1070-34-4Relevant articles and documents
A New Class of Linear Tetrapyrroles: Acetylenic 10,10a-Didehydro-10a-homobilirubins
Tu, Bin,Ghosh, Brahmananda,Lightner, David A.
, p. 8950 - 8963 (2003)
Novel bilirubin analogues with dipyrrinones conjoined to an acetylene rather than a methylene group were synthesized and examined spectroscopically. Despite the increased separation of the dipyrrinones forced by replacing a -CH2- by a -C≡C- unit, molecular dynamics calculations show that, like bilirubin, they may still engage in intramolecular hydrogen bonding to carboxylic acid groups when the propionic acid chains are slightly lengthened, e.g., butanoic acids. Unlike bilirubin, however, which is bent in the middle and has a ridge-tile shape, the acetylene orients the attached dipyrrinones along a linear path, and intramolecular hydrogen bonding preserves a twisted linear molecular shape. The extended planes of the dipyrrinones intersect along the -C≡C- axis at an angle of 136° for the conformation stabilized by intramolecular hydrogen bonding in the bis-butyric acid rubin (lb). With shorter acid chains (propionic), only one CO2H can engage an opposing dipyrrinone in intramolecular hydrogen bonding, and in this energy-minimum conformation of the linear pigment 1a, the intersection of the extended planes of the dipyrrinones has an angle of 171°. Spectroscopic evidence for such linearized and twisted structures was found in the pigments' NMR spectral data and their exciton UV-vis and induced circular dichroism spectra.
Tetracarboxylatoplatinum(IV) complexes featuring monodentate leaving groups - A rational approach toward exploiting the platinum(IV) prodrug strategy
H?fer, Doris,Varbanov, Hristo P.,Legin, Anton,Jakupec, Michael A.,Roller, Alexander,Galanski, Markus,Keppler, Bernhard K.
, p. 259 - 271 (2015)
A series of novel symmetrically and unsymmetrically coordinated platinum(IV) complexes with monodentate carboxylato ligands was synthesized. The compounds exhibit a general coordination sphere of [Pt(en)(OCOR)2(OCOR′)(OCOR″], where the carboxylato ligands are represented by acetato and succinic acid monoester ligands. Dicarboxylatoplatinum(II) complexes were synthesized and oxidized symmetrically or unsymmetrically to obtain platinum(IV) complexes, which were subsequently carboxylated with noncyclic anhydrides. The compounds were investigated in detail by elemental analysis, mass spectrometry, infrared and multinuclear (1H, 13C, 15N, 195Pt) NMR spectroscopy as well as by X-ray diffraction in some cases. The reduction behavior was followed by NMR spectroscopy, while stability and lipophilicity were examined by analytical reversed phase HPLC measurements. Cytotoxic properties were studied in three human cancer cell lines derived from cisplatin sensitive ovarian teratocarcinoma (CH1/PA-1), cisplatin insensitive colon carcinoma (SW480) and non-small cell lung cancer (A549). Thereby, the most lipophilic (yet water soluble) platinum(IV) complexes showed promising IC50 values in the low micromolar and even nanomolar range, demonstrating the significant advantage of using equatorially coordinated monodentate carboxylato ligands.
Novel sulfonated carbonaceous materials from p-toluenesulfonic acid/glucose as a high-performance solid-acid catalyst
Zhang, Baohua,Ren, Jiawen,Liu, Xiaohui,Guo, Yun,Guo, Yanglong,Lu, Guanzhong,Wang, Yanqin
, p. 629 - 632 (2010)
A novel carbon-based solid-acid catalyst was simply prepared for the first time by the thermal treatment of p-toluenesulfonic acid (TsOH) with d-glucose at 180 °C in a sealed autoclave and it was proved to have high acidity and to be a highly efficient solid-acid catalyst in the reactions such as esterification of succinic acid with ethanol. Crown Copyright
Synthesis of protected α-amino acids: Via decarboxylation amination from malonate derivatives
Dai, Qipu,Fu, Hui,Hu, Changwen,Li, Peihe,Li, Xiaoying,Wang, Zheng
, p. 4439 - 4446 (2020)
A general and efficient strategy for the synthesis of protected α-amino acids is reported. The method uses malonate derivatives as the starting materials and Cs2CO3 as a base at 60 degrees, giving α-amino acid derivatives in moderate yields by releasing CO2. This methodology shows broad substrate scope (primary and secondary acids), excellent functional group tolerance and high efficiency to give the desired products under mild reaction conditions. It also allows the construction of β and γ-amino acids and other unnatural products.
