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51.
以呋喃、水合肼和马来酸酐为原料,合成了去甲去氢斑蝥素酰亚胺缩水杨醛,其结构经NMR、MS和元素分析证实,并测定了产物的抑菌活性及与牛血清蛋白(BSA)的相互作用。结果表明,标题化合物对大肠杆菌和金黄色葡萄球菌都有较好的抑菌活性,其对BSA为静态荧光猝灭,在293、303和310 K时猝灭常数分别是3.39×10~4、3.29×10~4和3.13×10~4(L/mol);化合物与BSA主要通过疏水作用力结合,其结合距离为2.688nm,结合位点数为1.049(303K)。 相似文献
52.
Wenjie Ma Dr. Hongxiang Wu Sha Liu Dr. Tongyao Wei Prof. Dr. Xiang David Li Dr. Han Liu Prof. Dr. Xuechen Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(1):e202214053
Chemical synthesis of proteins bearing base-labile post-translational modifications (PTMs) is a challenging task. For instance, O-acetylation and S-palmitoylation PTMs cannot survive Fmoc removal conditions during Fmoc-solid phase peptide synthesis (SPPS). In this work, we developed a new Boc-SPPS-based strategy for the synthesis of peptide C-terminal salicylaldehyde (SAL) esters, which are the key reaction partner in Ser/Thr ligation and Cys/Pen ligation. The strategy utilized the semicarbazone-modified aminomethyl (AM) resin, which could support the Boc-SPPS and release the peptide SAL ester upon treatment with TFA/H2O and pyruvic acid. The non-oxidative aldehyde regeneration was fully compatible with all the canonical amino acids. Armed with this strategy, we finished the syntheses of the O-acetylated protein histone H3(S10ac, T22ac) and the hydrophobic S-palmitoylated peptide derived from caveolin-1. 相似文献
53.
An efficient and simple method for the synthesis of new benzopyranopyrimidines via a pseudo four-component reaction of salicylic aldehydes, malononitrile and various amines in the presence of a catalytic amount of LiClO4 is reported. The advantages of this procedure are mild reaction conditions, high yields of products and operational simplicity. 相似文献
54.
Chiral Half‐sandwich Pentamethylcyclopentadienyl Rhodium(III) and Iridium(III) Complexes with Schiff Bases from Salicylaldehyde and α‐Amino Acid Esters [1] A series of diastereoisomeric half‐sandwich complexes with Schiff bases from salicylaldehyde and L‐α‐amino acid esters including chiral metal atoms, [(η5‐C5H5)(Cl)M(N,O‐Schiff base)], has been obtained from chloro bridged complexes [(η5‐C5Me5)(Cl)M(μ‐Cl)]2 (M = Rh, Ir). Abstraction of chloride from these complexes with Ag[BF4] or Ag[SO3CF3] affords the highly sensitive compounds [(η5‐C5Me5)M(N,O‐Schiff base]+X? (M = Rh, Ir; X = BF4, CF3SO3) to which PPh3 can be added under formation of [(η5‐C5Me5)M(PPh3)(N,O‐Schiff base)]+X?. The diastereoisomeric ratio of the complexes ( 1 ‐ 7 and 11 ‐ 12 ) has been determined from NMR spectra. 相似文献
55.
Reaction of RuCl2(PPh3)3 with N‐Phenyl‐pyridine‐2‐carbaldehyde thiosemicarbazone (C5H4N–C2(H)=N3‐N2H–C1(=S)N1HC6H5, Hpytsc‐NPh) in presence of Et3N base led to loss of ‐N2H‐proton and yielded the complex [Ru(pytsc‐NPh)2(Ph3P)2] ( 1 ). Similar reactions of precursor RuCl2[(p‐tolyl)3P]3 with a series of thiosemicarbazone ligands, viz. pyridine‐2‐carbaldehyde thiosemicarbazone (Hpytsc), salicylaldehyde thiosemicarbazone (H2stsc), and benzaldehyde thiosemicarbazone (Hbtsc), have yielded the complexes, [Ru(pytsc)2{(p‐tolyl)3P}2] ( 2 ), [Ru(Hstsc)2{(p‐tolyl)3P}]2 ( 3 ), and [Ru(btsc)2{(p‐tolyl)3P}2] ( 4 ), respectively. The reactions of precursor Ru2Cl4(dppb)3 {dppb = Ph2P–(CH2)4–PPh2} with H2stsc, Hbtsc, furan‐2‐carbaldehyde thiosemicarbazone (Hftsc) and thiophene‐2‐carbaldehyde thiosemicarbazone (Httsc) have formed complexes of the composition, [Ru(Hstsc)2(dppb)] ( 5 ), [Ru(btsc)2(dppb)] ( 6 ), [Ru(ftsc)2(dppb)] ( 7 ), and [Ru(ttsc)2(dppb)] ( 8 ). The complexes have been characterized by analytical data, IR, NMR (1H, 31P) spectroscopy and X‐ray crystallography ( 1 and 5 ). The proton NMR confirmed loss of –N2H– proton in all the compounds, and 31P NMR spectra reveal the presence of equivalent phosphorus atoms in the complexes. In all the compounds, thiosemicarbazone ligands coordinate to the RuII atom via hydrazinic nitrogen (N2) and sulfur atoms. The arrangement around each metal atom is distorted octahedral with cis:cis:trans P, P:N, N:S, S dispositions of donor atoms. 相似文献
56.
