The simple and rapid quantification method for L-3,4-dihydroxyphenylalanine (L-DOPA) from plant sprout using liquid chromatography-mass spectrometry

Abstract

L-3,4-dihydroxyphenylalanine (L-DOPA) is one of the important secondary metabolites of plants and has been used for various purposes, such as in clinical treatment for Parkinson's disease and dopamine-responsive dystonia. In plants, L-DOPA is a precursor of many alkaloids, catecholamines, and melanin; the L-DOPA synthesis pathway is similar to that in mammals. L-DOPA acts as an allelochemical, has an important role in several biological processes, such as stress response and metabolism, in plants. L-DOPA is widely used in the clinical treatment as well as a dietary supplement or psychotropic drug, understanding of biosynthesis of L-DOPA in plant could lead to a stable supply of L-DOPA. This paper describes an improved method for simple and rapid quantification of L-DOPA content using liquid chromatography-tandem mass spectrometry. The standard quantitative methods for L-DOPA require multiple purification steps or relatively large amounts of plant material. In our improved method, quantification of L-DOPA was possible with extract of one-two pieces of cotyledon without any partitioning or column for purification. The endogenous L-DOPA (approximately 4,000 µg g −1 FW (fresh weight)) could be detected from the one pieces of cotyledon of the faba bean sprout using this method. This method was also effective for samples with low endogenous amounts of L-DOPA such as broccoli, Japanese white radish, pea, and red cabbage sprouts. Therefore, this improved method will allow to measurement of L-DOPA content easily and accurately from a small amount of plant tissue and contribute to understanding biosynthesis, catabolism, and transport of L-DOPA.

Water deprivation modifies the metabolic profile of lavender (Lavandula angustifolia Mill.) leaves

“…compared to control, respectively, p < 0.001) (Figures 3 and 4). Previous studies reported that dihydroxyphenylalanine acts as an allelochemical involved in several stress response pathways, and constitutes a precursor of many secondary metabolites, e.g., alkaloids, catecholamines, and melanin (Soares et al 2014;Etemadi et al 2018;Yumoto et al 2022;Saeed et al 2023). The significantly impacted secondary metabolism of lavender plants in response to WD was also confirmed by pathway analysis showing secondary metabolite biosynthesis with the highest pathway impact score of 1 (Figure S1).…”

“…In this study, we found that the precursor of shikimic acid was significantly ( p < 0.05) decreased upon prolonged WD (86% and 91% less at 7DAW and 10DAR compared to control, respectively), whereas the aromatic amino acid dihydroxyphenylalanine dramatically accumulated (2.3 and 6.6 folds higher at 7DAW and 10DAR compared to control, respectively, p < 0.001) (Figures 3 and 4). Previous studies reported that dihydroxyphenylalanine acts as an allelochemical involved in several stress response pathways, and constitutes a precursor of many secondary metabolites, e.g., alkaloids, catecholamines, and melanin (Soares et al 2014; Etemadi et al 2018; Yumoto et al 2022; Saeed et al 2023). The significantly impacted secondary metabolism of lavender plants in response to WD was also confirmed by pathway analysis showing secondary metabolite biosynthesis with the highest pathway impact score of 1 (Figure S1).…”

Electroanalytical Overview: The Determination of Levodopa (L-DOPA)

“…Note that it is reported that the global demand for L-DOPA has an annual market value of USD 2.64 billion in 2020. 75 For example, it is well-known that relatively high L-DOPA concentrations occur in natural sources, such as Mucuna and fava beans, which have been measured using LC-MS, 76 and other plant species, 77 which could lead to a dietary supplement; this is an area that could be beneficial for electroanalytical sensors.…”