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Carboxylic Acids, Carboxylic Acid Derivatives, and Acyl Substitution Reactions
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
As with any acid, there could be an alkane, alkene, or alkyne backbone. The -an, -en, or -yn must be included to properly identify the carboxylic acid. For the linear C6 acid, this requirement will lead to the names hexanoic acid, hexenoic acid, and hexynoic acid for the three cases mentioned. For this specific question, hexanoic acid refers to a carboxylic acid with an alkane backbone: CH3CH2CH2CH2CH2COOH. Why is the numerical position of the carboxyl group usually omitted from the name of a carboxylic acid?
High-performance polymers based on PEG and PAMAM dendrimer to inhibit clay swelling in water
Published in Petroleum Science and Technology, 2023
Hugo Noronha da Silva Barros, Matheus Andrade Weisblum, Maximiliano de Freitas Martins, Luiz Carlos Bertolino, Ítalo Guimarães Medeiros da Silva, Thiago Marconcini Rossi, Bluma Guenther Soares, Elizabete Fernandes Lucas
The structures of PEG2 (molar mass 200 g/mol) and PEG4 (molar mass 400 g/mol), modified at their ends with linear hydrocarbon chains of differing lengths (C2, C4, C6, C10 and C12), show that the inhibition capacity is associated with the length of the hydrocarbon chain, the molar mass of the entire molecule, and the sample aqueous solubility. For both PEG2 and PEG4, the best results are obtained for the derivative with hexanoic acid (C6), evidencing an optimum hydrocarbon chain length, in contrast to that statement by the literature, that is the efficiency increases as increasing the length of the hydrophobic chain. The molar mass of the molecule also affects the efficiency of this kind of additive: although PEG2C6 and PEG4C12 presents similar hydrophilic-lipophilic balance, the best performance is exhibited by PEG2C6, which presents lower molar mass.
Insights into the microbiomes for medium-chain carboxylic acids production from biowastes through chain elongation
Published in Critical Reviews in Environmental Science and Technology, 2022
Xingdong Shi, Lan Wu, Wei Wei, Bing-Jie Ni
The conversion of SCCAs into medium-chain carboxylic acids (MCCAs) can overcome these limitations through a biological process called chain elongation (CE). MCCAs generally refer to the linear carboxylic acids with 6 to 12 carbon atoms. In general, hexanoic acid (C6), heptanoic acid (C7) and caprylic acid (C8) are the commonest MCCAs produced from anaerobic fermentation (San-Valero et al., 2019; Wu et al., 2021a). Long carbon chain makes MCCAs hydrophobic and much easier than SCCAs to be separated from the fermentation broth (Dahiya et al., 2018; Steinbusch et al., 2011). MCCAs also obtain higher commercial value and energy density than traditional products (Steinbusch et al., 2011). Therefore, MCCAs have a wider range of applications, including antimicrobial agents (Angenent et al., 2016), food additives (Xu et al., 2015), precursors of liquid biofuels (Weimer & Kohn, 2016) and industrial raw materials (e.g. rubbers and dyes) (Wu et al., 2019).
Antibacterial activity and antibacterial mechanism of ethanol extracts of Lentinula edodes (Shiitake) and Agaricus bisporus (button mushroom)
Published in International Journal of Environmental Health Research, 2022
The compounds of the EEs of the extracts were determined by GC-MS (Table 1) and SPME- GCMS with mass spectral libraries (Table 2). The compounds of isosorbide/dianhydromannitol (21.8%), cyclopropanetetradecanoic acid, 2-octyl-, methyl ester (17.1%), glycerin (14.51%) were detected at a high rate in L. edodes ethanol extract by GCMS, the main components of L. edodes were 3-octanone(66.4%) and disulfide, dimethyl (9.29%) by SPME-GCMS. In SPME-GCMS of A. bisporus, 3-octanone (79.13%) and 1-hexanol, 2-ethyl-(9.02%) were found as main component of the mushroom. However, the main components of EE of A. bisporus were dianhydromannitol (20.1%), glycerin (12.3%), cyclopropanetetradecanoic acid, 2-octyl-, methyl ester (11.9%). by GCMS. The common compounds in both L. edodes and A. bisporus were 2-formylhistamine (0.25–0.2%), pyrimidine-2,4(1 H,3 H)-dione (5-amino-6-nitroso- (0.51–0.9%), 3-aminopyrrolidine (0.71–1.3%), aziridine, 2-(1,1-dimethylethyl)-3-methyl-trans (0.76–1.4%), pantolactone (0.47–0.3%), glycerin (14.51–12.3%), 1-nitro-2-acetamido-1,2-dideoxy-d-mannitol (0.24–2.18%), cyclopropanetetradecanoic acid, 2-octyl-, methyl ester (17.1–11.9%), respectively, in GCMS analysis. In SPME- GCMS, carbon dioxide (5.03–3.29%), heptane, 2,4,6,6-pentamethyl- (0.78–0.65%), hexanoic acid, ethyl ester (0.13–0.17%), 3-octanone (66.4–79.13%), and 3-octanol (2.61–1.84%) were the common compounds for L. edodes and A. bisporus, respectively.