木犀草素-铕(Ⅲ)配合物的制备及生物活性研究

采用紫外光谱法,以木犀草素与铕离子溶液为原料合成了木犀草素-铕配合物,配合物制备的最佳条件为:在1.0×10~(-4)mol/L、pH3.5的NaAc-HAc缓冲溶液中,木犀草素与铕离子按照摩尔比2∶1加入,30℃下反应40 min。同时对木犀草素、木犀草素-铕配合物的清除羟基自由基活性、抗氧化活性等进行了研究,研究结果表明配合物的活性明显优于木犀草素。     

木犀草素Zn(II)和Cu(II)配合物的合成及电化学性质研究

在无水乙醇溶液中,用木犀草素和醋酸铜、醋酸锌合成两种鲜见报道的木犀草素金属配合物,并通过元素分析、红外光谱、电子光谱和摩尔电导等表征手段,确定了配合物的结构。并研究了木犀草素Zn(II)和木犀草素Cu(II)配合物化学修饰碳糊电极在pH 5 B-R缓冲溶液中的电化学行为。     

木犀草素Zn(Ⅱ)和Cu(Ⅱ)配合物的合成及电化学性质研究

在无水乙醇溶液中,用木犀草素和醋酸铜、醋酸辞合成两种鲜见报道的木犀草素金属配合物,并通过元素分析、红外光谱、电子光谱和摩尔电导等表征手段,确定了配合物的结构。并研究了木犀草素Zn（Ⅱ）和木犀草素Cu（Ⅱ）配合物化学修饰碳糊电极在pH5 B-R缓冲溶液中的电化学行为。     

分子印迹固相萃取法提取花生壳中木犀草素

采用分子印迹技术,以木犀草素为模板分子、丙烯酰胺为功能单体、EGDMA为交联剂,合成了木犀草素印迹聚合物。将该印迹聚合物用于固相萃取,分离提取花生壳中的木犀草素。结果表明,该印迹聚合物对木犀草素具有较高的吸附性能和选择性,用印迹柱萃取得到的木犀草素纯度高出硅胶柱分离近20个百分点,达到96.2%。且MIPs-SPE柱与普通的硅胶柱相比,经过洗脱再生后可以反复使用多次。     

固体酸SO4/ZrO2区域选择性催化合成吲哚3位酰基化衍生物

研究了固体酸SO4/ZrO2区域选择性催化吲哚3位傅-克酰基化的反应.实验结果确定了吲哚及其衍生物在固体酸催化下的酰基化反应条件.通过吲哚衍生物和酰氯的酰基化反应合成出了一系列高区域选择性的吲哚系化合物,实验均取得了良好的效果.此方法为吲哚及其同系物的合成提供一条较为优化、绿色的合成新途径.     

吲哚衍生物合成方法研究新进展

吲哚及其衍生物具有非常重要的生物和药理活性,广泛应用于农业、医药等领域中。因此对吲哚及其衍生物合成方法的研究也越来越多。近年来经过化学家的努力,以2-炔基芳香胺分子内环化和芳香胺类化合物与炔反应来合成吲哚衍生物都取得了很大的进展,成为了重要的合成方法。主要对近十年来这两类方法即2-炔基芳香胺在各种不同催化条件下的分子内环化和各种不同取代的芳香胺类化合物与炔反应合成吲哚衍生物的研究进展进行了综述。     

分光光度法研究木犀草素与铁(Ⅲ)配合物

以木犀草素与氯化铁为原料,利用紫外分光光度法探讨了木犀草素(Luteolin,简写为Lut)与过渡金属离子(Fe3+)的配位作用,结果表明在pH=9.0~10.0、木犀草素与FeCl3物质的量之比为1∶1或2∶1时在60℃下反应2 h能形成较稳定的金属配合物。在乙醇溶液中,在最佳反应条件下合成了木犀草素-铁配合物,并利用紫外光谱对配合物进行了结构表征。     

调香中的木犀草

在日用调香术中,木犀草的香韵不是一种基本的花香香韵。但是,它那种独具一格的青香花香赋予香精一股独特的韵调。本世纪初,天然的木犀草花油被用于高档香精中,现在已没有天然的木犀草花油生产,在日用调香中应用的是配制的木犀草香精。产地、产量和生产方法木犀草(Reseda Odorata L.木犀草科)     

