙 (3b) 对大肠杆菌表现出与阳性对照药利福平相当的抗菌效果。     

丹皮酚腙类化合物的合成及其杀虫活性研究

为了研究3/5(3,5)-(二)硝基/氯丹皮酚酰腙类化合物和3/5(3,5)-(二)硝基丹皮酚腙类化合物中具有潜在应用价值的杀虫先导化合物,进一步开发基于丹皮酚的绿色杀虫剂,在1 mg/mL质量浓度下,采用小叶碟添加法分别测定了21个3/5(3,5)-(二)硝基/氯丹皮酚酰腙类化合物（1～21）和18个3/5(3,5)-(二)硝基丹皮酚腙类化合物（22～39）对三龄前期草地贪夜蛾的毒杀活性。结果表明,所测共计39个目标化合物中5个化合物（12、13、30、32和34）表现出最好的杀虫活性,其最终校正死亡率分别为75.0%、71.4%、71.7%、71.4%和70.4%,显著高于阳性对照川楝素（50.0%）,特别是化合物12,表现出显著的杀虫活性,其最终校正死亡率达75.0%;整体而言,丹皮酚腙类化合物杀虫活性优于丹皮酚酰腙类化合物;在丹皮酚C-3、C-5位引入硝基或氯原子,在其羰基位引入席夫碱（即酰腙和腙）,均能提高丹皮酚类衍生物的杀虫活性。     

百香果籽油的抗氧化活性研究

以百香果籽油清除羟基自由基能力和对超氧阴离子自由基的清除能力为指标,研究了百香果籽油的抗氧化活性。同时进一步采用Schaal烘箱法处理油样,在时间变化下,以过氧化值为指标,研究百香果籽油对花生油脂的抗氧化作用。实验结果表明,百香果籽油具有很好的清除超氧阴离子自由基的作用,抑制率维持在66%～95%之间;有较好的清除羟自由基作用,清除率能达到81.7%;对花生油脂有较好的抗氧化作用,抗氧化因子PF为1.67。百香果籽油具有较好的抗氧化能力。     

静磁场对黑胡椒提取物抗氧化活性的影响

将不同强度的静磁场分别作用于浸提、黑胡椒提取物预处理及抗氧化活性测定过程,研究磁场作用于不同过程对黑胡椒提取物抗氧化活性的影响.通过测定黑胡椒提取物体外条件下对1,1-二苯基-2-三硝基苯肼(DPPH)自由基的清除能力和对铁氰化钾的还原能力来评价黑胡椒提取物的抗氧化活性.结果表明,静磁场能够改变黑胡椒提取物清除DPPH自由基的能力和还原能力,但磁场作用于不同过程,其影响结果不同.静磁场作用于浸提和预处理过程时,黑胡椒提取物的抗氧化活性会受到抑制;静磁场作用于抗氧化活性测定过程时,黑胡椒提取物清除DPPH自由基的能力受到抑制,但其还原能力明显增强.     

油菜和荷花蜂花粉提取物的抗氧化性研究

采用超声法,分别以甲醇、水为溶剂提取油菜和荷花的蜂花粉活性成分,通过测定油菜和荷花蜂花粉的提取物对超氧阴离子自由基、羟基自由基的清除率及对脂质过氧化的抑制率,评价两种蜂花粉的抗氧化能力。结果表明:两种蜂花粉提取物均具有较强的抗氧化作用,油菜蜂花粉提取物比荷花蜂花粉提取物有更强的抗氧化性。油菜蜂花粉甲醇提取物对超氧阴离子自由基、羟基阴离子自由基清除率可达到83.2%,99.2%,对脂质过氧化的抑制率可达到92.2%。将蜂花粉抗氧化提取物分为甲醇部、水部溶剂萃取物,经抗氧化活性比较,其强弱顺序为甲醇部>水部。     

Antioxidant Activities of Extract and Fractions from the Hypocotyls of the Mangrove Plant Kandelia candel

The antioxidant activities of 70% acetone extract (70% AE) from the hypocotyls of the mangrove plant Kandelia candel and its fractions of petroleum ether (PF), ethyl acetate (EF), water (WF), and the LF (WF fraction further purified through a Sephadex LH-20 column), were investigated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results showed that all the extract and fractions possessed potent antioxidant activity. There was a significant linear correlation between the total phenolics concentration and the ferric reducing power or free radical scavenging activity of the extract and fractions. Among the extract and fractions, the LF fraction exhibits the best antioxidant performance. The MALDT-TOF MS and HPLC analyses revealed that the phenolic compounds associated with the antioxidant activity of the LF fraction contains a large number of procyanidins and a small amount of prodelphinidins, and the epicatechin is the main extension unit.     

