Flavone Glycosides from Strobilanthes Formosanus

Two new flavone glycosides, 3′‐hydroxy‐5,7‐dimethoxyflavone 4′‐O‐β‐D‐apiofuranoside ( 1 ), and 5,7‐dimethoxyflavone 4′‐O‐[β‐D‐apiofuranosyl(1→5)‐ β‐D‐glucopyranoside] ( 2 ) along with four known compounds, 4′‐hydroxy‐5,7‐dimethoxyflavone ( 3 ), 2,6‐dimethoxy‐1,4‐benzoquinone ( 4 ), lupeol ( 5 ) and betulin ( 6 ) were isolated from the stem and roots of Strobilanthes formosanus. Their structures were elucidated on the basis of their spectroscopic evidence.     

Colorimetric and ratiometric sensors derivated from natural building blocks for fluoride ion detection

Three novel colorimetric and ratiometric probes (SH-1~3) for fluoride ion detection were designed and synthesized from nature small molecules. Obvious yellow-to-orange color change of these probes in the THF was achieved only in presence of F^? among the eight anions (F^?, Cl^?, Br^?, I^?, H₂PO₄^?, HSO₄^?, CH₃COO^–, ClO₄^?), along with the emission shifting from green to orange red. These three probes are 1:1 complexed with fluoride ions, with complexation constant of around 0.1 × 10⁴ M^?1. The detection limit of probes SH-1~3 reached as low as around 1 μM. ¹H NMR titration study suggested that the fluoride ion induced deprotonation of the probe through hydrogen bonding interaction between amino group of probe and fluoride ion.     

Isolation of a flavone glucoside from Glycosmis mauritiana (Rutaceae)

From the ethyl acetate extract of the roots of Glycosmis mauritiana a flavone glucoside, luteolin 8-C-β-d-glucopyranoside was isolated. The structure was established by UV, IR, NMR and mass spectral studies.     

Synthesis of dihydrofuroflavonoids via palladium-catalyzed annulation of 1,3-dienes

The palladium-catalyzed annulation of 1,3-dienes by o-iodoacetoxyflavonoids provides an efficient approach to biologically interesting dihydrofuroflavonoids. This reaction is very general, regioselective, and a wide variety of terminal, cyclic, and internal 1,3-dienes can be utilized.     

An Efficient Synthesis of Polymethylene-bis-Aroyl Thiourea Derivatives under the Condition of Phase Transfer Catalysis

Reaction of polymethylene diamine with aroyl chloride and ammonium thiocyanate under the condition of solid-liquid phase transfer catalysis using polyethylene glycol-400(PEG-400) as the catalyst yielded polymethylene-bis-aroyl thiouiea derivatives 3a -- 3h in good to excellent yield     

4'-N,N-二甲氨基黄酮类衍生物的发光行为研究

共轭的分子内电荷转移化合物的光谱和光物理行为的研究，一直受到人们的关注[1-4]．特别在Grabowski、Rettig等人[5-6]提出了所谓“扭曲的分子内电荷转移”(TICT)激发态问题后更是受到重视，这不仅是由于这类化合物具有十分广泛的应用前景，如用作荧光、激光染料、有机非线性光学材料等，而且还存在着一系列有待解决的科学问题．如分子内的电子效应及构家效应等对分子内电荷转移过程及发光行为的影响，电荷转移化合物在经光照激发后可引起分予极化，在周围溶剂分子的作用下，可通过“自去偶”过程达到稳定的电行分离状态即所谓的TICT态…     

HPLC结合紫外光谱法快速定性定量分析四种竹叶黄酮碳苷

采用HPLC结合紫外光谱法,同时测定四种竹叶黄酮碳苷(荭草苷、异荭草苷、牡荆苷和异牡荆苷)。采用Waters XTerra MS C18色谱柱(250mm×4.6mm,5μm),流动相为乙腈和0.5%甲酸水溶液,等梯度洗脱,流速1mL·min-1,柱温30℃,检测波长360nm。建立各个组分在0.1~10.0mg·L-1范围内系列浓度的混合标准工作曲线,其相关系数R2均优于0.999,且在22min内得到较好分离。方法检出限介于0.03~0.07mg·L-1,定量限介于0.04~0.08mg·L-1。分别将标准品与样品中四种黄酮碳苷的紫外光谱(240~400nm)进行比对,荭草苷、异荭草苷、牡荆苷和异牡荆苷相应的光谱曲线形状以及特征吸收波长都表现出高吻合度。取竹叶样品经热回流提取,石油醚萃取及AB-8大孔树脂纯化后,再采用HPLC结合紫外光谱法检测得荭草苷、异荭草苷、牡荆苷和异牡荆苷四种黄酮碳苷相对于竹叶黄酮粉的百分含量分别为13.73,49.68,7.85和30.70mg·g-1,平均回收率为34.90%~87.64%,相对标准偏差为0.41%~10.83%。本方法实现了在较短时间内快速分析竹叶中四种黄酮碳苷,样品稳定,重现性好,为市售竹叶黄酮碳苷的质量控制提供参考。     

Mild alkaline hydrolysis of some 7-O-flavone glycosides. Application to a novel access to rutinose heptaacetate

Alkaline hydrolysis of some 7-O-flavone glycosides was performed through the 6,8-dibromo derivative. When the sugar linked to the aglycon has a 2-hydroxy group trans to the sugar-aglycon bond as in β-D-glucosides or rutinosides, hydrolysis occurred at room temperature under very mild conditions. Application to a novel preparation of rutinose heptaacetate by hydrolysis of a diosmin derivative is described.     

银杏叶提取物中黄酮类化合物的分光光度分析研究

建立了一种银杏叶提取物中黄酮类化合物的分光光度测定方法。研究表明在NaNO2存在下,pH在13.20～13.60范围内,银杏叶提取物与Al(NO3)3形成稳定的粉红色配合物,于λmax=510nm处进行分光光度分析。标准品选用芦丁,其标准曲线在4.606～55.27μg/mL范围内服从朗伯-比尔定律,相关系数为r=0.9998。回收率为98.58%～102.80%,RSD为0.111%。可用于银杏叶提取物中黄酮类化合物的测定。     

New Esters, 2-(4-Hydroxy-3-Methoxyphenyl)Ethyl Hexa- and Octacosanoates from the Leaves of Cinnamomum Reticulatum Hay

The leaves of Cinnamomum reticulatum Hay were extracted successively with hexane and acetone successively. Dipentadecyl ketone, n-dotriaconyl alcohol, 2-(4-hydroxy-3-methoxyphenyl)ethyl hexa- and octacosanoates ( two new esters from hexane extract ), β-sitosterol, fatty acid, vanillin, p-hydroxybenzaldehyde, genkwanin, vanillic acid, p-hydroxybenzoic acid, β-sitosteryl-l-β-glucopyranoside, meso-erythritol, glucose, and 4-(2-hydroxyethyl)-2-methoxyphenyl-l-β-D-glucopyranoside (from the acetone extract) were isolated. The structures of the new esters were elucidated by chemical and physical evidence.