Due to the difference in structure and chemical properties of amino acids, it is difficult to determine amino acids with different properties by GC-MS. A method was established for the simultaneous determination of 20 amino acids by using ethyl chloroformate (ECF) as the derivatization reagent and adjusting pH 9-10 in the second derivatization in this study. The results showed that 20 amino acids were well separated and the compounds in the 2-20 μg·mL^-1 concentrations were detected with a good linear response correlation coefficient r² greater than 0.99. The results of precision and system adaptability show that RSD < 10%, the average recovery of samples in the 78.3%-109.9%. The results showed that the method was simple and easy to use, and the derivatization method could be carried out in aqueous solution. The derivatization product was stable with wide linear range, thus this method could be used for the determination of a variety of biological samples such as Astragalus mongolicus, mouse urine sample and mouse serum sample.

Eighteen novel levofloxacin-thiadiazole HDACi conjugates were designed and synthesized from levofloxacin. The chemical structures of all conjugates were confirmed by ¹H NMR, ¹³C NMR and HR-MS spectra. The inhibitory activities of new conjugates were evaluated in an assay with a HDACs reagent kit, and their anti-tumor activities were tested in CCK-8 assay. The results showed that these new conjugates displayed potent inhibitory activity against HDACs, and the hydroxamate conjugates exhibited more potent activity than carboxylic acid and benzamide derivatives. Specifically, conjugate 5d exhibited the most potent anti-HDAC1 (IC₅₀=0.031±0.011 μmol·L^-1) and HDAC6 (IC₅₀=0.019±0.006 μmol·L^-1) activities, which was more potent than SAHA. Molecular docking studies suggest that the hydroxamate group of conjugate 5d was deeply inserted into the active site to interact with the residues in coordination with the zinc ion. Additionally, the thiadiazole group of conjugate 5d also engaged in hydrogen bonding with F679 in HDAC6, which had been linked to the selectivity of the HDAC isoforms. Moreover, these conjugates displayed significant antiproliferative effects on SW620, MGC-803, PC-3, NCIH460, MCF-7 and HepG2 cells, in particular, conjugate 5d showed the greatest potency against MGC-803 (IC₅₀=0.7±0.05 μmol·L^-1), NCIH460 (IC₅₀=2.3±0.421 μmol·L^-1), MCF-7 (IC₅₀=1.6±0.56 μmol·L^-1) and HepG2 (IC₅₀=3.9±0.26 μmol·L^-1), which was >3-fold more potent than SAHA. Additionally, all conjugates were nontoxic to health GES-1 cells, while SAHA showed some toxicity.

In this study, we aim to develop a pH-sensitive transmembrane peptide TH (AGYLLGHINLHH LAHL (Aib) HHIL-Cys) modified liposome loaded with immunoadjuvant α-galactosylceramides (αGC-TH-Lip) and then investigate its effect on the immune function in tumor-bearing mice and its immune mechanism of action. The liposomes were prepared by membrane dispersion-probe ultrasound method and the size and zeta potential of αGC-TH-Lip were also characterized. The uptake of TH modified liposomes (TH-Lip) and polyethylene glycols modified liposomes (PEG-Lip) in DC2.4 cells in vitro were analyzed and the activation of natural killer T (NKT), natural killer (NK) and macrophages in tumor-bearing mice were also measured after systemic administrations of samples. Besides, the degree of maturation of dendritic cell (DC), the number of cytotoxic T lymphocyte (CTL) and the differentiation of helper T cell (Th) were determined. The results showed the particle size of αGC-TH-Lip was about 117.9 nm and the zeta potential was about-8.37 mV under the neutral condition (pH 7.4) and the αGC-TH-Lip had high serum stability in 50% fetal bovine serum. The uptake of TH-Lip in DC2.4 cells in vitro was 1.48 times higher than that of PEG-Lip. After systemic administrations of the samples, the numbers of NKT cells, NK cells and macrophages in tumor-bearing mice were (0.43±0.048)%, (12.80±0.50)% and (3.13±0.26)%, respectively, and the number of mature DCs and CTLs reached (2.30±0.22)% and (32.30±0.80)% separately, which was significantly different from the con-trol group. Finally, we discovered the αGC-TH-Lip had the strongest induction effect on the differentiation of Th1 cells, while barely promote the differentiation of Th2 cells. All the above results demonstrated that the αGC-TH-Lip can improve the immune the activity of mice, enhance the effect of α-galactosylceramide and promote the differentiation of lymphocytes toward the direction of cellular immunity, which consequently achieve a better anti-cancer immune activity.

