[Screening of G-quadruplex ligands from Macleaya cordata extract by contrast ultrafiltration with liquid chromatography-mass spectrometry and molecular docking].

G-quadruplex DNA has become an important target for tumor therapy and anti-tumor development. Modern pharmacology has proved that Macleaya cordata has anti-inflammatory, antibacterial, anti-tumor and other pharmacological effects. Affinity ultrafiltration method can screen active ingredients from compounds rapidly, but G-quadruplex DNA ligands are difficult to dissociate, which is a key step in conventional ultrafiltration method. In this paper, the filtrates after ultrafiltration were determined by HPLC-MS in substitution. The peaks with 20% reduction of MS response from the incubation vs control were considered to be ligand components to G-quadruplex. Two of the peaks with the relative abundance above 30% were identified as sanguinarine(SAN) and chelerine(CHE). Their circular dichroism conformations further proved that SAN and CHE are active ligands of HT4. In addition, another two gradients with high relative abundance were identified as protopine(PRO) and allpcryprotopine(ALL). The binding rate of SAN, CHE, PRO and ALL was calculated according to the HPLC-MS results, and the results showed a consistency with that of the molecular docking method. The proposed method can be used to screen active components from mixture.

Simultaneous determination of free and total paclitaxel in blood in a three-phase laminar flow microchip.

In this study, a three-phase laminar flow microfluidic chip (TPL chip) combined with HPLC was developed for monitoring free and total concentrations of paclitaxel (PTX) in blood simultaneously. A diluted whole blood sample (aqueous phase) was introduced into the chip, ethyl acetate (organic phase) was introduced into the chip for extraction, and an interphase was used to prevent the blood sample from coming into direct contact with the organic phase. Because only free drug can quantitatively diffuse into the organic extraction phase and the free drug fraction has a linear relationship with the dilution factor of blood, both the free and total drug concentrations can be obtained by detecting the concentration of paclitaxel in the organic extraction phase. The governing factor such as flow rate for extraction was optimized. Docetaxel was used as an internal standard. The reliability of the quantitative diffusion of molecules in the TPL chip was proved by the methodological investigation of PTX in PBS sample, which showed a good linearity in the concentration range of 0.5 - 100 µg/mL and a detection limit of 7 ng/mL. Good repeatibilities for retention time (RSD of PTX is 1.23%, docetaxel is 1.14%, n = 5) and peak area ratio of PTX to docetaxel (RSD is 4.38%) were obtained. For blood sample analysis, only 100 µL of sample was needed and whole pretreatment was finished in 35 min, and a recovery of 94~117% were obtained. The provided method showed advantages in fast analysis speed, minimum sample handing, and potential ability of automation, and integration.

Integration of laminar flow extraction and capillary electrophoretic separation in one microfluidic chip for detection of plant alkaloids in blood samples.

The design, construction and testing for integration of liquid-liquid extraction (EX) and capillary electrophoretic (CE) separation on one glass microchip was reported. In this EX-CE chip, a 1.5 cm-long and 200 µm-wide EX channel was used for extraction based on the two-phase laminar flow, followed by a single-cross CE unit for on-line analysis without any auxiliary devices. One side of the EX channel surface for the organic solvent phase was selectively modified to be hydrophobic while the surface of the other side for the aqueous phase remained hydrophilic, and the extraction product reservoir is also used as the sample reservoir for the subsequent chip separation in the CE channel. With the surface-directed liquid flow behavior and liquid level adjustment in various reservoirs of the EX-CE chip, no disturbance occurred between the extraction (EX) and capillary electrophoretic (CE) units. A small heating block was placed under the chip to accelerate solvent evaporation after liquid-liquid extraction. Sanguinarine (SAN), a plant alkaloid, was used as a model analyte to evaluate the performance of the EX-CE chip. The influences of organic solvent type and liquid flow speed on the extraction efficiency were investigated. Rhodamine 123 (Rh123) was used as an internal standard for quantification of Sanguinarine (SAN) in a physiological buffer (e.g. PBS) or blood samples. A good linearity in the concentration range of 0.05 µg mL-1 to 0.1 mg mL-1 for SAN in PBS was obtained, with the detection limit of 0.5 ng mL-1. Good repeatibilities for migration times (RSD of SAN is 0.63%, Rh123 is 0.91%, n = 5) and peak area ratio of SAN to Rh123 (RSD is 1.3%, n = 5) were obtained. For blood sample analysis, only 20 µL of sample was needed, and the whole analysis was finished in 17 min. In addition to the advantages in fast analysis speed, minimum sample handling, potential automation, the reported method showed an on-line sample pre-concentration capability.

Four Pentasaccharide Resin Glycosides from Argyreia acuta.

Four pentasaccharide resin glycosides, acutacoside F-I (1-4), were isolated from the aerial parts of Argyreia acuta. These compounds were characterized as a group of macrolactones of operculinic acid A, and their lactonization site of 11S-hydroxyhexadecanoic acid was esterified at the second saccharide moiety (Rhamnose) at C-2. The absolute configuration of the aglycone was S. Their structures were elucidated by established spectroscopic and chemical methods.

Three new resin glycosides compounds from Argyreia acuta and their α-glucosidase inhibitory activity.

