1188-21-2Relevant articles and documents
A Novel Chiral Ferrocenyl Phosphine Ligand from Sugar: Applications in Rh-Catalyzed Asymmetric Hydrogenation Reactions
Liu, Duan,Li, Wenge,Zhang, Xumu
, p. 4471 - 4474 (2002)
(Matrix Presented) A new chiral ferrocenyl diphosphine ligand 3 was synthesized from readily available D-mannitol. Rh-complex with this ligand showed high enantioselectivity and reactivity in the asymmetric hydrogenation of dehydroamino acid derivatives and itaconic acid derivatives. Up to over 99% ee and 10 000 TON were achieved with this catalytic system.
STUDIES ON AI-77s, MICROBIAL PRODUCTS WITH GASTROPROTECTIVE ACTIVITY. STRUCTURES AND THE CHEMICAL NATURE OF AI-77s
Shimojima, Yukiji,Hayashi, Hiroshi,Ooka, Tadaaki,Shibukawa, Mitsuru,Iitaka, Yoichi
, p. 2519 - 2528 (1984)
The structures and chemical nature of a novel gastroprotective substance AI-77-B (1) and its analogues AI-77-C (2), D (3), F (4) and G (5), which are produced by Bacillus pumilus AI-77, are described.The structure of 1 was confirmed to be 6-amino>-4(S),5(S)-dihydroxy-6-oxo-3(S)-aminohexanoic acid by X-ray in combination with chemical studies and the structures of 2, 3, 4 and 5 were determined by chemical syntheses from 1 and spectral analyses.
ASYMMETRIC HYDROGENATION CATALYZED BY AMINOPHOSPHINE-PHOSPHINITERHODIUM COMPLEXES DERIVED FROM NATURAL AMINOALCOHOLS AND X-RAY CRYSTAL STRUCTURE OF (1,5-CYCLOOCTADIENE)-(S)-N-(DIPHENYLPHOSPHINO)-2-DIPHENYLPHOSPHINOXYMETHYLPYRROLIDINERHODIUM(I) PERCHLORATE
Cesarotti, E.,Chiesa, A.,Ciani, G.,Sironi, A.
, p. 79 - 92 (1983)
From the cheap and readily available amino alcohols (S)-pyrrolidinemethanol ((S)-prolinol), and (S)-α-N-ethyl-aminobutanol, we have obtained two new aminophosphine-phosphinite ligands: (S)-N-(diphenylphosphino)-2-diphenylphosphinooxymethylpyrrolidine ((S)-Prolophos) and (S)-1-diphenylphosphinoxy-2-N-ethyl-N-diphenylphosphinoaminobutane ((S)-Butaphos).The rhodium(I) complexes of these phosphines act as efficient homogeneous hydrogenation catalysts at ambient temperature and pressures for dehydro N-acetyl amono acids, dehydro N-benzoyl amino acids and itaconic acid.An X-ray diffraction study of the complex *THF has been shown that the crystals belong to the monoclinic space group P21 with a 10.680(2), b 10.448(2), c 18.207(3) Angstroem and β 104.97(1)o.Refinements based on 2105 significant counter reflections led to a final R value of 0.060.The cation is in a distorted square planar geometry, the rhodium atom being bound to the two phosphorus atoms and to the two double bonds of the diene molecule.
Rapid Room-Temperature Gelation of Crude Oils by a Wetted Powder Gelator
Ren, Changliang,Shen, Jie,Chen, Feng,Zeng, Huaqiang
, p. 3847 - 3851 (2017)
Phase-selective organogelators (PSOGs) not only exhibit ability to phase-selectively congeal oil from oily water but also allow easy separation of gelled oil from the body of water. However, all hitherto reported PSOGs either necessitate carrier solvents for their dissolution or suffer from an extremely slow action in gelling oil in the powder form. A previously unexplored generally applicable wetting strategy is now described to dramatically enhance, by up to two orders of magnitude, gelling speed of the resultant wet but non-sticky gelator in the powder form in crude oils of widely ranging viscosities. Such unprecedented rapid gelling speeds enable rapid gelation of six types of (un)weathered crude oils within minutes at room temperature, making PSOGs one step closer to their eventual practical uses as one of important oil spill control technologies.
Acetylation under ultrasonic conditions: Convenient preparation of N-acetylamino acids
Veera Reddy,Ravindranath
, p. 257 - 264 (1992)
An efficient and simple method of preparation of acetylamino acids from amino acids under ultrasonic conditions is described. The reactions proceed without racemization and the yields are almost quantitative.
Paecilopeptin, a new cathepsin S inhibitor produced by Paecilomyces carneus.
