[Research progress on the construction and applications of metal-organic frameworks in chromatographic stationary phases].

Metal-organic frameworks (MOFs) are a class of porous crystalline materials composed of metal centers or clusters assembled with organic ligands. These materials possess excellent properties, such as large surface areas, high porosities, uniform pore sizes, and diverse structures. Thus, MOFs have been widely applied in various fields, including catalysis, adsorption, sensing, sample pretreatment, and chromatographic separation. The applications of MOFs as stationary phases for chromatographic separation and analysis have attracted considerable attention from the research community in recent years. Compared with traditional chromatographic stationary phases, such as mesoporous silica, nanoparticles, and porous layers, MOFs possess flexible and tunable pore sizes and structures, thereby enabling precise control over their intermolecular interactions. Furthermore, the wide range of functional ligands and topologies of MOFs could potentially facilitate the separation and analysis of complex samples. These unique advantages render MOFs highly suitable for constructing novel chromatographic stationary phases.This article focuses primarily on the construction methods of MOFs as chromatographic stationary phases, and provides an overview of the latest research advancements in their applications in several chromatographic separation techniques such as high performance liquid chromatography (HPLC), gas chromatography (GC), and capillary electrochromatography (CEC). The existing methods for the preparation and construction of MOFs-based chromatographic stationary phases are classified and evaluated. The construction methods for MOFs as stationary phases for HPLC mainly include filling, precursor-doped polymerization, and post-modification. The construction methods for MOFs as stationary phases for GC predominantly include in situ growth, static coating, and dynamic coating. The stationary phases for CEC can be categorized into packed columns, monolithic columns, and open-tubular columns. Compared with monolithic and packed columns, open-tubular CEC (OT-CEC) offers numerous advantages, including a more flexible and convenient preparation method, enhanced compatibility with various separation media, and higher separation efficiency. Consequently, OT-CEC has emerged as an important method for investigating the preparation of stationary phases for CEC. Several methods such as physical adsorption, covalent attachment, and electrostatic interactions have been developed for the preparation and modification of MOFs-based CEC stationary phases, and extensive studies have been conducted to optimize the performance and applications of MOFs in OT-CEC. However, the existing methods for constructing MOFs-based chromatographic stationary phases present certain limitations. Therefore, the selection of the appropriate MOFs, optimization of their preparation methods, and examination of their performance in different separation modes have become the focus of intensive research.This review also summarizes the different analytical targets (e. g., chiral small molecules, biomacromolecules, and nonchiral molecules) and corresponding separation effects achieved using various MOFs-based chromatographic stationary phases. Finally, future studies focusing on the development of MOFs as chromatographic separation media are discussed. Overall, this review provides a valuable reference for the rational construction and practical applications of advanced MOFs-based chromatographic stationary phases.

Synergistic recognition of transferrin by using performance dual epitope imprinted polymers.

Transferrin (Trf) is a new type of active drug targeting carrier and disease biomarker that regulates the balance of iron ions in human body. The recognition and isolation of Trf is of great significance for disease diagnosis and treatment. Thus, a new type of magnetic dual affinity epitope molecularly imprinted polymer coated on Fe3O4 nanoparticles (Fe3O4@DEMIP) was successfully prepared for specific recognition of Trf. C-terminal nonapeptide and Trf glycan were selected as bi-epitope templates for metal chelation and boron affinity immobilization, respectively. 4-vinylphenylboric acid (4-VP), N-isopropyl acrylamide (NIPAM) and zinc acrylic were used as functional monomers. Results showed that Fe3O4@DEMIP exhibited excellent specific recognition ability adsorption capacity toward Trf, with an adsorption of 43.96 mg g-1 (RSD = 3.28%) and a more satisfactory imprinting factor (about 6.60) than that of other reported imprinting methods. In addition, Fe3O4@DEMIP displayed pH, temperature and magnetic sensitivity properties to realize temperature and pH-controlled recognition and release of target proteins and magnetic rapid separation. Furthermore, the Fe3O4@DEMIP coupled with high-performance liquid chromatography (HPLC) analysis was successfully used for specific recognition of Trf in biosamples. This study provides a reliable protocol for preparing metal chelation and boron affinity dual affinity bi-epitope molecularly imprinted polymers for synergistic and efficient recognition of biomacromolecules in the complex biological systems.

