Marynold Purificacion

Annually, the Philippines is burdened by a high number of infections and deaths due to Dengue. This disease is caused by the Dengue virus (DENV) and is transmitted from one human host to another by the female Aedes aegypti mosquito. Being a developing country, most of the high-risk areas in the Philippines are resource-limited and cannot afford equipment for detection and monitoring. Moreover, traditional clinical diagnoses of DENV infection are costly and time-consuming and require expertise. Hence, it is important to establish effective vector control and surveillance measures. In this study, we developed a DNA-based nanobiosensor for the colorimetric detection of Dengue virus serotype 2 (DENV-2) synthetic target DNA (stDNA S2) using gold nanoparticles (AuNPs). We successfully functionalized dextrin-capped gold nanoparticles with the designed DENV-2 oligonucleotide probes. The detection of the complementary stDNA S2, indicated by the pink-colored solution, was successfully performed within 15 min using 0.40 M NaCl solution. We were able to detect up to 36.14 ng/μL of stDNA S2 with some cross-reactivity observed with one non-complementary target. We believe that our study offers a basis for developing nanobiosensors for other DENV serotypes.

The cocoa pod borer (CPB)Conopomorpha cramerella(Snellen) (Lepidoptera: Gracillaridae) is one of the major constraints for cocoa production in South East Asia. In addition to cultural and chemical control methods, autocidal control tactics such as the Sterile Insect Technique (SIT) could be an efficient addition to the currently control strategy, however SIT implementation will depend on the population genetics of the targeted pest. The aim of the present work was to search for suitable microsatellite loci in the genome of CPB that is partially sequenced. Twelve microsatellites were initially selected and used to analyze moths collected from Indonesia, Malaysia, and the Philippines. A quality control verification process was carried out and seven microsatellites found to be suitable and efficient to distinguish differences between CPB populations from different locations. The selected microsatellites were also tested against a closely related species, i.e. the lychee fruit borerConopomorpha sinensis(LFB) from Vietnam and eight loci were found to be suitable. The availability of these novel microsatellite loci will provide useful tools for the analysis of the population genetics and gene flow of these pests, to select suitable CPB strains to implement the SIT.

Higher intake of plant protein is associated with lower risk in degenerative diseases caused by oxidative stress, thereby placing enormous demand in the identification of plant-based sources of protein like legumes. Rice bean (Vigna umbellata) is known to be a great source of low-cost and good nutritional quality protein for utilization in food products. This study characterized the soluble and hydrolyzed proteins from rice beans and assessed their antioxidant properties in vitro. The total soluble proteins from the rice bean were extracted using 35 mM potassium phosphate buffer (pH 7.2 M, 0.40 M NaCl) affording a concentration of 1.23 mg/mL. The isolated proteins were purified by a combination of gel filtration chromatography, ammonium sulfate precipitation and dialysis. SDS-PAGE was performed to monitor the changes in the protein profile after every purification step. Enzyme hydrolysis was also done using pepsin and a mixture of trypsin, chymotrypsin and thermolysin. The antioxidant activity of the protein extract and digest after 4 h of hydrolysis were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, and found to be 35.11% and 19.68%, respectively. The results indicate that rice beans can be utilized as a rich source of protein with antioxidant properties and can be a rich source of functional foods.