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Undergraduate Theses

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1998 - 20003

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Committee Member: search.filters.committeemember.Pama, Monita H.Has files: Yes

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    Comparative study of trace metals and common impurities of table salt produced in Leganes, Iloilo and Tibiao, Antique
    Calawag, Jerolet E. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2000-10)
    Trace metals such as cadmium (Cd), chromium (Cr) and lead (Pb) as well as the common impurities in salt like magnesium (Mg), calcium (Ca), sulfate, moisture, matter insoluble in water (MIW) and matter insoluble in acid (MIA) were analyzed using spectrophotometric (Flame Atomic Absorption &UV-vis Spectrophotometers) and gravimetric methods. Results showed that percentage concentrations of magnesium and calcium were significantly higher in sample A (Tibiao table salt) than in sample B (Leganes table salt) at 1- percent level of confidence. The percentage concentrations of MIW, MIA, moisture and sulfate were significantly higher in sample B than in sample A. Results of Uv-vis absorption spectroscopy indicated that both chromium and cadmium were absent in both samples while the lead concentrations in samples A and B were 10.9190 and 11.4831 ppm respectively. At 5% level of probability, the lead concentrations of both samples did not differ from each other. Using another technique of analyzing trace metals, the flame atomic absorption spectroscopy based on flame atomization, different results were obtained. Lead concentration in samples A and B were 6.4874 and 9.4977-ppm salt respectively. At 5 % level of probability, sample B had higher lead concentration than in sample A. The lead concentrations in both samples were all higher than 0.015 ppm, the allowable maximum limit of lead in water, or any drinks. The over-all results showed that sample B had higher contaminants than in sample A.
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    Isolation and purification and bioactive components from the fruit of Morinda citrifolia
    Barbarona, Hazel M. (Division of Phyisical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2000-10)
    Phytochemical screening done on the fruit of “noni” Morinda citrifolia revealed the presence of saponins and the absence of alkaloids. Sequential extraction of active components of noni using n-hexane, dichloromethane and ethyl acetate solvents gave yields of 0.09%, 0.31% and 0.11% as yields respectively. Crude methanolic concentrate of the noni fruit was subjected into four bioactivity tests. Toxicity bioassay showed 251.19 g/ml to be the LC50. Antimicrobial bioassay showed that S. aureus, B. subtilis, E. coli, and P. auruginosa organisms have no activity against the crude methanolic concentrate. In analgesic bioassay, the crude methanolic concentrate (16.37) is no better or has the same activity with the positive control mefenamic acid (17.51) based on the percentage reduction in squirms of the Swiss Websters mice. Antispasmodic activity showed that the crude methanolic concentrate of the fruit (55.47%) is as active as the positive control, loperamide (58.02%). In the three fractions, antispasmodic activity of n-hexane and dichloromethane have greater effect than the positive control (loperamide) while ethyl acetate has the same activity with it. The percentages traveled by charcoal in n-hexane (39.929) and dichloromethane (45.908) were lower than that of the positive control, loperamide (60.130) and ethyl acetate fraction (48.352). Antispasmodic bioassay on n-hexane purified through Vacuum Liquid Chromatography showed that the nine fractions (F1-F9) showed no significant difference with the positive control. Thin Layer Chromatography showed the presence of mono-, di-, and triterpenes; steroid glycosides and saponins in the noni fruit extract.
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    Bioactivity-guided screening of selected plants from UPV Miag-ao campus
    Arceo, Ma. Ofelia H. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 1998-05)
    Twelve selected ethnomedically-used plants were screened for alkaloids, saponins, and flavonoids. Nine out of twelve plants contained at most two of the phytochemicals tested, and three showed the absence of these phytochemicals. Methanolic extracts of three selected plants (Stachy/arpheta /amaicensis, Hyptis suaveo/ens, Semecarpus philippinensis) were examined for antibacterial activity against Staphylococcus aureus. Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. All extracts were found to be active at least against two of the microorganisms tested. The extract of Siachytarphe/a jamaicensis was found to be active against three out of four microorganisms and found to be the most bioactive. Stachyiarpheta jamaicensis was subjected to bioactivity-guided fractionation using solvents of increasing polarity - hexane, ethyl acetate, and n-butanol. The hexane extract was considered as the most bioactive fraction. Its chromatogram contained seven spots in which four turned blue violet after spraying with vanillin-H2SO4. The color change exhibited suggests the possible presence of saponins.