Selective separation and inexpensive purification of paclitaxel based on molecularly imprinted polymers modified with ternary deep eutectic solvents.

Paclitaxel (PTX) is a powerful anticancer natural product, with its separation and purification having been widely studied. In this work, new molecular imprinted polymers (MIPs) using deep eutectic solvents (DESs) with different molar ratios were prepared as functional monomers. These were then used as adsorbents in solid phase extraction (SPE) for the separation of PTX from its structural analogs. The polymers were characterized by energy disperive X-rays (EDX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and fourier transform infrared spectroscopy (FT-IR). The results suggested that the formative regular DES-MIPs had an even pore-size distribution and a large specific surface area. The dynamic adsorption and static adsorption showed that the DES-MIPs had excellent adsorption performance, with a maximum adsorption capacity and optimum adsorption time of 87.08 mg/g and 180 min, respectively. The selective adsorption experiments showed that the material had outstanding selectivity, and the maximum selectivity factor was 6.20. For stability, after six consecutive adsorption and desorption cycles, the DES-MIPs maintained the perfect stability and reusability. Furthermore, the fabricated SPE column was successfully utilized for extracting and eluting PTX. This study provides a reliable protocol for the separation and purification PTX from its structural analogs and the DES-MIPs materials have excellent potential application value in pharmaceutical industry.

Simultaneous extraction of several targets by using non-toxic dual template molecularly imprinted polymers in vivo and in vitro.

In this report, a non-toxic Dual Template Molecularly Imprinted Polymers (DMIPs) was synthesized with quercetin and schisandrin b as template molecules, using deep-eutectic solvents as functional monomers for the first time. The DMIPs were used to efficiently and simultaneously enrich quercetin and schisandrin b from the mixed crude extracts of penthorum and schisandra. The results indicated that the DMIPs exhibited rapid adsorption kinetics (80 min for adsorption equilibrium) and high selectivity. The largest adsorbing capacities to quercetin and schisandrin b were 23.58 mg/g and 41.64 mg/g, respectively. After presaturation with quercetin and schisandrin b, the nontoxic saturated DMIPs were fed to the mice. Blood samples of the mice were taken and both quercetin and schisandrin b were successfully detected. The pharmacokinetics of quercetin and schisandrin b were similar to reports in the literature where mice were directly fed with botanicals. Our study provides a reliable protocol such that DMIPs can be used to separate and enrich several target molecules simultaneously from complex biological systems. Our findings suggested that the DMIPs have potential application as a drug delivery system of compound herbal formulas.

Extraction of activated epimedium glycosides in vivo and in vitro by using bifunctional-monomer chitosan magnetic molecularly imprinted polymers and identification by UPLC-Q-TOF-MS.

In this work, efficient, sensitive bifunctional-monomer chitosan magnetic molecularly imprinted polymers (BCMMIPs) were fabricated and successfully applied to concentrate the metabolites of Epimedium flavonoids in rat testis and bone that were later analyzed using UPLC-Q-TOF-MS. Using chitosan and methacrylic acid as co-functional monomers, BCMMIPs exhibited a large adsorption capacity (7.60 mg/g), fast kinetics (60 min), and good selectivity. Chitosan is bio-compatible and non-toxic, and methacrylic acid provides multiple hydrogen bond donors. The BCMMIPs were injected into rat testis to specifically enrich the total flavonoid metabolites in vivo and were used to extract metabolites from bone in vitro. The results showed that the BCMMIPs coupled with UPLC-Q-TOF-MS successfully identified 28 compounds from testis and 18 compounds from bone, including 19 new compounds. This study provided a reliable protocol for the concentration of metabolites from complex biological samples, and several new metabolites of Epimedium flavonoids were found in vivo and in vitro.

