The Design of HPLC and UV-Spectrophotometric Methods for Assay of 5-hydroxytryptophan in Seeds of Griffonia simplicfolia

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5-Hydroxytryptophan is a naturally occurring amino acid found in significant levels in seeds of Griffonia simplicfolia. The overwhelming advantages it has over tryptophan in treating the numerous effects of serotonin deficiency syndrome have attracted the commercialization of seeds of Griffonia simplicifolia. Of much concern is the quality of the seeds, especially before export, as well as the final product. Hence, it was desired to establish HPLC and UV-spectrophotometric methods of assay for 5-HTP in seeds of Griffonia simplicifolia. Manipulating chromatographic conditions yielded an HPLC method in which 5- HTP in seeds of Griffonia simplicifolia could be assayed at a flow rate of 1, 5m1/min and a mobile phase composition of 3% methanol in NaH2PO4 buffer (p1-I 4.8). Crushing and shaking the seeds for l0mins in methanol-water (50:50) gave the maximum extraction of 5- HTP from the seeds. Using “amplem correction factor” developed from HPLC data, an UVspectrophotometric method of assay for 5-I-ITP was established which could be used in conjunction with the HPLC method in order to save time and cost of assaying bulk samples of the seeds. The level of 5-HTP in the seeds were found to decrease at a rate of 4.86% per month of storage under tropical atmospheric conditions. The methods developed in this work revealed that the seeds of Griffonia simplicifolia obtained in Ghana contained up to 20.83% fresh weight of 5-HTP.
A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the award of the Degree of Master of Science in Pharmaceutical Chemistry, 1999