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.

Green Synthesis of Zeolite/Fe2O3 Nanocomposites: Toxicity & Cell Proliferation Assays and Application as a Smart Iron Nanofertilizer.

PURPOSE: The aim of this study was to prepare zeolite/iron (III) oxide nanocomposites (zeolite/Fe2O3-NCs) as a smart fertilizer to improve crop yield and soil productivity. METHODS: Zeolite/Fe2O3-NCs were successfully produced by loading of Fe2O3-NPs onto the zeolite surface using a quick green precipitation method. The production of zeolite/Fe2O3 nanocomposites was performed under a mild condition using environmentally friendly raw materials as a new green chemistry method. The product was characterized using several techniques such as near and far Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). RESULTS: The results confirmed the formation of Fe2O3-NPs with mean particle sizes of 1.45, 2.19, and 2.20 nm on the surface of the zeolite per amount of 4, 7 and 12 wt% Fe2O3-NPs, respectively. Such results indicated that the size of the Fe2O3-NPs did not significantly change when Fe amounts increased from 7 to 12 wt% for the zeolite/Fe2O3-NCs. In terms of medical applications, in vitro cell studies demonstrated that zeolites and zeolite/Fe2O3-NCs were generally non-toxic to human fibroblast cells and significantly pernicious to human malignant melanoma cells. From MTS cytotoxicity assays, the concentration of Fe2O3 within the zeolite/Fe2O3-NCs that was effective at inhibiting the growth of malignant melanoma cells by 50% (the IC50 value) was ~14.9 wt%. The three types of nanocomposites were further tested as an iron smart nanofertilizer for the slow-release of iron ions. CONCLUSION: Advantages of this project include the production of non-toxic nanocomposites as a smart fertilizer to develop crops while the reaction involves the use of commercial and natural materials as low-cost raw materials with low energy usage due to a mild reaction condition, as well as the use of an environmentally friendly solvent (water) with no toxic residues.