[Preparation of magnetic carbon nitride composite toward phosphopeptide enrichment].

Protein phosphorylation plays an important role in cellular signaling and disease development. Advances in mass spectrometry-based proteomics have enabled qualitative and quantitative phosphorylation studies as well as in-depth biological explorations for biomarker discovery and signaling pathway analysis. However, the dynamic changes that occur during phosphorylation and the low abundance of target analytes render direct analysis difficult because mass spectral detection offers no selectivity, unlike immunoassays such as Western blot and enzyme-linked immunosorbent assay (ELISA).

[Recent advances in the quantification of drug metabolizing enzymes and transporters by proteomic approach].

With the advance of drug development and research techniques, the drug metabolic processes and mechanism can be more deeply achieved. As the drug metabolism and pharmacokinetics process are mediated by drug metabolizing enzymes and transporters, study of drug metabolizing enzymes and transporters has become an important part for drug development. The traditional immunoassays with low sensitivity and poor specificity can not reflect the accurate expression level of drug metabolizing enzymes and transporters.

A Highly Selective Ratiometric Two-Photon Fluorescent Probe for Human Cytochrome P450 1A.

Cytochrome P450 1A (CYP1A), one of the most important phase I drug-metabolizing enzymes in humans, plays a crucial role in the metabolic activation of procarcinogenic compounds to their ultimate carcinogens. Herein, we reported the development of a ratiometric two-photon fluorescent probe NCMN that allowed for selective and sensitive detection of CYP1A for the first time. The probe was designed on the basis of substrate preference of CYP1A and its high capacity for O-dealkylation, while 1,8-naphthalimide was selected as fluorophore because of its two-photon absorption properties.

Gomisin A is a Novel Isoform-Specific Probe for the Selective Sensing of Human Cytochrome P450 3A4 in Liver Microsomes and Living Cells.

Nearly half of prescription medicines are metabolized by human cytochrome P450 (CYP) 3A. CYP3A4 and 3A5 are two major isoforms of human CYP3A and share most of the substrate spectrum. A very limited previous study distinguished the activity of CYP3A4 and CYP3A5, identifying the challenge in predicting CYP3A-mediated drug clearance and drug-drug interaction.

An optimized ratiometric fluorescent probe for sensing human UDP-glucuronosyltransferase 1A1 and its biological applications.

This study aimed to develop a practical ratiometric fluorescent probe for highly selective and sensitive detection of human UDP-glucuronosyltransferase 1A1 (UGT1A1), one of the most important phase II enzymes. 4-Hydroxy-1,8-naphthalimide (HN) was selected as the fluorophore for this study because it possesses intramolecular charge transfer (ICT) feature and displays outstanding optical properties. A series of N-substituted derivatives with various hydrophobic, acidic and basic groups were designed and synthesized to evaluate the selectivity of HN derivatives toward UGT1A1.

Characterization of phase I metabolism of resibufogenin and evaluation of the metabolic effects on its antitumor activity and toxicity.

Resibufogenin (RB), one of the major active compounds of the traditional Chinese medicine Chansu, has displayed great potential as a chemotherapeutic agent in oncology. However, it is a digoxin-like compound that also exhibits extremely cardiotoxic effects. The present study aimed to characterize the metabolic behaviors of RB in humans as well as to evaluate the metabolic effects on its bioactivity and toxicity.

A highly selective probe for human cytochrome P450 3A4: isoform selectivity, kinetic characterization and its applications.

Bufalin 5β-hydroxylation was found to be an isoform-specific biotransformation probe substrate for cytochrome P450 3A4 (CYP3A4). The probe reaction was well-characterized and it can be used for measuring the real catalytic activities of CYP3A4 from different enzyme sources.

Trilinear decomposition method applied to removal of three-dimensional background drift in comprehensive two-dimensional separation data.

A novel technique for removal of three-dimensional background drift in comprehensive two-dimensional (2D) liquid chromatography coupled with diode array detection (LCxLC-DAD) data is proposed. The basic idea is to perform trilinear decomposition on the instrumental response data, which is based on the alternating trilinear decomposition (ATLD) algorithm. In model construction, the background drift is modeled as one component or factor as well as the analytes of interest, hence, the drift is explicitly included into the calibration.