Towards a bio-based industry: Benign catalytic esterifications of succinic acid in the presence of water
Budarin, Vitaly,Luque, Rafael,Macquarrie, Duncan J.,Clark, James H.
, p. 6914 - 6919 (2007)
The biorefinery of the future will need to integrate bioconversion and appropriate low environmental impact chemical technologies (Green Chemistry) so as to produce a wide range of products from biomass in an economically effective and environmentally acceptable manner. The challenge for chemists is to develop chemistry that works with fermentation-derived dilute, aqueous mixtures of oxygenated chemicals (platform molecules) rather than the petroleum-derived non-aqueous, non-oxygenated feedstocks we have been working with for 50+ years and to avoid energy intensive and wasteful concentration and purification steps. Here we show that a new family of tuneable mesoporous carbonaceous catalysts derived from starch can be used to accomplish efficient chemistry in aqueous solution. Our new aqueous catalytic chemistry relies on the ability to adjust the surface properties including the hydrophobicity-hydrophilicity balance of mesoporous Starbons by carbonisation at different temperatures (250-750°C). Simple treatment of these materials with sulfuric acid then provides a series of porous solid acids that can function under a range of conditions including dilute aqueous solution. The reactions of succinic acid (platform molecule) in aqueous alcohol demonstrate the outstanding activities of these new catalysts.
Bis- and Tris(carboxylato)platinum(IV) Complexes with Mixed Am(m)ine Ligands in the trans Position Exhibiting Exceptionally High Cytotoxicity
Hoffmeister, Bj?rn R.,Hejl, Michaela,Jakupec, Michael A.,Galanski, Markus,Keppler, Bernhard K.
, p. 1700 - 1708 (2015)
A series of seven diam(m)inebis(carboxylato)dihydroxidoplatinum(IV) and eleven diam(m)inetris(carboxylato)hydroxidoplatinum(IV) complexes with am(m)ine ligands in the trans position was synthesized and characterized by multinuclear 1H, 13C, 15N, 195Pt NMR spectroscopy. IC50 values for all eighteen substances were determined by means of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay for three human cancer cell lines. In cisplatin-sensitive CH1(PA-1) cancer cells, diam(m)inebis(carboxylato)dihydroxidoplatinum(IV) complexes displayed 50 % inhibitory concentrations in the micromolar range, whereas for the most lipophilic compounds of the diam(m)inetris(carboxylato)hydroxidoplatinum(IV) series, promising IC50 values in the nanomolar range were found.
Pig liver esterase catalyzed hydrolyses of diesters. A new route to the syntheses of achiral half-esters
Ager,Prakash
, p. 739 - 742 (1995)
Pig liver esterase catalyzed hydrolyses of diesters of alkanes, aromatic and heterocyclic compounds gave high yields of the corresponding half-esters under mild reaction conditions.
