Separation of polysaccharides from Lycium barbarum L. by high-speed countercurrent chromatography with aqueous two-phase system

The traditional method for isolation and purification of polysaccharides is time-consuming. It often involves toxic solvents that destroy the function and structure of the polysaccharides, thus limiting in-depth research on the essential active ingredient of Lycium barbarum L. Therefore, in this study, high-speed countercurrent chromatography (HSCCC) and aqueous two-phase system (ATPS) were combined for the separation of crude polysaccharides of Lycium barbarum L. (LBPs). Under the optimized HSCCC conditions of PEG1000-K2HPO4-KH2PO4-H2O (12:10:10:68, w/w), 1.0 g of LBPs-ILs was successfully divided into three fractions (126.0 mg of LBPs-ILs-1, 109.9 mg of LBPs-ILs-2, and 65.4 mg of LBPs-ILs-3). Moreover, ATPS was confirmed as an efficient alternative method of pigment removal for LBPs purification, with significantly better decolorization (97.1 %) than the traditional H2O2 method (88.5 %). Then, the different partitioning behavior of LBPs-ILs in the two-phase system of HSCCC was preliminarily explored, which may be related to the difference in monosaccharide composition of polysaccharides. LBPs-ILs-1 exhibited better hypoglycemic activities than LBPs-ILs-2 and LBPs-ILs-3 in vitro. Therefore, HSCCC, combined with aqueous two-phase system, was an efficient separation and purification method with great potential for separating and purifying active polysaccharides in biological samples.

Fluorescent/Colorimetric Dual-Mode Discriminating Gln and Val Enantiomers Based on Carbon Dots

Discrimination and quantification of amino acid (AA) enantiomers are particularly important for diagnosing and treating diseases. Recently, dual-mode probes have gained a lot of research interest because they can catch more detecting information compared with the single-mode probes. Thus, it is of great significance to develop a dual-mode sensor realizing AA enantiomer discrimination conveniently and efficiently. In this work, carbon dot L-TCDs were prepared by N-methyl-1,2-benzenediamine dihydrochloride (OTD) and l-tryptophan. With the assistance of H2O2, L-TCDs show an excellent discrimination performance for enantiomers of glutamine (Gln) and valine (Val) in both fluorescent and colorimetric modes. The fluorescence enantioselectivity of Gln (FD/FL) and Val (FL/FD) is 5.29 and 4.13, respectively, and the colorimetric enantioselectivity of Gln (ID/IL) and Val (IL/ID) is 13.26 and 3.42, individually. The chiral recognition mechanism of L-TCDs was systematically studied. L-TCDs can be etched by H2O2, and the participation of AA enantiomers results in different amounts of the released OTD, which provides fluorescent and colorimetric signals for identifying and quantifying the enantiomers of Gln and Val. This work provides a more convenient and flexible dual-mode sensing strategy for discriminating AA enantiomers, which is expected to be of great value in facile and high-throughput chiral recognition.

Construction of dual exponential amplification accompanied by multi-terminal signal output method for convenient detection of tumor biomarker FEN1 activity

As an important 5'-nuclease in DNA replication and damage repair, Flap endonuclease 1 (FEN1) has been considered as a potential tumor biomarker due to its overexpression in different human cancer cells. Here, we developed a convenient fluorescent method based on dual enzymatic repairing exponential amplification accompanied by multi-terminal signal output to realize the rapid and sensitive detection of FEN1. In the presence of FEN1, the double-branched substrate could be cleaved to produce 5' flap single strand DNA (ssDNA) which subsequently was used as a primer to initiate the dual exponential amplification (EXPAR) to generate abundant ssDNAs (X' and Y'), then the ssDNAs can respectively hybridize with the 3' and 5' ends of the signal probe to form partially complementary double strands (dsDNAs). Subsequently, the signal probe on the dsDNAs could be digested under the assistance of Bst. polymerase and T7 exonuclease, as well as releasing the fluorescence signals. The method displayed high sensitivity with the detection limit of 9.7 × 10^-3 U mL^-1 (1.94 × 10^-4 U) and also exhibited good selectivity towards FEN1 under the challenge from complicated samples including extracts of normal and cancer cells. Furthermore, it was successfully applied to screen FEN1 inhibitors, holding great promise in the screening of potential drugs targeting FEN1. This sensitive, selective and convenient method could be used for FEN1 assay without the complicated nanomaterial synthesis/modification, showing great potential in FEN1- related prediction and diagnosis.