Specific adsorption of tetracycline from milk by using biocompatible magnetic molecular imprinting material and evaluation by ECD.

Biocompatible magnetic molecularly imprinted polymers (BMMIPs) were prepared with Zein for the first time, and were used to enrich tetracycline compounds selectively. Innovative combination of BMMIPs and electrochemistry to obtain lower detection line to satisfy industrial detection demands. Using Zein as the crosslinking agent, the polymers were synthesized on the surface of Fe3O4 particles. The scanning electron microscope, transmission electron microscope and X-ray diffraction technologies were used to characterize BMMIPs. Through optimization, BMMIPs attained large adsorption capacity (236.40 mg/g) with fast kinetics (40 min) and followed the Langmuir isotherm and pseudo-second-order kinetic models. BMMIPs had good recognition ability, the selective factors of oxytetracycline, chlortetracycline, doxycycline were 4.78, 4.23, and 3.39, respectively. Excellent linearity was attained in the range of 0.025-500 µg/mL, with low detection limits and low quantitation limits of 0.025 and 0.083 µg/mL. According to our exploring, BMMIPs was ideal materials for enrichment of tetracycline in complex biological samples.

Preparation of restricted access molecularly imprinted polymers based fiber for selective solid-phase microextraction of hesperetin and its metabolites in vivo.

A novel restricted access molecularly imprinted polymers (RAMIPs) fiber was developed for solid-phase microextraction (SPME) of hesperetin and its metabolites in livers of live rats in vivo. Hesperetin as the template, N-isopropylacrylamide as the functional monomer, ethylene glycol dimethyl acrylate as the crosslinker, 2,2-azobisisobutyonnitrile as initiator and bovine serum albumin as the restricted access material were applied in the preparation process. Scanning electron microscopy and Fourier transform infrared spectroscopy were applied to characterize the polymers. The adsorption experiments indicated that RAMIPs-SPME fibers performed high selective recognition property to hesperetin. The selectivity experiment indicated that the adsorption capacity and selectivity of RAMIPs-SPME fibers to hesperetin was higher than that of quercetin, luteolin and baicalein. Macromolecules elimination test showed RAMIPs-SPME fibers could eliminate 94.80%-98.96% of macromolecules, which indicated that RAMIPs-SPME fibers can be used to extract analytes directly from complex biological samples. Furthermore, RAMIPs-SPME sampling combined to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was applied to capture and identify hesperetin and its metabolites in rat livers in vivo. Finally, hesperetin-7-O-glucuronide, hesperetin-3'-O-glucuronide, eriodictyol and homoeriodictyol were identified as the metabolites of hesperetin. In comparison with the MIPs fibers, commercial PDMS and DVB fibers, RAMIPs-SPME fibers possessed better exclusion effect to macromolecules and higher selectivity to hesperetin and its metabolites. The results demonstrated that the prepared RAMIPs-SPME fiber were proven to be effective tool for the selective adsorption and enrichment of hesperetin and its metabolites from the complex biological fluids.

In vitro anti-platelet aggregation effects of fourteen fruits and vegetables.

In the present study, the anti-platelet aggregation activity of 14 vegetables and fruits was tested in vitro. The aqueous, 90% ethanol and ethyl acetate extracts, as well as concentrated juices of 14 foods (fruits and vegetables) were prepared, and the anti-platelet aggregation activity of those extracts was analyzed on a platelet aggregation analyzer in vitro with adenosine 5'-diphosphate (ADP), bovine thrombin (THR) and arachidonic acid (AA) as aggregation inducers, respectively. Aspirin (ASP) was used as the positive control. A number of the tested foods had inhibitory effects in concentration-dependent manner on platelet aggregations induced by various agonists. Especially, some foods such as lemon, leek, garlic, scallion, ginger, tomato and grapefruit showed good anti-platelet aggregation effect similar or higher than that of positive control group i.e. aspirin (ASP). The results of present study provide scientific reference for reasonable selection of daily dietary with supplementary curative effects or prevention of cardiovascular diseases (CVD).

