Undergraduate Theses
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Item Mud crab (Scylla serrata) shells for the removal of humic acids from Santa Barbara well waterAsdillo, Reina Jean A. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2010-04)The chemical contamination of drinking water from a wide range of contaminants such as humic acids can potentially lead to health-related in living organisms, especially humans. In rural areas of the Philippines, the use of low cost methods to remove water pollutants is, therefore, of great interest. In this study, osterized mud crab (Scylla serrata) shells or exoskeletons from cooked crab wastes were used to remove humic acids from the Santa Barbara well water. Adsorption experiments were done to evaluate its capacity to remove humic acids from the well water. Adsorption Isotherms and Fourier Transform Infrared Spectroscopy were employed to study the characteristics of the adsorption of humic acids onto the OSSE (osterized Scylla serrata exoskeletons). Adsorption experiments showed that at an average 1.0010 g of OSSE and after six hours of agitation, an average 74.95% of humic substances were removed from 50 mL of Montinola, Santa Barbara well water sample. Isotherm experiments showed that the experimental data can be fitted in both Langmuir and Freundlich models with low K values of 0.0235 L/mg and 0.4450 (mg/g)(L/mg), respectively. Based on the results of the above experiments, OSSE is a good adsorbent for humic acids in well waters (although more research need to be done on the removal of the substances remaining in the water after OSSE treatment) and the U-OSSE (used osterized Scylla serrata exoskeletons) can possibly be recycled.Item Anti-inflammatory and antibacterial activities of Batuan (Garcinia binucao) fruitsAlbano, Zella Faye (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2010)In this study, fresh fruits of batuan (Garcinia binucao) was evaluated for its antiinflammatory and antibacterial activities. The anti-inflammatory assay using Carrageenan-Induced Paw Edema Method showed that n-hexane extracts (65.79%) and dichloromethane extracts (64.91%) exhibited anti-inflammatory activities comparable to Indomethacin, the positive control (67.11%). The antibacterial assay using Paper Disk Diffusion Method showed that crude methanolic extracts, n-hexane extracts and dichloromethane extracts at 1000pg/mL were most effective against Staphylococcus aureus. The microbial indexes were 0.39, 0.47 and 0.50 respectively. The positive control, Amoxicillin has a 3.39 microbial index. The components of the three most active extracts (crude methanolic, n-hexane and DCM extracts) from both assays were separated through Thin Layer Chromatography and subjected to phytochemical tests. Crude methanolic extracts contained alkaloids, phenolic compounds and cardiac glycosides. Both n-hexane and DCM extracts contained terpenes, alkaloids, saponins, phenolic compounds and cardiac glycosides. These bioactive compounds present may have been responsible for the antiinflammatory and antibacterial activities of the extracts.Item Optimization of extraction Conditions of water-soluble phenolics from tawa-tawa (Euphorbia hirta L.) based on Densitometric TLC using gallic acid as marker compoundAborka, Ma. Ayanne B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)The present study aimed to optimize the extraction conditions of water-soluble phenolics for tawa-tawa (Euphorbia hirta L.) with gallic acid as the compound of interest. Water was used as extraction solvent. The effect of the interactions of different extraction temperature (50°C, 60°C and 70°C) and extraction time (20 min, 40 min and 60 min) were investigated. To evaluate the importance of the parameters on the extraction efficiency of gallic acid, a factorial design was used. The normal probability plot and estimates of standard error showed that time and temperature were both significant parameters. It further showed that time was a more significant contributor than temperature to the extraction efficiency of gallic acid. The results revealed that interaction of time and temperature did not have significant effects. The ANOVA results showed that only extraction parameter with significant effect was time (p < 0.05). Temperature and its interaction with time did not have significant effects. Based on the desirability values generated by Design-Expert 9.0.4, the optimal conditions in extracting gallic acid were the following: extraction time of 60 minutes and extraction temperature of 70°C. Results of FTIR analysis confirmed the presence of the following functional groups: O-H, C=O, C-O, C-H (aromatic), C=C (benzene) and out-of-plane bending or oops. Gallic acid in tawa-tawa is present in esterified form and exists as part of hydrolysable tannins.Item Antioxidant and antibacterial activities of bika (Ampelocissus martini panch) seed oilAngot, Rose Imee Lyn N. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)Ampelocissus martini Planch, locally known as Bika, is a native tropical plant generally found in Southeast Asia. It is abundant in Panay Island, particularly in the provinces of Antique and Iloilo. Despite that the fruit is being consumed as food, used as medicine, and made into wine, very few scientific studies pertaining to Bika grape exist. Hence, this study focused on its antioxidant and antibacterial activities. The antioxidant activities were carried out through the % DPPH radical scavenging activity and reducing power method. Results show that the Bika seed oil has antioxidant activity. Its IC50 using DPPH assay is 23.63 ppm. Moreover, it also showed a significant antioxidant activity based on the results from the reducing power assay. Both results demonstrated that Bika grape seed oil have antioxidant activity. On the other hand, the mean zones of inhibition using disk diffusion assay was used to assess the antibacterial activity of Bika seed oil against Escherichia coh and Staphylococcus aureus. Only the antibiotic Gentamicin showed active antibacterial property, whereas the Bika seed oil showed little zone of inhibition, only goes to show that it has an inactive antibacterial property.
