箬竹叶中黄酮类化合物的高效液相色谱分析

用高效液相色谱法，以苯基柱为固定相，甲醇－水为流动相，并应用二极管阵列检测技术，分离和制备了箬竹叶中８种黄酮类化合物，经结构鉴定，确证６种为结构相近的黄酮甙类化合物，并以其中的芦丁的为标准，测定了８种黄酮类化合物在箬竹叶中的含量。     

刺五加味中黄酮类化合物的分析

利用电喷雾多级串联质谱（ESI－MS^n)技术，分析了刺五加叶中黄酮类化合物，并根据黄酮类化合物的特征显色反应，采用紫外－可见分光光度法，对刺五加叶中总黄酮的含量进行了测定。分析结果表明：刺五加叶含有槲皮素及其相关的黄酮甙类化合物，其含量达37．25％。     

液晶研究（I）—4′—酰基—4—羟基—1,1′—联苯酯类液晶的合成与…

以４′－羟基联苯为原料合成了８种新型４′－酰基－４－羟基联苯酯类化合物，除化合物５外，均为新的近晶相流晶化合物，它们具有较宽的相变温度范围和较高的热稳定性，用偏光显微镜和差热分析仪研究了它们的相行为，讨论了分子结构对液晶相行为的影响。     

基于漂浮有机液滴凝固液相微萃取的黄酮类化合物分配系数及含量测定

以漂浮有机液滴凝固液相微萃取（SFODLPME）对中药中黄酮类化合物进行富集,建立SFODLPME-HPLC快速测定中药材样品中低丰度黄酮类化学成分含量的方法. 并讨论了黄酮类化合物富集倍数与浓度之间的关系、富集倍数与供相体积之间的关系,定义和阐述了EF1μg?mL-1及其物理意义,计算了漂浮有机液滴凝固相体积及黄酮类化合物的表观分配系数. 在SFODLPME的优化条件下结合高效液相色谱测得8种黄酮类成分的线性范围均为0.01~10.00μg/ml;检测限在1.0~0.01ng/mL;精密度RSD<7.0%;药材中分析物的回收率在96.0% ~104.2%. 当加入萃取溶剂体积为40μl 时,形成漂浮有机液滴凝固相体积为52±14μl;8种黄酮类成分的表观分配系数在44.8~243.9之间.     

液晶研究（Ⅰ）──4＇－酰基－4－羟基－1，1＇－联苯酯类液晶的合成与性质

以４＇－羟基联苯为原料合成了８种新型４＇－酰基－４－羟基联苯酯类化合物．除化合物５＿ｈ外，均为新的近晶相液晶化合物．它们具有较宽的相变温度范围和较高的热稳定性．用偏光显微镜和差热分析仪研究了它们的相行为，讨论了分子结构对液晶相行为的影响．     

超高效液相色谱－串联质谱法测定蜂蜜中24种酚酸和黄酮类化合物

建立了超高效液相色谱－串联质谱（UPLC－MS/MS）同时测定蜂蜜中24种酚酸和黄酮类化合物的方法。样品经水溶解,SHIMSEN Styra MAX固相萃取柱净化,超高效液相色谱－串联质谱测定,外标法定量。结果表明,24种化合物在2 ~ 1 000 μg/L范围内线性关系良好,相关系数（r2）均大于0.998,方法定量下限为2 ~ 10 μg/kg;在200、400、1 000 μg/kg加标水平下,平均回收率为60.3% ~ 111%,相对标准偏差为0.80% ~ 8.5%。采用该方法测定15批次5种植物源蜂蜜样品,结果显示样品中均含有不同浓度的没食子酸、短叶松素、高良姜素、松属素、原儿茶酸、对香豆酸、对羟基苯甲酸、咖啡酸、槲皮素、异鼠李素、莰菲醇和柯因等18种化合物,均不含有迷迭香酸和桑色素。该方法前处理简单、快速、灵敏、稳定,可用于蜂蜜中酚酸类和黄酮类物质的测定。     

基质固相分散-高效液相色谱法测定蜂巢中7种黄酮类化合物

采用基质固相分散-高效液相色谱法(MSPD-HPLC)同时测定蜂巢中芦丁、桑色素、木犀草素、槲皮素、芹菜素、白杨素和山奈素的含量。以硅胶为基质固相分散剂与样品混合均匀后装柱,以甲醇为洗脱剂进行洗脱。洗脱液在Pinnacle II C18分离柱上分离,以乙腈-0.2%(φ)磷酸溶液为流动相进行梯度洗脱,检测波长为260nm。7种黄酮类化合物的质量浓度在一定范围内与峰面积呈线性关系,检出限(3S/N)在0.07~0.32mg·L-1之间。方法用于测定蜂巢中7种黄酮类化合物,加标回收率在84.9%~95.9%之间,测定值的相对标准偏差(n=6)在2.3%~6.3%之间。     

