HPTLC—Densitometry Method for Simultaneous Determination of Major Lignans and Flavonoids in Podophyllum hexandrum

JPC – Journal of Planar Chromatography – Modern TLC - A new quantitative method using thin-layer chromatography silica gel 60F254 plates as the stationary phase and the mobile phase...     

鬼臼葡聚糖的化学结构

从植物鬼臼根的沸水提取液中分离出一个水溶性多糖EPS。它是由单一葡萄糖残基构成的葡萄糖, 分子量约为1.6×10^4。经酸全水解, 甲基化反应, 高碘酸氧化, Smith降解, KI-I~2反应, IR, ^1H NMR和^1^3C NMR分析, 证明其化学结构为1,4-葡萄糖残基为主链, 并在6-O位有侧链的葡聚糖。     

Studies of crude chloroform extract of roots ofPodophyllum emoddii var. chinesis Sprague by micellar electrokinetic chromatography

Chromatographia - A crude chloroform extract of the roots ofPodophyllum emoddii var. chinesis Sprague was studied by micellar electrokinetic chromatography. Four peaks belonging to podophyllotoxin,...     

Identification and characterization of Podophyllum emodi by API-LC/MS/MS

An API-LC/MS/MS method was developed for the identification of the medicinal herb Podophyllum emodi based on the profile of its aryltetrahydronapthalene and related lignan marker compounds. This was done by matching the structural information from the tandem mass spectrometric data with those lignan marker compounds already reported for the herb. The method could be employed in the absence of reference standards for the markers and was particularly useful in view of the scarcity of supply of these chemical standards. It has been used successfully to differentiate Podophyllum emodi from two commonly used medicinal herbs of a different genus but having similar appearance, Radix clematidis and Radix gentiana, as well as a closely related herb, Podophyllum peltatum.     

Isothermal microcalorimetric investigation of the toxic action of the effective constituents of Podophyllum emodi Wall on Tetrahymena thermophila BF5

The effects of podophyllotoxin (PPT), etoposide (VP16), and teniposide (VM26) on the growth of Tetrahymena thermophila BF₅ (T.t.BF₅) was investigated by the TAM AIR isothermal microcalorimetric system. The extent and duration of toxic effects on T.t.BF₅ metabolism were evaluated by studying the growth rate constant (k), inhibitory ratio (I), maximum heat-output power (P _max), peak time of maximum heat-output power (t _p), and total heat production (Q _t). Experimental results showed that the value of t _p increased and the value of k and P _max decreased with the increasing compound concentrations. Furthermore, the growth rate constant k was linear with compound concentration. The corresponding I was obtained from different k values. According to the IC₁₀ (the concentration of inhibitor when the inhibitory ratio is 10 %), the relative toxicity of the three compounds was PPT (IC₁₀ = 49.6 μg mL^?1) > VP16 (IC₁₀ = 117.5 μg mL^?1) > VM26 (IC₁₀ = 359.1 μg mL^?1). The preliminary investigation of structure–activity relationships showed that the thienyl group was likely responsible for reducing the toxicity of the compounds.     

Simultaneous Determination of Nine Flavonoids in Dalbergia odorifera by LC

A rapid and accurate HPLC method has been developed for the simultaneous determination of nine major flavonoids, namely 3-hydroxymelanettin, melanettin, stevenin, butein, isoliquiritigenin, dalbergin, 2,4-dihydroxy-5-methoxybenzophenone, pinocembrin, 4-methoxydalbergione in Dalbergia odorifera. The samples were separated on an Aglient Zorbax SB-C₁₈ column (250 × 4.6 mm, 5 m) with a gradient of acetonitrile and 1% aqueous acetic acid (/) at a flow rate of 1.0 mL min^–1 and detected at 350 nm. The complete separation was obtained within 30 min for the nine target flavonoids. All calibration curves showed good linearity (r² > 0.999) within test ranges. The repeatability was evaluated by intra- and inter-day assays and RSD values were less than 4.0%. The recoveries were between 92.0% and 104.5%. The developed method was successfully applied to the analysis of 32 commercial samples of D. odorifera.     

LC Analysis of Lignans from Schisandra sphenanthera Rehd. et Wils.

Schisandra sphenanthera Rehd. et Wils. is widely used in traditional Chinese medicine. A rapid and convenient method to separate and quantify four lignans (schisandrin, schisantherin A, deoxyschizandrin, and γ-schizandrin) was established by reversed-phase liquid chromatographic. On a Shimadzu C₁₈ column (Phenomenex, 150 × 4.6 mm; 5 μm particle size), an isocratic flow elution program and a simplified sample pretreatment approach were used in the experiment. Samples from different parts of S. sphenanthera were extracted by chloroform and then separated with methanol and deionized water (70:30 v/v) at a flow rate of 0.8 mL min^?1. The detection wavelength was set at 280 nm. The content of lignans in fruits is the highest, and the quantities of schisantherin A, deoxyschizandrin, and γ-schizandrin from fruits are 0.56, 0.54 and 0.30%, respectively. Schisandrin is not detected in all the plant extracts. This research forms a basic framework for the better use of S. sphenanthera in medicine.     