木犀草素分子印迹聚合物的合成

以木犀草素为模板分子,偶氮二异丁腈为引发剂,丙烯酰胺为功能单体,N,N-亚甲基双丙烯酰胺为交联剂,在极性溶剂中合成了木犀草素分子印迹聚合物(LMIP)。考察了溶剂用量及种类和功能单体对合成的影响,得到了最佳合成工艺条件,简化了模板分子的洗脱工艺。红外光谱分析表明:洗脱前分子印迹聚合物中原木犀草素在1 270 cm-1处的O—H吸收峰移至1 300 cm-1处,说明模板分子被功能单体、交联剂经聚合交联固定在聚合物中,洗脱后该峰完全消失;扫描电子显微镜观察发现:洗脱后的分子印迹聚合物表面凹凸不平,产生了大量吸附模板分子的空穴。探讨了LMIP的吸附特性,用与木犀草素结构相似的槲皮素作对比实验,分子印迹聚合物对木犀草素的吸附量(33.653μmol/g)明显高于槲皮素的吸附量(8.654μmol/g),表明LMIP对模板分子具有较高的吸附选择性。     

木犀草素在C_(60)衍生物修饰电极上的电化学行为

将新型的C_(60)吡咯烷衍生物(FPD)的异构体之一修饰于玻碳电极表面,通过循环伏安法研究了木犀草素在FPD/GCE上的电化学行为,结果显示该电极对木犀草素的氧化还原过程具有良好的电催化活性。在最优实验条件下,在2×10~(-8)mol/L~10~(-5)mol/L浓度区间范围内,氧化峰电流与木犀草素的浓度呈线性关系,其线性方程为:I_(pc)=-0.0103C-3.5955(R~2=0.9901),检测限为6.6×10~(-9) mol/L。表明所制备的修饰电极对木犀草素的测定具有较高的灵敏度和良好的选择性。     

Synthesis and In Vitro Evaluation of C-7 and C-8 Luteolin Derivatives as Influenza Endonuclease Inhibitors

The part of the influenza polymerase PA subunit featuring endonuclease activity is a target for anti-influenza therapies, including the FDA-approved drug Xofluza. A general feature of endonuclease inhibitors is their ability to chelate Mg²⁺ or Mn²⁺ ions located in the enzyme’s catalytic site. Previously, we screened a panel of flavonoids for PA inhibition and found luteolin and its C-glucoside orientin to be potent inhibitors. Through structural analysis, we identified the presence of a 3′,4′-dihydroxyphenyl moiety as a crucial feature for sub-micromolar inhibitory activity. Here, we report results from a subsequent investigation exploring structural changes at the C-7 and C-8 positions of luteolin. Experimental IC₅₀ values were determined by AlphaScreen technology. The most potent inhibitors were C-8 derivatives with inhibitory potencies comparable to that of luteolin. Bio-isosteric replacement of the C-7 hydroxyl moiety of luteolin led to a series of compounds with one-order-of-magnitude-lower inhibitory potencies. Using X-ray crystallography, we solved structures of the wild-type PA-N-terminal domain and its I38T mutant in complex with orientin at 1.9 Å and 2.2 Å resolution, respectively.     

Biochemical activity of centipedegrass against fall armyworm larvae

Centipedegrass,Eremochloa ophiuroides (Munro) Hack, severely inhibits growth of the fall armyworm larva,Spodoptera frugiperda (J.E. Smith). Fresh centipedegrass extracts and extract fractions were deposited on Celufil, incorporated into meridic-based diets and bioassayed against neonate larvae of the fall armyworm in the laboratory. The methanol extract (F₁) caused the greatest reduction in larval weight. When F₁, was partitioned between méthylene chloride and water, the activity was transferred to the water-soluble fraction (F₅), which, when further fractionated using preparative C-18 reverse-phase chromatography, yielded active F₇ and F₈ fractions. Gas chromatograph-mass spectrometry and high-pressure liquid chromatography (HPLC) showed F₇ to be 95% caffeoylquinic acids with chlorogenic acid as the major constituent. HPLC analysis of F₈ revealed maysin [2-O- -L-rhamnosyl-6-C-(6-deoxy-Xylo-hexos-4-ulosyl)luteolin] and other luteolin derivatives. Chlorogenic acid and other caffeoylquinic acids, maysin, and other luteolin derivatives are the major factors responsible for the antibiotic resistance of centipedegrass to larvae of the fall armyworm.     

