Benzyl and methyl fatty hydroxamic acids based on palm kernel oil as chelating agent for liquid-liquid iron(III) extraction

Enzymatic Synthesis of Ricinoleyl Hydroxamic Acid Based on Commercial Castor Oil, Cytotoxicity Properties and Application as a New Anticancer Agent

BACKGROUND

New anticancer agents that rely on natural/healthy, not synthetic/toxic, components are very much needed.

METHODS

Ricinoleyl hydroxamic acid (RHA) was synthesized from castor oil and hydroxylamine using Lipozyme TL IM as a catalyst. To optimize the conversion, the effects of the following parameters were investigated: type of organic solvent, period of reaction, amount of enzyme, the molar ratio of reactants and temperature. The highest conversion was obtained when the reaction was carried out under the following conditions: hexane as a solvent; reaction period of 48 hours; 120 mg of Lipozyme TL IM/3 mmol oil; HA-oil ratio of 19 mmol HA/3 mmol oil; and temperature of 40°C. The cytotoxicity of the synthesized RHA was assessed using human dermal fibroblasts (HDF), and its application towards fighting cancer was assessed using melanoma and glioblastoma cancer cells over a duration of 24 and 48 hours.

RESULTS

RHA was successfully synthesized  and it demonstrated strong anticancer activity against glioblastoma and melanoma cells at as low as a 1 µg/mL concentration while it did not demonstrate any toxicity against HDF cells.

CONCLUSION

This is the first report on the synthesis of RHA with great potential to be used as a new anticancer agent.

Development of a new method for biomonitoring of multiple metals in occupational exposure

The assessment of co-exposure to several types of metal contamination poses a hurdle for occupational monitoring. Determination of elements in biological samples is an important way to evaluate occupational exposure. However, optimized methods for the extraction of multiple metals from biological samples have not been reported in recent studies. Therefore, solid-phase extraction (SPE) based on the functionalized nano-zeolite Y was suggested for the biomonitoring of metal co-exposure. SPE was conducted with ammonium pyrrolidine dithiocarbamate (APDC) surrounded by Triton X-100 micelles, which were loaded into the pores of nano-zeolite Y. In this study, SPE was optimized for pre-concentration of trace amounts of chromium (Cr), cadmium (Cd), and lead (Pb) in urine samples with respect to the pH, APDC concentration, elution condition, amount of functionalized nano-zeolite Y, and sample volume. This method has been successfully optimized for the extraction of the mentioned multiple metals with >97% efficiency and an acceptable reproducibility with a coefficient variation of <10%. This method could be used in the extraction of multiple metals in environmental and occupational exposure conditions. In this study, urine samples of welding workers were evaluated following this optimized method.

Study on the spectrophotometric detection of free fatty acids in palm oil utilizing enzymatic reactions

In this paper, a comprehensive study has been made on the detection of free fatty acids (FFAs) in palm oil via an optical technique based on enzymatic aminolysis reactions. FFAs in crude palm oil (CPO) were converted into fatty hydroxamic acids (FHAs) in a biphasic lipid/aqueous medium in the presence of immobilized lipase. The colored compound formed after complexation between FHA and vanadium (V) ion solution was proportional to the FFA content in the CPO samples and was analyzed using a spectrophotometric method. In order to develop a rapid detection system, the parameters involved in the aminolysis process were studied. The utilization of immobilized lipase as catalyst during the aminolysis process offers simplicity in the product isolation and the possibility of conducting the process under extreme reaction conditions. A good agreement was found between the developed method using immobilized Thermomyces lanuginose lipase as catalyst for the aminolysis process and the Malaysian Palm Oil Board (MPOB) standard titration method (R² = 0.9453).