A Minor New Flavone from Scutellaria baicalensis Georgi

A new flavone,6,2′-dihydroxy-5,7,8,6′-tetramethoxyflavone,was isolated from the roots of Scutellaria baicalensis. Its structure was established on the basis of spectral evidences.     

An efficient strategy based on two-stage chromatography and in vitro evaluation for rapid screening and isolation of acetylcholinesterase inhibitors from Scutellaria baicalensis Georgi

The extraction of Scutellaria baicalensis Georgi was investigated using the response surface methodology-genetic algorithm mathematical regression model, and the extraction variables were optimized to maximize the flavonoid yield. Furthermore, a simple and efficient ultrafiltration–liquid chromatography–mass spectrometry and molecular docking methods were developed for the rapid screening and identification of acetylcholinesterase inhibitors present in Scutellaria baicalensis Georgi. Subsequently, four major chemical constituents, namely baicalein, norwogonin, wogonin, and oroxylin A, were identified as potent acetylcholinesterase inhibitors. This novel approach, involving the use of ultrafiltration–liquid chromatography–mass spectrometry and molecular docking methods combined with stepwise flow rate counter-current chromatography and semi-preparative high-performance liquid chromatography, could potentially provide a powerful tool for the screening and extraction of acetylcholinesterase inhibitors from complex matrices and be a useful platform for the production of bioactive and nutraceutical ingredients.     

黄芩的1H NMR指纹图谱研究

利用PFT-NMR 核磁共振波谱仪测定了黄芩提取物的¹H NMR图谱,对黄芩提取物的¹H NMR指纹图谱进行了解析,并与黄芩苷元、千层纸素A、汉黄芩素和黄芩苷进行了比较,获得了黄芩提取物的特征峰,并利用向量夹角法计算了不同指纹图谱的相似度;结果表明不同黄芩提取物的¹H NMR指纹图谱都显示出黄酮类有效成分特征共振峰,并具有很好的重现性和高度的特征性,可以成为黄芩真伪鉴别的依据;不同黄芩的¹H NMR指纹图谱的相似度计算结果定量地评价了不同指纹图谱的相似性.     

Py-GC/MS分析烟用添加剂黄芩浸膏的热裂解产物

采用在线热裂解气相色谱-质谱法(Py-GC/MS)法研究了黄芩浸膏热裂解行为。在氦气氛围中,将黄芩浸膏分别在300、450、600、750和900℃下进行热裂解,并以GC/MS对其裂解产物进行定性和半定量分析,并用黄芩浸膏进行了卷烟加香试验。结果表明:①黄芩浸膏在这一系列裂解温度下检测到的挥发性热裂解产物分别为12种、19种、40种、55种和46种;②黄芩浸膏低温区(300℃～450℃)裂解后产生大量醛类、酮类、酯类和呋喃类物质,这些物质是构成卷烟香味的重要物质,能改善卷烟吸味、减轻刺激性;③在高温区(750℃～900℃)产生大量的芳香族化合物,如苯、甲苯、乙苯、萘等。该研究为香味物质在卷烟燃烧过程中的挥发性物质提供了例证。     

Preparation of a novel molecularly imprinted polymer for the highly selective extraction of baicalin

The selective extraction of baicalin is important to its quality control especially when the matrices are complicated. In this work, a novel molecularly imprinted polymer was prepared for the selective extraction of baicalin in herbs. The molecularly imprinted polymer was synthesized by the copolymerization of 4‐vinyl pyridine and ethylene glycol dimethacrylate in the presence of baicalin by a precipitation polymerization method. After the optimization of parameters for molecularly imprinted polymer preparation, including the functional monomer, porogen, sampling solvent, and washing solvent, good selectivity was obtained, with an imprinting factor of about 4, which is much better than that achieved by the bulk‐polymerization method. The performances of the prepared molecularly imprinted polymers were systematically investigated, including adsorption kinetics, isotherm experiment, and Scatchard analysis. On the basis of the good adsorptive capability of the prepared molecularly imprinted polymer, it was also applied for the pretreatment of baicalin in Scutellaria baicalensis Georgi. The result showed that most of the matrices were removed and baicalin was selectively enriched.     

