马占相思树皮单宁含量的影响因素研究

研究了产地、树龄、部位以及贮存时间对马占相思树皮单宁含量的影响。结果表明:不同产地的该种树皮的单宁含量差异较大;树龄对树皮的单宁含量影响较明显,随着树龄的增加,单宁含量逐渐减少;从主干的根部往顶部,树皮的单宁含量逐渐降低,非单宁含量逐渐增加;贮存时间的延长,单宁含量减少,因此,贮存时间不能过长。研究结果表明马占相思树皮是适合工业生产的一种优良栲胶原料。     

紫外法和皮粉法测定塔拉单宁含量的对比研究

分别采用紫外法和皮粉法对5种不同含量的塔拉单宁进行对比研究,并利用SPSS软件对单宁含量测定结果进行显著性检验,结果表明：高纯度塔拉单宁(93%)分别用紫外法和皮粉法测定单宁含量时实验结果并未显著差异(P>0.05),而4种纯度为60%左右塔拉单宁的实验结果均具有显著性差异(P<0.05),皮粉法测得的单宁含量均比用紫外法测得的结果高,差值约为1.5%～2.0%,并由此计算出紫外法测定塔拉单宁含量计算公式中的矫正常数p为1.03。紫外-可见吸收光谱与HPLC分析结果表明：塔拉单宁与五倍子单宁的最大吸收峰均为276 nm,同质量浓度下塔拉单宁的吸收峰强度高于五倍子单宁,塔拉单宁成分出峰时间主要在20～40 min,五倍子单宁主要在30～45 min。     

落叶松树皮栲胶单宁含量快速测定法

测定凝缩类栲胶的单宁含量的紫外分光光度法,是一种新型快速、精确简便的分析方法。但是,用它测出的是每升配制液中所含单宁的克数,而不是干基单宁含量。对栲胶厂而言,人们最关心的并不是单宁的克/升含量,而是它的干基含量和纯度。如果测出了单宁的克/升含量,还得用重量法测定干物含量,才能求出干基单宁含量,仍然相当费时。曾     

马占相思树皮单宁含量的影响因素研究

研究了产地、树龄、部位以及贮存时间对马占相思树皮单宁含量的影响。结果表明：不同产地的该种树皮的单宁含量差异较大；树龄对树皮的单宁含量影响较明显，随着树龄的增加，单宁含量逐渐减少；从主干的根部往顶部，树皮的单宁含量逐渐降低，非单宁含量逐渐增加；贮存时间的延长，单宁含量减少，因此，贮存时间不能过长。研究结果表明马占相思树皮是适合工业生产的一种优良栲胶原料。     

桉树皮单宁分析

对广西高峰林场桃源分厂4年生的大叶桉和尾叶桉树皮的单宁含量进行了分析,并分别进行了栲胶的试制。分析结果表明:大叶桉和尾叶桉树皮单宁属于缩合类单宁,树皮单宁含量分别为7.6%和7.8%,纯度分别为67.9%和70.3%;大叶桉树皮栲胶单宁含量为65.4%,尾叶桉树皮栲胶单宁含量为63.3%。桉树皮可作为新品种栲胶原料,其栲胶值得推广应用。     

木麻黄抗感青枯病品系单宁含量差异

用液相色谱对抗青枯病木麻黄和感青枯病木麻黄中的单宁含量进行比较,结果显示抗病木麻黄中的总单宁含量在接种前后均高于感病木麻黄,说明单宁与木麻黄的抗病性有关。其中第1类单宁物质可能在抗病性中其主要作用。     

单宁紫外吸收特性及其在PVA薄膜中的应用

采用紫外可见分光光度计对单宁酸、橡梳单宁和黑荆树单宁等进行定性扫描,探讨了不同种类单宁的紫外吸收特性,并考察了不同种类单宁的混和物的紫外吸收特性。将单宁添加到聚乙烯醇树脂中制成薄膜,探讨了单宁的种类和添加量对聚乙烯醇薄膜的紫外吸收特性的影响。结果表明：聚乙烯醇薄膜的紫外吸收特性不仅与单宁的种类有关,还与单宁的添加量有关。随着聚乙烯醇薄膜中单宁含量的增加,其对紫外吸收的效果越好。     