Amino-terminated supramolecular cucurbit [6] uril pseudorotaxane complexes immobilized on magnetite@silica nanoparticles: A highly efficient sorbent for salvianolic acids.

In this study, a novel amino-terminated supramolecular cucurbit [6] uril (CB [6]) pseudorotaxane motif coated magnetic nanoparticles (MNPs) was successfully fabricated through cucurbit [6] uril promoted azide-alkyne cycloaddition. The physicochemical properties of the obtained functional MNPs were investigated by scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffractometer, vibrating sample magnetometer, thermal gravimetric-derivative thermogravimetric analysis, and Zeta potential analyzer. Due to the abundant carboxyl groups in the structure of CB [6] and amino residue on the surface of the pseudorotaxane motif MNPs, the prepared materials were employed to extract salvianolic acids (SAs) for the first time. A series of significant parameters in the extraction and elution process, including sample pH, acetonitrile percentage, ionic strength and extraction temperature, as well as eluent type and desorption time, were examined systematically. Based on the results, the electrostatic interaction, van der Waals interaction, hydrophilic interaction and hydrogen bonding formation between the analytes and sorbent were speculated. The equilibrium state of static adsorption study indicated the outstanding adsorption capacity of pseudorotaxane motif MNPs toward six SAs to be 15-80 mg/g, providing much better adsorption affinity for SAs compared with MNPs only modified with amino, and their adsorption behaviors were all fitted with Freundlich adsorption isotherm model. In addition, the developed pseudorotaxane motif MNPs offered good recyclability and stability. Taking advantage of these merits, four SAs from Salvia miltiorrhiza Bunge were successfully extracted using the prepared pseudorotaxane motif MNPs with relative recovery in the range from 95.1% to 106.5% and RSDs below 9.7%. These results demonstrated that the synthesized pseudorotaxane motif MNPs showed potential as a candidate in the extraction of SAs.

Comparative Analysis of Soluble Proteins in Four Medicinal Aloe Species by Two-Dimensional Electrophoresis and MALDI-TOF-MS.

Background: Aloe barbadensis Miller 1768, A. vera L. var. chinensis (Haw.) Berger 1908, A. ferox Miller 1768, and A. arborescens Miller 1768 are the most widely cultivated species of Aloe and are used in Asia along with 400 other Aloe species worldwide because of their potent and potential bioactivity. Objective: The objective was to analyze and compare the soluble proteins of four commonly used medicinal Aloe species. Methods: Aloe protein samples were obtained by TCA/acetone-saturated phenol-methanol/ammonium acetate combined extraction (phenol extraction), and then were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis. Finally, the differentially expressed proteins of four Aloe species were identified by matrix-assisted laser desorption ionization-time-of-flight-MS analysis. Results: The phenol extraction method was the most suitable method for the protein extraction of Aloe. Fifty differentially expressed proteins in four Aloe species were successfully identified and divided into eight functional categories. Furthermore, Malate dehydrogenase and ran-binding protein in A. barbadensis, cytoskeletal-related protein tubulin in A. vera var. chinensis and auxin-induced protein PCNT-115 in A. arborescens are closely related to their morphological characteristics. Conclusions: There are differences in the soluble proteins of the four Aloe species. Those proteins, related to the difference of their morphology of Aloe, might be used to identify different species. Highlights: Fifty differentially expressed proteins in four medicinal Aloe species were identified, and these proteins were classified into eight categories according to their biological functions. Four special proteins closely related to the morphological characteristics of Aloe were found and might be used to identify these four Aloe species.

Debittering of lemon juice using surface molecularly imprinted polymers and the utilization of limonin.

