A new ent-kaurane diterpene derivative from the stems of Eurya chinensis R.Br

One new ent-kaurane diterpene derivative (1), along with four known diterpenes, was isolated from the stems of Eurya chinensis R.Br. The structure of the new compound was established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 1 showed moderate anti-inflammatory activities with IC₅₀ value of 8.12 μM. This is the first example of diterpenoids with 4-hydroxy-4-(2-hydroxyethyl)-1-hydroxyl-cyclohexanoyl substituent.     

A new abietane diterpenoid glycoside from ajuga ovalifolia var. calantha

A new abietane diterpenoid glycoside, ajugaside B (1), along with three known compounds (2–4), were isolated from the whole plants of Ajuga ovalifolia var. calantha. The structure of the new compound (1) was elucidated by means of spectroscopic analyses (HRESIMS, IR, NMR and ECD). All of the isolated compounds were evaluated for their antitumor activities against MGC803, MCF-7, A549, HT29 and HepG2 cell lines. Compounds 3–4 showed moderate cytotoxicity against all tested cell lines with IC₅₀ values of 1.8–7.3?μM.     

Exploration and optimization of conditions for quantitative analysis of lignans in Schisandra chinensis by an online supercritical fluid extraction with supercritical fluid chromatography system

An online supercritical fluid extraction with supercritical fluid chromatography system could provide sequential extraction and quantitative analysis of lignans in Schisandra chinensis. Supercritical fluid extraction conditions were optimized at 15 MPa, 50°C, and 4 min with supercritical CO₂ adding 1% methanol; the elution volume and flow rate were set at 6 mL and 2 mL/min to blow extract out of the tank completely. The split‐flow rate was confirmed at 2.5%, which determines injection volume and accuracy of quantitative detection. The factors having negative influences on supercritical fluid chromatography retention in the online system, including sample loading forms and backpressure settings, are discussed in the paper. At last, an extraction‐quantitative method for lignans in Schisandra chinensis was developed, which could be finished within 19.5 min. The total content percentage of four lignans (Schisandrin, Schisandrin A, Schisandrin B and Schisandrol B) in four batches was respectively measured to be 1.42, 1.54, 1.62, and 1.90%.     

Optimization of the extraction of paclitaxel from Taxus baccata L. by the use of microwave energy

A simple and rapid microwave-assisted extraction (MAE) procedure was developed and optimized for the extraction of paclitaxel (Taxol) from the needles of yew trees Taxus baccata L. grown in Iranian habitats. The samples, immersed in a methanol-water mixture, were irradiated with microwaves in a closed-vessel system. The method was evaluated using a factorial design approach based on parameters such as extraction time, temperature, methanol concentration in water (v/v), and the ratio of grams of sample to 10 mL of solvent. Statistical treatment of the results revealed that the selected parameters were all significant except the extraction time. Optimum conditions would be 1.5 g samples in 10 mL solvent (90% methanol), an extraction temperature of 95 degrees C, and an extraction time of 7 min. The extracts has been analyzed by reverse-phase high-performance liquid chromatography with UV detection (LC/UV) at 227 nm for quantification. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for confirmation. The main advantage of the proposed MAE method versus conventional solvent extraction (CSE) are the considerable reductions in time (7 min versus 16 h) and in solvent consumption (20 mL versus 150 mL). The MAE procedure yielded extracts that could be analyzed directly without any preliminary clean-up or solvent exchange steps. Both extraction methods show RSDs lower than 10% and lead to comparable recoveries of paclitaxel (87-92%).     

Application of ultrahigh-performance liquid chromatography coupled with mass spectrometry for analysis of lignans and quality control of Fructus Schisandrae chinensis

Lignans in the drug Fructus Schisandrae chinensis (FSC) exhibit potent biological activities such as antihepatotoxic, antiasthmatic, and antigastric ulcer. An ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method has been developed to evaluate the quality of FSC through simultaneous qualitative and quantitative analysis of 15 lignans, including schizandrin A, B, and C; schizandrol A and B; gomisin B, C, D, E, G, H, J, and N; tigloylgomisin H; and angeloylgomisin H. The compounds were separated on a Zorbax Eclipse Plus C(18) (2.1 × 100 mm, 1.8 μm) column with a gradient elution of acetonitrile and 0.1% formic acid. Lignans were identified through their retention times, accurate mass data, and characteristic ions by comparison with a reference substance. All calibration curves showed perfect linear regression (r(2) > 0.99) within the test range. The limits of detection and quantitation fell in the ranges of 0.1-4 ng/mL for all the analytes with an injection of 10 μL. Good results were obtained with respect to repeatability (relative standard deviation <4.6%) and recovery (85.58-105.82%). Meanwhile, the entire sample analysis time was less than 10 min. This developed method provided a new basis for the overall assessment of the quality of FSC.     

A New Taraxastane‐Type Triterpene from Vitex trifolia var. simplicifolia

3‐Oxotaraxer‐14‐en‐30‐al ( 1 ), a new taraxastane‐type triterpene, together with 14 known compounds, taraxerone ( 2 ), 3‐epiursolic acid ( 3 ), 2α,3β‐dihydroxyurs‐12‐en‐28‐oic acid ( 4 ), lupeol ( 5 ), betulinic acid ( 6 ), casticin ( 7 ), artemetin ( 8 ), luteolin ( 9 ), 4‐hydroxybenzoic acid ( 10 ), docosanoic acid ( 11 ), tetracosanoic acid ( 12 ), cerotic acid ( 13 ), β‐sitosterol ( 14 ), and β‐daucosterol ( 15 ), was isolated from the leaves and twigs of Vitex trifolia var. simplicifolia . Compounds 2 – 6 were found for the first time in this plant. Their structures were established by spectroscopic analysis, including 2D‐NMR techniques. Cytotoxic activities of compounds 3 , and 5 – 10 were tested on the three cancer cell lines, PANC‐1, K562, and BxPC‐3. Results revealed that 7 exhibited cytotoxicity against PANC‐1, K562, and BxPC‐3, with IC₅₀ values of 4.67, 0.72, and 4.01 μg/ml, respectively, whereas 8 was inactive against these cancer cell lines. The structure? activity relationship of compound 7 and 8 indicated that the 3′‐OH group in polymethoxyflavonoids is essential for antitumor activity.     