甲醛缩合法快速测定缩合单宁含量的研究

本文利用甲醛缩合法测定了兴安落叶松缩合单宁的含量,通过与皮粉振荡法的结果比较,验证了甲醛缩合法的可行性,是一种快速简便的检验缩合单宁含量的测试方法。     

快速测定柞树叶凝缩类单宁的光谱分析法

由于植物单宁影响了食品的可口性,阻碍微生物、真菌和昆虫的生长,对小鸡和哺乳动物的毒性,逐渐受到了重视。因此在一些研究场合迫切需要快速测定植物组织内单宁含量。定量分析单宁传统方法如皮粉分析法和 Lwanthal 法有几个缺点:包括极费时、缺乏专一性和依赖于植物组织内的水抽出物,它不能真正测定出单宁的含量。快速色层分     

甲醛缩合法检验落叶松树皮栲胶单宁含量

介绍了甲醛缩合法检验落叶松树皮栲胶单宁含量的测定方法，与皮粉法对比结果表明，完全可以代替皮粉法的测定，是一种对落叶松树皮栲胶单宁含量测定快速、准确的方法。     

Effects of addition of condensed tannin on the structure and properties of silk fibroin film

Condensed tannin is a polymeric polyphenol compound, which has considerable protein‐binding ability and a variety of bioactivities, such as anti‐inflammatory, antithrombotic and antimicrobial activities. In this study, silk fibroin film was modified by adding condensed tannin. It was found that strong intermolecular interactions occurred between silk fibroin and tannin, and incorporation of 1–10% (w/w) tannin in the blend films resulted in more compact, stiffer but less elastic films. Swelling and dissolution trials showed that the addition of tannin significantly reduced the swelling and solubility of the films. The mechanical properties, swelling and solubility of the blend films varied as a function of tannin concentration, showing optimum values when containing 10% (w/w) tannin. The silk fibroin–tannin films all showed significant antioxidant activity and antibacterial activity against Gram‐positive bacteria, and the activities were positively related to the concentration of tannin. The results emphasized that the addition of condensed tannin could simultaneously improve the structural stability of silk fibroin film and impart functional properties. © 2016 Society of Chemical Industry     

Synthesis of new polymers containing tannin

A novel method for preparation of immobilized tannin on polyethylene has been suggested. A tannin-containing polymer was prepared by radiation-induced graft polymerization of glycidyl methacrylate onto porous polyethylene, followed by coupling tannin with the produced epoxide group. Reaction conditions for preparing immobilized tannin, such as the reaction temperature, pH, and the molar ratio of tannin to the epoxide group were investigated. The tannin content of the tannin-containing porous polyethylene was 20%, which is approximately equivalent to that of the conventional cellulose-based immobilized tannin. The adsorption isotherm for immobilized tannin and ferrous ion was determined.     

基于点击反应的单宁衍生物的合成及其性能

植物单宁与溴丙炔反应制备的炔化单宁与对十二烷基苯磺酰叠氮通过点击反应合成单宁衍生物。采用红外光谱仪和元素分析仪对单宁衍生物的结构进行表征，并研究其表面张力、抗氧化能力以及对细菌的抑制作用等性能。结果表明，在单宁分子的结构中引入长链烷基后，改善其亲脂性，制备出的单宁衍生物能显著降低水溶液的表面张力，当单宁衍生物质量浓度为0.8mg/mL时，可降低水溶液的表面张力至28.94mN/m；单宁衍生物对1,1-二苯基-2-苦基苯肼基自由基具有较强的清除能力，当单宁衍生物质量浓度为0.25mg/mL时，对1,1-二苯基-2-苦基苯肼基自由基的最大清除率可达97.08%；由于单宁脂溶性的增加及具有抗菌性能的三氮唑基团的引入，单宁衍生物对大肠杆菌和金黄色葡萄球菌的抑制作用明显增强。     

