An acceleration of microwave-assisted transesterification of palm oil-based methyl ester into trimethylolpropane ester

Microwave-assisted synthesis is known to accelerate the transesterification process and address the issues associated with the conventional thermal process, such as the processing time and the energy input requirement. Herein, the effect of microwave irradiation on the transesterification of palm oil methyl ester (PME) with trimethylolpropane (TMP) was evaluated. The reaction system was investigated through five process parameters, which were reaction temperature, catalyst, time, molar ratio of TMP to PME and vacuum pressure. The yield of TMP triester at 66.9 wt.% and undesirable fatty soap at 17.4% were obtained at 130 °C, 10 mbar, sodium methoxide solution at 0.6 wt.%, 10 min reaction time and molar ratio of TMP to PME at 1:4. The transesterification of palm oil-based methyl ester to trimethylolpropane ester was 3.1 folds faster in the presence of microwave irradiation. The total energy requirement was markedly reduced as compared to the conventional heating method. The findings indicate that microwave-assisted transesterification could probably be an answer to the quest for a cheaper biodegradable biolubricant.

Fatty Acids and Trans Fatty Acids Profile of Potato Chips and French Fries Marketed in Romania

The aim of the study was to evaluate the composition in fatty acids (FAi) and trans fatty acids (t-FAi) from potato chips and French fries using gas chromatography coupled with mass spectrometry (GC-MS). The fat sample was extracted with petroleum ether, using the Buchi B-811 automatic extraction unit, the Soxhlet Standard procedure. The extracted fat was saponified with sodium methoxide solution and the fatty acids derivatized into fatty acid methyl esters (FAME) with BF3 methanolic solution. Six potato chips samples and six French fries samples, coming from 3, respectively 5 brands, were purchased from supermarkets and fast foods in Bucharest, Romania. In potato chips, saturated (SFA), cis-monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) were present between 6.410 - 48.862%, 41.786 - 84.570%, respectively 5.567 - 28.274%, and in French fries ranged between 7.001 - 57.277%, 35.281 � 57.894%, respectively 7.442 � 49.392%. The tested samples showed that the level of total trans fatty acids (TFA) was less than 0.2% (undetectable - 0.124%). It can be concluded that potato chips and French fries marketed in Bucharest, Romania are safe for consumers in terms of TFA content.

CONSIDERATIONS ON THE USE OF HUMULUS LUPULUS L. AS AN ESTROGENIC AGENT

Introduction. Hops (Humulus lupulus L.) is used as a raw material for the production of beer but has also biological properties. Phytoestrogens present in the hops have an antioxidant, anti-inflammatory and probiotic role, while having an effect on the diseases of osteoporosis, diabetes and vasomotor effects (calf) during menopause. Material and method. 8-prenilnaringenine was prepared according to a modification of the initial method. To a cooled solution of naringenin was added a methanolic sodium methoxide solution and prenyl bromide. Results and discussions. The estrogenic effect has been attributed to substances such as β-acids, β-sitosterol, xanthohumol and desmethylxanthohumol. Further investigations have shown that 8-prenylnaringenine is a major hops estrogen. 8-prenilnaringenin acts on estrogen receptors that mediate bone osteoblastic formation and inhibit osteoclastic bone resorption.

Synthesis and Characterization of Substituted 4-Methoxy-1H-quinolin-2-ones

An efficient method for the synthesis of various substituted 4-methoxy-1H-quinolin-2-ones from various substituted aniline with malonic acid, phosphorous oxychloride, sodium methoxide and glacial acetic acid under different conditions is described. The title compounds were synthesized from three steps; the first step involved the synthesis of substituted 2, 4-dichloro quinoline from aniline (substituted), with malonic acid and phosphorous-oxychloride. In the second step, the substituted 2, 4 dichloro compounds was heated with freshly prepared methanolic sodium methoxide solution to give 2, 4-dimethoxy quinoline compounds, it was then refluxed with glacial acetic acid and hydrochloric acid to give the titled compounds in the final step. The purity of the synthesized compounds was confirmed by their C, H and N analysis and the structure was analyzed on the basics of Mass, FT-IR and1H NMR.

Asymmetric induction in the Sommelet rearrangement of chiral benzyl sulfonium salts

The Sommelet rearrangement of (+)-ethylmethyl-p-nitrobenzylsulfonium perchlorate, (+)-1, and (+)-ethylmethyl-p-chlorobenzylsulfonium perchlorate, (+)-2, are described. Elution of (+)-1 through an hydroxide exchange resin generated ethylmethylsulfonium p-nitro-benzylide (+)-3 which decomposed in methanol at room temperature to ethyl 2-methyl-5-nitro-benzyl sulfide, 6, and (+)-methyl α-(2-methyl-5-nitrophenyl)ethyl sulfide, (+)-7, with 18 to 20.3% asymmetric induction. Decomposition of (+)-2 in sodium methoxide solution at 70 °C for 2 h produced ethyl 2-methyl-5-chlorobenzyl sulfide, 8, and (+)-methyl α-(2-methyl-5-nitro-phenyl)ethyl sulfide, (+)-9, with 21 to 25.5% asymmetric induction. The lower estimates of asymmetric induction for each sulfide were made by comparison with specific rotations of authentic samples obtained by synthesis and resolution. The higher estimates were obtained by the use of a chiral lanthanide shift reagent Eu(hfbc)3 with the sulfone derivatives of these chiral sulfides. The ylide (+)-3 reacted with aldehydes in high yield to produce oxiranes with no induction of asymmetry.

New synthesis of S-alkyl-DL-homocysteines

A simple method for the synthesis of S-alkyl-DL-homocysteines is described. The method involves the reaction of homocysteine thiolactone with a primary alkyl halide in sodium methoxide solution.