UPV Theses and Dissertations
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Item Moss (Brachythecium sp.) and a filamentous green algae (Oedogonium sp.) as bunker oil sorbentsBautista, Norwell Brian C. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)Oil spills are very catastrophic and very destructive events. One way of controlling the dispersion of oil from these spills is by the use of sorbents. The procurement of commercial sorbents can be very costly. Thus, this study analyzed and evaluated the efficiency and effectivity of moss (Brachythecium sp.) and a green filamentous algae Oedogonium sp. as substitutes for commercial sorbents. Brachythecium sp. can grow in any moisture—rich environment and Oedogonium sp. algae grow freely in fish ponds and in any body of stagnant, oxygen-poor water. Thus, both samples are very abundant in the environment. Sorption capacity results showed that the moss Brachythecium sp. and the algae Oedogonium sp. can sorb five times and seven times its weight, respectively. In comparison, Peat Sorb, a commercial sorbent, was recorded to sorb 15 times its weight (Emedco, 2007). The minimum sorption capacity of the moss and algae samples was recorded to be approximately equal to their weight. The adsorption isotherms of both samples follow the Langmuir plot for monolayer adsorption. In the hexane capillary rise experiment, hexane rose significantly in ground moss (72.25 mm in 7 min.) and unground moss (64.80 mm in 7 min.) compared with unground algae (23.52 mm in 7 min.) and (20.70 mm in 7 min.), indicating that moss is more hydrophobic. In water, capillary rise, on the other hand, unground algae is a better medium (5.76 mm in 4 min) compared to the rest (ground algae - 4 mm, unground moss - 5.29 mm, and ground moss — 4.11 mm, all in 4 min.). Results also revealed that the moss Brachythecium sp. and the algae Oedogonium sp. expressed hydrophobic characters in the hexane-water system by remaining in the hexane layer after agitation. The moisture content of the algae (14.85%) is twice that of moss (7.94%). This gives the moss an advantage in oil sorption. The lipid contents of algae (15.58%) and moss (11.47%) do not comprise the majority of their biomass, but the lipids aid in increasing the samples’ affinity for non-polar substances. The samples may not sorb as effectively as the commercial sorbents, but they are abundant in the environment, thus, a cheaper alternative. Like Peat Sorb, which was processed from the biomass of Sphagnum sp. moss, the samples may undergo the same process that increases the hydrophobicity several-fold and gives oil-biodegradation capabilities.Item Optimization of parameters for the Fe-humic acid complex formation using cyclic voltammetryBautista, Coleen M. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)Humic acid extracted from an artesian well located at Sta. Barbara, Iloilo was used to generate an Fe-HA complex as a potential additive to bio floc systems to augment the essential mineral Fe. The humic acid obtained was black in color and had a powdery texture after oven-drying. The Fe-HA complex were prepared using Fe3+ ions at different pH values specifically at pH 8, 9 and 10. Formation of the complex was investigated using the cyclic voltammetry to determine the ideal conditions to maximize the binding of the metal ion. The results showed that there are two oxidation and reduction cycles which suggests that there are two species undergoing oxidation and reduction. It is possible that the free iron and the Fe in the complex are undergoing a redox cycle although the quinone group in the humic acid can also act as a redox center. Atomic Absorption Spectroscopy can help corroborate the amount of complex formed to help deduce the redox active center.Item Phytochemical screening, antibacterial and antioxidant activity of Ethanolic seed extract of Kadios (Cajanus cajan) from Igbaras, Iloilo, PhilippinesBautista, Lance Ruther E. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)Natural products are products which may have been chemically synthesized, through semi- or total synthesis. The presence of these natural sources gave us greater opportunity for discovery and different innovations, as answers to the emerging needs of the people. This study focused on the chemical properties, antibacterial and antioxidant activity, of Cajanus cajan, popularly known as Kadios, from Igbaras, Iloilo, Philippines. A total of 371.98 grams of air-dried C. cajan seeds was macerated to 1000 mL of ethanol for 72 hours. The concentrated extract was subjected to three tests and assays. All tests were done in triplicates. The test for phytochemicals, which served as the preliminary screening, revealed that the ethanolic extract of Kadios seeds contains alkaloids, flavonoids, phenols, saponins, tannins, quinones, and steroids. The antibacterial assay showed that the ethanolic seed extract of C. cajan can inhibit the growth of Gram-negative bacteria, E. coli, with zone of inhibition equal to 10.3 ±2.15 mm to 33 ± 1.63 mm. The antioxidant assay revealed that the extract has positive inhibition only at high concentration against DPPH, and so IC50 was further determined to be 27,310 ug/mL. Statistical analyses were also done, and confirmed that there is significant difference among the data at (P<0.05). Summing up, the extract has antibacterial activity and minimal or almost close to zero antioxidant activity, while containing a remarkable number of secondary metabolites causing the chemical activities of the extract.Item Antifungal activities of lemongrass (Cymbopogon citratus) essential oil -B-cyclodextrin inclusion complex incorporated in commercial fish feedsBaure, Jiaren G. