Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436693
Title: Phytochemical and pharmacological studies on some endemic Yucatecan medicinal plants
Author: Sanchez-Medina, Alberto
Awarding Body: University of Greenwich
Current Institution: University of Greenwich
Date of Award: 2007
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Abstract:
Four endemic medicinal plants from the Yucatan peninsula belonging to genera with little pharmacological and phytochemical reported information and used for medicinal purposes by local communities were selected. The species selected included Jacquinia flammea Millsp. ex Mez, Sideroxylon foetidissimum Jacq. subsp. gaumeri, Serjania yucatanensis Standl., and Serjania adiantoides Radlk. The root, stem/bank and leaves of each plant species were extracted using ethanol and the resulting crude extracts were tested for their cytotoxic effect using the modified MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay followed by a bioassay-guided fractionation of the most active extracts in order to identify the active metabolites. The initial cytotoxic evaluation against HeLa cells at two fixed concentrations (100 and 33.3 µg/mL) identified the root extracts f J. flammea, S. foetidissimum subsp. gaumeri and S. yucatanensis, and the stem/bank extract of S. adiantoides as the most active extracts. The crude extract of roots of J. flammea was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHCI3, EtOAc, BuOH and water). The resulting fractions were tested for their cytotoxic activity. The water fraction of the solvent partition showed the strongest activity against HeLa cells (IC50 = 28.61 ± 2.27 µg/mL). When tested against RAW 264.7 cells, the water fraction also showed significant activity (IC50 = 10.60 ± 1.83 µg/mL). The water fraction was subjected to chromatographic fractionation using open silica gel columns resulting in the isolation of a saponin as the most active metabolite against RAW 264.7 cells (IC50 = 4.76 ± 0.32 µg/mL). The isolated compound was identified using 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and NOESY and ROESY) NMR and mass spectrometry analysis as sakurasosaponin. The molluscicidal and antifungal activities of sakurasosaponin have been reported but no studies on its cytotoxic activity have been previously reported. The crude extract of roots of S. foetidissimum subsp. gaumeri was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHC13, EtOAc, and BuOH). The resulting fractions were tested for their cytotoxic activity. The BuOH extract of S. foetidissimum subsp. gaumeri showed the strongest activity against RAW 264.7 cells (IC50 = 35.12 ± 4.32 µg/mL) and it was subjected to further chromatographic fractionation using open silica gel columns yielding mixtures of saponin-containing fractions. The crude extract of roots of S. yucatanensis was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHCI3, EtOAc, and BuOH). The resulting fractions were tested for their cytotoxic activity. The crude extract of S. adiantoiodes did not show cytotoxic activity when tested against RAW 264.7 cells.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.436693  DOI: Not available
Keywords: QK Botany ; RS Pharmacy and materia medica
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