503-74-2Relevant articles and documents
LABDANE DERIVATIVES AND FLAVONES FROM GUTIERREZIA DRACUNCULOIDES
Bohlmann, Ferdinand,Grenz, Michael,Dahr, Autar K.,Goodman, Mark
, p. 105 - 108 (1981)
Key Word Index - Guiterrezia dracunculoids; Compositae; new labdane derivatives; new flavones. An investigation of the aerial parts of Gutierrezia dracunculoides afforded, in addition to known compounds, three new labdan derivatives, all related to lambertianic acid, 17-hydroxy- and 17-acetoxylambertianic acid and 7α-hydroxylambertianic acid, two esterifid and tree highly oxygnated flavones, 5,7,4'-trihydroxy-3,3'-dimethoxy-flavone-4'-O- and isovalerate, 3',5'-dihydroxy-3,5,6,7,8,4'hexamethoxyflavone, 5,3',5'-trihydroxy-3,6,7,8,4'-pentamethoxyflavone and 5,7,3'5'-tetrahydroxy-3,6,8,4-tetramethoxyflavone.The structures were elucidated by spectroscopic methods and a few chemical transformations.
The degradation mechanism of toxic atractyloside in herbal medicines by decoction
Chen, Liang-Yu,Hu, Anren,Chang, Chih-Jui
, p. 2018 - 2028 (2013)
Atractyloside (ATR) is found in many Asteraceae plants that are commonly used as medicinal herbs in China and other eastern Asian countries. ATR binds specifically to the adenine nucleotide translocator in the inner mitochondrial membrane and competitively inhibits ADP and ATP transport. The toxicity of ATR in medical herbs can be reduced by hydrothermal processing, but the mechanisms of ATR degradation are not well understood. In this study, GC-MS coupled with SPE and TMS derivatisation was used to detect ATR levels in traditional Chinese medicinal herbs. Our results suggest that ATR molecules were disrupted by decomposition, hydrolysis and saponification after heating with water (decoction) for a long period of time. Hydrothermal processing could decompose the endogenous toxic compounds and also facilitate the detoxification of raw materials used in the Chinese medicine industry.
Kinetics and mechanism of oxidation of L-leucine by alkaline diperiodatocuprate(III). A free radical intervention, deamination and decarboxylation
Naik, Keerti M.,Nandibewoor, Sharanappa T.
, p. 809 - 819 (2012)
The kinetics of oxidation of L-leucine by diperiodatocuprate (III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.10mol dm-3 was studied spectrophotometrically. The reaction between L-leucine and DPC in alkaline medium exhibits 1:4 stoichiometry (L-leucine: DPC). The reaction is of first order in [DPC] and has less than unit order in both [L-leucine] and [alkali]. However, the order in [Lleucine] and [alkali] changes from first order to zero order as their concentration increase. Intervention of free radicals was observed in the reaction. Increase in periodate concentration decreased the rate. The oxidation reaction in alkaline medium has been shown to proceed via a monoperiodatocuprate (III) - L-leucine complex, which decomposed slowly in a rate-determining step followed by other fast steps to give the products. The main oxidative products were identified by spot test and GC-MS. The reaction constants involved in the different steps of the mechanism were calculated. Indian Academy of Sciences.
Acylated glycosidic acid methyl esters generated from the convolvulin fraction of Rhizoma Jalapae Braziliensis by treatment with indium(III) chloride in methanol
Ono, Masateru,Oda, Satoko,Yasuda, Shin,Mineno, Tomoko,Okawa, Masafumi,Kinjo, Junei,Miyashita, Hiroyuki,Yoshimitsu, Hitoshi,Nohara, Toshihiro,Miyahara, Kazumoto
, p. 107 - 111 (2017)
Four hexaglycosides of methyl 3S,12S-dihydroxyhexadecanoate (1-4) were provided after treatment of the crude convolvulin fraction from Rhizoma Jalapae Braziliensis (the root of Ipomoea operculata (GOMES) MART., Convolvulaceae) with indium(III) chloride in
2α-ISO-VALEROYLOXYEPERUIC ACID, A DITERPENE FROM EUPATORIUM PETIOLARE
Calderon, J. S.,Quijano, L.,Garduno, M.,Gomez, F.,Rios, T.