Identification of anti-photoaging components of Olea europaea leaves based on spectrum-effect relationship

In this study, to identify bioactive components of Olea europaea leaves extract (OLE), chemometrics analyses including bivariate correlation analysis and partial least squares regression were used to establish the relationships between the chromatograms and anti-photoaging effect of OLE samples. Firstly, the fingerprint of olive leaves extract was determined by high-performance liquid chromatography (HPLC). Photoaging models of HaCaT cells were established by UVB irradiation. The photoaging resistance of OLE was evaluated by cell viability using the MTT assay. Chemometrics analyses showed that compounds 14, 19, 20, 24, 26, and 28 might be the major anti-photoaging components of OLE. Furthermore, after separation by HSCCC and NMR identification, compound 19 is luteoloside and compound 24 is oleuropein. Oleuropein and luteoloside were docked with collagenase (MMP-1), stromelysin (MMP-3), and gelatinase (MMP-9), respectively. The results showed that oleuropein and luteoloside inhibited their activity by directly interacting with MMP-1, MMP-3, and MMP-9, thereby exhibiting anti-photoaging activity. The current bioassay and spectrum-effect relationships are proper for associating sample quality with the active ingredient, and our finding would provide foundation and further understanding of the quality evaluation and quality control of Olea europaea.

Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8  (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

Discrimination of Geographical Origins of Wolfberry (Lycium barbarum L.) Fruits Using Stable Isotopes, Earth Elements, Free Amino Acids, and Saccharides

To develop sophisticated approaches for distinguishing goji origins, 325 wolfberry fruit samples of a certain cultivar, plant age, drying method, and collection season were gathered from 26 producing areas across Northwest China in 2017 and 2018. We employed 49 indices, including stable isotopes, earth elements, soluble amino acids, and saccharides, to identify the regions of origin of these goji fruits. Analysis of variance (ANOVA) and heritability analysis were used to assess the effects of the environment (producing areas), cultivar, plant age, drying process, and collection season. Samples from the same place can be classified and partially discriminated using principal component analysis (PCA). We were able to distinguish fruits produced in Zhongning County from those produced in the other five producing provinces using orthogonal projection to latent structure-discriminant analysis (OPLS-DA). Calcium (Ca), manganese (Mn), ornithine (Orn), cystine (Cys-Cys), glutamate (Glu), phenylalanine (Phe), phosphoserine (Ps), serine (Ser), lysine (Lys), taurine (Tau), proline (Pro), and tyrosine (Tyr) indices were chosen using S-plots and heritability analysis, and their repeatability was established with samples collected in 2018. The indices selected in this study can distinguish goji berries produced in Zhongning County from fruits originating from five other Provinces with high repeatability, which was validated with various cultivars, drying methods, harvest seasons, and plant ages and with heritability analysis.

A polysaccharide from Lycium barbarum L.: Structure and protective effects against oxidative stress and high-glucose-induced apoptosis in ARPE-19 cells