Shindo, Kazutoshi,Suzuki, Hidefumi,Okuda, Toru
, p. 2444 - 2448 (2002)
Paecilopeptin, a novel cathepsin S inhibitor, was produced and isolated from the culture supernatant of the fungal strain, Paecilomyces carneus. A spectroscopic analysis revealed the planar structure of paecilopeptin to be acetyl-Leu-Val-CHO. The stereochemistry of the constituent amino acids was analysed by chiral HPLC after oxidation and 6N HCl hydrolysis of paecilopeptin. The total synthesis of paecilopeptin was completed in six steps. Paecilopeptin inhibited human cathepsin S with an IC50 value of 2.1 nM in vitro.
Structure-activity relationship studies of dipeptide-based hepsin inhibitors with Arg bioisosteres
Kwon, Hongmok,Ha, Hyunsoo,Jeon, Hayoung,Jang, Jaebong,Son, Sang-Hyun,Lee, Kiho,Park, Song-Kyu,Byun, Youngjoo
supporting information, (2020/12/25)
Hepsin is a type II transmembrane serine protease (TTSP) associated with cell proliferation and overexpressed in several types of cancer including prostate cancer (PCa). Because of its significant role in cancer progression and metastasis, hepsin is an attractive protein as a potential therapeutic and diagnostic biomarker for PCa. Based on the reported Leu-Arg dipeptide-based hepsin inhibitors, we performed structural modification and determined in vitro hepsin- and matriptase-inhibitory activities. Comprehensive structure-activity relationship studies identified that the p-guanidinophenylalanine-based dipeptide analog 22a exhibited a strong hepsin-inhibitory activity (Ki = 50.5 nM) and 22-fold hepsin selectivity over matriptase. Compound 22a could be a prototype molecule for structural optimization of dipeptide-based hepsin inhibitors.
Oxidative damage of proline residues by nitrate radicals (NO3): A kinetic and product study
Nathanael, Joses G.,Nuske, Madison R.,Richter, Annika,White, Jonathan M.,Wille, Uta
supporting information, p. 6949 - 6957 (2020/10/02)
Tertiary amides, such as in N-acylated proline or N-methyl glycine residues, react rapidly with nitrate radicals (NO3) with absolute rate coefficients in the range of 4-7 × 108 M-1 s-1 in acetonitrile. The major pathway proceeds through oxidative electron transfer (ET) at nitrogen, whereas hydrogen abstraction is only a minor contributor under these conditions. However, steric hindrance at the amide, for example by alkyl side chains at the α-carbon, lowers the rate coefficient by up to 75%, indicating that NO3-induced oxidation of amide bonds proceeds through initial formation of a charge transfer complex. Furthermore, the rate of oxidative damage of proline and N-methyl glycine is significantly influenced by its position in a peptide. Thus, neighbouring peptide bonds, particularly in the N-direction, reduce the electron density at the tertiary amide, which slows down the rate of ET by up to one order of magnitude. The results from these model studies suggest that the susceptibility of proline residues in peptides to radical-induced oxidative damage should be considerably reduced, compared with the single amino acid.
GRANZYME B DIRECTED IMAGING AND THERAPY
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Page/Page column 108; 109, (2019/09/04)
Provided herein are heterocyclic compounds useful for imaging Granzyme B. Methods of imaging Granzyme B, combination therapies, and kits comprising the Granzyme B imaging agents are also provided.
Oxidative Damage in Aliphatic Amino Acids and Di- and Tripeptides by the Environmental Free Radical Oxidant NO3?: the Role of the Amide Bond Revealed by Kinetic and Computational Studies
Nathanael, Joses G.,Wille, Uta
, p. 3405 - 3418 (2019/03/11)
Kinetic and computational data reveal a complex behavior of the important environmental free radical oxidant NO3? in its reactions with aliphatic amino acids and di- and tripeptides, suggesting that attack at the amide N-H bond in the peptide backbone is a highly viable pathway, which proceeds through a proton-coupled electron transfer (PCET) mechanism with a rate coefficient of about 1 × 106 M-1 s-1 in acetonitrile. Similar rate coefficients were determined for hydrogen abstraction from the α-carbon and from tertiary C-H bonds in the side chain. The obtained rate coefficients for the reaction of NO3? with aliphatic di- and tripeptides suggest that attack occurs at all of these sites in each individual amino acid residue, which makes aliphatic peptide sequences highly vulnerable to NO3?-induced oxidative damage. No evidence for amide neighboring group effects, which have previously been found to facilitate radical-induced side-chain damage in phenylalanine, was found for the reaction of NO3? with side chains in aliphatic peptides.