A New Flavanone and a New Flavanone Glycoside from ScuteUaria baicalensis

A new flavanone （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 1 together with a new flavanone glycoside （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 7-O-13-D-glucopyranoside 2, were isolated from the dry roots of Scutellaria baicalensis. Their structures were elucidated on the basis of spectroscopic data.     

6,8-di-C-glycosyl flavones with β-furanoarabinose from Scutellaria baicalensis and their anti-inflammatory activities

Two flavone di-C-glycosides, a pair of isomers, were isolated from Scutellaria baicalensis. The structures of compounds 1 and 2 were elucidated by means of physical data, including 1D and 2D NMR and HR-ESI-MS. Supporting theoretical calculations of the compound conformational landscape has also been conducted for geometry optimization. This is the first report of the natural occurrence of β-furanoarabinoside. In addition, the effects of compounds 1 and 2 on NO, pro-inflammatory cytokines, PGE2 and COX-2 levels were measured in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. The pair of isomers exhibited significant inhibitory effects on inflammation.     

Determination of Metabolites from Scutellaria baicalensis by GC/MS and 1H NMR

The quality of medicinal herbs and their products is steadily becoming important in tandem with growing interest in complementary alternative medicine for treatment of diseases. Chemical assays with bioactive secondary compounds are usually used for chemical standardization in herbs for quality control purpose. In this study, an analytical platform comprising of a GC-MS technique with an unsupervised multivariate analysis and a complementary one-dimensional ¹H NMR technique was used to obtain the primary metabolite profiling of Scutellaria baicalensis obtained from different medical halls in Singapore. The key primary metabolites such as sucrose, proline, phenylalanine, fructose, and butanedioic acid for the biosynthesis of bioactive secondary metabolites in this medicinal herb were successfully characterized by the combination of the chromatography and spectroscopy techniques. Their results suggested that these compounds could serve as markers for quality control of the herb. The principal component analyses of the GC-MS data reliably discriminated between the various Scutellaria samples indicating that the developed platform was comprehensive and was applicable to assess the quality of other medicinal herbs.     

人工种植黄芩根、茎、叶、花、种子中营养元素的光谱分析

使用火焰原子吸收光谱法对人工种植黄芩的根、茎、叶、花、种子5个部位中的Ca,Cu,Fe,Mn,Zn,K六种矿物元素的含量进行了测定分析。结果表明,黄芩各部位均含有丰富的矿物元素,根中营养元素由高到低的顺序是为Ca>Fe>Cu>Mn>Zn>K,茎中的为Fe>Mn>Zn=Cu>K>Ca,叶中的为Fe>Mn>Zn>Cu>K>Ca,花中的为Ca>Fe>Mn>Zn>Cu>K,种子中的为Ca>Fe>Zn>Mn>Cu>K。研究认为人工种植黄芩茎、叶、花、种子中Fe, Mn, Zn含量皆较高,花和种子中还富含Ca, 根中富含Ca和Fe元素。     

赛里木湖贝加尔雅罗鱼Leuciscus leuciscus baicalensis生长研究

对赛里木湖贝加尔雅罗鱼的生长、食性和繁殖力等进行了观测研究．结果表明，贝加尔雅罗鱼在赛里木湖生长缓慢，1^ 龄平均体长4．5cm，11^ 龄为23．6cm；体重与体长的相关关系为W=0．142971L^3.072634。雄鱼最小性成熟年龄为2^ 龄。雌性最小性民熟年龄为3^ 龄，绝对怀卵量平均为21520粒，相对怀卵量为131粒／g，繁殖期在5月底至6月底．食物组成主要为钩虾和西藏拟骚．