63-84-3Relevant academic research and scientific papers
Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
supporting information, (2020/07/15)
The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
Biocascade Synthesis of L-Tyrosine Derivatives by Coupling a Thermophilic Tyrosine Phenol-Lyase and L-Lactate Oxidase
Jiang, Yiqi,Ju, Shuyun,Li, Guosi,Lian, Jiazhang,Lin, Jianping,Wu, Mianbin,Xue, Hailong,Yang, Lirong
supporting information, (2020/02/25)
A one-pot biocascade of two enzymatic steps catalyzed by an l-lactate oxidase and a tyrosine phenol-lyase has been successfully developed in the present study. The reaction provides an efficient method for the synthesis of l-tyrosine derivatives, which exhibits readily available starting materials and excellent yields. In the first step, an in situ generation of pyruvate from readily available bio-based l-lactate catalyzed by a highly active l-lactate oxidase from Aerococcus viridans (AvLOX) was developed (using oxygen as oxidant and catalase as hydrogen peroxide removing reagent). Pyruvate thus produced underwent C–C coupling with phenol derivatives as acceptor substrate using specially designed thermophilic tyrosine phenol-lyase mutants from Symbiobacterium toebii (TTPL). Overall, this cascade avoids the high cost and easy decomposition of pyruvate and offered an efficient and environmentally friendly procedure for l-tyrosine derivatives synthesis.
Levodopa methyl ester hydrochloride synthetic method
-
, (2017/09/01)
The invention relates to a synthesis method of L-dopa methyl ester hydrochloride, which comprises the following steps: by using veratone as a raw material, carrying out amidation to obtain 2-amino-3-(3,4-dimethoxyphenyl)propanamide, carrying out amide oxidation into carboxy group to obtain 2-amino-3-(3,4-dimethoxyphenyl)propionic acid, removing methoxy group to obtain 2-amino-3-(3,4-dihydroxyphenyl)propionic acid, and finally, carrying out methyl ester conversion and acidification to obtain the target product 2-amino-3-(3,4-dimethoxyphenyl)alanine methyl ester hydrochloric acid. The method has the advantages of accessible reaction raw materials, ingenious technique concept, simple steps and no use of virulent reagents, is simple to operate, conforms to the requirements for green chemical industry, and is suitable for industrial production.
FUNCTIONALIZED FLUORINE CONTAINING PHTHALOCYANINE MOLECULES
-
, (2015/03/16)
Functionalized fluorine containing phthalocyanine molecules, methods of making, and methods of use in diagnostic applications and disease treatment are disclosed herein. In some embodiments, the fluorine containing phthalocyanine molecules are functionalized with a reactive functional group or at least one cancer-targeting ligand (CTL). The CTL can facilitate more efficient binding and/or internalization to a cancer cell than to a healthy cell. The CTL can inhibit expression of oncoprotein in some embodiments. The pthalocyanine moiety can be used in diagnostic applications, such as fluorescence labeling of a cancer cell, and/or treatment applications, such as catalyzing formation of a reactive oxygen species (ROS) which can contribute to cell death of a cancer cell.
A versatile approach to noncoded β-hydroxy-α-amino esters and α-amino acids/esters from morita-baylis-hillman adducts
Ullah, Hamid,Ferreira, Andr V.,Bendassolli, Jos A.,Rodrigues, Manoel T.,Formiga, Andr Luiz B.,Coelho, Fernando
, p. 113 - 123 (2015/02/02)
A simple and straightforward approach to the diastereoselective synthesis of noncoded β-hydroxy-α-amino esters from Morita-Baylis-Hillman (MBH) adducts is described. The strategy is based on a one-pot sequence involving an oxidative cleavage of the double bond of silylated Morita-Baylis-Hillman adducts, followed by the reaction with hydroxylamine hydrochloride/pyridine to form oximes. The stereoselective reduction of the oximes with the mixture MoCl5·nH2O/NaBH3CN led to the corresponding anti-β-hydroxy-α-amino esters in four steps in good overall yield and with diastereoselectivity higher than 95%. A slight modification of the synthetic approach has allowed for the racemic synthesis of a set of noncoded α-amino esters/acids and DOPA
Kinetic characteristics of purified tyrosinase from different species of Dioscorea (YAM) in aqueous and non-aqueous systems
Ilesanmi, Olutosin Samuel,Ojopagogo, Yetunde Adedolapo,Adewale, Isaac Olusanjo
, p. 111 - 117 (2014/11/08)
Yam tubers could serve as a cost-effective source of tyrosinase for various applications. Here a novel but cheap method of purification, and some properties of the enzyme from four species of yam tubers having high tyrosinase activity are described. The native and subunit molecular weights of each of the purified tyrosinase were between 41-58 kDa and 24-27 kDa respectively. Optimum pH and temperature were 6.5 and 50 C respectively. Tyrosinase from tubers of Colocasia esculenta retained more than 50% activity in ethanol (≤&60%). All the purified enzymes were activated in 40% ether by between 120 and 170%, and maintained 100% residual activity at up to 65% ether for 17 h. Both the K;bsubesub & and V;bsubesub & increased in 40% ether, leading to a corresponding increase in k;bsubesubbsubesub &. All the enzymes had both monophenolase and diphenolase activities. β- Mercaptoethanol and to a lesser extent, glutathione were good inhibitors. In aqueous systems, the purified tyrosinase catalyzed formation of coloured products in the presence of some substrates such as catechol, pyruvic acid and ammonia. The catalytic properties of these enzymes especially in organic solvents suggest that they may find uses in some biotechnological applications.
