Metabolomics has played a central role in various areas of plant sciences, offering new perspectives for the advancement of agriculture, drug discovery, chemical ecology and taxonomy. Plant metabolomics (identification and quantification) aims to understand the relationship between biological systems and genetic, pathological and or environmental stimuli in terms of differential expression of the metabolism. Owing to the unique challenges, such studies require multidisciplinary skills involving biology, chemistry, statistics, and computer science for the extraction and complete understanding of information. In this sense, this review summarizes the main procedures that involve the steps of plant metabolomic study (design of experiments, sample preparation, analytical methods and data analysis), providing a comprehensive overview, showing the main challenges and limitations and possible solutions for the different approaches used.

Este trabalho descreve a validação completa de metodologia analítica empregando cromatografia gasosa capilar com padronização interna para quantificação da cumarina (1,2-benzopirona) em produtos contendo guaco (Mikania glomerata Spreng - Asteraceae): xarope, planta e extrato padronizado, além do estudo de estabilidade do fitoterápico em questão. Utilizou-se uma coluna capilar HP-5 (30 m x 0,32 mm x 0,25 µm), hidrogênio a 1,8 mL/min e rampa de temperatura de 100 ºC a 250 ºC, a 15 ºC/min. A temperatura do injetor (split 1:20) foi de 250 ºC, enquanto a do detector foi de 270 ºC. Os tempos de retenção dos padrões foram: 2,86 minutos para o 1, 2, 3, 4-tetrametilbenzeno, 4,45 minutos para o piperonal (padrões internos) e 5,36 minutos para a cumarina. Após o procedimento de extração da planta in natura, a recuperação da cumarina foi de 101,6 %, enquanto que para o xarope esta foi de 100,8 %. Os limites de detecção e quantificação foram 0,5 µg/mL e 1,5 µg/mL, respectivamente. A precisão, determinada para todas as amostras, apresentou desvios padrões relativos menores que 2,5 %. Os teores de cumarina presentes nas folhas, extrato e xarope foram de 0,38 % m/m, 1,33 mg/mL e 0,143 mg/mL, respectivamente.

This work describes a full validation of a capillary gas chromatography analytical methodology using internal standardization for the quantification of coumarin (1,2-benzopyrone) in guaco (Mikania glomerata Spreng - Asteraceae) products: syrup, plant and its extract, including the stability study of the phytomedicine. For the analysis, it was used an HP-5 capillary column (30 m x 0.32 mm x 0.25 µm), hydrogen at a flow rate of 1.8 mL/min and the increasing temperature gradient was: 100 ºC to 250 ºC, 15 ºC/min. The temperature of injector (split 1:20) and detector were kept at 250 ºC and 270 ºC, respectively. The retention times of the standards for the above conditions were 2.86 minutes for 1, 2, 3, 4-tetramethylbenzene, 4.45 min for piperonal (internal standards), and 5.36 minutes for coumarin. After extraction procedure, the recovery of coumarin determined for plant raw material was 101.6 %, while for syrup it was 100.8 %. Detection and quantification limits were 0.5 µg/mL and 1.5 µg/mL, respectively. Precision was determined for all samples and the results were lower than 2.5 %. The total amount of coumarin in plant raw material, its extract and syrup were 0.38% w/w, 1.33 mg/mL and 0.143 mg/mL, respectively.