, p. 2617 - 2619 (1983)
The diterpene acid 2α-iso-valeroyloxyeperuic acid was isolated from the aerial parts of Eupatorium petiolare.Its structure and stereochemistry were elucidated by spectroscopic methods and chemical correlation with eperuic acid. - Key Word Index: Eupatorium petiolare; Compositae; Eupatorieae; labdane type diterpenes; 2α-iso-valeroyloxyeperuic acid.
Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process
Fu, Qiang,Liang, Fu-Shun,Lou, Da-Wei,Pan, Gao-Feng,Wang, Rui,Wu, Min,Xie, Kai-Jun
supporting information, p. 2020 - 2024 (2022/03/31)
A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.
Method for preparing isovaleric acid, ligand and complex in catalytic system of isovaleric acid, and application of catalytic system
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Paragraph 0087-0111, (2020/02/29)
The invention provides a method for preparing isovaleric acid. According to the method, in the presence of a catalytic system, isovaleraldehyde is subjected to an oxidation reaction so as to obtain isovaleric acid, wherein the catalytic system comprises a catalyst which is a complex formed by a naphthalate ligand and a palladium-containing compound, the naphthalate ligand comprises a compound witha structure as shown in a formula I which is described in the specification. In the formula I, R1-R10 are respectively and independently selected from a group consisting of -NO2, -F, -Br, -Cl, -I, -H, -CH3, -CH2CH3, -OCH3, -CH(CH3)2 and -C(CH3)3; and preferably, at least one ester group in the compound with the structure as shown in the formula I is substituted at the beta position of a naphthalene ring. The invention provides the isovaleric acid preparation method with high selectivity, high yield and high safety.
Method for producing aliphatic carboxylic acid compound and pyridine compound adduct of aliphatic ketone compound
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Paragraph 0172; 0175-0176; 0182; 0185-0186; 0192; 0195-0196, (2020/05/02)
Provided are: a method for producing an aliphatic carboxylic acid compound safely and easily from a starting material that can be obtained or produced industrially without generating a harmful substance such as haloform; and a pyridine compound adduct of an aliphatic ketone compound. The method for producing an aliphatic carboxylic acid compound is a method for producing an aliphatic carboxylic acid compound represented by Formula (I), and comprises: a first step for obtaining a pyridine compound adduct by adding a pyridine compound to an aliphatic ketone compound having an alpha-methyl groupin the presence of an oxidizing agent; and a second step of hydrolyzing the pyridine compound adduct in the presence of a base. In the Formula, R1 represents a substituted or unsubstituted linear alkyl group having 4-8 carbon atoms or a substituted or unsubstituted branched alkyl group having 4-8 carbon atoms; M represents hydrogen, a metal belonging to Group 1 or Group 2 of the periodic table, amethyl group, an ethyl group, an n-propyl group or an isopropyl group.
Chemoselective Hydrogenation of α,β-Unsaturated Carbonyls Catalyzed by Biomass-Derived Cobalt Nanoparticles in Water
Song, Tao,Ma, Zhiming,Yang, Yong
, p. 1313 - 1319 (2019/01/25)
Herein, we report highly chemoselective hydrogenation of α,β-unsaturated carbonyls to saturated carbonyls catalyzed by cobalt nanoparticles supported on the biomass-derived carbon from bamboo shoots with molecular hydrogen in water, which is the first prototype using a heterogeneous non-noble metal catalyst for such organic transformation as far as we know. The optimal cobalt nanocatalyst, CoOx@NC-800, manifested remarkable activity and selectivity for hydrogenation of C=C in α,β-unsaturated carbonyls under mild conditions. A broad set of α,β-aromatic and aliphatic unsaturated carbonyls were selectively reduced to their corresponding saturated carbonyls in up to 99 % yields with good tolerance of various functional groups. Meanwhile, a new straightforward one-pot cascade synthesis of saturated carbonyls was realized with high activity and selectivity via the cross-aldol condensation of ketones with aldehydes followed by selective hydrogenation. More importantly, this one-pot strategy is applicable for the expedient synthesis of Loureirin A, a versatile bioactive and medicinal molecule, from readily available starting materials, further highlighting the practical utility of the catalyst. In addition, the catalyst can be easily separated for successive reuses without significant loss in both activity and selectivity.
Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 14365 - 14373 (2019/09/06)
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