Reaction of aliphatic tertiary amines with hydroperoxides

Trioctylamine acts as an antioxidant in fats at 70C but not at lower temperatures. A reactive antioxidant intermediate was sought. Dioctylhydroxylamine was obtained from the reaction of trioctylamine and t-butyl peroxide at 70C. The recrystallized product had antioxidant properties. About 0.1% existed as stable free radical by electron-spin resonance. Didecyl- and didodecylhydroxylamines were also synthesized from the corresponding tertiary amines. These and a sample of commercial diethylhydroxylamine also contained free radicals and possessed antioxidant activity.     

马铃薯皮中多酚类物质的抗氧化性研究

通过体外抗氧化体系测定马铃薯皮多酚的抗氧化活性。除超氧阴离子的能力;马铃薯皮多酚清除羟基自由基的能力;马铃薯皮多酚清除DPPH自由基的能力;马铃薯皮多酚对油脂的抗氧化能力。马铃薯皮多酚对超氧阴离子的清除率最高达18.33%,且在低浓度清除能力明显高于同浓度抗坏血酸(Vc);马铃薯皮多酚对羟基自由基的清除率最高达92.26%。对DPPH自由基清除率最高达86.08%。油脂中添加马铃薯皮多酚提取液,可以明显降低油脂的过氧化值(POV)。马铃薯皮多酚对超氧阴离子,羟基自由基和DPPH自由基都有很好的清除效果,且在一定程度上降低油脂过氧化值随时间而延长的程度,是很好的天然抗氧化剂。     

In vitro antioxidant properties of different parts of pomegranate flowers

The present study was designed to compare the antioxidant capacity of 70% ethanol extracts of petal, stamen and receptacle of pomegranate flowers (PF) by DPPH, reducing power, hydroxyl radicals (OH), DNA degradation and DNA breaking assays, as well as the peroxide value (POV). The different parts of PF showed significant activities in all the free radical scavenging tests. Among the parts, receptacle exhibited the highest inhibition of 44.86%, 61.21% and 44.47% in DPPH, OH and DNA degradation assays, respectively, and 63.96% reduction of ferricyanide to give Prussian blue colored complex in reducing power assay at maximum concentration tested, and showed the lowest POV of 68.51 meq/kg in experimental model of soybean oil after 12 days. Protection against oxidative damage to DNA molecules of various parts of flower was confirmed visually by DNA breaking assay. Total phenolic contents of the parts of flower and peel and leaves were estimated by Folin–Ciocalteu method and receptacle was found to contain the highest amount (148.41 ± 6.25 mg/g) of phenolics among the parts of flower, but the phenolic content of flower (petal, stamen and receptacle) was lower than peel, higher than leaves. Linear correlation (R² = 0.7139–0.9987) between antioxidant potential of various parts in different assays and phenolic contents was observed. This preliminary study indicates the antioxidant activity of PF, and moreover the results showed correlation with the amount of phenolic content present in different parts. Therefore, all parts of PF could be considered as a significant natural antioxidant source.     

Radical Scavenging Activity of Lipophilized Products from Transesterification of Flaxseed Oil with Cinnamic Acid or Ferulic Acid

Lipase-catalyzed transesterification of flaxseed oil with cinnamic acid (CA) or ferulic acid (FA) using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate whether the lipophilized products provided enhanced antioxidant activity in the oil. Lipase-catalyzed transesterification of flaxseed oil with CA or FA produced a variety of lipophilized products (identified using ESI-MS-MS) such as monocinnamoyl/feruloyl-diacylglycerol, dicinnamoyl-monoacylglycerol and monocinnamoyl-monoacylglycerol. The free radical scavenging activity of the lipophilized products of lipase-catalyzed transesterification of flaxseed oil with CA or FA toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·) were both examined in ethanol and ethyl acetate. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Unesterified FA showed the highest free radical scavenging activity among all substrates tested while CA had negligible activity. The esterification of CA or FA with flaxseed oil resulted in significant increase and decrease in the radical scavenging activity compared with the native phenolic acid, respectively. Based on the ratio of a substrate to DPPH· concentration, lipophilized FA was a much more efficient free radical scavenger compared to lipophilized CA and was able to provide enhanced antioxidant activity in the flaxseed oil. Lipophilized cinnamic acid did not provide enhanced radical scavenging activity in the flaxseed oil as the presence of natural hydrophilic antioxidants in the oil had much greater radical scavenging activity.     

何首乌多糖的纯化及功能性研究

考查何首乌中碱提多糖的分离纯化及其抗氧化、清除自由基的能力。从传统中药何首乌中提取碱溶性粗多糖组分,幵进行分级纯化,探讨不同多糖组分的抗氧化活性,包括清除DPPH、羟基自由基、H2O2以及金属螯合能力等。实验表明:分级纯化分别得到酸性多糖和中性多糖两个部分,均具有较强的金属螯合能力和清除羟自由基能力。其中酸性多糖的活性较强,且同时具有较强清除DPPH自由基的能力。