Kanglexin, a new anthraquinone compound, attenuates lipid accumulation by activating the AMPK/SREBP-2/PCSK9/LDLR signalling pathway
Li, Xin,Hu, Xueling,Pan, Tengfei,Dong, Lei,Ding, Lili,Wang, Zhenzhong,Song, Rui,Wang, Xiuzhu,Wang, Ning,Zhang, Yan,Wang, Jinhui,Yang, Baofeng
, (2021)
Hyperlipidaemia is one of the major risk factors for atherosclerosis, coronary heart disease, stroke and diabetes. In the present study, we synthesized a new anthraquinone compound, 1,8-dihydroxy-3-succinic acid monoethyl ester-6-methylanthraquinone, and named it Kanglexin (KLX). The aim of this study was to evaluate whether KLX has a lipid-lowering effect and to explore the potential molecular mechanism. In this study, Sprague-Dawley rats were fed a high fat diet (HFD) for 5 weeks to establish a hyperlipidaemia model; then, the rats were orally administered KLX (20, 40, and 80 mg kg?1·d?1) or atorvastatin calcium (AT, 10 mg kg?1·d?1) once a day for 2 weeks. KLX had prominent effects on reducing blood lipids, hepatic lipid accumulation, body weight and the ratio of liver weight/body weight. Furthermore, KLXdramatically reduced the total cholesterol (TC) and triglyceride (TG) levels and lipid accumulation in a HepG2 cell model of dyslipidaemia induced by 1 mmol/L oleic acid (OA). KLX may decrease lipid levels by phosphorylating adenosine monophosphate-activated protein kinase (AMPK) and the downstream sterol regulatory element binding protein 2 (SREBP-2)/proprotein convertase subtilisin/kexin type 9 (PCSK9)/low-density lipoprotein receptor (LDLR) signalling pathway in the HFD rats and OA-treated HepG2 cells. The effects of KLX on the AMPK/SREBP-2/PCSK9/LDLR signalling pathway were abolished when AMPK was inhibited by compound C (a specific AMPK inhibitor) in HepG2 cells. In summary, KLX has an efficient lipid-lowering effect mediated by activation of the AMPK/SREBP-2/PCSK9/LDLR signalling pathway. Our findings may provide new insight into and evidence for the discovery of a new lipid-lowering drug for the prevention and treatment of hyperlipidaemia, fatty liver, and cardiovascular disease in the clinic.
COMPOSITIONS AND METHODS FOR TREATING MORPHINE, HEROIN, AND ALCOHOL DEPENDENCE
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Page/Page column 8; 33, (2021/12/08)
This invention provides a composition of matter comprising a plurality of morphine-6-succinyl-BSA, wherein the average ratio of morphine-6-succinyl moieties to BSA is at least 7.0. This invention also provides a composition of matter comprising a plurality of heroin-6-succinyl-BSA, wherein the average ratio of heroin-6-succinyl moieties to BSA is at least 7.0. This invention further provides a composition of matter comprising a plurality of ethanol-succinyl-BSA, wherein the average ratio of ethanol-succinyl moieties to BSA is at least 7.0. This invention still further provides related pharmaceutical compositions, therapeutic methods, prophylactic methods, synthetic methods, and articles of manufacture.
Zeolite Y from kaolin clay of Kachchh, India: Synthesis, characterization and catalytic application
Gandhi, Dolly,Bandyopadhyay, Rajib,Soni, Bhavna
, (2021/11/23)
Kaolin clay obtained from Kachchh, Gujarat was used as alumina and silica source to synthesize zeolite Y by hydrothermal method. The synthesis route comprised of the following steps: sulfuric acid treatment at 110 ?°C (4 ?h) for impurity removal followed by calcination at 600 ?°C for 4 ?h, thermal activation of kaolin into metakaolin by NaOH fusion at 850 ?°C (8 ?h); aging of reaction mixtures at 50 ?°C (24 ?h); crystallization (24 ?h) followed by washing and drying. The synthesized zeolite Y was examined by multiple characterization techniques which revealed a pore volume of 0.22 ?cm3/g with pore size of 2.89 ?nm having essential surface area of 320 ?m2/g, indicating a porous material having majority of micropores and remaining mesopores. The zeolite exhibited good catalytic activity for succinic acid esterification using ethanol to produce monoethyl and diethyl succinate. The conversion of SA (72%) and yield (60%) of valuable diester indicated good conversion rate and selectivity at moderate reaction conditions. Detailed structural comparison with zeolite Y synthesized using standard chemical route is also carried out. This work demonstrated an effective way of preparing environmentally benign porous zeolite Y having high surface area and pore volume that can be useful for catalytic applications.
