Comparison of extraction efficiency of various methods to extract L-DOPA from Mucuna pruriens (L.) DC

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.