大孔吸附树脂对银杏叶黄酮类化合物吸附及解吸的研究

本文介绍了DM－130，LSA－10和LSA－20型三种大孔吸附树脂对银杏叶黄酮类化合物的吸附性能，考察了pH值，温度，浸出液浓度等影响吸附性能的因素，结果表明DM－130型树脂对黄酮类化合物具有较好的吸附效果。     

环糊精衍生物气相色谱手性毛细管柱的制备与考察

合成了３种新的含长烷基链的β－环糊精衍生物手性固定相。实验表明，随着烷基链长的增加，对手性卤代烃和酯的立体选择性有所提高；以ＯＶ－７为手性固定相的稀释剂对多数手性化合物的拆分效果好于ＯＶ－１７０１。２，６－Ｏ－二辛基－３－Ｏ三氟乙酰－β－环糊精／ＯＶ－７柱应用于不对称合成及催化中对映体的分离与测定和白酒中乳酸乙酯对映体含量的测定。     

Wittig反应的研究XXI．ω－唑烯类杀菌剂的合成

用相转移催化Ｗｉｔｔｉｇ反应由１，４－二溴丁烷和三苯瞬合成了ω－溴代烯类化合物，并由此制得了１５种ω－唑烯类化合物，并对部分化合物进行了杀菌活性测定．     

GC-MS方法分析杨梅果实精油中香气成分

采用气相色谱一质谱联用技术分析鉴定了木叶、东魁及黑炭3种新鲜杨梅果实精油样品的化学成分,并对三者成分进行对比分析.木叶梅果实精油中鉴定出55个化合物,以单萜类成分为主;东魁梅果精油中鉴定出49个化合物,以倍半萜烯和烷烃类成分为主;黑炭梅果精油中鉴定出化合物48种,以倍半萜烯和烷烃类成分为主.木叶杨梅中富含单萜而缺少倍半萜烯,这可能是其香气浓且易腐烂原因.     

胶原纤维固化杨梅单宁对UO22+的吸附

以胶原纤维为基质，通过交联剂将杨梅单宁固化在胶原纤维上制备吸附材料．实验结果表明，所制备的吸附材料对UO2^2 具有很强的吸附能力，当溶液中UO2^2 的浓度为7．5mmol/L、pH为5．0时，吸附容量达到1．19mmol UO2^2 /g(283．3mgU／g)．UO2^2 在固化杨梅单宁上的吸附平衡符合Freurldlich方程，升高温度，平衡吸附量增大。吸附动力学可用拟二级速度方程来描述，由动力学方程计算得到的平衡吸附量与实测的平衡吸附量基本相同，误差在4％以内．pH值对吸附过程有较大影响，适宜的pH在5-8之间。所制备的吸附材料具有优良的柱动力学特性，床层的有效利用率高；经解吸后的吸附柱其吸附性能基本不变。     

反相高效液相色谱法测定毛竹叶中总黄酮

用反相高效液相色谱法,RP－C8柱为固定相,甲醇－水－冰乙酸（40＋60＋2）为流动相,以芦丁为参照物外标法定量,辅以二极管阵列检测技术,测定了毛竹叶中总黄酮的含量,并与光度法作了比较。     

Alteration of foliar flavonoid chemistry induced by enhanced UV-B radiation in field-grown Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii

Chromatographic analyses of foliage from several tree species illustrate the species-specific effects of UV-B radiation on both quantity and composition of foliar flavonoids. Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective UV-B radiation. Foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu Bondapak/C(18) column HPLC system sampling at 254 nm. Total flavonoid concentrations in Quercus rubra foliage were more than twice (leaf area basis) that of the other species; Pseudotsuga menziesii foliage had intermediate levels and P. ponderosa had the lowest concentrations of total flavonoids. No statistically significant UV-B radiation-induced effects were found in total foliar flavonoid concentrations for any species; however, concentrations of specific compounds within each species exhibited significant treatment effects. Higher (but statistically insignificant) levels of flavonoids were induced by UV-B irradiation in 1- and 2-year-old P. ponderosa foliage. Total flavonoid concentrations in 2-year-old needles increased by 50% (1x ambient UV-B radiation) or 70% (2x ambient UV-B radiation) from that of 1-year-old tissue. Foliar flavonoids of Q. rubra under enhanced UV-B radiation tended to shift from early-eluting compounds to less polar flavonoids eluting later. There were no clear patterns of UV-B radiation effects on 1-year-old P. menziesii foliage. However, 2-year-old tissue had slightly higher foliar flavonoids under the 2x UV-B radiation treatment compared to ambient levels. Results suggest that enhanced UV-B radiation will alter foliar flavonoid composition and concentrations in forest tree species, which could impact tissue protection, and ultimately, competition, herbivory or litter decomposition.     

