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    Toxicity of the aqueous leaf extract of datilis (Muntingia calabura) on the fry and fingerling of Oreochromis niloticus
    Cagampang, Ma. Hazel C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-08)
    A 96-hour static bioassay on the effects datilis (Muntingia calabura) leaf extract on the fry and fingerlings of Oreochromis niloticus was conducted to determine the Average Median Lethal Concentration (LC50) of datilis (Muntingia calabura) leaf extract on the fry and fingerlings of Oreochromis niloticus and to describe the behavioral responses of the fish to the extract. The assay consisted of six treatments: 0, 12.5, 25, 50, 100, and 200 ppm concentrations of the extract. Physico-chemical conditions (e.g. temperature, pH, salinity, dissolved oxygen, ammonia, nitrite, and hardness level of water) were monitored. Results showed that the average LC50 at the 12, and 24- hour period of the extract in fingerlings (128.61 and 92.37 ppm) were significantly higher (P<0.05) than in the fry (65.45, and 60,99) respectively. Mortality was higher at higher concentrations than at lower concentrations of the extract. Highest mortality was in 200 ppm followed by 100 ppm, then 50 ppm. No death occurred in 0, 12.5 and 25 ppm concentrations of the extract. Mortality was also significantly higher (P<0.05) in fingerlings than in fry. The fish, exhibited avoidance - response reaction and loss of equilibrium. Possibly, the death and unusual behavior manifested by the fish may be due to saponins present in the extract. Physico—chemical conditions were within the tolerable range for the fish hence, these may not have contributed to the death of fish. This study provides preliminary data on the toxic effects of the aqueous leaf extract of datilis on the fry and fingerlings of ?Oreochromis niloticus.
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    A preliminary study on the average yield of crude capsaicin from common varieties of Capsicum frutescens L. at two stages (Young and mature) using three extracting solvent
    Cadornigara, Ma. Sylvia C. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 1998)
    Crude capsaicin content of the air dried and homogenized plant material of the three varieties of Capsicum frutescens L. namely cayenne, tobasco and ‘kitikot’ were determined using diethyl ether, 99.5 % ethanol and 1.0N NaOH as extracting reagents. Statistical analysis showed no significant difference on the average percent yield of crude capsaicin on the three varieties of Capsicum frutescens L. using similar extracting solvent, but a significantly higher yield of crude capsaicin was found with 99.5% ethanol and 1.0N NaOH. Through thin layer chromatography the major components of the extracts identified could probably be capsaicinoids (Rf 15-17), carotenoids (only in 99.5% ethanol, Rf 96-97), and capsanthin (Rf 27-29) using n-hexane-acetone.
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    Antimicrobial, antioxidant and phytochemical properties of ethanolic and water extracts of selected local spices from Miagao, Iloilo
    Besinga, Yvonne Grace M. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)
    Spices such as garlic, pepper and turmeric are indispensable in the daily food preparation and are reported to have compounds which prevent the microbial spoilage of food. This study evaluates the antimicrobial and antioxidant activities as well as the phytochemical properties of the ethanol and aqueous spice extracts of garlic, pepper and turmeric. The antioxidant activity was performed using l,l-diphenyl-2-picryl- hydrazyl (DPPH) Radical Scavenging Method and the antimicrobial activity was evaluated by Disk Diffusion Assay. Phytochemical compounds tested were alkaloids, flavonoids, terpenoids, phenol and saponins. In decreasing order, the potency of the antioxidant activities showed Ascorbic acid > turmeric ethanol extract >pepper water extract> pepper ethanol extract> turmeric water extract> garlic ethanol extract> garlic water extract. The antimicrobial activity was highest in turmeric aqueous extract in terms of mean inhibition zone (7.5±2.10) against E. coli. The most effective treatment against B. subtilis was turmeric ethanol with highest mean inhibition zone (6.87±1.13). And for S. aureus, garlic ethanol extract has the highest mean inhibition zone (7.80±1.32). Phytochemical screening tests showed that in all treatments, the most abundant phytochemical were alkaloids and terpenoids. This study indicates that the spices like garlic, pepper and turmeric have antimicrobial and antioxidant activity.