O/W型微乳对木犀草素增溶作用的研究

采用伪三元相图制备了肉豆蔻酸异丙酯-聚氧乙烯氢化蓖麻油-无水乙醇-水的微乳体系,用紫外分光光度法测定了在微乳体系和水中木犀草素的溶解度,探讨O/W型微乳对木犀草素的增溶作用。研究表明,木犀草素在微乳中的溶解度是水中的561倍,微乳对木犀草素有明显的增溶作用。     

Effects of Luteolin on Biofilm of Trueperella pyogenes and Its Therapeutic Effect on Rat Endometritis

Trueperella pyogenes is an opportunistic pathogen that causes suppurative infections in animals. The development of new anti-biofilm drugs will improve the current treatment status for controlling T. pyogenes infections in the animal husbandry industry. Luteolin is a naturally derived flavonoid compound with antibacterial properties. In this study, the effects and the mechanism of luteolin on T. pyogenes biofilm were analyzed and explored. The MBIC and MBEC of luteolin on T. pyogenes were 156 μg/mL and 312 μg/mL, respectively. The anti-biofilm effects of luteolin were also observed by a confocal laser microscope and scanning electron microscope. The results indicated that 312 μg/mL of luteolin could disperse large pieces of biofilm into small clusters after 8 h of treatment. According to the real-time quantitative PCR detection results, luteolin could significantly inhibit the relative expression of the biofilm-associated genes luxS, plo, rbsB and lsrB. In addition, the in vivo anti-biofilm activity of luteolin against T. pyogenes was studied using a rat endometritis model established by glacial acetic acid stimulation and T. pyogenes intrauterine infusion. Our study showed that luteolin could significantly reduce the symptoms of rat endometritis. These data may provide new opinions on the clinical treatment of luteolin and other flavonoid compounds on T. pyogenes biofilm-associated infections.     

纤维素酶预处理花生壳工艺条件优化

用纤维素酶预处理花生壳,以乙醇提取木犀草素。结果表明,纤维素酶预处理花生壳的最佳工艺条件为:酶解液pH值5.2,酶解温度50℃,酶解时间1.5 h,酶用量0.10%。在最佳预处理条件下预处理后的花生壳木犀草素的提取率可达2.831 0 mg/g,而未经纤维素酶预处理的花生壳木犀草素的提取率仅为1.518 0 mg/g。     

正交试验法优选花生壳中木犀草素提取工艺

研究了优化花生壳中木犀草素的提取工艺条件。通过正交试验,以提取物中木犀草素的含量为评价指标,优选提取工艺。确立了以质量浓度为70％乙醇、料液比1：10、提取3次、每次时间2h为优选工艺,花生壳中木犀草素能被有效提取。该工艺简捷,经济,可行,适合工业化生产。     

木犀草素酯化物的制备及其抗氧化活性研究

利用月桂酰氯酯化制备了脂溶性木犀草素。利用正交实验研究了反应物配比、反应温度及反应时间对制备木犀草素酯化物的影响。通过红外光谱对酯化物进行结构表征,并考察木犀草素酯化物在大豆油中的溶解性和抗氧化活性。制备木犀草素酯化物的最佳反应条件是:反应物配比n(木犀草素)∶n(月桂酰氯)=1∶2、反应温度50℃、反应时间5h,其在大豆油中的溶解度为2.02×104μg/mL,且在相同浓度下,抗氧化活性优于二丁基羟基甲苯(BHT)。结果表明:木犀草素酯化物在大豆油中的溶解度明显提高,并具有良好的抗氧化性能。     

花生壳中总黄酮和木犀草素提取工艺研究

研究花生壳中总黄酮和木犀草素的提取工艺.经正交试验,以提取物中总黄酮和木犀草素含量为评价指标.优选提取工艺.确立以75%乙醇为溶剂,料液比1:10,每次提取2h,提取3次为优选工艺,花生壳中总黄酮和木犀草素均可有效提取.该工艺简捷、经济、可行,适合工业化生产.