Undergraduate Theses

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Antifungal activities of lemongrass (Cymbopogon citratus) essential oil -B-cyclodextrin inclusion complex incorporated in commercial fish feeds
Baure, 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.
Hydrogel composites loaded with plant extract as an antibacterial and quorum sensing inhibiting wound dressing
Baranda, 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.
Phytochemical screening, antibacterial and antioxidant activities of the crude ethanolic extract of calamansi (Citrus microcarpa) peels
Baquiano, 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.
Phytochemical screening, antioxidant activity, and comparative bioefficacy assessment of Camansi (Artocarpus camansi) seed extracts for in vitro antibacterial activity
Bantayan, 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.
Community structure of beach forest species in Mag-aba, Pandan, Antique
Banogon, Tharrah Anne O. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)
The Philippine beach forest is one of the understudied and less-popular important ecosystem that provides great number of food and economic products in the country. In fact, we lost them much earlier than the mangrove community that there is miniscule information is existing about them. There is a need for understanding the forest status and community structure due to the rising threats of natural and anthropogenic factors. The unexplored forest patch in Barangay Mag-aba, Pandan, Antique can provide additional information on beach forest diversity and abundance in the country, thus the need for this study. This study aimed to record the different species and to provide description of the community of beach forest in Mag-aba, Pandan. Specifically, the objectives of this study are (1) identify, describe and classify the beach forest species present in the area, and (2) describe the community structure in terms of species composition, diameter at breast height and stand height, stand basal area, importance value, evenness and Shannon- Weiner Index of Diversity. The transect plot method adopted from English et al (1994) was used to obtained quantitative data. A total of 80 beach forest species representing 41 families were recorded. The family Fabaceae and the species Cocos nucifera dominated the forest community. The stand basal area of 83.24 m2 ha-1 reflects a mature beach forest community, however the community is made up of mostly low DBH classes (saplings and seedling) also indicating a regenerating forest. Mag-aba is characterized to have a low species diversity (H'=1.17), however the individual species are fairly distributed (J'- 0.83). These results are addition to the existing knowledge of beach forest community that would serve as information for conservation measures.
Antioxidative properties of the fruits of selected tomato (Lycopersicon esculentum Mill.) varieties
Baltazar, Gleza Wae D. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-05)
This study was conducted to compare the antioxidative properties of greenstage fruits of selected Lycopersicon esculentum Miller varieties (Diamante, Diamante Max, and Pidada) from Barangay Durog, Miagao, Iloilo. The fresh fruit samples were extracted with 95% ethanol. The crude extracts were concentrated using rotary evaporator. The antioxidant activity of the ethanolic fruit extracts was assayed for DPPH radical scavenging activity and the IC50 values were determined. The determination of the phenolic and flavonoid contents was done employing Folin- Ciocalteu method and aluminum chloride spectrophotometric method, respectively. The results show that the fruits of the studied L. esculentum varieties exhibit DPPH radical scavenging activity. The IC50 values, however, differ significantly among the varieties. The IC50 values for Diamante (24.22 ± 1.41 g/L) and Diamante Max (25.08 ± 0.45 g/L) are comparable but are significantly lower than Pidada (29.47 ± 1.33 g/L). These findings imply that Diamante and Diamante Max varieties have stronger antioxidative capacity than the Pidada variety. Moreover, the results indicate that the antioxidative property of L. esculentum is variety-dependent. The results of the determination of the total phenolic content, expressed in mg gallic acid equivalent (GAE) per g fresh sample, are in the order of 0.16 ± 0.02 mg GAE/g for Diamante > 0.15 ± 0.02 mg GAE/g for Diamante Max and Pidada. On the other hand, the results of the determination of the flavonoid content, expressed in μg quercetin equivalent (QE) per g fresh sample, are in the order of 6.31 ± 1.27 μg QE/g for Diamante >6.21 ± 0.88 μg QE/g for Diamante Max > 5.63 ± 0.94 pg QE/g for Pidada. No significant difference in the total phenolic and flavonoid contents was found among varieties. Nonetheless, the detection of phenolics and flavonoids, known antioxidants, supports the present results on the antioxidative property of the fruits of the L. esculentum varieties studied.