Condensed tannins,attine ants,and the performance of a symbiotic fungus

Field experiments indicate that the foliar concentration of condensed tannin affects the selection of leaf material ofInga oerstediana Benth., a tropical legume tree, by leaf cutter ants. In one study an increase in tannin concentration was correlated with a decrease in the acceptability of leaves to leaf-cutter ants, except at low tannin concentrations. Protein concentration was not correlated with acceptability nor was the ratio of protein to tannin. Results from a second study suggest that when the concentration of tannin was low the ants appear to select leaves on the basis of nutrient availability. Laboratory assays with the ants indicated that quebracho tannin, a commercially available condensed tannin, inhibits foraging ants. Again, at lower concentrations, quebracho tannin appeared to have little affect on the ants. The fungus the ants cultivate is a wood-rotting Basidiomycete that produces enzymes, such as polyphenol oxidase (PPO), that are capable of inactivating tannins. The activity of these PPOs may explain why leaf-cutter ants are undeterred by low concentrations of condensed tannins. I hypothesized that PPO activity would be absent from fungal cultures without tannin and that only high concentrations of tannin would inhibit the fungus. Cultures with and without tannin showed similar PPO activity. Thus PPO activity is constitutive. In fact, as fungal biomass increased, so did PPO activity. As hypothesized, only high concentrations of quebracho tannin inhibited PPO activity and fungal growth. However, it is not clear whether the ants can discriminate between concentrations that do and do not inhibit the fungus.     

新型水处理剂磷化单宁的合成及其性能研究

用三氯氧磷改性单宁,使单宁的酚羟基磷化,以提高其缓蚀性能。论文设计了合成路线,研究了反应温度、反应时间、反应物摩尔比、反应物浓度对合成反应的影响。通过仪器分析判定和证实了磷化单宁的结构。并评价了磷化单宁的缓蚀、阻垢、除氧和杀菌性能。     

球形聚合单宁-纤维素树脂的制备及吸附性能

单宁与多聚甲醛交联合成单宁酚醛聚合物,再以环氧氯丙烷为交联剂,将单宁酚醛聚合物与纤维素通过反相悬浮交联制备球形聚合单宁-纤维素树脂。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）对球形聚合单宁-纤维素树脂的结构进行了表征,并考察了球形聚合单宁-纤维素树脂对盐酸小檗碱的吸附性能。结果表明,球形聚合单宁-纤维素树脂具有多孔的结构,树脂网络中含有大量的酚羟基;球形聚合单宁-纤维素树脂对盐酸小檗碱具有较好的吸附性能,当盐酸小檗碱浓度为600 mg·L^-1、吸附温度为298 K时,最大饱和吸附量可达245.92mg·g^-1;球形聚合单宁-纤维素树脂对盐酸小檗碱的吸附过程符合Langmuir吸附等温模型和准二级吸附动力学方程,热力学研究数据表明球形单宁-纤维素树脂对盐酸小檗碱的吸附是一个自发放热的物理吸附过程。该树脂在分离提纯生物碱方面具有潜在的应用前景。     

Interaction of proteins with sorghum tannin: Mechanism,specificity and significance

The grain of some varieties of sorghum contains 2% or more condensed tannin; many other varieties contain no tannin at all. Agronomic advantages, e.g., resistance to bird depredation, are associated with high-tannin sorghums, which have relatively low nutritional value for nonruminants. The biological effects of tannin are a result of its propensity for binding proteins; both hydrogen bonding and hydrophobic interactions are involved. Sorghum tannins can bind dietary proteins and reduce their digestibility. Purified digestive enzymes are inhibited by tannin, but significant inhibition in vivo is unlikely. Proteins differ greatly in their affinity for tannin. Those with highest affinity are large, have an open structure, contain no bound carbohydrate and are rich in proline. Sorghum proteins of the alcohol-soluble prolamine fraction associate strongly with tannin, are difficult to remove during tannin purification and are found combined with tannin in the indigestible residue after in vitro digestion with pepsin. On germination, the seed may sacrifice a portion of these proteins to bind the tannin that might otherwise interfere with metabolism by inhibiting seed enzymes. During seed development, tannin molecules are relatively short and do not effectively precipitate proteins; as the seed dries, tannins undergo polymerization to an average of ca. 6 flavan-3-ol units/molecule. The antinutritional effects of sorghum tannins can be eliminated by soaking the grain in dilute aqueous alkali, but not by cooking. When rats are put on high-tannin sorghum diets, their parotid glands undergo hypertrophy and produce a group of unique salivary proteins with extremely high affinity for tannin. These proteins contain over 40% proline and are devoid of sulfur-containing and aromatic amino acids. This metabolic adaption may protect rats against tannin by binding and inactivating it immediately when it enters the digestive tract. Presented at the AOCS Meeting, May 11, 1983.