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1.
T Nishi F Saito H Nagahori M Kataoka Y Morisawa Y Yabe M Sakurai S Higashida M Shoji Y Matsushita 《Chemical & pharmaceutical bulletin》1990,38(1):103-109
Syntheses and biological activities of dipeptide renin inhibitors that contain statine analogues are described. The key steps of the synthetic approach to dipeptide renin inhibitors are the asymmetric synthesis of 2(R)-substituted-3-aminocarbonylpropionic acids and the diastereoselective syntheses of (3S,4S)-statine analogues. These inhibitors (2,14-40) inhibited human renin in the 3-140 nM range. Inhibitor ES 6864 (2) was found to be a highly potent inhibitor of human renin (IC50: 4.6 x 10(-9) M) and showed high enzyme specificity. Oral administration of ES 6864 at 3 mg/kg to conscious, sodium-depleted marmosets inhibited plasma renin activity (PRA) more than 80% after 1 h. 相似文献
2.
According to the traditional usage of the plant for antiinflammation and analgesia, Leucas aspera was tested for its prostaglandin (PG) inhibitory and antioxidant activities. The extract showed both activities, i.e., inhibition at 3 x 10(-4) g/ml against PGE(1)- and PGE(2)-induced contractions in guinea pig ileum and a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect. The separation guided by the activities in these dual assay methods provided eight lignans and four flavonoids, LA-1- -12, among which LA-1- -7 and LA-10- -12 were identified as nectandrin B, meso-dihydroguaiaretic acid, macelignan, acacetin, apigenin 7-O-[6"-O-(p-coumaroyl)-beta-D-glucoside], chrysoeriol, apigenin, erythro-2-(4-allyl-2, 6-dimethoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)propan-1-ol, myristargenol B, and machilin C, respectively. LA-8 was determined to be (-)-chicanine, the new antipode of the (+) compound, by spectroscopic methods including CD and ORD. Chiral-HPLC analysis of LA-9 showed that it was a mixture of two enantiomers, (7R, 8R)- and (7S, 8S)-licarin A. All of these components were first isolated from L. aspera. PG inhibition was observed in LA-1, LA-2, and LA-5, and antioxidant activity in LA-1- -3 and LA-8- -12. 相似文献
3.
Nakanishi I Miyazaki K Shimada T Iizuka Y Inami K Mochizuki M Urano S Okuda H Ozawa T Fukuzumi S Ikota N Fukuhara K 《Organic & biomolecular chemistry》2003,1(22):4085-4088
Electron-transfer reduction of molecular oxygen (O2) by the phenolate anion (1-) of a vitamin E model, 2,2,5,7,8-pentamethylchroman-6-ol (1H), occurred to produce superoxide anion, which could be directly detected by a low-temperature EPR measurement. The rate of electron transfer from 1- to O2 was relatively slow, since this process is energetically unfavourable. The one-electron oxidation potential of 1- determined by cyclic voltammetric measurements is sufficiently negative to reduce 2,2-bis(4-tert-octylphenyl)-1-picrylhydrazyl radical (DOPPH*) to the corresponding one-electron reduced anion, DOPPH-, suggesting that 1- can also act as an efficient radical scavenger. 相似文献
4.
Kudoh T Fukuoka M Ichikawa S Murayama T Ogawa Y Hashii M Higashida H Kunerth S Weber K Guse AH Potter BV Matsuda A Shuto S 《Journal of the American Chemical Society》2005,127(24):8846-8855
We previously developed cyclic ADP-carbocyclic ribose (cADPcR, 2) as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca(2+)-mobilizing second messenger. A series of the N1-ribose modified cADPcR analogues, designed as novel stable mimics of cADPR, which were the 2"-deoxy analogue 3, the 3"-deoxy analogue 4, the 3"-deoxy-2"-O-(methoxymethyl) analogue 5, the 3"-O-methyl analogue 6, the 2",3"-dideoxy analogue 7, and the 2",3"-dideoxydidehydro analogue 8, were successfully synthesized using the key intramolecular condensation reaction with phenylthiophosphate-type substrates. We investigated the conformations of these analogues and of cADPR and found that steric repulsion between both the adenine and N9-ribose moieties and between the adenine and N1-ribose moieties was a determinant of the conformation. The Ca(2+)-mobilizing effects were evaluated systematically using three different biological systems, i.e., sea urchin eggs, NG108-15 neuronal cells, and Jurkat T-lymphocytes. The relative potency of Ca(2+)-mobilization by these cADPR analogues varies depending on the cell-type used: e.g., 3"-deoxy-cADPcR (4) > cADPcR (2) > cADPR (1) in sea urchin eggs; cADPR (1) > cADPcR (2) approximately 3"-deoxy-cADPcR (4) in T-cells; and cADPcR (2) > cADPR (1) > 3"-deoxy-cADPcR (4) in neuronal cells, respectively. These indicated that the target proteins and/or the mechanism of action of cADPR in sea urchin eggs, T-cells, and neuronal cells are different. Thus, this study represents an entry to cell-type selective cADPR analogues, which can be used as biological tools and/or novel drug leads. 相似文献
5.
