Levodopa in Mucuna pruriens and its degradation.

Sabulal Baby,Rajani Kurup,Haridas Pulikkalpura,Paravanparampil Jacob Mathew

doi:10.1038/srep11078

Sabulal Baby, Rajani Kurup + Show 2 more

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https://doi.org/10.1038/srep11078

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Abstract

Mucuna pruriens is the best known natural source of L-dopa, the gold standard for treatment of Parkinsonism. M. pruriens varieties are protein rich supplements, and are used as food and fodder worldwide. Here, we report L-dopa contents in seeds of fifty six accessions of four M. pruriens varieties, M. pruriens var. pruriens, M. pruriens var. hirsuta, M. pruriens var. utilis and M. pruriens var. thekkadiensis, quantified by HPTLC-densitometry. L-dopa contents varied between 0.58 to 6.42 (%, dr. wt.). High and low L-dopa yielding genotypes/chemotypes of M. pruriens could be multiplied for medicinal and nutritional purposes, respectively. HPTLC profiles of M. pruriens seeds on repeated extraction (24 h) in 1:1 formic acid-alcohol followed by development in butanol:acetic acid:water (4:1:1, v/v) showed consistent degradation of L-dopa (Rf 0.34 ± 0.02) into a second peak (Rf 0.41 ± 0.02). An average of 52.11% degradation of L-dopa was found in seeds of M. pruriens varieties. Since M. pruriens seeds and/or L-dopa are used for treatment of Parkinson’s disease and as an aphrodisiac both in modern and/or traditional systems of medicine, the finding of high level of L-dopa degradation (in pure form and in M. pruriens extracts) into damaging quinones and ROS is very significant.

Highlights

Products of L-dopa autoxidation are cytotoxic to cellular systems[22,23,24,25]
In second generation M. pruriens var. pruriens seeds grown in the Experimental Plot (EP), L-dopa contents varied from 0.58 to 4.32%, and % second degradation peak (SDP) varied from zero to 3.34%
Fruiting was not observed in M. pruriens var. hirsuta and M. pruriens var. thekkadiensis in the Field Gene Bank (FGB). This is the first report of L-dopa quantification in M. pruriens var. hirsuta and M. pruriens var. thekkadiensis

Summary

Introduction

L-dopa is an antinutritional factor and its consumption causes vomiting, nausea, abdominal distention, dyskinesia etc[26]. Most L-dopa quantification studies in M. pruriens seeds and formulations by chromatographic techniques (HPTLC, HPLC) are on limited number of samples and involved prolonged, multistep extraction procedures in acidic media. We report (i) L-dopa contents in seeds of thirty accessions of the four M. pruriens varieties viz., M. pruriens var. Thekkadiensis (1), collected from various locations in Kerala in south India, (ii) L-dopa contents in second generation seeds of twenty-six accessions of M. pruriens var. Utilis (5) grown in an Experimental Plot (EP) under identical ecological conditions, (iii) degradation patterns of L-dopa in M. pruriens seed extracts, (iv) quantification of L-dopa degraded products in seeds (30 wild, 26 EP grown accessions) of four M. pruriens varieties and (v) characterization of L-dopa degraded moieties by HPTLC, DART-MS and LC/EI-MS We report (i) L-dopa contents in seeds of thirty accessions of the four M. pruriens varieties viz., M. pruriens var. pruriens (21), M. pruriens var. hirsuta (3), M. pruriens var. utilis (5) and M. pruriens var. thekkadiensis (1), collected from various locations in Kerala in south India, (ii) L-dopa contents in second generation seeds of twenty-six accessions of M. pruriens var. pruriens (21) and M. pruriens var. utilis (5) grown in an Experimental Plot (EP) under identical ecological conditions, (iii) degradation patterns of L-dopa in M. pruriens seed extracts, (iv) quantification of L-dopa degraded products in seeds (30 wild, 26 EP grown accessions) of four M. pruriens varieties and (v) characterization of L-dopa degraded moieties by HPTLC, DART-MS and LC/EI-MS

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