Advances in analytical methods for endogenous bile acids based on UPLC-MS/MS technology / 药学学报

Bile acids (BAs) are a group of endogenous steroid molecules that regulate lipid, glucose and energy metabolism. They play an important role in maintaining body homeostasis and physiological functions as key signaling molecules for host and gut microbial metabolism. The accurate characterization and quantification of BAs in vivo is of great importance in basic and clinical research. Over the past decades, enzymatic assay, enzyme-linked immunoassay, nuclear magnetic resonance (NMR), chromatography, and other related techniques have been developed and applied to the detection of BAs. The diverse structures of BAs, the existence of isomers and the complex matrix of biological samples pose great challenges for the detection of endogenous BAs. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is a robust analytical technique that combines the rapid separation capacities of UPLC with the powerful structural identification capabilities of MS/MS, facilitating the more rapid separation, characterization and accurate quantitative of target analytes in biological samples. UPLC-MS/MS has been widely used in the quantitative analysis of BAs in recent years for its high selectivity, high sensitivity, and high accuracy. This paper summarized the biosynthetic pathways of BAs, sample pretreatment methods, common analytical detection techniques, and highlights the current status of the application of UPLC-MS/MS technology in the analysis of endogenous BAs over the past five years, to provide a reference for the accurate detection of endogenous BAs and further research development and application.

SPME as a green sample-preparation technique for the monitoring of phytocannabinoids and endocannabinoids in complex matrices / 药物分析学报

The endocannabinoid system(ECS),particularly its signaling pathways and ligands,has garnered considerable interest in recent years.Along with clinical work investigating the ECS'functions,including its role in the development of neurological and inflammatory conditions,much research has focused on developing analytical protocols enabling the precise monitoring of the levels and metabolism of the most potent ECS ligands:exogenous phytocannabinoids(PCs)and endogenous cannabinoids(endocannabi-noids,ECs).Solid-phase microextraction(SPME)is an advanced,non-exhaustive sample-preparation technique that facilitates the precise and efficient isolation of trace amounts of analytes,thus making it appealing for the analysis of PCs and ECs in complex matrices of plant and animal/human origin.In this paper,we review recent forensic medicine and toxicological studies wherein SPME has been applied to monitor levels of PCs and ECs in complex matrices,determine their effects on organism physiology,and assess their role in the development of several diseases.

Desenvolvimento e validação de método analítico para determinação do 4-nerolidilcatecol (4-NRC) em solução de proteína plasmática para aplicação em estudos de microdiálise cutânea / Development and validation of analytical method to determine 4-nerolidylcatechol (4-NRC) in plasma protein solution used for cutaneous microdialysis studies

Este artigo aborda a validação de um método analítico para determinação, em amostras de microdiálise, de 4-nerolidilcatecol (4-NRC), uma substância natural extraída da Piper umbellata (Piperaceae) com comprovada atividade antioxidante. O sistema de cromatografia líquida (CLAE-PDA Shimadzu LC 20AT, bomba LC–20AT, injetor com autosampler SIL– 20A) foi acoplado a uma coluna C18 (Phenomenex® Synergi Fusion 4μ RP-80ª, 150 x 4,6 mm). A fase móvel constituiu-se de acetonitrila, metanol e água (54:20:26, v:v:v), sob fluxo de 1,0 mL min-1, com detecção a 280 nm, volume de injeção 30 μL e tempo de corrida 15 minutos. O método foi linear para concentrações de 5,0-200,0 μg mL -1 (r = 0,9996). Os limites de detecção e de quantificação foram, respectivamente, 1,35 e 4,5 μg mL-1. A precisão (DPR <5,0%) e exatidão (99,0 – 112,0%) ficaram dentro dos valores recomendados pela ANVISA. A robustez foi garantida medindo-se a influência da variação do fluxo e da proporção de acetonitrila da fase móvel. As amostras de albumina enriquecidas com 4-NRC e submetidas ao processo de extração apresentaram recuperação de 69 a 95%. O método desenvolvido pode ser aplicado à análise de 4-NRC, com finalidade de estudos de microdiálise cutânea, devido aos adequados parâmetros de validação obtidos.

This paper reports the validation of an analytical method for the determination, in skin microdialysis samples, of 4-nerolidylcatechol (4-NRC), a natural substance extracted from Piper (Pothomorphe) umbellata (Piperaceae) with recognized antioxidant activity. The liquid chromatographic system (HPLC-PDA Shimadzu LC20AT, pump LC-20AT, injector with autosampler SIL-20A) was coupled to a C18 column (Phenomenex® Synergi Fusion 4 μm RP-80 Å, 150 x 4.6 mm), with acetonitrile:methanol:water (54:20:26, v:v:v) as the mobile phase, flowing at 1.0 mL min-1, with detection by absorbance at 280 nm, injection volume 30 μL and running time 15 min. The method was linear for concentrations from 5.0 to 200.0 μg mL-1 (r=0.9996). Detection and quantitation limits were, respectively, 1.35 and 4.5 μg mL-1, precision (RSD < 5.0%) and accuracy (99.0-112.0%) within values recommended by ANVISA. The robustness was tested by measuring the effect of arying the flow-rate and the proportion of acetonitrile in the mobile phase. Microdialysis perfusion solution of albumin (BSA) spiked with 4-NRC and subjected to liquid-liquid extraction showed recovery from 69 to 95%. This method is applicable to the analysis of 4-NRC for the purpose of cutaneous microdialysis studies, in view of the acceptable validation parameters obtained.

Monitoramento da exposição a organoclorados: uma revisão sobre análises em matrizes biológicas / Monitoring organochlorine exposure: a review on biological matrices analysis

Agrotóxicos organoclorados (OC) são classificados como poluentes orgânicos persistentes e podem ser determinados em uma ampla variedade de matrizes ambientais e biológicas. O controle da exposição a estes químicos é considerado um desafio para as autoridades de saúde pública, desde que o espectro de efeitos adversos às populações inclui desregulação do sistema endócrino e carcinogenicidade. O objetivo deste artigo é apresentar uma revisão sobre os métodos de análise de OC em amostras biológicas, e discutir os fatores que mais influenciam o monitoramento biológico. Os métodos para análise de resíduos de OC requerem alta sensibilidade, e a etapa de extração dos analitos da matriz é crítica para garantir a qualidade dos resultados. Muitos métodos são disponíveis tais como a extração líquido-líquido, utilização de cartuchos ou discos para extração em fase sólida, extração em fase sólida com micro fibras e extração com barra agitadora. A matriz biológica mais utilizada para detectar OC é o soro, que pode ser convenientemente obtida.

Organochlorine pesticides (OC) are classified as persistent organic pollutants and can be determined in a great variety of environment and biological matrices. The control of the exposure to these chemicals is considered a challenge to the public health authorities, since the spectrum of adverse effects to the populations includes disruption of endocrine system and carcinogenicity. The objective of this study is to present a review about the methods of analysis of OC in biological samples, and to discuss the factors that most influence biological monitoring. The methods used for trace analysis of OC need to be highly sensitive and the extraction stage of the analytes from the matrix is a critical step to ensure the quality of results. Many methods are available such as liquid-liquid extraction, utilization of cartridges, disks and micro fibers for solid phase extraction, and extraction with stirring bars. The most used biological matrix for tracking OC is the serum, which can be very conveniently obtained.