Fujimoto H Nakamura E Okuyama E Ishibashi M 《Chemical & pharmaceutical bulletin》2004,52(8):1005-1008
In a screening study on immunomodulatory fungal metabolites, three known anthraquinones, carviolin (roseo-purpurin) (1), 1-O-methylemodin (2), omega-hydroxyemodin (citreorosein) (4), and a new anthraquinone, omega-acetylcarviolin (3), together with a known steroid, ergosta-4,6,8(14),22-tetraen-3-one (5) and a new steroid, 25-hydroxyergosta-4,6,8(14),22-tetraen-3-one (6) were isolated from an Ascomycete, Zopfiella longicaudata, and found to have moderate immunosuppressive activities. The structure-activity relationships of these metabolites are discussed. 相似文献
6.
Akiko Ohno Nana Kawasaki Kiyoshi Fukuhara Haruhiro Okuda Teruhide Yamaguchi 《Magnetic resonance in chemistry : MRC》2010,48(2):168-172
Complete NMR analysis of oxytocin (OXT) in phosphate buffer was elucidated by one‐dimensional (1D)‐ and two‐dimensional (2D)‐NMR techniques, which involve the assignment of peptide amide NH protons and carbamoyl NH2 protons. The 1H? 15N correlation of seven amide NH protons and three carbamoyl NH2 protons were also shown by HSQC NMR of OXT without 15N enrichment. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
7.
Practical two-dimensional high-spin organic polymers are newly designed and the electronic structures are examined on the basis of the ab initio two-dimensional unrestricted Hartree–Fock crystal orbital (UHF-CO) method. The present polymers can be oxidized up to six electrons per unit cell, and it is predicted that the three-electron and six-electron oxidations per unit cell lead to the high-spin organic polymers having superdegenerate band structures originating from the characteristic non-bonding crystal orbital patterns. 相似文献
8.
Akihiro Ito Haruhiro Ino Kazuyoshi Tanaka Katsuichi Kanemoto Tatsuhisa Kato 《The Journal of organic chemistry》2002,67(2):491-498
Syntheses of both the dimer (3) and the trimer (4) of all-para-brominated poly(N-phenyl-m-aniline)s (2c) were achieved in a one-pot procedure from the parent nonbrominated oligomers and benzyltrimethylammonium tribromide [(BTMA)Br(3)]. An X-ray crystallographic analysis revealed that 4 has a U-shaped structure, suggesting that 2c easily adopts helical structures. Furthermore, the redox properties were investigated by the UV-vis and EPR measurements. It was confirmed that the both 3 and 4 can be oxidized into the dications 3(2+) and 4(2+) with triplet spin-multiplicity. 相似文献
9.
Chiral Ammonium Betaine‐Catalyzed Highly Stereoselective Aza‐Henry Reaction of α‐Aryl Nitromethanes with Aromatic N‐Boc Imines 下载免费PDF全文
Dr. Daisuke Uraguchi Keigo Oyaizu Haruhiro Noguchi Prof. Dr. Takashi Ooi 《化学:亚洲杂志》2015,10(2):334-337
A highly stereoselective aza‐Henry reaction of α‐aryl nitromethanes with aromatic N‐Boc imines was established by using C1‐symmetric chiral ammonium betaine as a bifunctional organic base catalyst. Various substituted aryl groups for both imines and nitromethanes were tolerated in the reaction, and a series of precursors for the synthesis of unsymmetrical anti‐1,2‐diaryl ethylenediamines was provided. 相似文献
10.
Hiroshi Mizoguchi SangWon Park Haruhiro Hiraka Kazutaka Ikeda Toshiya Otomo Hideo Hosono 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(10):2975-2978
Using a high pressure technique and the strong donating nature of H−, a new series of tetragonal La2Fe2Se2O3‐type layered mixed‐anion arsenides, Ln2M2As2Hx, was synthesized (Ln=La or Sm, M=Ti, V, Cr, or Mn; x≈3). In these compounds, an unusual M2H square net, which has anti CuO2 square net structures accompanying two As3− ions, is sandwiched by (LaH)2 fluorite layers. Notably, strong metal–metal bonding with a distance of 2.80 Å was confirmed in La2Ti2As2H2.3, which has metallic properties. In fact, these compounds are situated near the boundary between salt‐like ionic hydrides and transition‐metal hydrides with metallic characters. 相似文献