Lycium barbarum polysaccharides (LBPs) are beneficial for vision; however, relevant research has mainly focused on entire crude polysaccharides, with the basis and exact structure of the polysaccharide rarely explored. In this study, LICP009-3F-2a, a novel polysaccharide from Lycium barbarum L., was separated and then purified using anion-exchange and size-exclusion chromatography. Structural characteristics were investigated using chemical and spectroscopic methods, which revealed that LICP009-3F-2a has an Mw of 13720 Da and is an acidic heteropolysaccharide composed of rhamnose (39.1%), arabinose (7.4%), galactose (22.5%), glucose (8.3%), galacturonic acid (13.7%), and glucuronic acid (4.0%). Linkage and NMR data revealed that LICP009-3F-2a has the following backbone: →2)-α-L-Rha-(1→2,4)-α-L-Rha- (1→4)-α-D-GalAp-(1→3,6)-β-D-Galp-(1→3,6)-β-D-Galp-(1→6)-β-D-Galp-(1→, with three main branches, including: α-L-Araf-(1→5)-α-L-Araf-(1→6)-β-D-Glcp-(1→2,4)-α-L-Rha-(1→, β-D-Glcp-(1→4)-β-D-Glcp-(1→3,6)-β-D-Galp-(1→, and β-D-Galp-(1→3)-β-D-Galp-(1→3,6) -β-D-Galp-(1→. Differential scanning colorimetry and thermogravimetric analysis showed that LICP009-3F-2a is thermally stable, while X-ray diffractometry showed that LICP009-3F-2a has a semi-crystalline structure. In addition, LICP009-3F-2a protects ARPE-19 cells from H₂O₂-induced oxidative damage by regulating the expression of antioxidant SOD1 and CAT enzymes and down-regulating MMP2 expression. Moreover, LICP009-3F-2a promotes the proliferation of ARPE-19 cells in a concentration-dependent manner, and protects ARPE-19 cells from hyperglycemia by inhibiting apoptosis.

Deep Exclusive Electroproduction of π^{0} at High Q^{2} in the Quark Valence Regime

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4  GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Preparation of highly purified oleuropein by combinative technology off line of HSCCC-PHPLC based on dual wavelength

Oleuropein is the main active substance in foods or functional foods produced from olive (Olea europaea L.) leaves. In the present study, the combinative technology off line of HSCCC-PHPLC based on dual wavelength was used to separate highly purified oleuropein from oleuropein extract. Response surface methodology was used to optimize the conditions of HSCCC. Furthermore, a large amount of higher purified oleuropein was obtained through HSCCC at the wavelength of 254 nm, and oleuropein with the purity greater than 98.5% was obtained by PHPLC at the wavelength of 300 nm. Finally, the purity and structure identification of highly purified oleuropein were determined by various methods and its stability was investigated. As a result, oleuropein was stable in solution, and had good stability under the condition of dark storage at 4°C within a week or under the condition of dark storage at -20°C within one year. PRACTICAL APPLICATION: In this study, an efficient method for purification and refining of oleuropein by combinative technology off line of HSCCC-PHPLC based on dual wavelength was established. Oleuropein with the purity greater than 98.5% was macro-obtained via the technology. The highly purified oleuropein could be used to control the quality of olive products.

Hepatoprotective effect of crude polysaccharide isolated from Lycium barbarum L. against alcohol-induced oxidative damage involves Nrf2 signaling

In the present work, we investigated the effect of Lycium barbarum L. polysaccharides (LBPs) on L-02 cells exposed to alcohol exploring the potential molecular mechanisms. Our results suggested that LBPs significantly prevented alcohol-induced hepatotoxicity with dose-dependent effect, indicated by both cell viability and diagnostic indicators of liver damage. Moreover, alcohol induced excessive oxidative stress, as evidenced by an increase of the malondialdehyde level and reactive oxygen species production, while reducing antioxidant enzymes (T-SOD, CAT, and GPx) in liver, were inhibited by administration of LBPs. Furthermore, LBPs reversed the cell apoptosis and increased the mitochondrial membrane potential in alcohol-treated liver cell. Studies of underlying mechanisms revealed that LBPs increased expression levels of Nrf2 expression, which in turn blocked proapoptotic signaling events, restoring the balance between proapoptotic Bax and antiapoptotic Bcl-2 proteins, suppressing activities of cytochrome C (Cyto c), caspase-3, and caspase-9 in L-02 cells stimulation by ethanol. In general, the results showed that the inhibition of alcohol-caused liver damage by LBPs is due at least in part to its antioxidant and antiapoptosis activity via Nrf2 signaling pathway.