Three new flavonol glycosides from the aerial parts of Rodgersia podophylla

Three new flavonol glycosides were isolated together with five known flavonoids and six bergenin derivatives from the aerial parts of Rodgersia podophylla. The structures of these new compounds were elucidated by spectral methods as kaempferol-3-O-alpha-L-5'-acetyl-arabinofuranoside (1), kaempferol 3-O-alpha-L-3'-acetyl-arabinofuranoside (2), and quercetin-3-O-alpha-L-3',5'-diacetyl-arabinofuranoside (3).     

Anti-allergic effect of the flavonoid myricitrin from Myrica rubra leaf extracts in vitro and in vivo

Flavonoids are ingested by the general population as anti-oxidant and anti-inflammatory agents. In this study, we investigated the effects of myricitrin, a flavonoid rich in Myrica rubra leaf, upon anti-inflammatory action. Myrica rubra leaf extracts inhibited pro-inflammatory TNFα production in a macrophage cell line, Raw264.7 cells. We observed that the serum IgE levels in the leaf extract-treated DO11.10, a mouse allergy model, were down-regulated. HPLC was performed to demonstrate that M. rubra leaf extracts contain a large amount of myricitrin. We observed an inhibitory effect of HPLC-purified myricitrin on TNFα production in Raw264.7 cells. Thus, myricitrin may be of potential interest in the management of inflammatory conditions.     

UVB Radiation Induced Increase in Quercetin: Kaempferol Ratio in Wild-Type and Transgenic Lines of Petunia

The use of genetically modified plants offers unique opportunities to study the role of specific flavonoids in plant UVB protection. Along with a parental wild-type Mitchell Petunia, two transgenic lines with altered flavonoids were also examined; Lc with enhanced levels of antho-cyanins due to the action of a maize flavonoid regulatory gene Leaf color, and AFLS that carries an antisense fla-vonol synthase construct and is known to have reduced flavonol levels in flowers. All three lines were grown in near ambient sunlight, sunlight lacking UVB (280–320 nm) radiation and sunlight with 25% added UVB. Ultra-violet-B radiation induced significant reductions in the rates of leaf expansion and seedling growth in all three lines. The presence of anthocyanins did not appear to afford Lc plants any special protection from UVB. Ul-traviolet-B treatment induced increases in total flavonol content in young plants of all three lines, and this effect decreased with increasing leaf age. Notably, increasing UVB levels led to an increase in the ratio of quercetin: kaempferol with all three cultivars. The AFLS transgenic, contrary to expectations based on its genetic construction, had normal levels of flavonols in the leaves and the highest Q:K ratio of the three cultivars. This transgenic was the least susceptible to UVB, which may indicate an enhanced protective role for quercetin. Because both quercetin and kaempferol have similar UVB screening properties, quercetin may exert this role by other means.     

Constituents of the leaves of Woodfordia fruticosa Kurz. I. Isolation, structure, and proton and carbon-13 nuclear magnetic resonance signal assignments of woodfruticosin (woodfordin C), an inhibitor of deoxyribonucleic acid topoisomerase II

Woodfruticosin (woodfordin C), a new cyclic dimeric hydrolyzable tannin having an inhibitory activity toward deoxyribonucleic acid (DNA) topoisomerase II, has been isolated from the leaves of Woodfordia fruticosa Kurz (Lythraceae) along with three known flavonol glycosides and three known flavonol glycoside gallates. The structure of wood fruticosin (woodfordin C) was determined by the use of two-dimensional nuclear magnetic resonance (2-D NMR) spectroscopy including heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond connectivity (HMBC) techniques. Detailed analyses of the proton and carbon-13 NMR (1H- and 13C-NMR) spectra of six known flavonoids were performed.     

Detection of fortification of ginkgo products using nanoelectrospray ionization mass spectrometry

We report here a negative ionization nanoelectrospray ionization mass spectrometry (nanoESI-MS) technique that simultaneously detects active components, terpenes and intact flavonol glycosides, and toxic ginkgolic acids in ginkgo products. Unlike the conventional methods that hydrolyze flavonol glycosides to flavonoids for analysis, this technique directly detects intact flavonol glycosides, enabling differentiation of these natural glycosides from the synthetic flavonoids. Thus, it allows the detection of fortification of ginkgo products, alleviating a common problem encountered by the conventional methods. Analysis of 14 commercial ginkgo products using this technique demonstrates large variations and deviation from the well-accepted standardized ginkgo extract. Four products showed evidence of fortification with synthetic surrogates. Two products were found to have toxic ginkgolic acids that exceed the 5 microg g(-1) limit by as much as 60000 fold. These results emphasize the importance of appropriate monitoring of ginkgo product quality.