A rapid fluorescence polarization immunoassay (FPIA) has been developed for the determi-nation of aflatoxins in samples of naturally-contaminated herbal teas. The tracers were synthesized by chemical method and determined by thin layer chromatography (TLC) and mass spectroscopy (MS). Fluorescence polarization was evaluated by the detection of polarized light. The results showed that the limit of detection (LOD) of FPIA for aflatoxins was 20 ng·mL^-1, the IC₅₀ was 371.80 ng·mL^-1, and the linear range of the developed FPIA was 92.76-252.32 ng·mL^-1. Compared with conventional HPLC methods, the FPIA developed in this study has the advantages of short analysis time and low cost. This method may be suitable for high-throughput screening of aflatoxins in herbal teas.

The purpose of this study was to investigate the thermodynamics of naringenin (NAR)-isonicotinamide (INT) cocrystal (stoichiometric ratio, 1:2) formed in different solvents. The dissolution behavior of cocrystal was explored in the water. Solubility of NAR-INT cocrystals under various temperatures were measured, followed by fitting the complexation model to calculate the thermodynamic parameters solubility products (K_sp), complexation constants (K₁₂) and Gibbs energy change (ΔG) of cocrystal during formation progress. Ternary phase diagrams (TPDs) of the NAR-INT-solvent systems under various temperatures were plotted. Based on the non-linear simulation, 1:2 complexation model was well fitted to the NAR-INT cocrystal formation in ethanol, isopropanol and ethyl acetate, while no complexation model was more suitable for that in methanol. The cocrystallization reaction was exothermic and spontaneous (ΔG < 0, ΔH < 0, ΔS < 0). K_sp increased while K₁₂ decreased when increasing temperature, suggesting that the two components could cocrystallize more easily at the lower temperature. In comparison to TPDs in other solvents, the area of homogeneous liquid phase in ethyl acetate was the smallest, indicating the easiest formation of NAR-INT cocrystal in ethyl acetate. The current study provides a theoretical foundation for preparation and optimization of scale-up NAR-INT cocrystals.

Polar auxin transport gene PIN (PIN-FORMED) determines the concentration gradient of auxin and plays an important role in development and secondary metabolism of plants. This study was designed to analyze the bioinformatics and expression of the PIN genes in Panax ginseng to explore a novel way of breeding ginseng varieties. Heatmap and cluster analysis of PIN2, PIN3, PIN6 was performed in four-year-old Jilin ginseng. Sequence homology alignment, RT-PCR amplification, sequencing and bioinformatics analysis were used to identify three PIN family genes PgPIN2, PgPIN3 and PgPIN6 in P. ginseng. PIN expression in ginseng adventitious root and culture seedling was analyzed with qRT-PCR technique. Results suggested that in ginseng adventitious root tip, PgPIN3 and PgPIN6 exhibited a high level of expression; in ginseng culture seedling root, PgPIN2 showed a high level of expression; in four-year-old Jilin ginseng at the fruit ripening stage, PgPIN2 and PgPIN6 were highly expressed in root and rhizome, while PgPIN3 had a high level in ginseng leaf, fruit and root. Tissue specific expression profile showed that PgPIN2 and PgPIN6 probably were involved in the development and tropism growth in ginseng roots, while PIN3 might be in relation to the growth and development of the aerial part of plants.