In this work, surface molecularly imprinted polymers (SMIPs) were prepared as a specific sorbent to remove the limonin from the lemon juice for the first time, and then the MIPs containing limonin were directly made into a water-soluble gel to treat inflammation of mice. The resulting polymers were characterized by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectrometer spectra. And the polymerization conditions and adsorption performances of the resultant nanomaterials were further investigated in detail. Results showed that the MIPs have higher adsorption capacity (27.72 mg/g) compared with surface molecularly non-imprinted polymers (NIPs) (8.12 mg/g). The selectivity experiment indicated that the polymers had excellent selective recognition for limonin and the selectivity factors were calculated as 2.75 and 1.83 for nomilin and obakunone, respectively. The MIPs were successfully used as adsorbent for selectively removing limonin from lemon juice and the MIPs extracted almost all the limonin from lemon juice according to the HPLC results. Furthermore, the MIPs with limonin were processed into water-soluble gel, which can be used to reduce the inflammation and enhance wound healing of model mice.

pH-dependent surface electrostatic effects in retention on immobilized artificial membrane chromatography: Determination of the intrinsic phospholipid-water sorption coefficients of diverse analytes.

The passive membrane permeability of drugs may be potentially predicted by phospholipid-water sorption coefficient (KPLIPW) through immobilized artificial membrane (IAM) chromatography. However, for predominantly ionized compounds, unexpected confounding electrostatic interaction would influence the accurate determination of KPLIPW, accompanied by the mobile phase with varied pH and ionic strength. In order to measure the intrinsic phospholipid-water sorption coefficient (KIAM,intr) for diverse analytes, a mathematic model by characterizing the confounding electrostatic effects was developed in this study. Based on the developed electrostatic model, additional electrostatic repulsion/attraction interactions with the charged IAM surface were characterized for organic cations/anions. Considering that most of the IAM chromatography data was determined under physiological conditions, the KPLIPW values of all compounds were calculated with the ionic strength of 0.1 M and the pH value of 7. Generally, KPLIPW was hardly affected by the pH and ionic strength of mobile phase for those electroneutral compounds. KIAM,intr was 0.28 log units smaller than apparent phospholipid-water sorption coefficient (KIAM,app) for cations. In contrast, KIAM,intr was larger than KIAM,app by 0.28 log units for anions. Herein, KIAM,intr of diverse analytes can be easily calculated by the developed electrostatic model. For application, KIAM,intr was further compared with intrinsic Caco-2 permeability, and good sigmoidal correlations (R2 = 0.76) were established between them for organic cations and neutral compounds but not for organic anions.

Evaluation of thrombin inhibitory activity of catechins by online capillary electrophoresis-based immobilized enzyme microreactor and molecular docking.

An online capillary electrophoresis (CE)-based thrombin (THR) immobilized enzyme microreactor (IMER) method was established to screen THR inhibitors in this study. S-2366 was used as chromogenic substrate for determination of THR activity and other kinetic constants. After continuously run for 50 times, the prepared IMER could still remain 89% of the initial immobilized enzyme activity. The Michaelis-Menten constant (Km) of immobilized THR was measured as 0.514 mmol/L and the half-maximal inhibitory concentration (IC50) and inhibition constant (Ki) of argatroban on THR were determined as 78.07 and 26.53 nmol/L, respectively, which indicated that CE-based THR IMER was successfully established and could be applied to screen THR inhibitors. Then the prepared IMER was used to investigate the inhibitory potency on THR of four main catechins in green tea including epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG). The results showed that ECG and EGCG had good THR inhibition activity and their inhibition rates at concentration of 200 µmol/L were 53.2 ±â€¯3.8% and 55.8 ±â€¯2.6%, respectively, which was in consistent with the results of microplate reader assay. Additionally, molecular docking results showed that the benzopyran groups of ECG and EGCG were inserted into the THR active pocket and interacted with residues LYS60F, TRP60D, TRY60A, IEU99, GLY216, HIS57 and SER195, but EC and EGC did not. Therefore, the developed CE-based THR IMER is reliable method for measuring THR inhibitory activity of natural inhibitors.

