The structure of vinyl ethers determines the direction of the C–O bond cleavage by alkalide K−, K+(15-crown-5)2 1. Highly reactive organopotassium compounds are intermediate products formed in the system containing phenyl vinyl ether, butyl vinyl ether, ethylene glycol butyl vinyl ether or trie...

Racemic trans-paroxol, trans-N-methylparoxetine and trans-paroxetine containing two chiral centres were stereoselectively separated using countercurrent chromatography with hydroxypropyl-β-cyclodextrin as the chiral selector. A two-phase solvent system composed of n-butyl acetate and 0.1 mol L−...

dl-2-Aminobutyric acid (α-aminobutyric acid or AABA) is a non-protein amino acid with important physiological properties, and with considerable relevance in different areas, such as fundamental research and pharmaceutical industry. In this paper, the binary mutual diffusion coefficients of AABA...

The pseudotetrahedral complexes of [Cu(PPh3)2(L)], where L=8-hydroxy-2-methylquinoline-7-carboxylic acid (1), 8-hydroxy-2,5-dimethylquinoline-7-carboxylic acid (2) or 5-chloro-8-hydroxy-2-methylquinoline-7-carboxylic acid (3) have been synthesized and structurally characterized by X-ray crystall...

Quinoline-2-carboxylic acid derivatives cap the N-terminal of several natural cyclic peptides with antitumoral activity. A new and convenient route for the preparation of 3-hydroxyquinoline-2-carboxylic acid is discussed. The preparation of the title compound is accomplished by a four-step proce...

By renitrating 3-nitrofluoranthene in the presence of fuming nitric acid, some additional nitro-derivatives were induced; they were identified as 3,7-, 3,9- and 3,4-dinitrofluoranthene (DNF), and two trinitrofluoranthenes (TNF, 3,4,7- and 3,4,8- or 3,4,9-isomers) on the basis of the results of m...

The potent antineoplasic pseudopeptide dolastatin 10 isolated from the sea hare Dolabella auricularia was examined by a combination of one and two dimensional NMR techniques (DQF-COSY, HOHAHA, ROESY, HMQC, and HMBC) followed by restrained molecular-dynamics (MD) simulations to elucidate its conf...

A high-performance capillary electrophoresis (HPCE) assay was used to determine the concentration of a potent cytotoxic agent, dolastatin-10, in human plasma. Following extraction from plasma, using a solid-phase C18 cartridge, capillary zone electrophoresis was used to separate, detect and quan...

We have described the synthesis of the two complex units (2R,3R,4S)-dolaproine (Dap) and (3R,4S,5S)-dolaisoleuine (Dil) of dolastatin 10 from natural amino acids. The stereoselective syntheses of N-Boc-Dap (4a) and N-Boc-(2S)-iso-Dap (4b) were performed by employing crotylation of N-Boc-l-prolin...

Dolastatin 10 (1) is a highly potent cytotoxic microtubule inhibitor (cytotoxicity IC50

Three isoxazole bioisosteres of glutamic acid derived from the specific AMPA receptor agonist (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) were synthesized and tested electrophysiologically and in different receptor binding systems. (RS)-2-Amino-3-(3-hydroxy-5-trifluorom...

Tuberculosis (TB) is a major infectious disease associated increasingly with drug resistance. Thus, new anti-tubercular agents with novel mechanisms of action are urgently required for the treatment of drug-resistant TB. In prior work, we identified compound 1 (cyclohexyl(4-(isoquinolin-5-ylsulf...

The mixed anhydride of oxalic and phosphoric acids, oxalyl phosphate, has been prepared by reaction of oxalyl chloride and inorganic phosphate in aqueous solution. The product was purified by anion exchange chromatography and characterized by 31P and 13C NMR. This acyl phosphate has a half-life ...

Urinary stones are the third most commonly reported urinary tract disease. Kidney stones are one of the most common types of urinary stones that most of them (70–80%) are calcium oxalate. Oxalic acid is highly oxidized organic compounds, which found in dietary and produced by the intestinal mic...

Chemotherapy-induced peripheral neuropathy (CIPN) is a major dose limiting side-effect of several commonly used chemotherapeutic agents (such as cisplatin) that profoundly impairs patient quality of life. Unfortunately, neither prophylactic strategies nor symptomatic treatments have proven usefu...

Structural elucidation of three chalcone dimers, (lophirones F, G and H) isolated from Lophira lanceolata stem bark, and their permethylethers, is discussed using spectral chemical evidence.

Lophirone A, a new biflavonoid have been isolated from the stem bark of Lophira lanceolata. The structure was elucidated by MS, 2D 1H and 13C NMR including INADEQUATE to determine the carbon framework. It involved an aryl shift from one flavonoid unit to the second.

The influence of chalcone dimers, lophirones B and C on redox status and respiratory chain activity of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was investigated. Minimum inhibitory concentrations (MIC) of lophirones B and C against E. coli, P. aeruginosa and S. aureus a...

The interaction between the transport protein bovine serum albumin (BSA) and the natural product lophirone B, was investigated by spectroscopic techniques combined with a computational method (molecular docking). From the KSV and kq values it was concluded that lophirone B quenches the fluoresce...

We evaluated the inactivation of DNA gyrase on the oxidative stress response and sensitivity of A. baumannii to lophirones B and C. The sensitivity of parental and the mutant strains of A. baumannii to lophirones B and C was determined using minimum inhibitory concentration (MIC) and time-kill s...