Three new phenolic compounds, acutacoside C (1), acutacoside D (2) and acutacoside E (3) were isolated from the aerial part of Argyreia acuta. The oligosaccharide chain was composed of two glucoses and three rhamnoses, and the aglycone was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). The core of the three compounds was operculinic acid B, which was rare in resin glycosides. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-3 have been evaluated for inhibitory activity against α-glucosidase, which all showed weak inhibitory activities.

Two pentasaccharide resin glycosides from Argyreia acuta.

Two new compounds of acutacosides 1 and 2, pentasaccharide resin glycosides were isolated from the aerial parts of Argyreia acuta. The core of the two compounds was operculinic acid A, and they were esterfied at the same position, just one substituent group was linked at C-2 of Rha. The absolute configuration of the aglycone in the two compounds was established by Mosher's method, which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). Their structures were established by a combination of spectroscopic and chemical methods.

[UPLC fingerprint of rhei radix et rhizoma from different habitats].

OBJECTIVE: To establish the UPLC fingerprint of Rhei Radix et Rhizoma and reference crude drugs, analyze the characteristics among fingerprints of three species of reference crude drugs and the common components of Rhei Radix et Rhizoma, and compare the application of different analysis methods. METHODS: UPLC procedure was performed on ACQUITY BEH C18 chromatographic column with mobile phase consisted of water (contained 0.1% phosphoric acid)-acetonitrile (gradient elution) at a flow rate of 0.21 mL/min. Detection wavelength was set at 260 nm and the column temperature was set at 30 degrees C. Fingerprints were analyzed by similarity evaluation, cluster analysis and principal component analysis. RESULTS: There were obvious characteristics among fingerprints of three species of reference crude drugs, 19 common chromatographic peaks were obtained from Rhei Radix et Rhizoma and 14 peaks were identified according to standard reference substances and by HPLC-MS. The cluster analysis and similarity evaluation showed the same result that 21 batches of sample were grouped into 5 categories and the result had no direct correlation with the botanical species. Both the contents of4 important ingredients suggested by principal component analysis and the whole fingerprint analysis were necessary in quality evaluation of Rhei Radix et Rhizoma. There was certain limitation in quality evaluation of multiple sources drug which analysis by similarity evaluation and cluster analysis. CONCLUSION: The method with good reproducibility and separation saves time and solvent, it can be used in identification of three species of reference crude drugs but can not be used in species identification of commercial Rhei Radix et Rhizoma.

[Study on the extraction process of total flavonoids from Psoralea corylifolia by enzyme-assisted technique].

OBJECTIVE: To study the optimum extraction process of total flavonoids from Psoralea coryl folia by cellulose-assisted technique. METHODS: Based on single-factor experiments, the effects of pH value, temperature of enzymatic hydrolysis, time of enzymatic hydrolysis and enzyme amount on the extraction yields of total flavonoids from Psoralea corylifolia were studied by response surface methodology. RESULTS: The optimum enzyme-assisted extraction process was: pH value 4.9, temperature 46 degrees C, time 150 min and enzyme amount 7.2 mg/g,under this condition,the relative error of the observed and predicted values was 1.16%. CONCLUSION: The optimum enzyme-assisted extraction process is simple and feasible, the extraction rate of total flavonoids increases by 28% compared with ultrasonic extraction, so it can be used to extract total flavonoids from Psoralea corylifolia.

[Study on the effects of different compatibility of guizhi decoction on component of volatile oil from Cinnamomum cassia by GC-MS].

OBJECTIVE: To study the changes of volatile oil from different compatibility of Guizhi decoction and explore their connection. METHODS: The volatile oil of Cinnamomum cassia and different compatibility of Guizhi decoction extracted by steam distillation were analyzed by GC-MS. RESULTS: The main components of volatile oil in Cinnamomum cassia were found in different compatibility of Guizhi decoction and they accounted the most amount of total volatile oil,but the contents of the main components were decreased, there were more components existed in different compatibility of Guizhi decoction than those in Cinnamomum cassia, the new components came from Zingiber officinale mostly. CONCLUSION: GC-MS can be used to reflect the changes of volatile oil from different compatibility of Guizhi decoction, and the result will provide some evidence for the research of regular pattern of compatibility in Guizhi decoction.

[Studies on phloroglucinol derivatives of Dryopteris fragrans L].

OBJECTIVE: To study the phloroglucinol derivatives of Dryopteris fragrans. METHODS: Isolation and purification were carried out on repeated silica gel, Sephadex LH-20 column chromatography and prepare HPLC. The structures of the compounds were determined by physicochemical properties and spectral analysis. RESULTS: Four compounds were isolated and identified as aspidin PB (I), dryofragin (II), aspidinol (III), aspidin BB (IV). CONCLUSION: Compounds IV is isolated from this plant for the first time.

[Study on terpene of Dryopteris fragrans L].

OBJECTIVE: To study the terpene of Dryopteris fragrans. METHODS: Isolation and purification were carried out on repeated silica gel, Sephadex LH-20 column chromatography and prepare HPLC. The structures of the compounds were determined by physicochemical properties and spectral analysis. RESULTS: Four compounds were isolated and identified as 10-hydroxyl-15-oxo-alpha-cadinol (I), albicany acetate (II), alpha-cadinene (III), albicanol (IV). CONCLUSION: Compounds I is isolated from this plant for the first time.