Protective effect of Lycium barbarum polysaccharide on ethanol-induced injury in human hepatocyte and its mechanism

The purpose of this research is to study the effect of Lycium barbarum polysaccharide on ethanol-induced liver injury and its mechanism. The cell survival rate, the apoptosis rate, and the intracellular ROS level was detected by MTT assay, flow cytometry, laser confocal microscopy, and fluorescence spectrophotometry, respectively. The antioxidative indices were determined by ELISA kits and the protein level was detected by western blot. The result showed Lycium barbarum polysaccharide could protect ethanol-induced cell injury by reducing cell apoptosis and regulating the levels of indicators related to oxidative stress, such as ROS, MDA, SOD, etc. In addition, LBP could increase the nuclear expression of Nrf2 protein and significantly up-regulate the expression levels of Nrf2 protein and its downstream proteins, such as HO-1, NQO1, and GCLC in the cell nucleus. Therefore, Lycium barbarum polysaccharide has a protective effect on ethanol-induced liver cell injury and it plays the role in cell apoptosis pathway and oxidative stress pathway. PRACTICAL APPLICATIONS: Lycium barbarum is a kind of food that can be used as food and medicine in China. The result showed that Lycium barbarum polysaccharide could protect ethanol-induced liver cell injury, which is beneficial to the application of LBP in functional food.

Icephobic, Pt-Cured, Polydimethylsiloxane Nanocomposite Coatings

To explore novel coatings with potential for easy release of ice (icephobicity), a series of platinum-cured silicone coatings was prepared incorporating SYL-OFF 7210, designated MQ-R, as a nanoscale reinforcing component. These optically transparent coatings are designated according to cure temperature and MQ-R wt %, for example, Pt-PDMS(25)-20 for 25 °C cure and 20 wt % MQ-R. Surface characterization included dynamic contact angles and morphology by atomic force microscopy. Bulk characterization was accomplished with stress-strain measurements at 25 °C and dynamic mechanical analysis from -110 to 150 °C. Ice adhesion tests at -10 °C showed modulus had a dominant effect in increasing τ_ice, the peak removal force. At -30 °C, storage modulus was greater for coatings cured at 100 °C compared to 25 °C, but ice removal tests at -30 °C (-22 °F) consistently showed τ_ice for Pt-PDMS(100) MQ-R compositions was less than τ_ice for corresponding Pt-PDMS(25) coatings. This unexpected result was explained by proposing that supercooled water at hydrophilic interfacial sites (-10 °C) does not impede ice removal but frozen water pins ice at -30 °C. Interestingly, MQ-R was found to be a reactive filler that increased modulus after 100 °C cure especially for Pt-PDMS(100)-30 (3 MPa) and Pt-PDMS(100)-40 (5 MPa). In summary, by virtue of resistance to ice adhesion Pt(PDMS) coatings with low MQ-R content have potential for conferring energy savings and safety while high MQ-R content results in noteworthy mechanical properties.

A small proton charge radius from an electron-proton scattering experiment

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, r_p. In 2010, a new method using muonic hydrogen atoms¹ found a substantial discrepancy compared with previous results², which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen^3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, r_p = 0.831 ± 0.007_stat ± 0.012_syst femtometres, is smaller than the most recent high-precision e-p measurement⁵ and 2.7 standard deviations smaller than the average of all e-p experimental results⁶. The smaller r_p we have now measured supports the value found by two previous muonic hydrogen experiments^1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant⁸-one of the most accurately evaluated fundamental constants in physics.

