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On the pH and Acid Neutralizing Capacity Profile of Manila Bay Coastal Water Samples in Manila, Philippines

Abstract

For any body of water, its pH and acid neutralizing capacity (ANC) are two important determinants of its overall condition. The ANC has to be high enough to maintain the pH at an optimal level in order to resist acidification and thereby sustain marine life. An assessment of the pH and ANC of Manila Bay coastal waters along Manila and Pasay, Philippines, was done using 16 collected coastal water samples from four different and equally divided geographic sectors along Roxas Boulevard. The pH of the samples was measured using a pH meter while the ANCs were determined via potentiometric titration against sulfuric acid (H2SO4). Read More

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Detection of Paralytic Shellfish Poisoning (PSP) Toxins in Philippine Mussel Samples by Electrospray Mass Spectrometry

Abstract

The occurrence of toxic red tide outbreaks is an environmental and public health hazard in the Philippines. Thus, it is necessary to develop ‘monitoring programs to protect the shellfish industry and the general public. Previous methods for the detection of paralytic shellfish poisoning (PSP) toxins make use of mouse bioassays and/or fluorescence detection through High Performance Liquid Chromatography (HPLC). The mouse bioassay, while cheap and rapid, requires a large amount of sample, and is capable of detection of toxin concentrations that are already near the regulatory limit. Read More

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Antimicrobial Compounds from Spondias purpurea

Abstract

The dichloromethane, ethyl acetate, ethanol and water extracts of the freeze-dried bark of Spondias purpurea were tested for antimicrobial activities against seven microorganisms. Results of the study indicated that all the extracts at 30 µg have low antimicrobial activities against E. Coli, P. aeruginosa and T. mentagrophytes. The water and ethanol extracts showed low activity against C. Albicans, while the ethyl acetate extract gave low activity against A. niger. All the extracts were inactive against S. Aureus and B. subtilis. Read More

Hydrothermal Synthesis and Characterization of an Akaganeite-type Iron Oxide Octahedral Molecular Sieves

Hydrothermal Synthesis and Characterization of an Akaganeite-type Iron Oxide Octahedral Molecular Sieves

Abstract

Iron oxide octahedral molecular sieve with 2×2 tunnel, designated as FeOx-OMS (2×2) was successfully synthesized by hydrothermal method. FeOx-OMS (2×2) has high degree ofpurity and higher thermal stability than those of previously reported akaganeite-type materials. The X-ray powder diffraction (XRD) pattern shows peaks that are characteristic of pure akaganeite-system. Based on its TGA profile, its thermal stability is reported up to 255 ° C. and beyond 402 °C new phases are formed which is a mixture of hematite and magnetite-based on its XRD pattern. Read More

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Diterpenes from the Soft Coral Clavularia inflata (Coelenterata, Octocorallia, Stolonifera)

Abstract

Three diterpenes were isolated from the dichloromethane extract of the Stolonifer Clavularia inflata. The structure of (3S,4S)-clavulara-l (15), 17- diene-3,4-diol 1 was elucidated by 1 D and 2D NMR spectroscopy while the structures of (4R)-clavulara-l(l5),17-diene-4-o1 2 and (lR,4R)clavulara- 17-ene-l,4-dioI3 were determined by comparing their proton NMR spectra with those previously reported. Read More

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Genomic Characterization and Physical Mapping of Shigella flexneri Serotype-Specific Antigen V Temperate Bacteriophage

Abstract

Shigella flexneri hosts a temperate bacteriophage SfV responsible for the conversion of serotype Y strains (3,4) to serotype Sa (V; 3,4) through its glucosyl transferace gene. This enzyme mediated conversion effects a molecular antigenic conversion in glucosyl or glycosylic moiety attachment generating a corresponding immunogenic shift in the O-antigen component of the outer membrane lipopolysaccharide immune response among Shigellosis patients. With respect to vaccine development, further investigation into SfV’s complete genome is crucial to explore and distinctly locate other genetic horizontal transfer contributing immunogenicity aside from the somatic antigen and proteins encoded by the invasion plasmid. Read More

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Synthesis of sugar functionalized tetrathiafulvalene

Abstract

The synthesis and chemistry of the water soluble sugar functionalized tetrothiafulvalenes are discussed. The use of a suitable protecting group for the coupling between oxone and thiones is given along with deprotection and subsequent nucleophilic substitution with halosugars. The potential applications of these promising sugar derivatized tetrathiafulvalenes are hereby enumerated. Read More

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A Flavone from Vitex parviflora

Abstract

The chloroform extract of the air-dried leaves of Vitex parviflora afforded retusin by silica gel chromatography. Its structure was elucidated by extensive ID and 2D NMR spectroscopy. Antimicrobial tests indicated that retusin has moderate activity against the fungi, A. niger and low activity against the bacteria, P. aeruginosa. It was found inactive against the fungi, C. albicans and T. mentagrophytes and the bacteria: E. coli, S. aureus and B. subtilis. Read More

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An Antifungal Sesquiterpene Lactone from Pseudoelephantopus spicatus

Abstract

A sesquiterpene lactone was obtained from the chloroform extract of Pseudoelephantopus spicatus Rohr. Its structure was elucidated by ID and 2D NMR spectroscopy. It was found to exhibit antifungal activity against C. albicans and A. niger. Read More

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Synthesis of D-Galactose-Modified 1,3- Dithiole-2-Thione Derivative

Abstract

The chemistry of tetrathiafulvalene (TTF) derivatives has been extensively investigated in recent years because of their ability to form charge transfer compounds and their potential as conductors and superconductors. However, careful literature search showed that nothing is mentioned about TTF or any of its derivatives bonded to sugar. Such compounds may prove interesting from the point of view of molecular electronics and biosensors. In this paper, we report the successful synthesis of the first dithiolate-sugar derivative, a precursor to TTF-sugar.

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