Metabolite Profiling and Identification
BOC Sciences provides comprehensive metabolite profiling and identification services for the analysis, isolation, and characterization of metabolites in biological matrices to support drug discovery and safety studies. We combine NMR, LC-MS/MS and bioinformatics analysis methods to accurately identify metabolites in complex biological samples and provide analytical services to identify unknown metabolites.
Introduction
Metabolite profiling and identification play a key role in drug discovery, which aims not only to screen metabolites, but also to develop new drugs because their metabolites are more potent and less toxic than the drugs themselves.
Drug metabolism, also known as biotransformation of drugs, is the process by which the chemical structure of a drug is changed by the action of drug metabolizing enzymes after absorption and distribution in the body.
There are two results of drug biotransformation in vivo:
- inactivation, becoming a drug without pharmacological activity;
- activation, from the original no pharmacological activity to some organ targets to become pharmacologically active metabolites or even produce toxic metabolites. There are also metabolites of drugs that still maintain their original pharmacological effects.
The metabolic reactions of drugs can be broadly divided into four types: oxidation, reduction, hydrolysis and conjugation. Phase I metabolism can be oxidation, reduction and hydrolysis reactions, and phase II metabolism is binding reaction. Some drugs can be metabolized by several different types of reactions at the same time. The liver is the main metabolic organ of drugs and is rich in various enzymes required for phase I and phase II metabolism.
The sites where metabolic reactions occur are predicted based on the basic structure of the compound, and some common sites where metabolic reactions occur are summarized in the table below.
| Phase I Metabolism | |
| Site: group/atom | Metabolic transformation type |
| 0 atom/N atom directly attached to the hydrocarbon group | O-dehydrocarbonyl/N-dehydrocarbonyl |
| Aromatic ring/α-H atom | Oxidation (formation of -OH) |
| N atom/S atom | Oxidation (formation of N oxides/S oxides) |
| Heteroatom (F, Br, C1) | Dehybridization atom, oxidation |
| Unsaturated bond | Desaturation |
| Amino | Deamidation oxidation (to form ketone or alcohol) |
| Nitro/hydroxyl/ketone | Reduction (hydrogenation) |
| Esters/Amides | Hydrolysis |
| Phase II Metabolism | |
| Site: group/atom | Metabolic transformation type |
| Hydroxyl group/carboxyl/amino/sulfhydryl group | Glucuronidation |
| Hydroxyl group | Sulfate esterification |
| primary amino group | Acetylation |
| N, O, S | Methylation |
| Electrophilic group | Glutathione binding reaction |
Technology Platform
Techniques for metabolite profiling and identification include high-resolution mass spectrometry (MS) for accurate mass determination, high-resolution, high-throughput nuclear magnetic resonance (NMR), capillary electrophoresis (CE), high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography (UPLC) techniques. With the support of these technology platforms, a series of data sets suitable for metabolite identification can be generated and supported by powerful bioinformatics tools to automate the analysis of the data in order to accurately identify the metabolites represented by each signal. Based on the experiments, a metabolite database based on various spectra can be established to make the identification of metabolites more convenient and feasible.
- Background Subtraction (BS)
BS is a technique for selective detection of metabolites based on a specific algorithm that deducts endogenous background interference signals from blank samples from the mass spectrometry data of biological samples after drug administration.
- Mass spectrometry full scan
Generally for the first metabolite analysis of a sample a full scan is used, by running a generic LC-MS method to obtain a comprehensive metabolite profile.
- Neutral loss
Neutral loss can be used to find metabolites that have similar cleavage patterns to the prototype drug or known metabolites. Neutral loss scanning is one of the unique data acquisition methods for triple quadrupole tandem mass spectrometers. It works primarily by scanning the primary mass spectrum (MS1) and the secondary mass spectrum (MS2) simultaneously, while the mass difference Δm between MS2 and MS1 is always maintained, and the final spectrum will show those ions from the primary spectrum that have lost neutral fragments (Δm) through cleavage.
Why Choose BOC Sciences?
- High throughput, qualitative and quantitative assay techniques for metabolites
- Automated analysis of data
- Complete sample pre-treatment, data acquisition, and data analysis
- Interpretation of pharmacological, pharmacokinetic, and toxicological data
- Provides critical information on metabolite formation
- Study metabolites in many different matrices
- Consistent, high-quality data with protocols that can be adapted to specific customer requirements
What Can We Do?
BOC Sciences' team of scientists can design custom experiments to overcome the complex metabolite analysis challenges of the pharmaceutical industry while ensuring timely delivery of data and detailed scientific reports that meet relevant regulatory requirements. Our flexible custom metabolite profiling and identification is designed to meet the needs of our global customers and can be provided as part of a drug PK/PD study or as a stand-alone study.