This review summarizes the chemoenzymatic synthesis of the biologically active natural products based on a combination of chemical diastereoselectivity and enzymatic enantioselectivity using biocatalyst. Asymmetric reduction of 2-methyl-3-keto ester with yeast gave the optically active syn-2-methyl-3-hydroxy ester, which was converted to natural product such as (-)-oudemansin B. Asymmetric hydr...

Biodiesel is usually produced by transesterification of vegetable oils or animal fats with chemical catalysts, especially in the presence of strong acidic or basic solutions, such as hydrochloric acid, sulphuric acid, sodium hydroxide, sodium methoxide and potassium hydroxide. Homogeneous alkali catalysts can convert triglycerides to their corresponding fatty acid methyl esters (FAMEs) with hig...

Biodiesel has emerged as an alternative to non-renewable diesel fuel. Growing demand for biodiesel has given birth to mal practices such as adulteration which degrade its quality. The present study has dealt with the optimization of biodiesel production from Jatropha curcas oil using a five-level-four-factorial central composite design based on response surface methodology in 54 experimental ru...

Synthetic dipeptides comprising mixtures of enantiomers, diastereomers, or sequential isomers were converted into their N-perfluoroacetyl dipeptide esters (perfluoroacetyl: trifluoroacetyl, pentafluoroacetyl, heptafluorobutyryl; ester: methyl, 1-propyl, 2-propyl, 2,2,2-trifluoroethyl) and analyzed by GC-MS on the chiral stationary phases Chirasil-L-Val and Lipodex-E using helium as carrier gas....

Epoxyeicosatrienoic acids were isolated and purified from female rabbit kidneys. They were identified as a group, prior to resolution, by packed column gas-liquid chromatography-mass spectroscopic techniques as their methyl esters as well as their trimethylsilyl bromohydrin methyl esters. Initial capillary gas-liquid chromatography-mass spectral analysis of the corresponding hydrogenated pentaf...

Wastes produced during fermentation and distillation of crude sugarcane juice in rum factories were evaluated as a new source of waxes. The chemical composition of the crude wax extracted from adsorbat of the wastes on fuller's earth was studied by GC-mass spectrometry. Series of linear alkanes (C19-C33), and wax esters constitute the main components. In addition, phytosterols, triterpene methy...

3. The ether-extractable acids were separated into solid and liquid acid fractions, converted into methyl esters and fractionally distilled. The light petroleum-insoluble compounds were separated from the fractions. Analyses of the acids are given (Table 2): these show that the increases after cholesterol feeding occur in the solid, liquid and light petroleum-insoluble fractions. 4. The methyl ...

Fatty acid methyl esters and dimethylacetals suitable for gas chromatographic analysis were prepared by treatment of lipids with boron fluoride-methanol (140 g BFI per liter of methanol). This reagent is stable and easy to handle. Reaction conditions were investigated for triglycerides, diglycerides, monoglycerides, free fatty acids, sterol esters, phosphatidyl ethanolamines, phosphatidyl serin...

Background Biomass-derived jet fuel is an alternative jet fuel (AJF) showing promise of reducing the dependence on fossil fuel and greenhouse gas emissions. Hydroprocessed esters and fatty acids (HEFA) concept is also known as one of the pathways for producing bio jet fuel. HEFA fuel was approved by the American Society for Testing and Materials in 2011, and can be blended up to 50% with conven...

Biodiesel consists of monoalkyl esters of long chain fatty acids. It is produced from vegetable oils or fats either by chemical transesterification with methanol or ethanol. The cost of lipases and the relatively slower reaction rate remain as the major obstacles for enzymatic production of biodiesel as opposed to the conventional chemical processes. The enzymatic process offers several advanta...