LC Analysis of Lignans from Schisandra sphenanthera Rehd. et Wils.

Schisandra sphenanthera Rehd. et Wils. is widely used in traditional Chinese medicine. A rapid and convenient method to separate and quantify four lignans (schisandrin, schisantherin A, deoxyschizandrin, and γ-schizandrin) was established by reversed-phase liquid chromatographic. On a Shimadzu C₁₈ column (Phenomenex, 150 × 4.6 mm; 5 μm particle size), an isocratic flow elution program and a simplified sample pretreatment approach were used in the experiment. Samples from different parts of S. sphenanthera were extracted by chloroform and then separated with methanol and deionized water (70:30 v/v) at a flow rate of 0.8 mL min⁻¹. The detection wavelength was set at 280 nm. The content of lignans in fruits is the highest, and the quantities of schisantherin A, deoxyschizandrin, and γ-schizandrin from fruits are 0.56, 0.54 and 0.30%, respectively. Schisandrin is not detected in all the plant extracts. This research forms a basic framework for the better use of S. sphenanthera in medicine.

     

GC-MS分析南方红豆杉种子中的挥发油

采用水蒸气蒸馏法提取南方红豆杉种子中的挥发油，测得南方红豆杉种子挥发油的收率为2．5％。通过GC-MS技术分析了南方红豆杉种子中挥发油的化学成分。按照GC／MS通用法则，初步确定了24种化合物的结构。并用峰面积归一化法得出在挥发油中的各化学成分。其中主要成分酸类占挥发油总量的81．28％．其次的烷烃类化合物为12．74％，醛类化合物为1．80％，不饱和烷烃类化合物1．44％，醇类化合物占0、89％，酯类化合物为0．52％，胺类化合物为0．34％。这几类物质占种子中挥发油总量的99．01％。     

Lignans and Triterpenes from the Root of Pseuderanthemum carruthersii var. atropurpureum

Two new lignans, pseuderesinol (1), pseuderanoside (2) and a new triterpene, pseuderanic acid (3) were isolated from the dried root of Pseuderanthemum carruthersii (SEEM.) GUILL. var. atropurpureum (BULL.) FOSB. (Acanthaceae), together with ten known compounds, including five lignans, (+)-eudesmin (4), (+)-magnolin (5), (+)-syringaresinol (6), (+)-episyringaresinol (7), (+)-1-hydroxysyringaresinol (8) and five triterpenes, squalene (9), oleanolic acid (10), lupeol (11), betulin (12), betulinic acid (13). Their chemical structures were elucidated by 1D- and 2D-NMR, computational quantum chemistry, as well as high resolution-electrospray ionization (HR-ESI)-MS spectroscopic analysis. The acetylcholinesterase inhibition and cytotoxic activities against HeLa and MCF-7 cancer cell lines were evaluated on some purified compounds at the concentration of 100?μg/mL. Pseuderesinol (1) and magnolin (5) exhibited moderate cytotoxic activities against the MCF-7 cancer cell line.     

Inner wall coating of micro-LC columns. Wall effects in LC

An elastic inner wall coating in the fused silica capillaries used for Micro-LC (LC on packed fused silica capillary columns) stabilizes the packed bed and thus increases column efficiency and life expectancy. Probably the particles of packing material are partly forced into the elastic polymer layer which thus holds the packing in position. Bonded polymers of very different chemical polarity can be used with equally good results. Variation of the coating layer thickness shows that there is an optimum value around 0.3 μm. A discussion of various wall effects in LC columns is presented. The i.d. of the columns is a most important parameter in this respect.     

Three New Arylnaphthalide Lignans from the Aerial Parts of Bupleurum marginatum Wall. ex DC.

Three new arylnaphthalide lignans, 5‐(4‐hydroxy‐3‐methoxyphenyl)furo[3′,4′: 6,7]naphtho[2,3‐d]‐1,3‐dioxol‐6(8H)‐one ( 1 ), 10‐(4‐hydroxy‐3‐methoxyphenyl)furo[3′,4′: 6,7]naphtho[1,2‐d]‐1,3‐dioxol‐9(7H)‐one ( 2 ), and 10‐(3,4‐dimethoxyphenyl)‐6‐hydroxyfuro[3′,4′: 6,7]naphtho[1,2‐d]‐1,3‐dioxol‐9(7H)‐one ( 3 ), together with two known ones, chinensin ( 4 ) and isodiphyllin ( 5 ), were isolated from the aerial parts of Bupleurum marginatum Wall . ex DC. The structures of the three new lignans were established by means of NMR spectroscopic studies, including HQSC, HMBC, and ROESY.     