Investigation of Interactions between Thrombin and Ten Phenolic Compounds by Affinity Capillary Electrophoresis and Molecular Docking.

Thrombin plays a vital role in blood coagulation, which is a key process involved in thrombosis by promoting platelet aggregation and converting fibrinogen to form the fibrin clot. In the receptor concept, drugs produce their therapeutic effects via interactions with the targets. Therefore, investigation of interaction between thrombin and small molecules is important to find out the potential thrombin inhibitor. In this study, affinity capillary electrophoresis (ACE) and in silico molecular docking methods were developed to study the interaction between thrombin and ten phenolic compounds (p-hydroxybenzoic acid, protocatechuic acid, vanillic acid, gallic acid, catechin, epicatechin, dihydroquercetin, naringenin, apigenin, and baicalein). The ACE results showed that gallic acids and six flavonoid compounds had relative strong interactions with thrombin. In addition, the docking results indicated that all of optimal conformations of the six flavonoid compounds were positioned into the thrombin activity centre and had interaction with the HIS57 or SER195 which was the key residue to bind thrombin inhibitors such as argatroban. Herein, these six flavonoid compounds might have the potential of thrombin inhibition activity. In addition, the developed method in this study can be further applied to study the interactions of other molecules with thrombin.

SDS-PAGE and 2-DE protein profiles of Ganoderma lucidum from different origins.

Ganoderma lucidum (Chizhi in Chinese) is one of the most valuable and widely used medicinal fungi in traditional Chinese medicines (TCMs). Most of previous studies were focused on the triterpenoids and polysaccharides of G. lucidum, whereas less attention had been paid on the protein, which is another bioactive compound in it. In the present study, protein maps of fourteen G. lucidum samples were comprehensively analyzed by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2-DE). The results indicated that there were significant differences in protein profiles of G. lucidum samples from different origins. Furthermore, previous reported bioactive proteins from the fruiting bodies of G. lucidum, were mainly distributed in 4 taxa (A, B, C and D) based on their molecular weights on the 2-DE maps. The proteins should be considered as marker for the quality control of G. lucidum, because the proteomic variation may affect on their pharmacological activities.

Magnetic molecularly imprinted polymer for the selective extraction of hesperetin from the dried pericarp of Citrus reticulata Blanco.

In present study, novel magnetic molecularly imprinted polymers for hesperetin were successfully prepared by surface molecular imprinting method using functionalized Fe3O4 particles as the magnetic cores. Hesperetin as the template, N-Isopropylacrylamide as the functional monomer, ethylene glycol dimethyl acrylate as the crosslinker, 2,2-azobisisobutyonnitrile as initiator and acetonitrile-methanol (3:1, v/v) as the porogen were applied in the preparation process. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscope, x-ray diffraction and vibrating sample magnetometry were applied to characterize the magnetic molecularly imprinted polymers. The adsorption experiments indicated that the magnetic molecularly imprinted polymers performed high selective recognition property to hesperetin. The selectivity experiment indicated that the adsorption capacity and selectivity of polymers to hesperetin was higher than that of luteolin, baicalein and ombuin. Furthermore, the magnetic molecularly imprinted polymers were employed as adsorbents for extraction and enrichment of hesperetin from the dried pericarp of Citrus reticulata Blanco. The recoveries of hesperetin in the dried pericarp of Citrus reticulata Blanco ranged from 90.5% to 96.9%. The linear range of 0.15-110.72 µg/mL was obtained with correlation coefficient of greater than 0.9991. The limit of detection and quantification of the proposed method was 0.06 µg/mL and 0.15 µg/mL, respectively. Based on three replicate measurements, intra-day RSD was 0.71% and inter-day RSD was 2.31%. These results demonstrated that the prepared magnetic molecularly imprinted polymers were proven to be an effective material for the selective adsorption and enrichment of hesperetin from natural medicines, fruits and et al.

Adsorbed hollow fiber-based biological fingerprinting for the discovery of platelet aggregation inhibitors from Danshen-Honghua decoction.

