Enzymatic synthesis of phenyl fatty hydroxamic acids from canola and palm oils

Phenyl fatty hydroxamic acids (PFHAs) were synthesized from canola or palm oils and phenyl hydroxylamine (FHA) catalyzed by Lipozyme TL IM or RM IM. The reaction was carried out by shaking the reaction mixture at 120 rpm. The optimization was carried out by changing the reaction parameters, namely; temperature, organic solvent, amount and kind of enzyme, period of reaction and the mol ratio of reactants. The highest conversion was obtained when the reaction was carried out under the following conditions: temperature, 39°C; solvent, petroleum ether; kind and amount of lipase, 80 mg Lipozyme TL IM/mmol oil; reaction period, 72 h and FHA-oil ratio, 7.3 mmol FHA/ mmol oil. The highest conversion percentage of phenyl hydroxylaminolysis of the Ladan and Kristal brands commercial canola oils, palm stearin and palm kernel oils were 55.6, 52.2, 51.4 and 49.7 %, respectively

Preparation of fatty hydroxamic acid from canola oil.

Fatty hydroxamic acids were synthesized from canola oil by hydroxylaminolysis using lipozyme as catalyst. The products ware converted to copper fatty hydroxamate and precipitated in acetone. The precipitate was treated with nitric acid solution to release fatty hydroxamic acids and extracted to chloroform. The fatty hydroxamic acids were obtained by solvent evaporation under reduced pressure. Qualitative identification of hydroxamic acids were carried out by observing colour of the complexes with vanadium(V), iron(III) and copper(II) which were purple, dark red and green, respectively. The FTIR spectrum of the product showed the existence of the characteristic amide peaks at 3270 and 1642 cm -. Among four oil samples studied, canola oil of Ladan brand gave the highest yield of fatty hydroxamic acids

Synthesis of zinc sulphide nanoparticles from thermal decomposition of zinc N-ethyl cyclohexyl dithiocarbamate complex

Synthesis of nanostructured semiconductor materials from various single source precursors has been massively explored for potential applications in modern technology. Thermal decomposition method has been employed to prepare nanoparticles zinc sulphide from zinc N-ethyl cyclohexyl dithiocarbamate precursor. Effect of heat treatment at different calcination duration on the structural, morphological, compositional and band gap properties of zinc sulphide were investigated. The obtained samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. XRD showed the precursor was decomposed to hexagonal zinc sulphide after 2–6 h of calcination duration at 400 °C. The sizes of zinc sulphide (ZnS) nanoparticles obtained from TEM analysis were about 6–11 nm. The existence of the hexagonal ZnS phase is not affected by the calcination duration, while only a slight difference in the crystallinity and crystallite size of ZnS is observed from XRD analysis. EDX analyses reveal that the as-prepared ZnS nanoparticles have an approximate composition of Zn and S close to 1:1, giving a possible composition of ZnS. Besides, direct band gap energy of ZnS was found to be around 3.78–3.95 eV

Enzymatic synthesis of fatty hydroxamic acid derivatives based on palm kernel oil.

Fatty hydroxamic acid derivatives were synthesized using Lipozyme TL IM catalyst at biphasic medium as the palm kernel oil was dissolved in hexane and hydroxylamine derivatives were dissolved in water: (1) N-methyl fatty hydroxamic acids (MFHAs); (2) N-isopropyl fatty hydroxamic acids (IPFHAs) and (3) N-benzyl fatty hydroxamic acids (BFHAs) were synthesized by reaction of palm kernel oil and N-methyl hydroxylamine (N-MHA), N-isopropyl hydroxylamine (N-IPHA) and N-benzyl hydroxylamine (N-BHA), respectively. Finally, after separation the products were characterized by color testing, elemental analysis, FT-IR and 1H-NMR spectroscopy. For achieving the highest conversion percentage of product the optimum molar ratio of reactants was obtained by changing the ratio of reactants while other reaction parameters were kept constant. For synthesis of MFHAs the optimum mol ratio of N-MHA/palm kernel oil = 6/1 and the highest conversion was 77.8%, for synthesis of IPFHAs the optimum mol ratio of N-IPHA/palm kernel oil = 7/1 and the highest conversion was 65.4% and for synthesis of BFHAs the optimum mol ratio of N-BHA/palm kernel oil = 7/1 and the highest conversion was 61.7%

Synthesis and mesomorphic properties of non-symmetric liquid crystalline dimers containing azobenzene groups

Four novel nonsymmetric dimers containing azobenzene mesogenic groups were synthesized. The nonsymmetric dimers compounds namely, ethyl 4-[(4-{4-(4-((4-nitrophenyl)diazenyl)phenoxy)alkyloxy}phenyl)diazenyl]benzoate were obtained from the alkylation of ethyl 4-[(4-(4-bromoalkyloxy)phenyl)diazenyl]benzoate with 4-[(4-nitrophenyl)diazenyl]phenol. The mesomorphic properties of the compounds were determined by DSC and polarizing optical microscopy. The first member of the series was nonliquid crystalline while all other homologues display nematic and smectic A phases. The trans-azobenzene groups of the dimers display a high-intensity –* transition at about 365nm and a low-intensity n–* transition at around 465 nm, therefore, photochromism can be achieved by the introduction of the azo linkage to the dimeric liquid crystalline molecules