AiFang Zheng JinLong Chen Genhua Wu Ganlin Wu Yuan Guang Zhang HePing Wei 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(1):265-270
Salicylaldehyde rhodamine B hydrazone (SRBH) was developed as a new spectrofluorimetric probe for the selective and sensitive detection of CrO42− in acidic conditions. The proposed method was based on the special oxidation reaction between non-fluorescent SRBH by potassium dichromate to produce a highly fluorescent rhodamine B, as a product. Under the optimum conditions described, the fluorescence enhancement at 591 nm was good linearly related to the concentration of CrO42− from 1.0 × 10−8 to 3.0 × 10−7 M (0.42–12.6 ng mL−1) with a correlation coefficient of R2 = 0.9989 (n = 10) and a detection limit of 1.5 × 10−9 M (0.063 ng mL−1). The relative standard deviation (R.S.D.) was 2.0% (n = 6). The proposed method was also successfully applied to the determination of chromium (VI) in drinking water, river water and synthetic samples. 相似文献
57.
Michail N. Elinson Alexey I. Ilovaisky Valentina M. Merkulova Pavel A. Belyakov Alexander O. Chizhov Gennady I. Nikishin 《Tetrahedron》2010,66(23):4043-6439
The new type of solvent-free cascade reaction was found: the direct heating of the mixture of salicylaldehyde, malononitrile or cyanoacetate and nitroalkanes at 60 °C in the presence of catalytic amounts of KF or NaOAc results in the formation of 2-amino-4-(1-nitroalkyl)-4H-chromene-3-carbonitriles or methyl 2-amino-4-(1-nitroalkyl)-4H-chromene-3-carboxylates in 80-90% yields. Thus, the new simple and efficient solvent-free ‘one-pot’ way to substituted medicinally privileged 2-amino-4H-chromene scaffold was found directly from such simple and reasonable starting compounds as salicylaldehyde, malononitrile or cyanoacetate and nitroalkanes. 相似文献
58.
Several primary amines are known to be endogenous substances, and they are to be detected at very low concentration level. Novel water-soluble azo dyes as precolumn derivatizing reagents were synthesized for the analysis of primary amines with strong visible-light absorption by CZE. A coupling reaction was used to introduce a sulfophenylazo group to salicylaldehyde or 1-hydroxy-2-naphthaldehyde to extend the conjugation and to improve the solubility in water of the derivatizing reagents, as well as the target compounds of the reaction products with the primary amines. Two azo dyes of 5-(4-sulfophenylazo)salicylaldehyde sodium salt (AZO1) and 4-(4-sulfophenylazo)-1-hydroxy-2-naphthaldehyde sodium salt (AZO2) were synthesized. Separation of eight kinds of n-alkylamines was performed by CZE after the derivatization with AZO1 or AZO2. The addition of Brij 35 to the running electrolyte and to the sample solutions was necessary to improve the solubility and the resolution among the analytes. Both reagents, AZO1 and AZO2, were compared with each other in terms of the reaction time of derivatization, the detection sensitivity and the total analysis time. The derivatization process using AZO2 was applied to the determination of four biogenic amines, histamine, tyramine, cadaverine and putrescine, and LODs at around micromolar level were achieved for the four amines. 相似文献
59.
A convenient and efficient procedure for one‐pot preparation of double Schiff bases through a three component reaction of salicylaldehyde, ammonium acetate and aliphatic aldehyde was described. In this reaction, N,N′‐bis(salicylidene)‐1,1‐diaminoalkanes was easily obtained in excellent yields and short reaction times under mild reaction condition. 相似文献
60.
A series of cyclopenta[b]chromen‐1(9H)‐one derivatives is prepared in high yields by a one‐pot reaction of substituted salicylaldehydes and cyclopentane‐1,3‐dione in ionic liquids of [BMIm]Br, the procedure is very mild and environmentally benign. 相似文献