Membrane proteins are the main undertakers of biofilm function, and also the most important target group for innovative drug discovery and research. About 60% of drugs targets are membrane proteins. Due to the obvious aggregation and denaturation tendency of membrane proteins in aqueous solution, it is difficult to simulate the membrane like environment to maintain the correct conformation of membrane proteins in vitro, which results in the slower-growing research on the structure and function of membrane proteins and related ligand drugs than that of water-soluble proteins. Membrane protein stabilization technology is the premise of establishing high specificity, high sensitivity and high throughput drug screening methods for membrane protein ligands, which is of great significance. In this paper, some techniques for stable separation and purification of membrane proteins are reviewed, including detergents, artificial membranes, polymers, lentiviral particles and so on, as well as their specific applications in drug screening.

The paper aims to establish the method to determine the monosaccharide composition and monosaccharide ratio in propylene glycol alginate sodium sulphate (PSS). Samples were hydrolyzed with trifluoroacetic acid, neutralized with sodium hydroxide solution after the reaction conditions for sample pretreatment were optimized via orthogonal analysis. A high performance anion exchange chromatograghy (HPAEC) coupled with pulsed amperometric detector (PAD) was performed on a CarboPac^®PA20, using 200 mmol·L^-1 sodium hydroxide solution and 1 mol·L^-1 sodium acetate solution as mobile phase. The established HPAEC-PAD method was validated by testing the linear relationship, precision and accuracy, and showed exclusive, sensitive, rapid and wide use. The monosaccharide composition of PSS from different manufacture can be accurately determined with great significance for the structural identification of PSS.

α-Glucosidase inhibitors play an important role in the treatment of diabetes. This study established a high-resolution bioassay profiling platform for rapidly screening α-glucosidase inhibitors in natural product extracts. Five α-glucosidase inhibitors were identified from Malus hupehensis, namely, 3-hydroxyphloridzin, quercetin-3-O-β-D-glucopyranoside, phloridzin, avicularin and quercitrin. The establishment and successful application of this platform provides a powerful tool for the efficient discovery of anti-diabetic active ingredients in complex systems.

Chinese traditional medicine has provided, since ancient times, a basis for health care and medicine to the Chinese nation and for China's national stability. Identification of the constituents responsible for therapeutic and undesired effects of Chinese herbal medicines is a type of key research facilitating the modernization of these medicines. For a complex Chinese herbal medicine, multi-compound pharmacokinetic research is a useful approach to identifying its constituents that are bioavailable (in their unchanged and/or metabolized forms) at loci responsible for the medicine's therapeutic action and to characterizing the compounds' disposition and pharmacokinetics related to the action. In addition, such pharmacokinetic research is also useful for identifying herbal compounds associated with the medicine's adverse effects and drug-drug interaction potential. Over the past decade, great advances have been achieved in the theory, methodology, associated techniques, and their application of such multi-compound pharmacokinetic research, which has become an emerging field in pharmacokinetics. In this perspective, we elaborate on the methodology, technical requirements, and key analytical techniques of multi-compound pharmacokinetic research on Chinese herbal medicines, describe research examples regarding investigation of pharmacokinetics and disposition of a class of bioactive herbal constituents (ginsenosides of Panax notoginseng root) and pharmacokinetics-based identification of potential therapeutic compounds from a dosed Chinese herbal medicine (LianhuaQingwen capsule), and discuss follow-up development for the multi-compound pharmacokinetic research.

Oligonucleotides have attracted the widespread attention in disease diagnosis and gene therapy. At present, the nucleic acid drugs are at the forefront of biomedical and pharmaceutical research. The bioanalysis of therapeutic oligonucleotides has been slow, however, due to the requirements for pharmacokinetic/toxicokinetic and pharmacodynamic studies in pharmaceutical development. Conventionally, the hybridization-enzyme linked immunosorbent assay (hybridization-ELISA) is widely used in the bioanalysis of therapeutic oligonucleotides. Recentlly, many technologies such as real-time quantitative PCR (qPCR) and high performance liquid chromatography (HPLC)-based technologies have also showed a broad application prospects in the bioanalysis of therapeutic oligonucleotides. However, each technology has its own advantages and limitations. This review summarizes the currently used techniques in the bioanalysis of oligonucleotide therapeutics and reviews the challenges of regulated bioanalysis.

Metabonomics technology was employed to investigate and identify the mechanisms and metabolic pathways of the crude and wine-processed Fructus Corni extracts on anti-hepatic fibrosis effects in rats, and to compare and analyze the potential mechanism of enhanced interference of the wine-processed Fructus Corni on hepatic fibrosis effects in rats. The rats were randomly divided into the blank control group, the model group, the colchicine group, the crude Fructus Corni groups with low, medium, and high-doses, and the wine-processed Fructus Corni groups with low, medium, and high-doses, and there were six rats in each group. The hepatic fibrosis model was established by subcutaneous injection of 40% carbon tetrachloride, and the intragastric administration was performed at the third week of modeling. The blood and liver samples of rats were taken and carried out for pharmacodynamic index detection and UHPLC-Q-TOF-MS/MS analysis after intragastric administration for six weeks. The results of pharmacodynamic investigation showed that both the crude and wine-processed Fructus Corni had the effects of anti-hepatic fibrosis in rats. Metabonomics analysis indicated that, compared to the blank control group, the twenty-four potential biomarkers related to hepatic fibrosis were screened and identified in the model group, which mainly involved in primary bile acid metabolism, glycerol phospholipid metabolism, pentose and glucuronide metabolism, retinol metabolism, and arachidonic acid metabolism. The crude and wine-processed Fructus Corni extracts had different degrees of callback effects on the ten of the above potential biomarkers, and the effect of wine-processed Fructus Corni was better than that of crude one. The present study clarifies the mechanism of enhanced efficiency of wine-processed Fructus Corni from the perspective of plasma metabolism, and provides the theoretical foundation for further development and clinical application of Fructus Corni.