Investigation on Adsorption Mechanism of Peptides with Surface-Modified Super-Macroporous Resins

Macroporous adsorption resins (MARs) have experienced rapid growth because of their unique properties and applications. Recently, it was discovered that a series of MARs with super-macroporous and diverse functional groups were synthesized to adsorb and enrich peptides; however, the detailed change mechanism of pore diameter and element composition and peptide adsorption mechanism have not yet been established. In this study, MARs and modified MARs were prepared by the surfactant reverse micelles swelling method and Friedel-Crafts reaction, and the pore diameter and element changes of these super-macroporous resin particles were accurately determined to elucidate formation processes of modified MARs. The adsorption mechanism of four peptides on different MARs was investigated. Sieving effect, electrostatic, hydrophobic, and hydrogen bonds interactions were found to play a major role in the adsorption process of peptides. Compared to that of the traditional resins, the adsorption capacity of super-macroporous MARs for peptides enormously increased. Electrostatic interactions have been explained perfectly by determining the isoelectric point. The molecular docking technology proved that the hydrogen-bonding receptor in MARs was a crucial factor for the adsorption capacity by autodock 4.26 and gromacs 5.14. These findings will enable selective adsorption of peptides by MARs, which also provides a theoretical basis for the construction of specific resin to adsorb different peptides.

Preparation of metal–organic frameworks with bimetallic linkers and corresponding properties

A series of metal–organic frameworks (MOFs) with bimetallic linkers were synthesized through a facile reflux route.

Design, synthesis, and anticancer properties of isocorydine derivatives

Isocorydine (ICD), an aporphine alkaloid, is widely distributed in nature. Its ability to target side population (SP) cells found in human hepatocellular carcinoma (HCC) makes it and its derivative 8-amino-isocorydine (NICD) promising chemotherapeutic agents for the treatment of HCC. To improve the anticancer activity of isocorydine derivatives, twenty derivatives of NICD were designed and synthesized through chemical structure modifications of the aromatic amino group at C-8. The anti-proliferative activities of all synthesized compounds against human hepatocellular (HepG2), cervical (HeLa), and gastric (MGC-803) cancer cell lines were evaluated using an MTT assay. The results showed that all the synthetic compounds had some tumor cell growth inhibitory activity. The compound COM33 (24) was the most active with IC₅₀ values under 10 μM (IC₅₀ for HepG2 = 7.51 µM; IC₅₀ for HeLa = 6.32 μM). FICD (12) and COM33 (24) were selected for further investigation of their in vitro and in vivo activities due to their relatively good antiproliferative properties. These two compounds significantly downregulated the expression of four key proteins (C-Myc, β-Catenin, CylinD1, and Ki67) in HepG2 cells. The tumor inhibition rate of COM33 (24) in vivo was 73.8% after a dose 100 mg/kg via intraperitoneal injection and the combined inhibition rate of COM33 (24) (50 mg/kg) with sorafenib (50 mg/kg) was 66.5%. The results indicated that these isocorydine derivatives could potentially be used as targeted chemotherapy agents or could be further developed in combination with conventional chemotherapy drugs to target cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT), the main therapeutic targets in HCC.

Discovery and identification of potential biomarkers for alcohol-induced oxidative stress based on cellular metabolomics

Biomarkers involved in alcohol-induced oxidative stress play an important role in alcoholic liver disease prevention and diagnosis. Alcohol-induced oxidative stress in human liver L-02 cells was used to discover the potential biomarkers. Metabolites from L-02 cells induced by alcohol were measured by high-performance liquid chromatography and mass spectrometry. Fourteen metabolites that allowed discrimination between control and model groups were discovered by multivariate statistical data analysis (i.e. principal components analysis, orthogonal partial least-squares discriminate analysis). Based on the retention time, UV spectrum and LC-MS findings of the samples and compared with the authentic standards, eight biomarkers involved in alcohol-induced oxidative stress, namely, malic acid, oxidized glutathione, γ-glutamyl-cysteinyl-glycine, adenosine triphosphate, phenylalanine, adenosine monophosphate, nitrotyrosine and tryptophan, were identified. These biomarkers offered important targets for disease diagnosis and other researches.

