molecular models reveals very low, if any, strain in the planar arrangements shown for the three donor groups of the ligan’d. Since resonance between the imine and aromatic ring would tend to keep the bonds adjacent to the imine nitrogens in the same plane, the planar arrangement for the ligands shown in B and C is favored over other possible structures. Additional evidence for the proposed chelate
分子模型显示,配体的三个供体组显示的平面排列中的应变非常低(如果有的话)。由于亚胺和芳环之间的共振倾向于将与亚胺氮相邻的键保持在同一平面上,因此 B 和 C 中所示配体的平面排列优于其他可能的结构。可以通过比较图 1 中的红外光谱获得所提出的螯合物结构的其他证据。在 2500-2600 cm 附近是否存在宽带。-l 表示 Cu(I1) 螯合物没有分子间氢键,而 Fe(II1) 和 Ni(I1) 螯合物的这种键合量增加。这些带的强度与无、一、和两个能够形成分子间氢键的吡啶鎓质子,分别如结构 A、B 和 C 所示。根据红外证据,对于 Fe(II1) 和 Ni(I1),不能排除水与金属配位且 3-吡啶醇基团参与分子间氢键的替代结构。另一方面,根据已知的金属离子与有机配体中各种类型的供体基团之间的亲和力,这种替代结构被认为是不可能的。
Direct Observation of Acyl Nitroso Compounds in Aqueous Solution and the Kinetics of Their Reactions with Amines, Thiols, and Hydroxamic Acids
Acyl nitrosocompounds or nitrosocarhonyls (RC(O)N═O) are reactive short-lived electrophiles, and their hydrolysis and reactions with nucleophiles produce HNO. Previously, direct detection of acyl nitroso species in nonaqueous media has been provided by time-resolved infrared spectroscopy demonstrating that its half-life is about 1 ms. In the present study hydroxamicacids (RC(O)NHOH) are oxidized
酰基亚硝基化合物或亚硝基羰基化合物(RC(O)N = O)是反应性短寿命的亲电试剂,它们的水解和与亲核试剂的反应会生成HNO。以前,时间分辨红外光谱法可直接检测非水介质中的酰基亚硝基,证明其半衰期约为1毫秒。在本研究中,异羟肟酸(RC(O)NHOH)在缓冲水溶液(pH 5.9-10.2)中被电化学氧化,产生瞬态物质,其特征在于它们在314-330 nm处具有最大吸收。这些瞬态物质通过一级反应分解,主要产生HNO和相应的羧酸,因此归因于RC(O)N = O。RC(O)N = O在水溶液中足够长的半衰期首次允许研究其与各种亲核试剂的反应动力学,这表明亲核反应性遵循硫醇盐>异羟肟酸酯>胺的顺序。CH的金属螯合物3 C(O)NHOH以Cu II > Zn II > Ni II > Co II的功效顺序催化CH 3 C(O)N = O的水解,其中在不存在异羟肟酸酯的情况下,只有Cu II催化水解
Selective Synthesis and Structural Elucidation of <i>S</i>-Acyl- and <i>N</i>-Acylcysteines
作者:Alan R. Katritzky、Srinivasa R. Tala、Nader E. Abo-Dya、Kapil Gyanda、Bahaa El-Dien M. El-Gendy、Zakaria K. Abdel-Samii、Peter J. Steel
DOI:10.1021/jo900853s
日期:2009.9.18
N-(Acyl)-1H-benzotriazoles 6a−f react with l-cysteine 5 at 20 °C to give exclusively (i) N-acyl-l-cysteines 8a−e in the presence of triethylamine in CH3CN−H2O (3:1), but (ii) S-acyl-l-cysteines 7a−e in CH3CN−H2O (5:1) in the absence of base. Structures 7b, 7d and 8b, 8d are supported by 2D NMR spectroscopic methods including gDQCOSY, gHMQC, gHMBC, and 1H−15N CIGAR-gHMBC experiments. The structure of
N-(酰基)-1 H-苯并三唑6a - f在20°C下与1-半胱氨酸5反应,仅在CH 3 CN-H中存在三乙胺的情况下仅生成(i)N-酰基-1-半胱氨酸8a - e 2 O(3:1),但(ii)CH 3 CN-H 2 O(5:1)中在不存在碱的情况下的S-酰基-1-半胱氨酸7a - e。结构7b,7d和8b,8d支持2D NMR光谱方法,包括gDQCOSY,gHMQC,gHMBC和1 H - 15 N CIGAR-gHMBC实验。化合物8d的结构也通过单晶X射线衍射来支撑。
Urea derivative, process for producing the same, and use
申请人:Kubo Keiji
公开号:US20070093501A1
公开(公告)日:2007-04-26
The present invention provides a urea derivative or a salt thereof, which is useful as a therapeutic agent for thrombosis. The derivative is represented by Formula (I):
wherein Cy is an aromatic hydrocarbon group which may be substituted or an aromatic heterocyclic group which may be substituted; R
1
is a hydrogen atom or a hydrocarbon group which may be substituted; V is —C(O)—, —S(O)—, or —S(O)
2
—; W is —N(R
2
)—, —O—, or a bond (wherein R
2
is a hydrogen atom or a hydrocarbon group which may be substituted); X is alkylene which may be substituted; Y is —C(O)—, —S(O)—, or —S(O)
2
—; Z is a bond, a chain hydrocarbon group which may be substituted, or —N═; ring A is a non-aromatic nitrogen-containing heterocyclic ring which may be substituted; ring B is a nitrogen-containing heterocyclic ring which may be substituted; and
[Chemical formula 2]
,
are each independently a single bond or a double bond; provided that R
1
may be bonded to R
2
to form a non-aromatic nitrogen-containing heterocyclic ring and that R
2
may be bonded to a substituent of X to form a non-aromatic nitrogen-containing heterocyclic ring which may be substituted.
Disclosed are (1) a cyclic hexapeptide represented by formula [I] or a salt thereof:
wherein X and Y each represent a-amino acid residues, A represents a D-acidic-a-amino acid residue, B represents a neutral-a-amino acid residue, C represents an L-a-amino acid residue and D represents a D-a-amino acid residue having an aromatic ring group; and (2) a pharmaceutical composition comprising the peptide represented by formula [I] or a pharmaceutically acceptable salt thereof as an active ingredient.