Synthesis of surrogate molecules is particularly useful for generating in sight of structural-activity relationships, understanding processes and improving the performance. In order to improve upon the physico-chemical properties of biodiesel, methyl, ethyl, isopropyl and n-butyl esters of beta-branched fatty acid have been synthesized, initiating from beta-branched alcohols. Beta-branched alcohols upon oxidation gave corresponding acids, which were converted to their esters. The synthesized esters have substantially better oxidative stability, exhibited by Rancimat oxidation induction period of more than 24 h. The cloud point of synthesized esters is < -36 degrees C, pour point is < -42 degrees C and CFPP is < -21 degrees C, which is substantially better than fatty acid methyl esters. Besides achieving the objective of better oxidative stability and improved low temperature properties, the synthesized surrogate esters have viscosity in the range of 4.2-4.6 cSt at 40 degrees C, meeting the international diesel and biodiesel standards. The cetane number of synthesized esters is 62-69, which is much better than diesel and biodiesel. The blends of the synthesized esters in diesel at 5% and 10% meet Indian standards of diesel.
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http://dx.doi.org/10.1016/j.biortech.2009.01.032 | DOI Listing |
An Acad Bras Cienc
January 2025
Universidade Federal do Pará, Instituto de Ciências Exatas e Naturais, Laboratório de Investigação Sistemática em Biotecnologia e Biodiversidade Molecular, Rua Augusto Corrêa, 01, 66075-110 Belém, PA, Brazil.
In the present study, 5-Hydroxy-2-(Oleoyloxymethyl) -4H-pyran-4-one (KMO 3), and their chelated with Cu(II) and Fe(III) ions were synthesized to explore their inhibitory activity against tyrosinase and cytotoxicity. To this end, the structures of the obtained compounds were confirmed by ATR/FT-IR, 13C and 1H-NMR, and UV-vis techniques. The results show that chelating fatty ester presents the bands at 1567m, 1511w cm-1 attributed to the coordinated carbonyl (Cu(II)←[O=C]2), and the bands at 1540m, 1519m cm-1 which were attributed to the coordinated carbonyl (Fe(III)←[O=C]3).
View Article and Find Full Text PDFJ Mater Chem B
January 2025
School of Pharmacy, Queen's University Belfast, Belfast BT9 7AF, UK.
This study explores the formulation and characterization of poly(vinyl alcohol) (PVA)-based composite hydrogels synthesized through solid-state crosslinking. Comprehensive assessments were conducted on their physicochemical properties, leachables, and immunogenicity. Swelling experiments demonstrated that the incorporation of poly(vinylpyrrolidone) (PVP) enhanced water retention, while chitosan had a minimal effect on swelling behavior.
View Article and Find Full Text PDFChemSusChem
January 2025
Lomonosov Moscow State University: Moskovskij gosudarstvennyj universitet imeni M V Lomonosova, Department of Chemistry, Leninskie Gory, 1-3, 119991, Moscow, RUSSIAN FEDERATION.
Spirocyclic alkyl amino carbene (SCAAC) Ru complexes demonstrate outstanding activity and selectivity in ethenolysis of methyl oleate (MO) or fatty acid methyl esters (FAMEs), and 5,6-dimethoxyindane derivative was the most active catalyst to date. For the further catalyst design, we proposed modifying the spirocyclic fragment by fusion of saturated carbo- or heterocycle, linked to the 5,6-positions of indane or 6,7- positions of tetralin. Another suggested way of the modification of SCAAC complex was the insertion of chromane fragment to the carbene ligand.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Organic Chemistry, University of Leipzig, 04103 Leipzig, Germany.
The enantioselective synthesis of 1,4-dicarbonyl compounds continues to pose a significant challenge in organic synthesis, and a catalytic process which generates two adjacent stereogenic centers with full stereochemical control is lacking until now. The 1,4-relationship of the functional groups requires an Umpolung strategy as one of the α-carbonyl positions has to be inverted into an electrophilic center to react with a normal enolate. We report herein the highly enantio- and diastereoselective addition of silyl ketene acetals toward electrophilic 1-azaallyl cations to furnish chiral 4-hydrazonoesters, which are masked 1,4-dicarbonyl compounds.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Despite advancements in high-resolution screening techniques, the identification of novel perfluoroalkyl and polyfluoroalkyl substances (PFAS) remains challenging without prior structural information. In view of this, we proposed and implemented a new data-driven algorithm to calculate spectral similarity among PFAS, facilitating the generation of molecular networks to screen for unknown compounds. Using this approach, 81 PFAS across 12 distinct classes were identified in soil samples collected near an industrial park in Shandong Province, China, including the first reported occurrence of 12 iodine-substituted PFAS.
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