Development of a high-performance thin layer chromatography (HPTLC)-densitometric method for the estimation of quercetin and kaempferol in Euphorbia hirta (Tawa-tawa) extract
Baladjay, Diane Monique S. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)
A sensitive, fast, efficient, and repeatable high-performance thin-layer chromatographic (HPTLC) method has been developed for simultaneous analysis of quercetin and kaempferol from the extracts of the aerial parts of Euphorbia hirta. In the development of the HPTLC method, different extraction parameters were evaluated and quantification of quercetin and kaempferol in the extract of E.hirta was performed using a densitometric software, Quantiscan™. Among the different combinations of mobile phases used, best separation was achieved in toluene: ethyl acetate: formic acid: methanol (5: 6: 2: 1) solvent system. E.hirta was extracted using the developed extraction method which involves the use of 80% ethanol, 8 minutes of sonication and serial extraction until 3rd extraction. This determined method provides a maximum yield of the compounds at minimum time and cost. The method was also validated for linearity and precision specifically repeatability. The results show that the produced calibration is linear, as supported by the obtained correlation coefficient (r) of > 0.999 and coefficient of determination (R2) of > 0.997. Moreover, the obtained slopes of the calibration curves show that the method is most sensitive towards quercetin and least sensitive to gallic acid. The method was also found out to be repeatable and precise as the %RSD for both the inter-day and intra-day trials obtained a value less than <2%. The present method is being reported for the first time and can be used for routine quality control and quantification of quercetin and kaempferol in various plant samples, extracts, and market formulations.
Carnival in Norman Wilwayco's two novels and selected short stories
Azarcon, John Carlo S. (Division of Humanities, College of Arts and Sciences, University of the Philippines Visayas, 2014-03)
This study analyzes Norman Wilwayco’s two novels and selected short stories using Mikhail Mikhailovich Bakhtin’s theory on Carnival and its applications on literature and popular culture. As a two time Don Carlos Palanca Awardee, Norman Wilwayco’s works present a new kind of writing style that manifest current conditions of his society which demands literary analysis and criticism. The researcher focused on three main elements of Carnival, mainly: Reversal of Hierarchies, Billingsgate Language, and the Grotesque Body and show how these are applied in his works. The researcher looked into and discovered how the author used these elements to create a carnivalized world which depicts and uplifts Philippine popular culture in his works.
Selfies: Managing identities on Facebook among UPV students
Asturias, JLee Mei G.; Torres, Agape May T. (Division of Humanities, College of Arts and Sciences, University of the Philippines Visayas, 2016-05)
This study is a descriptive research on the filters commonly used in self-presentation on Facebook among college students. It describes the level of self-presentation and identifies the factors that influence self-presentation through selfies. The data comes from 310 undergraduate students of the University of the Philippines Visayas College of Arts and Sciences in school year 2015-2016, selected through purposive sampling and with the use of a standardized questionnaire distributed through snowball technique. Data analysis makes use of descriptive statistics such as measures of central tendency using frequency, percentage distribution and rank. The researchers conclude that there is an existing pattern on how respondents filter their selfies on Facebook. These filters are in terms of size, focus, angle, location, and occasion. The data also shows the manifestation of culture and relationships in posting selfies on Facebook. This research supports the theory Identity Management which suggests that identities are managed by individuals at different junctures of their culture and relationships. This study also concludes that UPV CAS students use selfies as a means of self-presentation and that the respondents agree towards positive self-presentation on Facebook.
Effects of alginate coating loaded with lemongrass essential oil-cyclodextrin inclusion complex on the postharvest quality of calamansi(Citrus microcarpa)
Astorga, Krizzia Anne B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2018-06)
Calamansi (Citrus microcarpa) is locally grown in the Philippines and is considered to be an important commodity because of its wide range of uses. Losses of this fruit in the country already reached up to 30% because of postharvest degradation. To address this problem, three coating treatments (1% alginate, 1% alginate loaded with lemongrass essential oil-B-cyclodextrin inclusion complex, and 1% alginate loaded with lemongrass essential oil-hp-B-cyclodextrin inclusion complex) were made for the purpose of examining their potential in the preservation of the postharvest quality of calamansi. Quality parameters such as color and weight loss of calamansi, as well as pH, FTIR spectra, total soluble solids, and titratable acidity of the fruit juice were evaluated in a span of 15 days at room temperature storage. Results show that the prepared edible coatings did not significantly preserve the postharvest quality of calamansi (p > 0.05) as coated samples resulted to earlier appearances of yellow and brown peel color, higher weight loss percentages, pH, and total soluble solids content. Out of the three coating treatments, fruit samples coated with 1% alginate resulted to lower weight loss percentages, pH, TSS, and TA. Fruit samples coated with 1% alginate loaded with lemongrass essential oil-hp-B-cyclodextrin inclusion complex resulted to the highest pH, TSS, and TA, while those coated with 1% alginate loaded with lemongrass essential oil-B-cyclodextrin inclusion complex resulted to the highest weight loss percentages. Data on the titratable acidity weren’t conclusive since the results obtained were not in agreement to the expected outcome. The ineffectiveness of the coatings may be a result of unfavorable storage conditions and incompatibility of the coating materials or formulations on the calamansi.

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