Population pharmacokinetics is an emerging discipline developed from the combination of classical pharmacokinetic compartment model and statistics principles, which has been received more and more attention in recent years. Population pharmacokinetics plays important roles in all stages of new drug research. In the early preclinical phase, population pharmacokinetic analysis can help to achieve the preliminary prediction of parameters from animal to human, optimize clinical trial designs, and shorten the time required for new drugs from laboratory to clinical trials. In clinical trials and applications stage, population pharmacokinetic research can help researchers investigate the related covariates that affecting pharmacokinetic behavior of patients comprehensively, and find potential drug-drug interactions in clinical. In addition, population pharmacokinetics has a unique advantage in pediatric drug development due to its strong analysis ability of sparse data. This paper provides a summary on the history and methods of population pharmacokinetics, and the application in new drug discovery and development.

D-galactose (D-gal)-induced aging model is widely used in the study of the pharmacodynamics of antiaging drugs. The model has a shorter life-span, disorders in learning and memory, reduced immune function and other aging characteristics. Regular and quantitative injection of D-gal solution to rats can produce symptoms of natural aging models that are used in screening of antiaging drugs, and their pharmacological activities. This paper provides a summary of the mechanism of rat model induced with D-gal solution. The methods of building and evaluation of the aging models are provided. The theoretical basis is included to facilitate the subsequent research and experiment in the mechanism study of aging and antiaging medicines.

Translating of scientific advances into clinical practice is a major challenge in the stroke research field in the past decades. There were many reasons involved:animal models might not accurately capture all aspects of clinical stroke in humans, the blind and randomized design principle was not closely followed, the inclusion and exclusion criteria was not previously established, sample size was inadequate, endpoint was not scientific nor blindly assessed, inadequate reporting of data and statistical flaws. To bridge the gap between experimental and clinical research, international consortia have attempted to establish standardized guidelines for study design and data report, which include optimizing animal models as well as experimental design, using innovative approaches to assess endpoint, making raw data and negative results available, establishing prior registration mechanism, conducting multicenter preclinical randomized controlled trials (pRCTs), systematic reviews and meta-analysis of preclinical studies, evolving the original focus on neuroprotection into a broader consideration of the role of neurovascular unit and ischemic cascade.

This study was designed to explore the effect of apigenin (Api) on dendritic cell (DCs) maturation and function in murine spleen cells. The single spleen cell was isolated, and then cultured with lipopolysaccharide (LPS) in the present and absence of apigenin. After 24 h, the toxicity of Api and the T cell proliferation were determined by CCK8 kit. In addition, we collected the cell-free supernatants to measure cytokine production using ELISA, collected the cells to determine the DC maturation using flow cytometry. Finally, we purified Api and/or LPS-treated CD11c⁺ DCs which were pulsed with ovalbumin (OVA)_323-339 and then were adoptive transferred into C57BL/6 mice to detect the OVA_323-339-specific T cell proliferation and T helper (Th1) and Th2 cell secreting IFN-γ and IL-4 production, respectively. We found that Api did not affect splenocyte viability, but inhibited the production of pro-inflammatory cytokine IL-1β, IL-6 and TNF-α, not anti-inflammatory cytokine IL-10. In addition, Api inhibited the expression of co-stimulatory CD80, CD86 and MHCII of CD11c⁺ DCs. Finally, compared to LPS+OVA DCs group, DCs from Api and LPS co-treated splenocytes (Api+LPS+DCs) impaired OVA_323-339-specific T cell proliferation and the production of IFN-γ and IL-4 in CD4⁺ T cells, which had the similar responses with OVA+DCs. These data suggest that Api exhibits anti-inflammatory properties via inhibiting DC activation and function, as a new immune-modulator, which may induce immune-tolerance with a benefit to those with chronic inflammation.