The molecular identification of Fritillaria taibaiensis and its relatives was studied by real-time PCR with a TaqMan-MGB probe. DNA was extracted from F. taibaiensis and its relatives. According to the sequence of ITS1 region, the mutation sites of F. taipaiensis and its related species were identified by MEGA7.0 software. The specific primers (a pair) and a TaqMan-MGB probe were designed by Primer Premier 6.0 software. In the Roche LightCycler 96 system, the lowest limit of detection for F. taipaiensis DNA template was 0.002 39 ng·μL^-1, and the optimal T_m value range was 60 and 61℃. Specificity identification showed that the method had good specificity for F. taipaiensis, as it could be distinguished from other 13 different Fritillaria species including F. unibracteata. Since this method could accurately identify F. taipaiensis and its related species, it provides technical support for rational development of F. taipaiensis resources, management of Chinese medicinal market and supervision of raw materials in Chinese medicine manufacturing enterprises.

IMM0306 is a recombinant human signal regulatory protein α-anti-CD20 mouse chimeric antibody fusion protein, intended to treat refractory or recurrent CD20 positive B-cell non-Hodgkin lymphoma (B-NHL) in clinical. In this study, an ELISA method was established to evaluate the pharmacokinetics of IMM0306 in human serum. The experiment was approved by the Ethics Committee of the Cancer Hospital of the Chinese Academy of Medical Sciences (No. CTR20192612). Recombinant human CD47 protein was coated with the plate overnight, blocking the plate with 5% skin milk for 2 h. After washing, 100 μL per well standard and unknown samples were added, and incubated for 1.5 h. After washing, the detection antibody Anti-IMM0306-Biotin was added and incubated for 1 h, and then HRP-labeled streptavidin was added for 1 h, and the color was detected. The optimal concentration of coating reagent was 2 μg·mL^-1 by ELISA method, and the optimal dilution of anti-IMM0306-biotin and SA-HRP were 1:500 and 1:5 000, respectively. The lower limit of quantitation was 4 ng·mL^-1, and the standard curve range was 4-100 ng·mL^-1. The verification results of the method meets the corresponding acceptance criteria, and can be used in IMM0306 clinical pharmacokinetic studies.

GeXIVA[1,2] is a new type of conotoxin recently discovered in the transcriptome of Conus generalis and it is expected to be used clinically as a new type of analgesic. This study established and verified a sandwich enzyme-linked immunosorbent assay method for the marine drug GeXIVA[1,2] in the plasma of rats and Beagle dogs. The mouse monoclonal antibody 4B2 and biotin-labeled rabbit polyclonal antibody 2# were developed. The checkerboard method was used to optimize the antibody pairing concentration, minimum dilution ratio, incubation temperature, and incubation time to establish an antibody sandwich ELISA detection method. Verify the established testing methods. The established ELISA method has a quantitative range of 1.25-80 ng·mL^-1 in rat and Beagle plasma. The precision, accuracy, selectivity, specificity, stability, dilution linearity, and hook effect all meet the requirements for biological sample analysis. All the procedures for the animal experiments were approved by the Animal Ethics Committee of the Institute (Permit Number: IACUC-DWZX-2020-698). This method can support the preclinical pharmacokinetic study of the marine drug GeXIVA.

FGF21-164 is a fusion protein obtained by structural modification and coupling of endogenous FGF21. It is a candidate drug used in the treatment of glucose and lipid metabolic disorders caused by obesity. In this study, the candidate peptide mass spectrometry information of the protein hydrolyzed by trypsin was predicted by Skyline software and verified by high resolution mass spectrometry. The specific surrogate peptide (YLYTDDAQQTEAHLEIR) with the best mass response was selected after optimizing ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Under ESI positive ion mode, the parent ion m/z 689.3 with 3 charge and the product ion m/z 738.4 with single charge can be monitored. After dilution by PBS, the serum samples were denatured under 60℃ and alkylated to reduce the matrix effect, then incubated with trypsin at 37℃ for 2 h, to obtain the surrogate peptide. The chromatographic separation was carried out on an EclipsePlus C₁₈ column (2.1 mm×50 mm, 1.8 μm) using aqueous solution containing 0.1% formic acid (phase A) and acetonitrile solution containing 0.1% formic acid (phase B). Finally, the concentration of FGF21-164 fusion protein in mouse serum was quantitatively analyzed by external standard method by monitoring the above ion pairs using triple quadrupole mass spectrometer. This method showed a good linearity in the range of 2.50-500 μg·mL^-1 (r=0.998 8), and was successfully applied to the pharmacokinetic study of FGF21-164 fusion protein in mice. This experiment was approved by the Experimental Animal Ethics Committee of Shanghai Institute of Materia Medica, Chinese Academy of Sciences (batch number: 20180004040450). Compared with the endogenous FGF21, the t_1/2 of FGF21-164 fusion protein was prolonged from 0.5 h to 2.6 h, which is expected to prolong the therapeutic efficacy of this protein.