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UPV Theses and Dissertations

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Committee Member: search.filters.committeemember.Janagap, Steve P.SDG: search.filters.sdg.SDG 15 - Life on land

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    Extraction of humic substances from vermicompost and application as component matrix for slow-release fertilizers
    Boloron, Nina Loren R. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)
    Humic acid was extracted from vermicomposts (hereafter referred as VCHAs) by alkali/acid fractionation and their concentration were determined to be 54.79 (± 0.25) g HS/kg vermicompost in average. The extracted humic substances from vermicomposts were also determined to contain an average K+ of 0.0671 (± 0.0053) g K/kg vermicompost. The Fourier transform infrared spectra of crude VCHSs show similar spectral features with humic acids extracted from vermicomposted materials. The VCHSs were complex with K nutrient and encapsulated in cross-linked Ca-alginate to form vermicompost humic substance — potassium slow-release fertilizer bead (VCHS-K SRF). The synthesized VCHS-K SRF were subjected to total nutrient analysis, swelling kinetics, and slow release test to evaluate the role of nutrient compositions on its capability and capacity as slow- release fertilizer. Results for total nutrient analysis show that with an increase in nutrient loading, encapsulation efficiency is low and nutrient concentration is low. These findings imply that at neutral pH of HS solution, binding sites are saturated with Na+, therefore with having the same affinity as K+ , minimal ion exchange took place and it became difficult for K+ to bind to the HS complex. It also suggests that the amount of polymer coating and the degree of crosslinking were not sufficient to hold all nutrients. Discrepancies on the amount of released K+ was also observed on the release profile as a product of errors on acid digestion and matrix effect, this lead to elevated amounts of release by the VCHS-K SRF. The result of the release behavior profile of VCHS-K SRF shows that with an increase in enriched nutrient load, the release rate is faster. The results on the release profile of the VCHS-K SRF exhibited a parabolic and burst release. This finding in relation to the observed fluctuations on the absorbency pattern suggests that internal pressure build-up on the polymer matrix caused abrasions on the surface of the polymer coating resulting to the instantaneous release of nutrient and absorbed water. Overall, the VCHS-K SRF cannot be classified as a slow-release fertilizer. The present findings suggest the need for further improvement on the study of VCHS-K SRF from vermicompost.
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    Anti-inflammatory and antibacterial activities of Batuan (Garcinia binucao) fruits
    Albano, 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.
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    Antioxidant and antibacterial activities of bika (Ampelocissus martini panch) seed oil
    Angot, 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.