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)During the wet season in the Philippines, fish feeds can be contaminated with mycotoxins, affecting fish production. The addition of essential oil (EO) is one of the ways to prevent this, but it is prone to physical and chemical reactions. Thus, this study aims to encapsulate lemongrass essential oil (LGEO) in B-cyclodextrin (B-CD) to produce an inclusion complex (IC) that can be used as an additive in commercial tilapia feeds to prevent or minimize fungal contamination. The inclusion complex was made using the co-precipitation method and was characterized by Fourier Transform Infrared (FTIR) Spectroscopy. The spectrum was similar to that of citral, a major component of lemongrass essential oil that is responsible for inhibiting fungi. The antifungal activities of pure and encapsulated LGEO at varying concentrations against Aspergillus species were carried out by the Agar Well Diffusion assay. Results showed that A. flavus was more susceptible in LGEO and IC compared with A. fumigatus. The tested concentration of EO could inhibit both fungi. However, it would take 50% IC to effectively inhibit the growth of both fungi. The stability of the inclusion complex in commercial fish feeds was also evaluated. The feeds were stored in an area with the appropriate conditions that could promote the growth of molds, such as temperature (>27°C), moisture levels (14%), and relative humidity levels (>70%). The results showed that the encapsulated LGEO was effective in extending the shelf life of the feeds and was best observed at a concentration of 5 g kg-1 IC. The oil remained active for nine days, wherein about 10- 40% of the feeds with 5 g kg-1 IC were covered with molds. On the other hand, about 70-100% of the surface of the feeds with essential oil was contaminated with molds after nine days, which indicated that encapsulation of EO was needed to maintain its effectiveness as an antifungal agent.Item Isolation and partial characterization of globulin from Cassava (Manihot esculenta Crantz) tubersBarbosa, May R. (Division of Physical Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)Soluble globulin was isolated using an extraction buffer (0.4 M NaCl in 35 mM potassium phosphate buffer, pH 7.6 with 0.02% Na azide). The isolated globulin was subjected to solubility tests with different NaCl concentrations. It has the highest solubility in 1.25M NaCl (1.09%), but no significant differences existed among the NaCl concentrations by analysis using one-way ANOVA at a = 0.05. Three major bands existed at LOOM NaCl dissolved globulin with molecular weight ranges of 28-33kDa, 38- 43kDa, and 65-70kDa relative to BSA. Two of these bands (38-43kDa and 65-70kDa) were observed in 0.50M and 0.75M NaCl soluble globulin. The 1.25M and 1.50M NaCl concentrations gave a single band (28-33kDa) each, while no clear bands were observed in other NaCl concentrations. Amino acid analysis revealed glutamic acid (12.09%) as the most abundant amino acid component of cassava globulin. Nine (9) essential amino acids were present. Of these nine, lysine (10.50%) is the most predominant. Cystine (0.39%) has the lowest percentage, followed by methionine (1.76%).Item Isolation and purification and bioactive components from the fruit of Morinda citrifoliaBarbarona, 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.Item Hydrogel composites loaded with plant extract as an antibacterial and quorum sensing inhibiting wound dressingBaranda, Marivic M. (Division of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)Delayed wound healing is often caused by bacterial infection. Furthermore, the persistent inflammation brought by the formation of biofilm via quorum sensing causes pain and discomfort. In a novel effort, this study fabricated an antibacterial and quorum sensing inhibiting hydrogel dressing loaded with plant extracts. KC-PVP hydrogel composites were loaded separately with lg/mL C. longa and H. durvillei extract under optimized conditions. The hydrogels were characterized through swelling test and FTIR analysis. It was determined that C. longa-loaded and H. durvillei-loaded hydrogels have a maximum swelling capacity of 175% and 135%, respectively. The antibacterial efficacy and the quorum sensing inhibition activity of extract-loaded hydrogels were evaluated using soft-layer agar well diffusion method. Hydrogel loaded with C. longa extract displayed 47.0 (±1.0), 45.0 (±1.0), and 32.33 (±0.58) mm mean growth inhibition against S. aureus, E. coli, and P. aeruginosa, respectively. H. durvillei extract-loaded hydrogels inhibited the growth of S. aureus, E. coli, and P. aeruginosa by 45.33 (±0.58), 43.67 (±1.52), and 33.33 (±0.58) mm in diameter, respectively. The quorum-sensing inhibition zone of C. longa extract and H. durvillei extract-loaded hydrogels were 49.63 (±0.40) and 49.37 (±1.11) mm in diameter, respectively. Overall, the extract-loaded hydrogel composites exhibited good antibacterial and quorum-sensing inhibiting activity, potentially for wound treatment.Item Phytochemical screening, antibacterial and antioxidant activities of the crude ethanolic extract of calamansi (Citrus microcarpa) peelsBaquiano, Clarie Dean C. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2015-06)Citrus fruits are well-known sources of vitamin C, and like most other whole foods, they also contain an impressive list of other essential nutrients and high amounts of phytochemicals. Calamansi, scientifically known as Citrus microcarpa, is a native citrus plant cultivated throughout the Philippines. Calamansi is chiefly utilized for its pulp and juice but the peels and pressed pulp, covering each individual segment of the edible portion and seeds are considered as wastes and thrown away. To further utilize the rind or peels, this study was conducted to investigate the antioxidant and antibacterial properties of the crude ethanolic extract of C. microcarpa peels. Presence of select phytochemicals was also tested. The antioxidant and antibacterial activities were investigated using the DPPH (2,2-diphenyl-picrylhydrazyl) free radical scavenging assay and Kirby-Bauer disc diffusion susceptibility method, respectively. Results of the phytochemical screening have confirmed the presence of alkaloids, flavonoids, tannins, terpenoids, steroids and saponins in the extract. Crude ethanolic extract of C. microcarpa peels also showed activity against DPPH radicals with a half maximal inhibitory concentration (IC50) of 14.46 pL/mL, a much higher IC50 value compared to the positive control, ascorbic acid, with 8.36 pL/mL. The antibacterial activity assay of the extract showed minimal inhibition against E. coli and S. aureus.Item Phytochemical screening, antioxidant activity, and comparative bioefficacy assessment of Camansi (Artocarpus camansi) seed extracts for in vitro antibacterial activityBantayan, Andrea Marie B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)This study was conducted to compare and assess the antibacterial and antioxidative properties, and to screen for the presence of phytochemical constituents in the different solvent-derived extracts of Artocarpus camansi seeds from Mintal, Davao City. Phytochemical analysis revealed the presence of alkaloids, flavonoids, glycosides, phenol, steroids, tannins, and terpenoids in the methanol extract. The antibacterial efficacy was determined by agar well diffusion method against B. subtilis and E. coli. Streptomycin was used as a standard drug for the study of antibacterial activity. Sensitivity in terms of zones of inhibition and phytochemical composition of the different extracts were also determined. Results showed that all extracts were effective against both of the bacteria tested with the pet. ether and DCM extracts showing moderate activity, and the methanol extract exhibiting strong activity against B. subtilis and E. coli. Furthermore, methanol extract of A. camansi seeds possessed strong DPPH radical scavenging activity. In the DPPH method, the pet. ether, DCM, and methanol extracts showed free radical inhibition of 18.96±0.16%, 21.62±0.14%, and 90.05±0.08%, respectively. The IC50 value obtained for the methanol seed extract at concentration 0.05 g/mL was 6.67±0.004 g/L. The current findings suggest that the phytochemicals present in the methanol extract of Artocarpus camansi seeds (alkaloids, flavonoids, glycosides, phenol, steroids, tannins, and terpenoids) may be responsible for the antibacterial and antioxidant activity.Item Bioaccumulation of cadmium, copper and lead by Hydrilla (Hydrilla vericillata)Baniago, Arjay C. (Division of Pysical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2007-04)Bioaccumulation of cadmium, copper, and lead by Hydrilla (Hydrilla verticillata) were tested to 5 different initial concentrations. The water contaminant sample was composed of mixed cadmium, copper and lead metals supplied as nitrate salts. These were analyzed for the decrease in concentrations at 24-hour intervals for 5 days using the SpectrAA 55B Atomic Absorption Spectrometer. Plants exposed only for 5 days were digested and analyzed. The plant growth was normal at lower concentrations and showed higher removal efficiency. H. verticillata showed maximum removal percentage on the 5th day of exposure at 5 mg L-1 for cadmium (90.47%) and copper (95.20%) but for lead was on the 1st day (96.74%). The order of metal ion removal and the actual uptake for the three metals by H. verticillata is Pb>Cu>Cd, but at lower concentration, cadmium was absorbed more than copper. The copper and lead uptakes by H. verticillata are superior as compared to other aquatic plants uptakes. Lead uptake at higher concentrations might be due to physicochemical adsorption of the metal to the plant components and not on metabolism-mediated uptake, because plant condition does not have an adverse effect on the uptake