For lead compound discovery from natural products, hollow fiber cell fishing with chromatographic analysis is a newly developed method. In this study, an adsorbed hollow fiber-based biological fingerprinting method was firstly developed to discover potential platelet aggregation inhibitors from Danshen-Honghua decoction. Platelets were seeded on the fiber and their survival rate was tested. Results indicated that more than 92% platelets survived during the whole operation process. Ranitidine and tirofiban were used as positive and negative control respectively to verify the reliability of the presented approach. The main variables such as amount of extract and stirring time that affect the adsorbed hollow fiber-based biological fingerprinting process were optimized, and the repeatability of this method was also investigated. Finally, 12 potential active compounds in Danshen-Honghua decoction were successfully detected using the established approach and structures for nine of them were tentatively identified by liquid chromatography with mass spectrometry analysis. In addition, the in vitro platelet aggregation inhibition test was carried out for five of the nine hit compounds, and three active components, namely, lithospermic acid, salvianolic acid A, and salvianolic acid B were confirmed. These results proved that the proposed method could be an effective approach for screening platelet inhibitors from plant extracts.

Comparing coagulation activity of Selaginella tamariscina before and after stir-frying process and determining the possible active constituents based on compositional variation.

CONTEXT: Selaginella tamariscina (P. Beauv.) Spring (Selaginellaceae) (ST) has been widely used in China as a medicine for improving blood circulation. However, its processed product, S. tamariscina carbonisatus (STC), possesses opposite haemostatic activity. OBJECTIVE: To comprehensively evaluate the activity of ST and STC on physiological coagulation system of rats, and seek potential active substances accounting for the activity transformation of ST during processing. MATERIALS AND METHODS: The 75% methanol extracts of the whole grass (fine powder) of ST and STC were prepared, respectively. Male Sprague-Dawley rats were randomly divided into five groups: control group, model group, model + ST group, model + STC group and positive control group (model + Yunnanbaiyao). The duration of intragastric administration was 72 h at 12 h intervals. Haemorheology parameters were measured using an LB-2 A cone-plate viscometer and the existed classic methods, respectively. SC40 semi-automatic coagulation analyzer was employed to determine coagulation indices. Meanwhile, HPLC and LC-MS were applied for chemical analyses of ST and STC extracts. RESULTS: STC shortened tail-bleeding time, increased whole blood viscosity (WBV) and plasma viscosity (PV), decreased erythrocyte sedimentation rate blood (ESR), reduced activated partial thromboplastin time (APTT) and increased the fibrinogen (FIB) content in the plasma of bleeding model rats. Although ST could shorten APTT and TT, the FIB content was significantly decreased by ST. Dihydrocaffeic acid with increased content in STC vs. ST showed haemostatic activity for promoting the platelet aggregation induced by collagen and trap-6, and reducing APTT and PT significantly with a concentration of 171.7 µM in vitro. Amentoflavone with reduced content in STC vs. ST inhibited ADP and AA-induced platelet aggregation significantly with a concentration of 40.7 µM. DISCUSSION AND CONCLUSIONS: As the processed product of ST, STC showed strong haemostatic activity on bleeding rat through regulating the parameters involved in haemorheology and plasma coagulation system. Two active compounds, dihydrocaffeic acid and amentoflavone, might be partially responsible for the haemostatic and anticoagulant activity of STC and ST, respectively.

Preparation and evaluation of magnetic molecularly imprinted polymers for the specific enrichment of phloridzin.