Vitrifolin A: A Norlabdane Diterpenoid from the Fruits of Vitex trifolia Linn. var. simplicifolia Cham

A new norlabdane diterpenoid, named vitrifolin A, was isolated from the fruits of Vitex trifolia Linn. var. simplicifolia Cham. Its structure was elucidated by mean of spectroscopic methods, including HRESIMS, IR, 1D and 2D NMR. The inhibitory effect of vitrifolin A on nitric oxide production in lipopolysaccarideactivated mouse macrophages was also evaluated.     

UFLC–MS/MS method for simultaneous determination of six lignans of Schisandra chinensis (Turcz.) Baill. in normal and insomniac rats brain microdialysates and homogenate samples: towards an in‐depth study for its sedative‐hypnotic activity

Schisandra chinensis (Turcz.) Baill., a traditional Chinese medicine, has been clinically used for the treatment of insomnia for centuries. The insomnia mechanism and the possible active ingredients of S. chinensis remain largely unknown. The objective of this study was to develop a method to detect its components which could pass through the blood brain barrier (BBB) by determining the brain microdialysate and brain tissue homogenate samples and then obtain the pharmacokinetic profile in brain for comprehensive understanding of its hypnotic clinical efficacy. Therefore, an efficient, sensitive and selective ultra fast liquid chromatography/tandem mass spectrometry method for the simultaneous determination of six sedative and hypnotic lignans (schisandrin, schisandrol B, schisantherin A, deoxyshisandrin, γ‐schisandrin and gomisin N) of Schisandra chinensis (Turcz.) Baill. in rat brain tissue homogenate and brain microdialysates has been developed and validated. The analysis was performed on a Shim‐pack XR‐ODS column (75 mm × 3.0 mm, 2.2 µm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The method was validated in brain homogenate and microdialysate samples, which all showed good linearity over a wide concentration range (r² > 0.99), and the obtained lower limit of quantification was 0.1 ng · ml^?1 for the analytes in brain microdialysate samples. The intra‐ and inter‐day assay variability was less than 15% for all analytes. The study proved the six lignans, as sedative and hypnotic ingredients, could pass through the BBB with brain targeting, distributed mainly in the hypothalamus and possessed complete pharmacokinetics process in brain. The results also indicated that significant difference in pharmacokinetic parameters of the analytes was observed between two groups, while absorptions of these analytes in insomniac group were significantly better than those in normal group. Copyright © 2013 John Wiley & Sons, Ltd.     

An efficient strategy for the extraction and purification of lignans from Schisandra chinensis by a combination of supercritical fluid extraction and high‐speed counter‐current chromatography

An efficient strategy for extracting and separating five lignans from Schisandra chinensis (Turcz.) Baill has been developed using supercritical fluid extraction (SFE) and high‐speed counter‐current chromatography (HSCCC) in the present study. First, the extraction was performed by a preparative SFE system under 15 MPa of pressure at 36°C for 4 h. Then, the SFE extract was successfully separated and purified by HSCCC with a two‐phase solvent system composed of n‐hexane/ethyl acetate/methanol/water (6:4:5:5, 6:4:6:4, 6:4:8:2, v/v) in a stepwise elution mode. The fractions were analyzed by HPLC, and the chemical structures of the products were identified by ESI‐MS and ¹H NMR spectroscopy. As a result, a total of 12.5 mg of schisandrin at 98.0% purity, 7.1 mg of gomisin A at 98.1% purity, 1.8 mg of schisantherin B at 93.3% purity, 4.4 mg of deoxyschisandrin at 92.9% purity, and 6.8 mg of γ‐schisandrin at 89.1% purity were obtained from 300 mg crude extract in a one‐step purification.     

Simultaneous Analysis of Seven Bioactive Compounds in Sambucus Chinensis Lindl by HPLC

Following optimization of extraction, separation, and analytical conditions, a simple, rapid, and sensitive HPLC-UV method was developed for the simultaneous determination of seven major bioactive components in Sambucus chinensis Lindl, including chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, kaempferol-3-O-β-D-galactopyranoside, kaempferol-3-O-β-D-glucopyran-oside, and kaempferol-3-O-(6-actyl)-β-D-galacto-pyranoside. The good chromatographic separation was performed on a Gemini C₁₈ reversed-phase analytical column (250 mm × 4.6 mm, 5 μm) by gradient elution with acetonitrile and formate aqueous buffer (containing 0.8% formic acid, V/V) at a flow rate of 1.0 mL/min. The detection wavelength was set at 326 nm. The intra-day and inter-day precisions were evaluated with the R.S.D. values less than 4.0%. The mean recoveries of the seven compounds were in the range of 92.4%–104.8%. The method was successfully applied to determine the seven bioactive compounds in six different origins of Sambucus chinensis Lindl samples, and there was a significant variation in the contents of the seven compounds among the six samples. Therefore, this method provided a new basis of overall assessment for routine use in the quality control of Sambucus chinensis Lindl.