Long-Wavelength Fluorescence Detection of Flavonoids in Orange Juices by LC

A new post-column liquid chromatographic reaction system for the determination of flavonoids in orange juices is based on the use of the long wavelength fluorophor cresyl violet and cerium(IV) in a cetyl trimethylammonium bromide micellar medium. Two flavone aglycones (quercetin and kaempferol), a flavonone aglycone (naringenin), one flavone-O-glycoside (rutin) and two flavanone-O-glycosides (hesperidin and naringin) have been used as analyte models. The reaction process involves the interaction between the analyte, cerium(IV) and cresyl violet giving rise to a decrease in the fluorescence, measured at λ _ex 585, λ _em 625 nm, which is proportional to the analyte concentration. Dynamic ranges of the calibration graphs and detection limits, obtained with standard solutions of the analytes are (ng mL^?1): quercetin (12.2–4,000, 3.7), kaempferol (3.5–1,000, 1.0), naringenin (6.7–1,000, 2.0), rutin (5.0–800, 1.5), hesperidin (10.1–1,000, 3.0), and naringin (17.8–800, 1.8). The determination coefficients were higher than 0.993 in all instances. The precision of the method, expressed as RSD%, was established at two concentration levels, with values ranging between 2.8 and 6.2%. The practical usefulness of the developed method is demonstrated by the analysis of natural and commercial orange juices, which were filtered, diluted and directly injected into the chromatographic system, with apparent recoveries between 86.9 and 107.0%.     

Simultaneous Quantification of Seven Flavonoids in Flos Gossypii by LC

Species of the genus Achillea have been used in traditional folk medicine for centuries. In Europe taxa of the Achillea millefolium group are widely spread, their correct taxonomic differentiation by morphological and anatomical characteristics encounters some difficulties. Several species of the polyploid A. millefolium group however, can be characterised by their distinct sesquiterpene pattern. Analysis is usually performed by LC using conventional RP stationary phases. Likewise, it has been proven that non-porous RP stationary phases are an excellent alternative for sensitive and more rapid separations of plant extracts. In the present work a Kovasil MS-C18 1.5 μm non-porous packing was used with an acetonitrile-water gradient for the analysis of Achillea flower extracts. Detection and identification of the respective sesquiterpenes has been achieved by diode array detection and LC coupled APCI+ and ESI+ mass spectrometry.     

LC Determination of Gemfibrozil in Tablets

A simple, selective, precise and accurate reversed phase-HPLC assay for analysis of gemfibrozil in tablets was developed and validated. Separation and quantification were achieved on a Phenomenex C₁₈ column under isocratic conditions using a mobile phase (methanol:water, 80:20, v/v) maintained at 1.1 mL min⁻¹. UV-detection was at 280 nm. Atorvastatin was selected as an internal standard. The standard curves were linear over the range of 0.5–3.0 μg mL⁻¹ (r > 0.999). The limits of detection and quantification were 0.20 and 0.51 μg mL⁻¹, respectively. The recoveries for gemfibrozil were above 99.01%. The intra-day and inter-day precision (RSD) for gemfibrozil were below 1.74 and 1.83%, respectively. No chromatographic interferences from the tablet excipients were found. The results of the developed procedure in tablets were compared with those of the reference method to assess gemfibrozil content. Statistical comparison of the results with the reference method using spectrofluorimetric method showed excellent agreement and proved no significant difference in accuracy and precision. This HPLC method is fast and simple for the analysis of gemfibrozil in pharmaceutical preparations.     

Chromatographic Determination of Lignans (Antioxidants) in Food Products

Interest in lignans is continually growing in recent years because of their strong antioxidant properties and other biological characteristics, positively affecting human health. Methods for the extraction, identification, and determination of lignans are developed; lignan species and their quantity in food products are determined, and databases of lignans in food products have been created in several countries (Finland, Netherlands, United States, Canada, United Kingdom, Japan, and Spain). In this review, we consider chromatographic methods (gas, liquid, supercritical fluid, and thin-layer chromatography) used to identify and determine natural lignans and isolate them in an individual state. Most natural lignans are found in flax and sesame seeds, cereals, some vegetables, fruits, and berries.     

六月霜中总黄酮和元素含量的分析

用分光光度法测定了六月霜中总黄酮的含量,用原子吸收分光光度法测定了六月霜中元素的含量。结果表明,六月霜中总黄酮含量为６％,Ｍｎ含量较高。