In present study, magnetic molecularly imprinted polymers (MMIPs) were successfully prepared for specific recognition and selective enrichment of phloridzin from the leaves of Malus doumeri (Bois) A. Chev and rats' plasma. The magnetic Fe3O4 were prepared by the solvothermal reaction method and followed by the modification of TEOS and functionalization with APTES. Using functionalized Fe3O4 particles as the magnetic cores, phloridzin as template, ethylene glycol dimethacrylate (EGDMA) as cross-linker and 2,2-azobisisobutyonnitrile (AIBN) as initiator, the MMIPs were prepared through APTES to associate the template on the surface of the magnetic substrate. The structural features and morphological characterizations of MMIPs were performed by FT-IR, SEM, TEM, XRD, TGA and VSM. The adsorption experiments revealed that the MMIPs presented high selective recognition property to phloridzin. The selectivity experiment indicated that the adsorption capacity and selectivity of polymers to phloridzin was higher than that of baicalin and 2,3,5,4'-ttrahydroxy stilbene-2-O-ß-D-glucoside. Furthermore, the MMIPs were employed as adsorbents for extraction and enrichment of phloridzin from the leaves of M. doumeri and rats' plasma. The recoveries of phloridzin in the leaves of M. doumeri ranged from 81.45% to 90.27%. The maximum concentration (Cmax) of phloridzin in rats' plasma was detected as 12.19 ± 0.84µg/mL at about 15min after oral administration of phloridzin (200mg/kg). These results demonstrate that the prepared MMIPs are suitable for the selective adsorption of phloridzin from complex samples such as natural medical plants and biological samples.

Identification of the Adulterated Asini Corii Colla with Cytochrome c Oxidase Subunit I Gene-based Polymerase Chain Reaction.

BACKGROUND: Asini Corii Colla (ACC) (namely donkey hide gelatin, E'jiao in Chinese) was one of the most valuable tonic traditional Chinese medicines which is an infallible remedy to promote hematopoiesis. It should be produced by fresh or dried donkey hide according to Chinese Pharmacopeia (2015 edition) with a long-time decoction, while as donkey and horse (or mule) all belong to equids so their hides or their hide gelatins are share much in common, that cause the difficult in distinguishing raw materials donkey hide from horse/mule hide for manufacturer, and the challenge in the quality evaluation of ACC for regulatory authority to identify the adulterated with horse hide. OBJECTIVE: To establish an effective quality evaluation methods for ACC focused on the qualitative-based identification of the raw material's authenticity, mainly to identify the species origin of the gelatins. MATERIALS AND METHODS: DNA extracted from (1) Raw materials (hides of donkey, horse, mule, bovine and pig); (2) Five hide-glues (bovine, pig, donkey, horse and mule hide-glue); (3) 11 batches of ACC commercial products made by different manufactures from local drug stores. Polymerase chain reaction (PCR) method with newly designed horse-specific primers I and primer pair II. RESULTS: Use the primer pair I, a 234 bp target product could be amplified sensitively from the DNA sample of horse/mule adulterated commercial ACC products, though the DNA in commercial products is severely degraded. A 219 bp product could be amplified specifically from the DNA sample of horse/mule hide, while the results were all negative for the DNA templates of donkey hide, its gelatin and ACC products without adulteration. CONCLUSION: The developed PCR method based on primer I and II provide an effective approach to identify the species origin of highly processed product ACC (primer pair I) as well as to distinguish the raw material donkey hide (primer pair II), which might enlighten a new strategy to the Quality Evaluation of ACC. SUMMARY: Though the quality of commercial Asini Corii Colla (ACC) products varies greatly and produce with nondonkey hide was one the most common adulteration, the effective method to constrain such adulteration remains to be establishedThe gelatins made by donkey, horse, bovine, pig, mule shares much in common with each other, not only in contents of amino acids but also the profiles of protein in sodium dodecyl sulfate polyacrylamide gel electrophoresis, isoelectric focusing, gel filtration chromatography and two-dimensional electrophoresisThe adulteration in ACC by using horse/mule hide, which is most difficult to detect, could be identified by Polymerase chain reaction methods with newly designed horse/mule-specific primer. Abbreviations Used: ACC: Asini Corii Colla; TCMs: Traditional Chinese Medicines; SDS-PAGE: Sodium dodecyl sulfate polyacrylamide gel electrophoresis; IEF: Isoelectric focusing; GFC: Gel filtration chromatography; 2-DE: Two-dimensional electrophoresis; PCR: Polymerase chain reaction.