NOVEL MULTIMERIC MOLECULES, A PROCESS FOR PREPARING THE SAME AND THE USE THEREOF FOR MANUFACTURING MEDICINAL DRUGS
-
, (2010/06/16)
The invention relates to a compound of the formula (I): in which k and j are independently 0 or 1, Y is a macrocycle in which the cycle includes 9 to 36 carbon atoms and is functionalised by three amino functions and by a chain for attaching the spacer arm Z via an X bond, Rc is a binding pattern with a receptor of the TNF superfamily, X is a chemical function for binding the Y group to the space arm, and Z is a bi-, tri- or tetra-functional spacer arm.
NOVEL MULTIMERIC CD40 LIGANDS, METHOD FOR PREPARING SAME AND USE THEREOF FOR PREPARING DRUGS
-
, (2010/08/07)
The invention concerns a compound of formula (I), wherein Y represents a macrocycle whereof the cycle comprises 9 to 36 atoms, and is functionalized by three amine or COOH functions; Rc represents a group of formula H—Xa—Xb—Xc—Xd—Xe—(Xf)i—, wherein i represents 0 or 1, Xn is in particular selected among lysine, arginine, ornithine residues, Xb is in particular selected among glycine, asparagine, L-proline or D-proline residues, Xc et Xd are in particular selected among tyrosine, phenylalanine or 3-nitrotyrosine residues, Xe et Xf are in particular selected among the following amino acid residues: NH2—(CH2)n—COOH, n ranging from 1 to 10 or NH2—(CH2—CH2—O)m—CH2CH2COOH, m ranging from 3 to 6, provided that one at least of the amino acid residues Xa, Xb, Xc and Xd is different from the corresponding amino acid in the sequence of the natural CD40 143Lys-Gly-Tyr-Tyr146 fragment
Stereospecificity of mushroom tyrosinase immobilized on a chiral and a nonchiral support
Marin-Zamora, Maria Elisa,Rojas-Melgarejo, Francisco,Garcia-Canovas, Francisco,Garcia-Ruiz, Pedro Antonio
, p. 4569 - 4575 (2008/02/09)
Mushroom tyrosinase was immobilized from an extract onto glass beads covered with the cross-linked totally cinnamoylated derivates of D-sorbitol (sorbitol cinnamate) and glycerine (glycerine cinnamate). The enzyme was immobilized onto the support by direct adsorption, and the quantity of immobilized tyrosinase was higher for sorbitol cinnamate, the support with the higher number of esterified hydroxyls per unit of monosacharide, than for glycerine cinnamate. The results obtained from the stereospecificity study of the monophenolase and diphenolase activity of immobilized mushroom tyrosinase are reported. The enantiomers L-tyrosine, DL-tyrosine, D-tyrosine, L-dopa, DL-dopa, D-dopa, L-α-methyldopa, DL-α-methyldopa, L-isoprenaline, DL-isoprenaline, L-adrenaline, DL-adrenaline, L-noradrenaline, and D-noradrenaline were assayed with tyrosinase immobilized on a chiral support (sorbitol cinnamate), whereas L-tyrosine, DL-tyrosine, D-tyrosine, L-dopa, DL-dopa, D-dopa, L-α-methyldopa, and DL-α-methyldopa were assayed with tyrosinase immobilized on a nonchiral support (glycerine cinnamate). The same Vmaxapp values for each series of enantiomers were obtained. However, the Kmapp values were different, the L isomers showing lower values than the DL isomers, whereas the highest K mapp value was obtained with D isomers. No difference was observed in the stereospecificity of tyrosinase immobilized on a chiral (sorbitol cinnamate) or nonchiral (glycerine cinnamate) support.
Derivatives of L-pimaric acid in the synthesis of chiral organophosphorus ligands from decahydrophenanthrene series
Tolstikov,Karpyshev,Tolstikova,Khlebnikova,Sal'nikov,Mamatyuk,Gatilov,Bagryanskaya
, p. 1134 - 1148 (2007/10/03)
Starting with maleopimaric and fumaropimaric acids were prepared chiral organophosphorus ligands from decahydrophenanthrene series. Cationic complexes of Rh(I) prepared therefrom were tested for catalysts of asymmetric hydrogenation of unsaturated precursors of N-acethylphenylalanine and its derivatives.