Design and preparation of porous polymer particles with polydopamine coating and selective enrichment for biomolecules

Pore size distribution of novel gigaporous polymer particles were visualized characterization by laser scanning confocal microscopy, and this gigaporous materials had preferable selective enrichment performance for biomolecules.

qKAT: a high-throughput qPCR method for KIR gene copy number and haplotype determination

Killer cell immunoglobulin-like receptors (KIRs), expressed on natural killer cells and T cells, have considerable biomedical relevance playing significant roles in immunity, pregnancy and transplantation. The KIR locus is one of the most complex and polymorphic regions of the human genome. Extensive sequence homology and copy number variation makes KIRs technically laborious and expensive to type. To aid the investigation of KIRs in human disease we developed a high-throughput, multiplex real-time polymerase chain reaction method to determine gene copy number for each KIR locus. We used reference DNA samples to validate the accuracy and a cohort of 1698 individuals to evaluate capability for precise copy number discrimination. The method provides improved information and identifies KIR haplotype alterations that were not previously visible using other approaches.

Orientation-dependent nanostructure arrays based on anisotropic silicon wet-etching for repeatable surface-enhanced Raman scattering

Repeatable fabrication of sensitive plasmonic substrates through a simple procedure has become a major challenge for SERS-based sensing and imaging. Herein, a new class of high-performance SERS substrates, including pyramid, ridged-hexagon, and quasi-triangle nanostructures, is successfully fabricated based on the nanosphere lithography technique and anisotropic wet etching. Using the wafer-scale Cr-hole array as the etching mask, cavity-templates of various configurations are fabricated by the orientation-dependent wet etching technique, from where the nanostructure arrays are finally peeled-off. The anisotropic wet etching on (100), (110), and (111) silicon wafers has been systematically studied at the nanoscale revealing the formation mechanism of these cavity-templates. The peeled-off nanostructure arrays provide high-density tips and/or gaps (about 2.5 × 10(7) mm(-2)) and thus facilitate the generation of "hot spots". The distribution of the electromagnetic field is visualized by the finite difference time domain calculation. And the calculation results are validated by SERS characterization. The SERS enhancement factors of these substrates are in the order of 10(6)-10(7), with the maximum enhancement factor of 1.32 × 10(7) yielded by the ridged-hexagon arrays. The proposed nanostructure arrays present excellent homogeneity and reproducibility (with the largest relative standard deviation of 16.43%) for the reason that the SERS-active substrates are peeled-off from an identical template. The cost-effective fabrication, high sensitivity, good homogeneity and well-performed reproducibility demonstrate that these orientation-dependent NSs are good candidates for SERS-based in vitro and in situ detection and biosensing.

DPPH-HPLC-DAD analysis combined HSCCC for screening and identification of radical scavengers in Cynomorium songaricum Rupr

A speedy, efficient and reproductive technique to systematically isolate antioxidant compounds from complex natural products.

Study on pharmacokinetics and tissue distribution of the isocorydine derivative (AICD) in rats by HPLC-DAD method

A simple and effective high-performance liquid chromatography with diode-array detection method coupled with a liquid-liquid extraction pretreatment has been developed for determining the pharmacokinetics and tissue distribution of a novel structurally modified derivative (8-acetamino-isocorydine) of isocorydine. According to the in vivo experiments data calculations by DAS 2.0 software, a two-compartment metabolic model was suitable for describing the pharmacokinetic of 8-acetamino-isocorydine in rats. 8-Acetamino-isocorydine was absorbed well after oral administration, and the absolute bioavailability was 76.5%. The half-life of 8-acetamino-isocorydine after intravenous and oral administration was 2.2 h and 2.0 h, respectively. In vivo, 8-acetamino-isocorydine was highly distributed in the lungs, kidney and liver; however, relatively little entered the brain, suggesting that 8-acetamino-isocorydine could not easily pass through the blood brain barrier. Our work describes the first characterization of the pharmacokinetic parameters and tissue distribution of 8-acetamino-isocorydine. The acquired data will provide useful information for the in vivo pharmacology of 8-acetamino-isocorydine, and can be applied to new drug research.